WO2023205055A1

WO2023205055A1 - Dual-trap toilet having improved pressurization and flushing

Info

Publication number: WO2023205055A1
Application number: PCT/US2023/018698
Authority: WO
Inventors: JR. Richard B. Sudol; Nitin S. KOLEKAR; David Grover; Robert M. Jensen; Antonio Esposito
Original assignee: As America, Inc.
Priority date: 2022-04-22
Filing date: 2023-04-14
Publication date: 2023-10-26
Also published as: WO2023205056A1

Abstract

A toilet assembly may comprise a toilet tank to hold flush water, a flush valve assembly positioned in the toilet tank, a trapway in flow communication with the toilet bowl, a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway. Between flush cycles, the tank may store a volume of flush water. The flush water may be divided between different regions of the tank that are defined by the structure of the container. Between flush cycles, the container and the trapway may contain pressurized air. A force exerted by pressurized air in the trapway on water in a lower trap may cause an upstream water level in the lower trap to be lower than a downstream water level in the lower trap.

Description

DUAL-TRAP TOILET HAVING IMPROVED PRESSURIZATION AND FLUSHING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/333,971, filed April 22, 2022, U.S. Provisional Application No. 63/333,973, filed April 22, 2022, and U.S. Provisional Application No. 63/333,977, filed April 22, 2022, the entire contents of which are incorporated herein by reference.

FIELD

[0002] The present disclosure relates generally to dual-trap toilets.

BACKGROUND

[0003] Conventional dual-trap toilets comprise a trapway that is configured to trap water in two separate locations. A first upstream trap may be located directly downstream of the toilet bowl and may be configured to hold water in the toilet bowl in between flush cycles. A second downstream trap may be located between the first trap and an outlet from the trapway to a drainage pipe. The dual-trap configuration may prevent sewer gases from leaking out of the sewer through drainage pipe while also providing a quieter flush cycle than other flush toilets (e.g., single trap toilets).

SUMMARY

[0004] As discussed above, dual-trap toilets may comprise a trapway that is configured to hold both water and pressurized air between flush cycles. Specifically, dual-trap toilets may comprise a trapway configured to trap water in an upstream trap and a downstream trap between flush cycles. Between flush cycles, positively pressurized air may be contained in the trapway between the upstream trap and the downstream trap. This pressurized air may be fluidly coupled to a second portion of positively pressurized air contained in the toilet tank. When a flush cycle is initiated, water may be discharged from the toilet tank into the toilet bowl, which may cause the pressure of the air in the trapway to drop. The drop in pressure may create a siphon in the trapway that pulls the contents of the toilet bowl into and out of the trap way.

[0005] The distribution of flush water and pressurized air in the trapway, along with the position, shape, and size of various components of the trapway, may impact the efficiency with which fluids flow through the trapway during a flush cycle. The present disclosure provides dual-trap toilet assemblies configured to optimize the distribution of flush water and pressurized air in order to provide more efficient flush cycles. The trapway may have a variable diameter at different locations along the fluid flow path in order to reduce clogging. An interface between the trapway and the toilet tank may be positioned and shaped to optimize flow of air and water during flush cycles.

[0006] A first toilet assembly may comprise a toilet tank to hold flush water, a flush valve assembly positioned in the toilet tank, a toilet bowl, a trapway in flow communication with the toilet bowl, a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway. The container may be in flow communication with the toilet tank and may have an open lower end and a closed upper end, wherein the upper end of the container contains a first portion of pressurized air when the toilet assembly is between flush cycles. The trapway may comprise a sump trap, a first upstream weir, a lower trap, and a second downstream weir. The connecting tube may be coupled to the trapway at a position between the sump trap and the lower trap and may provide flow communication between the container and the trapway. The trapway may contain a second portion of pressurized air when the toilet assembly is between flush cycles. A volume of the first portion of pressurized air may be less than or equal to 30% of a volume of the second portion of pressurized air.

[0007] In some embodiments of the first toilet assembly, between flush cycles, the first portion of pressurized air is positioned above flush water in the container.

[0008] In some embodiments of the first toilet assembly, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in one or both of the first portion of pressurized air and the second portion of pressurized air. [0009] In some embodiments of the first toilet assembly, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in one or both of the first portion of pressurized air and the second portion of pressurized air.

[0010] In some embodiments of the first toilet assembly, between flush cycles, the first portion of pressurized air and the second portion of pressurized air are pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

[0011] In some embodiments of the first toilet assembly, the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

[0012] In some embodiments of the first toilet assembly, the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

[0013] In some embodiments of the first toilet assembly, the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet.

[0014] In some embodiments of the first toilet assembly, the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound a vacuum chamber of the container.

[0015] In some embodiments of the first toilet assembly, the inner wall bounds an inner chamber of the container.

[0016] In some embodiments of the first toilet assembly, a vertical distance between a top surface of the connecting tube and an inner surface of the upper end wall is greater than or equal to 10 mm and less than or equal to 35 mm.

[0017] In some embodiments of the first toilet assembly, an internal diameter of the connecting tube is greater than or equal to 12 mm and less than or equal to 20 mm. [0018] In some embodiments of the first toilet assembly, between flush cycles, a vertical distance between a top surface of the connecting tube and a water level in the toilet tank is greater than or equal to 45 mm and less than or equal to 55 mm.

[0019] A second toilet assembly may comprise a toilet tank to hold flush water, a flush valve assembly positioned in the toilet tank, a toilet bowl, a trapway in flow communication with the toilet bowl, a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway. The container may be in flow communication with the toilet tank and may have an open lower end and a closed upper end. The trapway may comprise a sump trap, a first upstream weir, a lower trap, and a second downstream weir. The connecting tube may be coupled to the trapway at a position between the sump trap and the lower trap and may provide flow communication between the container and the trapway. The trapway may contain pressurized air when the toilet assembly is between flush cycles. The pressurized air in the trapway may exert force on water in the lower trap such that an upstream water level in the lower trap is lower than a downstream water level in the lower trap by an offset distance of greater than or equal to 15 mm between flush cycles.

[0020] In some embodiments of the second toilet assembly, between flush cycles, the container comprises pressurized air positioned above flush water.

[0021] In some embodiments of the second toilet assembly, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in the pressurized air in the trap way.

[0022] In some embodiments of the second toilet assembly, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in the pressurized air in the trap way.

[0023] In some embodiments of the second toilet assembly, between flush cycles, the pressurized air in the trapway is pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure. [0024] A third toilet assembly may comprise a toilet tank, a flush valve assembly positioned in the toilet tank, a toilet bowl, a trapway in flow communication with the toilet bowl, a container positioned in the toilet tank, wherein the container comprises an inner chamber and a vacuum chamber, and a connecting tube extending from an interior of the container to the trapway. The container may be in flow communication with the toilet tank and may have an open lower end and a closed upper end. The trapway may comprise a sump trap, a first upstream weir, a lower trap, and a second downstream weir. The connecting tube may be coupled to the trapway at a position between the sump trap and the lower trap and may provide flow communication between the container and the trapway. During a flush cycle, the toilet assembly may flush a volume of flush water. A first portion of the volume of flush water may be stored in the tank prior to the flush cycle, a second portion of the volume of flush water may be stored in the vacuum chamber prior to the flush cycle, and a third portion of the volume of flush water may stored in the inner chamber prior to the flush cycle. The third portion is greater than or equal to 40% of the volume of flush water.

[0025] In some embodiments of the third toilet assembly, the first portion is less than or equal to 20% of the volume of flush water.

[0026] In some embodiments of the third toilet assembly, the second portion is less than or equal to 40% of the volume of flush water.

[0027] In some embodiments of the third toilet assembly, between flush cycles, the container comprises pressurized air positioned above flush water in the vacuum chamber.

[0028] In some embodiments of the third toilet assembly, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in pressurized air in the trap way.

[0029] In some embodiments of the third toilet assembly, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in pressurized air in the trapway.

[0030] In some embodiments of the third toilet assembly, between flush cycles, pressurized air in the trapway is pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

BRIEF DESCRIPTION OF THE FIGURES

[0031] The following figures show various views and/or associated data for dual-trap toilets, in accordance with some embodiments. The dual-trap toilets shown in the figures may, in some embodiments, have any one or more of the characteristics described herein.

[0032] FIGS. 1 A and IB show perspective views of a dual-trap toilet, in accordance with some embodiments.

[0033] FIG. 2 shows a cross-sectional view of a dual-trap toilet, in accordance with some embodiments.

[0034] FIG. 3 shows a perspective cutaway view of a dual-trap toilet, in accordance with some embodiments.

[0035] FIG. 4 shows a partial cross-sectional view of a dual-trap toilet, in accordance with some embodiments.

[0036] FIGS. 5A-5D show various cutaway and cross-sectional views of a tank of a dualtrap toilet, in accordance with some embodiments.

[0037] FIGS. 6A and 6B show views of a toilet bowl and/or trapway of a dual-trap toilet, in accordance with some embodiments.

[0038] FIG. 7 shows a cross-sectional view of a dual-trap toilet and a lower seal offset height, in accordance with some embodiments.

[0039] FIG. 8 shows a portion of a trapway for a dual-trap toilet, in accordance with some embodiments.

[0040] FIG. 9 shows dimensions for a flow path for a trapway for a dual-trap toilet, in accordance with some embodiments. [0041] FIG. 10 shows trap diameter dimensions for a trapway for a dual -trap toilet, in accordance with some embodiments.

[0042] FIG. 11 shows an interface between a connecting tube and a trapway of a dualtrap toilet, in accordance with some embodiments.

DETAILED DESCRIPTION

[0043] Dual-trap toilets comprise a trapway that is configured to trap water in two separate locations. In some embodiments, dual-trap toilets may have a trapway including a sump trap, a first upstream weir, a lower trap, and a second downstream weir. A container positioned in the toilet tank may be coupled by a connecting tube that extends between an interior of the container and the trapway. The connecting tube may be coupled to the trapway at a position between the sump trap and the lower trap and may provide flow communication between the container and the trapway. Between flush cycles, the container and the trapway may contain positively pressurized air. The positively pressurized air in the trapway between flush cycles may push upwards on water in the sump trap and may result in a larger water spot in the toilet bowl than would be present if not for the positively pressurized air. Additionally, the positively pressurized air in the trapway between flush cycles may push downwards on water in the lower trap, such that a water level in an upstream end of the lower trap may be lower than a water level in a downstream end of the lower trap.

[0044] Upon initiation of a flush cycle, a flush valve seal may lift off of a flush valve inlet to the flush valve to open the flush valve, and flush water may be discharged from the toilet tank and the container through the flush valve and into the toilet bowl. As used herein, the term “flush water” may refer to any water that passes out of a toilet tank (or any subcomponent thereof, such as a container positioned inside a toilet tank, an inner chamber of said container, and/or a vacuum chamber of said container) during a flush cycle. Discharging the flush water during a flush cycle may exert a negative pressure on air in an upper end of the container, connecting tube, and trapway portion between the sump trap and the lower trap. The negative pressure may cause a drop to atmospheric pressure or to partial vacuum. The negative pressure may help create a siphon to pull water and waste through the sump area and into and out of the trapway. [0045] During a flush cycle, flush water may exit the tank, a container positioned within the tank, an inner chamber of the container, and/or a vacuum chamber of the container. In some embodiments, some or all or none of the flush water may flow from the tank (considered separately from the container positioned within the tank) during a flush cycle. In some embodiments, some or all some or all or none of the flush water may flow from the container (considered separately from the tank) during a flush cycle. In some embodiments, some or all some or all or none of the flush water may flow from the vacuum chamber of the container (considered separately from other portions of the container and from the tank) during a flush cycle. In some embodiments, some or all some or all or none of the flush water may flow from the inner chamber of the container (considered separately from other portions of the container and from the tank) during a flush cycle.

[0046] One or more components of a dual trap toilet may be configured to optimize a ratio of positively pressurized air located in various portions of the toilet between flush cycles. In some embodiments, a first portion of positively pressurized air is located in an upper end of the container in the tank between flush cycles, while a second portion of positively pressurized air is located in the trapway between water in the sump trap and water in the lower trap between flush cycles. (In some embodiments, the second portion of positively pressurized air may also include air located in the connecting tube and/or in an interface portion between the connecting tube and the trapway.)

[0047] A flush cycle may be considered completed upon closing the flush valve and refilling the toilet tank, sump trap, and lower trap. Upon completion of a flush cycle, new flush water entering the toilet tank may also enter the container via one or more openings positioned in the container wall. Entry of water into the container may compress air into an upper end of the container and may return the air contained in the regions defined by the upper end of the container, the connecting tube, and the trapway portion between a sump trap and a lower trap to atmospheric pressure and/or to a positive pressure above atmospheric pressure.

[0048] A dual-trap toilet may have a trapway that is shaped to optimize flow of air and water during flush cycles. The trapway may flow from an upstream end that couples to the toilet bowl to a downstream end that couples to a drain pipe. From upstream end to downstream end, the trapway may include a sump trap, a portion extending upward from the sump trap, a first (upstream) weir, a connecting portion extending downward from the first (upstream) weir, a lower trap, a portion extending upward from the lower trap, a second (downstream) weir, and a portion extending downward from the second (downstream) weir.

[0049] An interface between (or included as part of) the connecting tube may be positioned and shaped to optimize flow of air and water during flush cycles. The interface may have an upper end that couples to a lower end of the connecting tube, and may have a lower end that couples to the trapway. The lower end may couple to the trapway at a location between the sump trap and the lower trap, such that positively-pressurized air may be delivered, through the interface, to the area of the trapway between the water in the sump trap and the water in the lower trap. The lower end may couple to an upper wall of the trapway above the first upstream weir and/or to an upper/outer wall of the connecting portion.

[0050] The trapway may a variable diameter at different locations along the trapway; said variable diameter may optimize flow of air and water during flush cycles. The interface may have an upper end that couples to a lower end of the connecting tube and may have a lower end that couples to the trapway. The lower end may couple to the trapway at a location between the sump trap and the lower trap, such that positively-pressurized air may be delivered, through the interface, to the area of the trapway between the water in the sump trap and the water in the lower trap. The lower end may couple to an upper wall of the trapway above the first upstream weir and/or to an upper/outer wall of the connecting portion. In some embodiments, a diameter of the trapway may be measured at any of the trapway components referred to above and may in some embodiments differ from one or more other components at any of the trapway components referred to above. When trapway diameter is referenced, it may be understood to refer to a diameter of a circular trapway and/or to a diameter in at least one direction of an elliptical and/or irregularly-shaped trapway.

Dual-trap toilets

[0051] Dual-trap toilets comprise a trapway that is configured to trap water in two separate locations. A first upstream trap may be located directly downstream of the toilet bowl and may be configured to hold water in the toilet bowl in between flush cycles. A second downstream trap may be located between the first trap and an outlet from the trapway to a drainage pipe. The dual-trap configuration may prevent sewer gases from leaking out of the sewer through drainage pipe while also providing a quieter flush cycle than other flush toilets (e.g., single trap toilets).

[0052] FIGS. 1 A and IB show perspective views of a dual-trap toilet, in accordance with some embodiments. Specifically, FIGS. 1 A and IB illustrate perspective views of a dual-trap toilet 100 comprising a toilet bowl 102, a toilet tank 104, and a trapway 106. In some embodiments, toilet bowl 102, toilet tank 104, and trapway 106 may be in flow communication. In some embodiments, as shown in FIG. IB, toilet 100 may comprise a flush control 108. Flush control 108 may comprise one or more handles, push buttons, levers, chains, position sensors, and/or motion sensors that are configured to initiate a flush cycle when engaged by a user.

[0053] Between flush cycles, toilet bowl 102 may contain a volume of water. In some embodiments, a volume of water contained in toilet bowl 102 between flush cycles may be about 0.5 gallons, about 0.75 gallons, about 1 gallon, about 1.25 gallons, about 1.5 gallons, about 1.75 gallons, about 2 gallons, about 3 gallons, about 4 gallons, or about 5 gallons. In some embodiments, a volume of water contained in toilet bowl 102 between flush cycles may be greater than or equal to 2.5 gallons, 3.5 gallons, 4.5 gallons, 5.5 gallons, 6.5 gallons, 7.5 gallons, or 8.5 gallons. In some embodiments, a volume of water contained in toilet bowl 102 between flush cycles may be less than or equal to 2 gallons, 1.5 gallons, 1 gallon, 0.5 gallons, or 0.1 gallons.

[0054] Toilet tank 104 may be configured to contain flush water. Toilet tank 104 may be configured to fluidly connect to a water supply. In some embodiments, when a flush cycle is initiated, toilet tank 104 may be configured to discharge a volume of contained flush water into toilet bowl 102. Toward the end of a flush cycle, toilet tank 104 may be configured to replenish the discharged volume of water by receiving water from the water supply.

[0055] When a flush cycle is initiated (e.g., by a user who engages flush control 108), the contents of toilet bowl 102 may be siphoned into trapway 106. Trapway 106 may be configured to fluidly connect to a sewer system (or to one or more drain pipes that connect to a sewer system). During a flush cycle, the siphoned contents of toilet bowl 102 may be directed through trapway 106 and into the sewer system. [0056] Trapway 106 may comprise a sump trap and a lower trap. The sump trap may be directly downstream of toilet bowl 102 and the lower trap may be downstream of the sump trap. When toilet 100 is between flush cycles, water may collect in both the sump trap and the lower trap. The collection of water in the sump trap and the lower trap may form a series of water seals which prevent leakage of sewer gas out of trapway 106. The water that collects in the sump trap between flush cycles may be the volume of water contained in toilet bowl 102 between flush cycles, as described above.

[0057] When toilet 100 is between flush cycles, toilet tank 104 and trapway 106 may be configured to contain positively pressurized air. The positively pressurized air contained in trapway 106 may be contained between a sump trap and a lower trap and may exert upward pressure on water collected in the sump trap and downward pressure on water collected in the lower trap. In some embodiments, the upward pressure exerted on the water collected in the sump trap by the pressurized air contained in trapway 106 may raise the water level of water contained in toilet bowl 102 between flush cycles. The raised water level of water contained in toilet bowl 102 may reduce or prevent soiling of toilet bowl 102.

[0058] In some embodiments, when a flush cycle is initiated and flush water is discharged from toilet tank 104 into toilet bowl 102, a negative pressure may be exerted on the air contained in toilet tank 104 and the air contained in trapway 106. The negative pressure may cause the pressure within toilet tank 104 and/or trapway 106 to decrease to atmospheric pressure and/or to a partial vacuum. This decrease in pressure may generate a siphon in trapway 106 that may cause the contents of toilet bowl 102 to be pulled into and subsequently out of trapway 106.

[0059] Toward the end of a flush cycle, water may again collect in toilet bowl 102 and trapway 106. Upon completion of a flush cycle, toilet tank 104 may be configured to receive new flush water from a water supply. As toilet tank 104 refills with flush water, the air contained in toilet tank 104 may be compressed, thereby increasing the pressure of the air contained in toilet tank 104 and/or the air contained in trapway 106 to atmospheric pressure and/or to a pressure above atmospheric pressure. When the air contained in toilet tank 104 and/or the air contained in trapway 106 return(s) to positively pressurized states, the flush cycle may be completed. [0060] FIG. 2 shows a cross-sectional view of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 2 illustrates a cross-sectional view of a toilet 200 comprising a toilet bowl 202, a toilet tank 204, a trapway 206, and a flush control 208. In some embodiments, toilet bowl 202, toilet tank 204, trapway 206, and/or flush control 208 may include features of toilet bowl 102, toilet tank 104, trapway 106, and/or flush control 108 shown in FIG. 1A and/or FIG. IB.

[0061] A container 218 and a flush valve 224 may be positioned within and in flow communication with toilet tank 204. Container 218 may have an irregular toroidal structure that defines a vacuum chamber, an inner chamber, and an outer region in toilet tank 204 that is external to and surrounds both container 218 and the inner chamber. In some embodiments, flush valve 224 may be positioned in the inner chamber defined by container 218 such that container 218 encircles flush valve 224.

[0062] Between flush cycles, toilet tank 204 may be configured to contain flush water. Between flush cycles, a first volume of flush water may be contained the outer region in toilet tank 204 that is external to and surrounds container 218 and the inner chamber defined by the structure of container 218, a second volume of flush water may be contained in the central cavity region defined by the structure of container 218, and a third volume of flush water may be contained in a vacuum chamber contained within the internal irregular annular region of container 218.

[0063] Toilet bowl 202 may be fluidly connected to toilet tank 204 via a fluid pathway 222. Flush valve 224 may be in flow communication with fluid pathway 222 which may, in turn, be in flow communication with toilet bowl 202. In some embodiments, a flush valve gasket 210 may be positioned at an interface between flush valve 224 and fluid pathway 222. Flush valve gasket 210 may form a mechanical seal between flush valve 224 and fluid pathway 222 in order to prevent flush water and/or air from leaking out of toilet tank 204 and into toilet bowl 202 between flush cycles (i.e., to prevent water and/or air leakage from toilet tank 204 when flush valve 224 is closed).

[0064] Fluid pathway 222 may be in flow communication with a rim channel 236 that encircles the rim of toilet bowl 202. During a flush cycle, a portion of flush water may be transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236. The flush water may then be transmitted into toilet bowl 202 from rim channel 236 through one or more rim outlets.

[0065] The portion of flush water transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236 may be between about 0.5-2 liters, about 1-3 liters, about 1-4 liters, or about 1-5 liters. Optionally, the portion of flush water transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236 may be less than or equal to 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, or 5 liters.

Optionally, the portion of flush water transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236 may be greater than or equal to 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, or 5 liters.

[0066] In some embodiments, less than 50% of the total volume of flush water delivered from toilet tank 204 to toilet bowl 202 during a flush cycle may be transmitted through rim channel 236. In some embodiments, greater than 50% of the total volume of flush water delivered from toilet tank 204 to toilet bowl 202 during a flush cycle may be transmitted through rim channel 235.

[0067] A lower portion of toilet bowl 202, referred to hereinafter as sump area 214a, may be in flow communication with a first upstream portion 214u of trapway 206 through a trapway inlet 207. The first upstream portion 214u of trapway 206, sump area 214a of toilet bowl 202, and a first downstream portion 214d of trapway 206 may together form a sump trap 214, which may contain flush water between flush cycles.

[0068] In some embodiments, fluid pathway 222 may be in flow communication with a jet channel 238. Jet channel may be adjacent to an upstream end of trapway 206 and may be fluidically coupled to sump trap 214 via a jet hole 240. During a flush cycle, a portion of flush water may be transmitted from toilet tank 204, through fluid pathway 222, and into jet channel 238. In some embodiments, the flush water that is transmitted into jet channel 238 may be transferred into sump trap 214 through jet hole 240 in order to generate a siphon in toilet 200. In some embodiments, the flush water that is transmitted into jet channel 238 may be transferred into sump trap 214 through jet hole 240 at the end of the flush cycle to refill sump trap 214. [0069] In some embodiments, the ratio of the volume of flush water transmitted through rim channel 236 during a flush cycle to the volume of flush water transmitted through jet hole 240 during a flush cycle may be approximately 7: 1, 6: 1, 5: 1, 4: 1, 3: 1, 2: 1, 1 : 1, 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, or 1 :7. Optionally, the ratio of the volume of flush water transmitted through rim channel 236 during a flush cycle to the volume of flush water transmitted through jet hole 240 during a flush cycle may be less than or equal to 7: 1, 6: 1, 5: 1, 4: 1, 3: 1, 2: 1, 1 : 1, 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, or 1 :7. Alternatively, the ratio of the volume of flush water transmitted through rim channel 236 during a flush cycle to the volume of flush water transmitted through jet hole 240 during a flush cycle may be greater than or equal to 7: 1, 6: 1, 5: 1, 4: 1, 3: 1, 2: 1, 1 : 1, 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, or 1 :7.

[0070] Trapway 206 may comprise a first upstream weir 226 configured to contain the water that collects in sump trap 214. First upstream weir 226 may be a high point of a lower wall of trapway 206 that is downstream of the first downstream portion 214u of trapway 206 and may be positioned above a highest point of trapway inlet 207. In some embodiments, first upstream weir 226 may be positioned above the highest point of toilet bowl 202 - trapway 206 interface by an offset distance of about 0.5 inches, about 1 inch, about 1.5 inches, about 2 inches, about 2.5 inches, or about 3 inches. In some embodiments, first upstream weir 226 may be positioned above the highest point of toilet bowl 202 - trapway 206 interface by an offset distance greater than or equal to 2 inches, 2.5 inches, 3 inches, 3.5 inches, or 4 inches. In some embodiments, first upstream weir 226 may be positioned above the highest point of toilet bowl 202 - trapway 206 interface by an offset distance less than or equal to 6 inches, 5.5 inches, 5 inches, 4.5 inches, or 4 inches.

[0071] Trapway 206 may be configured to fluidly connect to a sewer system via a trapway outlet 220. As a result, sewer gases may enter trapway 206 through trapway outlet 220. The water that is contained in sump trap 214 between flush cycles may form a water seal in toilet bowl 202. The water seal may prevent sewer gases which may have entered trapway 206 from leaking out of toilet bowl 202. Between flush cycles, the water seal in toilet bowl 202 may be vertically lower than first upstream weir 226. In some embodiments, a vertical distance between the water seal in toilet bowl 202 and first upstream weir 226 may be about 0.1 inches, about 0.2 inches, about 0.3 inches, about 0.4 inches, or about 0.5 inches. In some embodiments, a vertical distance between the water seal in toilet bowl 202 and first upstream weir 226 may be greater than or equal to 0.2 inches, 0.5 inches, 0.8 inches, or 1 inch. In some embodiments, a vertical distance between the water seal in toilet bowl 202 and first upstream weir 226 may be less than or equal to 2 inches, 1.8 inches, 1.5 inches, or 1.2 inches.

[0072] Trapway 206 may comprise a lower trap 216 positioned downstream of first upstream weir 226 between a second upstream portion 216u of trapway 206 and a second downstream portion 216d of trapway 206. Between flush cycles, water may collect in lower trap 216 to form a pair of water seals to provide a second barrier against sewer gases which may enter trapway 206 via trapway outlet 220. The downstream water seal of the pair of water seals may be vertically higher than an upstream water seal of the pair of water seals. Trapway 206 may comprise a second downstream weir 228 configured to contain water in lower trap 216. Second downstream weir 228 may be a high point of a lower wall of trapway 206 that is downstream of the second downstream portion 216d of trapway 206.

[0073] Container 218 may house a connecting tube 230 configured to provide flow communication between container 218 and trapway 206. Connecting tube 230 may extend from an interior region of container 218 into trapway 206. In some embodiments, connecting tube 230 may be coupled to trapway 206 at a position between sump trap 214 and lower trap 216. A trapway-tank interface 212 may be positioned between sump trap 214 and lower trap 216 and may be configured to couple to connecting tube 230. In some embodiments, connecting tube 230 may comprise a backflow preventer.

[0074] FIG. 3 shows a perspective cutaway view of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 3 illustrates a cross-sectional view of a toilet 300 comprising a toilet bowl 302, a toilet tank 304, a trapway 306, and a flush control 308. In some embodiments, toilet 300 may include one or more features of toilet 200 shown in FIG. 2 and/or toilet 100 shown in FIGS. 1 A and IB.

[0075] Toilet tank 304 may comprise one or more features of toilet tank 204 of toilet 200 shown in FIG. 2. In some embodiments, toilet tank 304 may be configured to house a container 318, a flush valve 324, and a fill valve 334. Container 318 and flush valve 324 may include one or more features of container 218 and flush valve 224, respectively. Fill valve 334 may be configured to fluidly connect to a water supply in order to facilitate the transmission of flush water from the water supply to toilet tank 304. In some embodiments, fill valve 334 may comprise a backflow preventer. [0076] Toilet bowl 302 may be fluidly coupled to flush valve 324 via a fluid pathway 322. A flush valve gasket 310 may form a mechanical seal between flush valve 324 and fluid pathway 322 in order to prevent water from leaking out of toilet tank 304 and into toilet bowl 302 in between flush cycles. In some embodiments, fluid pathway 322 may be in flow communication with a rim channel 336 and/or a jet channel 338. Rim channel 336 may include one or more features of rim channel 236 shown in FIG. 2. Jet channel 338 may include one or more features of jet channel 238 shown in FIG. 2.

[0077] Trapway 306 may comprise one or more features of trapway 206 of toilet 200 shown in FIG. 2 and/or trapway 106 of toilet 100 shown in FIGS. 1 A and IB. Trapway 306 may comprise a sump trap 314 (defined by a first upstream portion 314u of trapway 306, a sump area 314a in toilet bowl 302, and a first downstream portion 314d of trapway 306), a first upstream weir 326, a lower trap 316 (positioned between a second upstream portion 316u of trapway 306 and a second downstream portion 316d of trapway 306), and a second downstream weir 328. Trapway 306 may be fluidly coupled to toilet tank 304 via a trapwaytank interface 312. In some embodiments, trapway 306 may comprise an outlet 320 configured to fluidly connect to a drainage pipe into a sewer system.

[0078] FIG. 4 shows a partial cross-sectional view of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 4 shows a partial cross-sectional view of a toilet 400. Toilet 400 may comprise a toilet bowl 402 that is fluidly coupled to a toilet tank via a flush valve outlet 404. Toilet bowl 402 may be fluidly coupled to a trapway 410 through a trapway inlet 411. A sump trap 412 may be defined by a first upstream portion 412u, a sump area 412a, and a first downstream portion 412d of trapway 410. A first upstream weir 416 of trapway 410 may be positioned downstream of sump trap 412. A lower trap 414 may be positioned between a second upstream portion 414u and a second downstream portion 414d of trapway 410, and a second downstream weir 418 may be positioned downstream of lower trap 414. Trapway 410 may be fluidly coupled to a toilet tank via a trapway-tank interface 408. In some embodiments, one or more features of toilet 400 may include one or more features of toilet 300 shown in FIG. 3, toilet 200 shown in FIG. 2, and/or toilet 100 shown in FIGS. 1A-1B. The distribution of flush water and pressurized air in the toilet tank

[0079] As described with reference to FIGS. 1-4, dual-trap toilets may comprise a toilet tank that is configured to contain flush water. The toilet tank may house a container that may be coupled to the trapway by a connecting tube that is configured to provide flow communication between the container and the trapway. The container may be divided into a plurality of chambers. In between flush cycles, the flush water in the toilet tank may be divided between a region of the toilet tank outside of the container and the plurality of chambers within the container. One of the chambers (a vacuum chamber) may have a closed upper end and may be configured to contain pressurized air when the toilet is between flush cycles. The pressurized air in the vacuum chamber may have a pressure greater than the ambient pressure of air in the toilet tank. The connecting tube may fluidically couple the upper end of the vacuum chamber to the trapway. As a result of the coupling between the trapway and the upper end of the vacuum chamber, the trapway may also contain pressurized air when the toilet is between flush cycles.

[0080] In addition to the vacuum chamber, the container may comprise an inner chamber that may have an upper end that is open to the toilet tank, allowing air to flow freely between the inner chamber and the region of the tank that is outside of the container. The inner chamber may also house a flush valve that is fluidically coupled to a toilet bowl of the dualtrap toilet. Upon initiation of a flush cycle, a flush valve seal may be lifted from an inlet to the flush valve to open the flush valve, and flush water may be discharged from the toilet tank and the container through the flush valve and into the toilet bowl. The discharging flush water may reduce the pressure of the air contained in the vacuum chamber of the container and air contained in the trapway of the toilet. This reduction in pressure may induce a siphon that pulls the contents of the toilet bowl into the trapway and subsequently into the sewer system.

[0001] As flush water exits the toilet tank, the water level in the vacuum chamber may rapidly drop, and air pressure within the vacuum chamber and within the trapway may drop from positive pressure to negative pressure (e.g., below the ambient pressure of air within the toilet tank). Upon completion of a flush cycle, the flush valve may close, and the toilet tank may re-fill with flush water. The air pressure within the upper end of the vacuum chamber - and, as a result of the coupling provided by the connecting tube, the air pressure within the trapway - may continue to increase until the toilet tank has replenished its flush water supply. Once the toilet tank has replenished its flush water supply, the toilet may return to its between-flush-cycle state.

[0081] FIGS. 5A-5D show various cutaway and cross-sectional views of a tank of a dualtrap toilet, in accordance with some embodiments. Specifically, FIGS. 5A-5C show a topview cutaway (FIG. 5A), a cross-sectional view (FIG. 5B), a side-view cutaway (FIG. 5C), and a close-up view (FIG. 5D) of various components of a toilet tank 500 of a dual trap toilet. In some embodiments, tank 500 may include one or more features of toilet tank 304 of toilet 300 shown in FIG. 3, toilet tank 204 of toilet 200 shown in FIG. 2, and/or toilet tank 104 of toilet 100 shown in FIGS. 1 A-1B.

[0082] Tank 500 may be formed from a tank wall 502. In some embodiments, a flush control 504 may be positioned on tank wall 502. In some embodiments, tank 500 may house a container 506, a fill valve 508, and a flush valve 510. Fill valve 508 may be configured to fluidly couple to a water supply via one or more openings in tank wall 502. Flush valve 510 may be fluidly coupled to a flush valve outlet 520 that fluidly connects to a toilet bowl of the dual -trap toilet. In some embodiments, flush valve 510 may comprise a valve body that extends from a valve inlet to a flush valve outlet 520. In some embodiments, flush valve 510 may comprise a valve cover with a seal 530 configured to enclose the valve outlet 520.

[0083] Flush control 504 may be configured to initiate a flush cycle upon receiving input from a user. Specifically, upon receiving input from a user, flush control 504 may be configured to cause flush valve seal 530 to lift away from valve outlet 520 to flush valve 510 in order to open flush valve 510, thereby causing flush water that is contained in tank 500 to be discharged into the toilet bowl of the dual-trap toilet. Flush water may be discharged from tank 500 through a plurality of openings 532. The discharge of flush water into the toilet bowl may induce a siphon in a trapway of the dual-trap toilet. In some embodiments, when the level of flush water in tank 500 has fallen below a threshold level with respect to flush valve 510 (e.g., below a lower edge of a head of flush valve 510), the siphon may be broken. Upon completion of the flush cycle, flush valve seal 530 may close, and fill valve 508 may open so that the supply of flush water in tank 500 may be replenished. In some embodiments, a flush valve gasket 518 may be positioned between flush valve 510 and flush valve outlet 520 in order to prevent flush water from leaking into the toilet bowl in between flush cycles. [0084] Container 506 may have an irregular toroidal (i.e., “donut”-shaped) structure defined by an inner wall 514, a continuous side wall 516, and an upper wall 512 that together define a plurality of interior chambers within container 506. These interior chambers may form an irregular annular region and may include a vacuum chamber 522 comprising a lower portion 522a and an upper portion 522b as well as an inner chamber 523. Vacuum chamber 522 may be bounded by inner wall 514, continuous side wall 516, and upper wall 512. Inner chamber 523 may be a central cavity region bounded by inner wall 514. Flush valve 510 may be positioned within inner chamber 523.

[0085] Vacuum chamber 522 may be fluidically coupled to inner chamber 523 and to tank 500 through a plurality of openings 536 in a lower end of container 506. In some embodiments, the plurality of openings 536 may comprise at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 openings. In some embodiments, the plurality of openings 536 may comprise between 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, or 14-16 openings.

[0086] One or more of the regions of tank 500 defined by the structure of container 506 may be configured to contain a portion of the total volume of flush water held in tank 500 between flush cycles. In addition, between flush cycles, one or more of the regions of tank 500 defined by the structure of container 506 may be configured to contain pressurized air. The manner in which the total volume of flush water is distributed among the chambers may provide for efficient flush operation (e.g., may provide a high MAP score at low flush water volume).

[0087] Prior to the initiation of a flush cycle, tank 500 (including container 506) may store a total volume of flush water. In some embodiments, the total volume of flush water stored in tank 500 may be about 0.5 gallons, about 0.75 gallons, about 1 gallon, about 1.25 gallons, about 1.5 gallons, about 1.75 gallons, about 2 gallons, about 3 gallons, about 4 gallons, or about 5 gallons. In some embodiments, the total volume of flush water stored in tank 500 may be greater than or equal to 2.5 gallons, 3.5 gallons, 4.5 gallons, 5.5 gallons, 6.5 gallons, 7.5 gallons, or 8.5 gallons. In some embodiments, the total volume of flush water stored in tank 500 may be less than or equal to 2 gallons, 1.5 gallons, 1 gallon, 0.5 gallons, or 0.1 gallons. [0088] A first portion of the total volume of flush water in tank 500 may be stored in a region of tank 500 that is exterior to container 506 (i.e., a region that excludes vacuum chamber 522 and inner chamber 523 of container 506). In some embodiments, the first portion may be about 10%, about 20%, about 30%, about 40%, or about 50% of the total volume of flush water in tank 500. In some embodiments, the first portion may be less than or equal to 50%, 40%, 30%, 20%, 10%, or 5% of the total volume of flush water in tank 500. In some embodiments, the first portion may be greater than or equal to 20%, 30%, 40%, 50%, or 60% of the total volume of flush water in tank 500.

[0089] In some embodiments, less than one quarter of the flush water during a flush cycle may flow from a region of tank 500 that is exterior to container 506 (i.e., a region that excludes vacuum chamber 522 and inner chamber 523 of container 506). In some embodiments, the percentage of flush water flowing from tank 500 (considered separately from the container and/or subcomponents of the container) may be less than or equal to 30%, 25%, 24%, 22%, 20%, 18%, 16%, 15%, or 10%. In some embodiments, the percentage of flush water flowing from tank 500 (considered separately from the container and/or subcomponents of the container) may be greater than or equal to 30%, 25%, 24%, 22%, 20%, 18%, 16%, 15%, or 10%. In some embodiments, the percentage of flush water flowing from tank 500 (considered separately from the container and/or subcomponents of the container) may be greater than or equal to 16% and less than or equal to 20%. In some embodiments, the percentage of flush water flowing from tank 500 (considered separately from the container and/or subcomponents of the container) may be greater than or equal to 14% and less than or equal to 22%. In some embodiments, the percentage of flush water flowing from tank 500 (considered separately from the container and/or subcomponents of the container) may be equal to about 18%.

[0090] A second portion of the total volume of flush water in tank 500 may be stored in vacuum chamber 522 when the toilet is between flush cycles. In some embodiments, the second portion may be about 10%, about 20%, about 30%, about 40%, or about 50% of the total volume of flush water in tank 500. In some embodiments, the second portion may be less than or equal to 50%, 40%, 30%, 20%, 10%, or 5% of the total volume of flush water in tank 500. In some embodiments, the second portion may be greater than or equal to 20%, 30%, 40%, 50%, or 60% of the total volume of flush water in tank 500. [0091] In some embodiments, less than one third of the flush water during a flush cycle may flow from vacuum chamber 522. In some embodiments, the percentage of flush water flowing from vacuum chamber 522 may be less than or equal to 40%, 35%, 34%, 32%, 30%, 28%, 26%, 25%, or 20%. In some embodiments, the percentage of flush water flowing from vacuum chamber 522 may be greater than or equal to 40%, 35%, 34%, 32%, 30%, 28%, 26%, 25%, or 20%. In some embodiments, the percentage of flush water flowing from vacuum chamber 522 may be greater than or equal to 27% and less than or equal to 31%. In some embodiments, the percentage of flush water flowing from vacuum chamber 522 may be greater than or equal to 25% and less than or equal to 33%. In some embodiments, the percentage of flush water flowing from vacuum chamber 522 may be equal to about 29%.

[0092] A third portion of the total volume of flush water in tank 500 may be stored in inner chamber 523 when the toilet is between flush cycles. In some embodiments, the third portion may be about 40%, about 50%, about 60%, about 70%, about 80%, or about 90% of the total volume of flush water in tank 500. In some embodiments, the third portion may be less than or equal to 90%, 80%, 70%, 60%, or 50% of the total volume of flush water in tank 500. In some embodiments, the third portion may be greater than or equal to 30%, 40%, 50%, 60%, or 70% of the total volume of flush water in tank 500.

[0093] In some embodiments, more than half of the flush water during a flush cycle may flow from inner chamber 523. In some embodiments, the percentage of flush water flowing from inner chamber 523 may be greater than or equal to 40%, 45%, 50%, 52%, 54%, 56%, 58%, 60%, 65%, or 70%. In some embodiments, the percentage of flush water flowing from inner chamber 523 may be less than or equal to 40%, 45%, 50%, 52%, 54%, 56%, 58%, 60%, 65%, or 70%. In some embodiments, the percentage of flush water flowing from inner chamber 523 may be greater than or equal to 54% and less than or equal to 58%. In some embodiments, the percentage of flush water flowing from inner chamber 523 may be greater than or equal to 52% and less than or equal to 60%. In some embodiments, the percentage of flush water flowing from inner chamber 523 may be equal to about 56%.

[0094] As shown, the upper end 522b of vacuum chamber 522 may be closed off from the interior of tank 500 by upper wall 512 of container 506. This may allow vacuum chamber 522 to contain positively pressurized air in upper end 522b when the toilet is between flush cycles. A connecting tube 524 may be positioned within vacuum chamber 522 and may fluidically couple the upper portion 522b of vacuum chamber 522 to the toilet’s trapway. As a result, the trapway may also contain pressurized air when the toilet is between flush cycles. Connecting tube may include a connecting tube gasket 526 positioned between a connecting tube outlet 528 and the trapway in order to prevent flush water from leaking out of tank 500 and into the trapway. In some embodiments, the positive pressurization of the first portion of pressurized air in vacuum chamber 522 may be equal to the positive pressurization of the second portion of pressurized air in the trapway.

[0095] In some embodiments, the positive pressurization of the first portion of pressurized air in vacuum chamber 522 may be any of about 0.1 cm of water, 0.2 cm of water, 0.3 cm of water, 0.5 cm of water, about 0.8 cm of water, about 1.1 cm of water, about 1.4 cm of water, about 1.7 cm of water, about 2.0 cm of water, about 2.3 cm of water, about 2.6 cm of water, or about 2.9 cm of water, to any of about 3.2 cm of water, about 3.5 cm of water, about 3.8 cm of water, about 4.1 cm of water, about 4.4 cm of water, about 4.7 cm of water, about 5.0 cm of water, or more. In some embodiments, the positive pressurization of the first portion of pressurized air in vacuum chamber 522 may be greater than or equal to 0.1 cm of water, 0.2 cm of water, 0.3 cm of water, 0.5 cm of water, 0.8 cm of water, 1.1 cm of water, 1.4 cm of water, 1.7 cm of water, 2.0 cm of water, 2.3 cm of water, 2.6 cm of water, or 2.9 cm of water. In some embodiments, the positive pressurization of the first portion of pressurized air in vacuum chamber 522 may be less than or equal to 3.2 cm of water, 3.5 cm of water, 3.8 cm of water, 4.1 cm of water, 4.4 cm of water, 4.7 cm of water, or 5.0 cm of water. As used herein, reference to positive pressurization in centimeters of water may refer to pressurization above atmospheric pressure by an amount of additional pressure equal to the given centimeters of water. For example, “positive pressurization of 5 cm of water” may refer to 5 cm of water above atmospheric pressure, or an absolute pressure of about 1.0048 atm.

[0096] Between flush cycles, the first portion of positively pressurized air contained in vacuum chamber 522 may have a first volume and the second portion of positively pressurized air contained in the trapway may have a second volume. The first volume of pressurized air contained in vacuum chamber 522 may be less than the second volume of pressurized air contained in the trapway. In some embodiments, the first volume may be less than or equal to half the second volume. In some embodiments, the first volume may be less than or equal to 50%, 40%, 30%, 28%, 26%, 24%, 22%, 20%, 18%, 16%, 14%, 12%, or 10% the second volume. In some embodiments, the first volume may be greater than or equal to 20% and less than or equal to 24%. In some embodiments, the first volume may be greater than or equal to 18% and less than or equal to 26% the second volume. In some embodiments, the first volume may be equal to about 22% the second volume.

[0097] The position of connecting tube 524 within vacuum chamber 522 may impact the timing of vacuum formation for siphon initiation during a flush cycle. A vertical distance 538 between a top surface of connecting tube 524 and an inner top surface of vacuum chamber 522 may be greater than or equal to 5, 10, 15, 20, 25, 30, or 35 mm. Alternatively, a vertical distance 538 between a top surface of connecting tube 524 and an inner top surface of vacuum chamber 522 may be less than or equal to 45, 40, 35, 30, 25,20, or 15 mm. Connecting tube 524 may be positioned in vacuum chamber 522 such that, between flush cycles, a vertical distance between a top surface of connecting tube 524 and a water level in tank 500 exterior to container 506 is greater than or equal to 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75 mm. Alternatively, connecting tube 524 may be positioned in vacuum chamber 522 such that, between flush cycles, a vertical distance between a top surface of connecting tube 524 and a water level in tank 500 exterior to container 506 is less than or equal to 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, or 50 mm.

[0098] The size of connecting tube 524 may also impact the timing of vacuum formation for siphon initiation during a flush cycle. An opening 540 in the top surface of connecting tube 524 may have a diameter of about 2, about 4, about 6, about 8, about 10, about 12, about 14, about 16, about 18, or about 20 mm. In some embodiments, opening 540 may have a diameter greater than or equal to 2, 4, 6, 8, 10, 12 or 14 mm. In some embodiments, opening 540 may have a diameter less than or equal to 20, 18, 16, 14, 12, or 10 mm. An internal diameter of connecting tube 524 may be about 12, about 14, about 16, about 18, about 20, or about 22 mm. In some embodiments, an internal diameter of connecting tube 524 may be greater than or equal to 10, 12, 14, 16, 18, 20, 22, or 24 mm. In some embodiments, an internal diameter of connecting tube 524 may be less than or equal to 30, 28, 26, 24, 22, 20, 18, or 16 mm. Pressurized air in the trapway

[0099] Between flush cycles, the trapway of a dual-trap toilet may contain a volume of positively pressurized air. The volume of positively pressurized air contained in the trapway may be a second of two portions of positively pressurized air contained in the dual-trap toilet. In some embodiments, the second portion of positively pressurized air may also include air located in a connecting tube (e.g., connecting tube 524 of tank 500 shown in FIG. 5) and/or in an interface portion between the connecting tube and the trapway. The first of the two portions of positively pressurized air contained in the dual trap toilet may be contained in the toilet tank. Between flush cycles, the positively pressurized air in the trapway may push upwards on water being held in the sump trap, which may result in a larger water spot in the toilet bowl than would be present if not for the positively pressurized air in the trapway. Between flush cycles, the positively pressurized air in the trapway may push downwards on water being held in the lower trap such that a water level in an upstream end of the lower trap may be lower than a water level in a downstream end of the lower trap. In some embodiments, when a flush cycle is initiated, the discharge of flush water into the toilet bowl may exert a negative pressure on the air in the tank and/or the air in the trapway, causing the pressure to drop to atmospheric pressure or to a partial vacuum. This drop in pressure may generate a siphon in the trapway that may pull the contents of the toilet bowl into and out of the trapway. Upon completion of the flush cycle, the flush water in the toilet tank may be replenished, which may restore the positive pressurization of the air contained in the trapway.

[0100] FIGS. 6A and 6B show views of a toilet bowl and/or trapway of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 6A shows a toilet bowl 602 and a trapway 610 of a dual-trap toilet 600. Trapway 610 comprises a sump trap 612 (positioned between a first upstream portion 612u and a first downstream portion 612d of trapway 610), a first upstream weir 616, a lower trap 614 (positioned between a second upstream portion 614u and a second downstream portion 614d of trapway 610), a second downstream weir 618, and a trapway outlet 620. Trapway outlet may be configured to fluidly couple to a drainage pipe that connects to a sewer system. FIG. 6B shows a portion of trapway 610 located between a downstream end of sump trap 612 and second downstream weir 618. In some embodiments, the portion of trapway 610 that is located between the downstream end of sump trap 612 and the upstream end of lower trap 614 may be configured to contain positively pressurized air in between flush cycles. [0101] Upon initiation of a flush cycle, toilet bowl 602 may be configured to receive flush water from the toilet tank of dual-trap toilet 600 via a flush water inlet 604. The discharge of flush water from the toilet tank, through flush water inlet 604, and into toilet bowl 602 may exert a negative pressure on the volume of pressurized air contained in trapway 610 between the downstream end of sump tank 612 and the upstream end of lower trap 614. The negative pressure exerted air in trapway 610 may cause the pressure of the air in trapway 610 to drop to atmospheric pressure or to partial vacuum. This drop in the pressure of the air in trapway 610 may create a siphon in trapway 610 that pulls the contents of toilet bowl 602 (e.g., flush water and/or waste) out of toilet bowl 602, through trapway 610, and into the sewer system via trapway outlet 620.

[0102] The portion of trapway 610 that contains the positively pressurized air between flush cycles may be fluidly coupled to a volume of pressurized air contained in a toilet tank of dual -trap toilet 600. In some embodiments, the fluid coupling between trapway 610 and the toilet tank may be facilitated by a connecting tube that is positioned in the toilet tank (e.g., connecting tube 524 of toilet tank 500 shown in FIG. 5C). The connecting tube may couple to trapway 610 via a connecting tube outlet 606 that is fluidly coupled to a trapway -tank interface 608.

[0103] In some embodiments, the positive pressurization of the portion of pressurized air in the toilet tank may be equal to the positive pressurization of the portion of pressurized air in the trapway. In some embodiments, between flush cycles, the portion of positively pressurized air contained in the toilet tank may have a first volume and the portion of positively pressurized air contained in trapway 610 may have a second volume. The second volume of pressurized air contained in trapway 610 may be greater than the first volume of pressurized air contained in the toilet tank. In some embodiments, the second volume may be greater than or equal to twice the first volume. In some embodiments, the first volume of pressurized air in the toilet tank may be less than or equal to 50%, 40%, 30%, 28%, 26%, 24%, 22%, 20%, 18%, 16%, 14%, 12%, or 10% the second volume of pressurized air in trapway 610. In some embodiments, the first volume may be greater than or equal to 20% and less than or equal to 24% the second volume of pressurized air in trapway 610. In some embodiments, the first volume may be greater than or equal to 18% and less than or equal to 26% the second volume of pressurized air in trapway 610. In some embodiments, the first volume may be equal to about 22% the second volume of pressurized air in trapway 610. [0104] FIG. 7 shows a cross-sectional view of a dual-trap toilet and a lower seal offset height, in accordance with some embodiments. Specifically, FIG. 7 shows a dual-trap toilet 700 comprising a toilet bowl 702 and a trapway 704. Trapway 704 may comprise a sump trap 708 (defined by a first upstream portion 708u and a first downstream portion 708d of trapway 704 and comprising a sump area 708a of toilet bowl 702), a first upstream weir 714, a lower trap 710 (positioned between a second upstream portion 71 Ou and a second downstream portion 710d of trapway 704), and a second downstream weir 716. In some embodiments, trapway 704 may be fluidly coupled to a toilet tank of dual-trap toilet 700 via a trapway-tank interface 706. Between flush cycles, sump trap 708 may be configured to hold a first volume of water. The volume of water held in sump trap 708 may create a water spot in toilet bowl 702. Between flush cycles, lower trap 710 may be configured to hold a second volume of water. In some embodiments, the first volume of water held in sump trap 708 and the second volume of water held in lower trap 710 may provide a series

[0105] In some embodiments, between flush cycles, trapway 704 may be configured to contain a volume of positively pressurized air. The volume of pressurized air may be contained between a downstream end 708d of sump trap 708 and an upstream end 71 Ou of lower trap 710. In some embodiments, between flush cycles, the positively pressurized air may exert upward pressure on water in sump area 708a. This may create a larger water spot in toilet bowl 702 than would be possible without the positively pressurized air in trapway 704.

[0106] In some embodiments, between flush cycles, positively pressurized air in trapway 704 may exert downward pressure on water being held in lower trap 710. Specifically, the positively pressurized air in trapway 704 may exert a downward pressure on an upstream end 71 Ou of lower trap 710. This downward pressure may cause the upstream water level in lower trap 710 to be offset from the downstream water level in lower trap 710 by an offset distance 712. In some embodiments, offset distance 712 may be greater than or equal to 1 mm, 2 mm, 3 mm, 5 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. In some embodiments, offset distance 712 may be less than or equal to 1 mm, 2 mm, 3 mm, 5 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. In some embodiments, offset distance 712 may be greater than 14 mm and less than 16 mm. In some embodiments, offset distance 712 may be greater than 13 mm and less than 17 mm. In some embodiments, offset distance 712 may be equal to about 15 mm.

Trapway shape

[0107] The shape of a trapway of a dual-trap toilet may be configured to optimize flow of air and water during a flush cycle. An upstream end of the trapway may be fluidly coupled to an outlet in the toilet bowl of the dual-trap toilet and a downstream end of the trapway may be configured to fluidly couple to an inlet to a drainage pipe that leads to a sewer system.

Between the upstream end and the downstream end, the trapway may comprise a sump trap, a first upstream weir, a first connecting portion extending downward from the first upstream weir, a lower trap, a second connecting portion extending upward from the lower trap, a second downstream weir, and a third connecting portion extending downward from the second downstream weir. The shape of the first connecting portion may form an arc that extends laterally outwards from the first upstream weir and then bends laterally back toward the lower trap. The first connecting portion may comprise a single arced portion, multiple arced portions (e.g., having different arc radii and/or arcing in different directions), a single straight-line portion, and/or multiple straight-line portions.

[0108] FIG. 8 shows a trapway of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 8 shows a trapway portion 800 comprising a first upstream weir 802, a lower trap 804, a second downstream weir 806, and a connecting portion 808. First upstream weir 802 may be positioned downstream of a sump trap of the dual-trap toilet. Connecting portion 808 may extend from a downstream end of first upstream weir 802 to an upstream end of lower trap 804.

[0109] As shown, first upstream weir 802 may comprise a first arced shape 812 that arcs about a first center-point 816. Similarly, lower trap 804 may comprise a second arced shape 814 that arcs about a second center-point 818. Connecting portion 808 may extend outwards laterally (e.g., horizontally) and then arc back inwards laterally while extending downwards vertically. Connecting portion 808 may comprise a central arced path 820 between first upstream weir 802 and lower trap 804. First arced shape 812, second arced shape 814, and/or central arced path 820 may trace the center of a fluid flow path through trapway portion 800. [0110] An upstream end of central arced path 820 may extend laterally away from first upstream weir 802, while a downstream end of central arced path 820 may extend laterally toward lower trap 804. In some embodiments, connecting portion 808 may be greater than or equal to 80, 90, 100, 110, 120, 130, 140, or 150 mm in (vertical) height. In some embodiments, connecting portion 808 may be less than or equal to 80, 90, 100, 110, 120, 130, 140, or 150 mm in (vertical) height. In some embodiments, a lateral extent over which connecting portion 808 extends in the lateral (e.g., horizontal) direction may be greater than or equal to 20, 30, 40, 50, 60, 70, or 80 mm. In some embodiments, a lateral extent over which connecting portion 808 extends in the lateral (e.g., horizontal) direction may be less than or equal to 20, 30, 40, 50, 60, 70, or 80 mm.

[OHl] The distance at which a portion of connecting portion 808 is disposed from first upstream weir 802 and from lower trap 804 may be understood with reference to a first line 822 extending between first center-point 816 and second center-point 818 and a second line 824 that is parallel to the first line and forms a tangent with central arced path 820 of connecting portion 808. First line 822 may be vertical or may angle outward or in the same direction in which central arced path 820 protrudes outward, as it extends downward, or may angle inward, in an opposite direction in which central arced path 820 protrudes outward, as it extends downward.

[0112] In some embodiments, a point 828 at which second line 824 is tangent to central arced path 820 may be equidistant between first upstream weir 802 and lower trap 804. In some embodiments, point 828 at which second line 824 is tangent to central arced path 820 may be closer to first upstream weir 802 than lower trap 804. In some embodiments, point 828 at which second line 824 is tangent to central arced path 820 may be closer to lower trap 804 than first upstream weir 802.

[0113] Second line 824 may be offset from first line 822 by an offset distance 826. In some embodiments, offset distance 826 may be greater than or equal to 40, 50, 60, 62, 64, 66, 68, 70, 80, or 90 mm. In some embodiments, offset distance 826 may be less than or equal to 40, 50, 60, 62, 64, 66, 68, 70, 80, or 90 mm. In some embodiments, offset distance 826 may be greater than 64 and less than 68 mm. In some embodiments, offset distance 826 may be of greater than 62 and less than 70 mm. In some embodiments, offset distance 826 may be about 65.7 mm. [0114] Trapway portion 800 may be fluidly coupled to a toilet tank of the dual -trap toilet via an interface 810 which may be located at a position between the sump trap (which may be located upstream of first upstream weir 802) and lower trap 804. Interface 810 may be fluidly coupled to a connecting tube that is positioned within the toilet tank and configured to provide fluid communication between the toilet tank and the trapway. In some embodiments, interface 810 may be a portion of the connecting tube.

[0115] Interface 810 may have an upper end that couples to a lower end of the connecting tube and may have a lower end that couples to trapway portion 800. The lower end may couple to the trapway at a location between the sump trap (which may be located upstream of first upstream weir 802) and lower trap 804 such that positively-pressurized air may be delivered, through the interface, to connecting portion 808. The lower end of interface 810 may couple to an upper wall of trapway portion 800 above first upstream weir 802 and/or to an upper/outer wall of the connecting portion 808.

[0116] The lower end of interface 810 may extend from a first edge 830 that couples to the trapway at a most-upstream extent (referring to the direction of flow of water in the trapway) to a second edge 832 that couples to the trapway at a most-downstream extent (referring to the direction of flow of water in the trapway). The lower end of interface 810 may be wider in at least one direction than an upper end of trapway portion 800. In some embodiments, the lower end of interface 810 may be wider in a first dimension that it is in a second dimension. Optionally, interface 810 may have a generally triangular or “shark fin” shape extending from a narrow (e.g., circular) upper end to a lower end that is wider in one dimension.

[0117] First edge 830 may be positioned directly above first upstream weir 802. In some embodiments, first edge 830 may be positioned on the upper wall of the trapway at a location that is less than or equal to 1, 2, 3, 4, 5, 10, or 15 mm from a location directly above first upstream weir 802. In some embodiments, first edge 830 may be positioned on the upper wall of the trapway at a location that is greater than or equal to 1, 2, 3, 4, 5, 10, or 15 mm from a location directly above first upstream weir 802.

[0118] Second edge 832 may be positioned directly level with first upstream weir 802. In some embodiments, second edge 832 may be positioned on the upper/outer wall of the trapway at a location that is less than or equal to 1, 2, 3, 4, 5, 10, or 15 mm from a location directly level with first upstream weir 802. In some embodiments, second edge 832 may be positioned on the upper/outer wall of the trapway at a location that is greater than or equal to 1, 2, 3, 4, 5, 10, or 15 mm from a location directly level with first upstream weir 802.

[0119] In some embodiments, a wall of interface 810 may be tangent to the upper wall of the trapway at first edge 830 of the lower end of interface 810. In some embodiments, a wall of interface 810 may be tangent to the upper/outer wall of the trapway at second edge 832 of the lower end of interface 810.

[0120] FIG. 9 shows dimensions for a flow path for a trapway for a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 9 shows a flow path 900 for a dualtrap toilet trapway that comprises a sump trap 902, a first upstream weir 904, a connecting portion 906, a lower trap 908, and a second downstream weir 910. Sump trap 902 may be downstream of and fluidly coupled to a toilet bowl of the dual-trap toilet. During a flush cycle, fluid may be transmitted along flow path 900. In other words, during a flush cycle, fluid may flow from sump trap 902, over first upstream weir 904, through connecting portion 906, through lower trap 908, and over second downstream weir 910 before being transmitted out of the trap way.

[0121] Between flush cycles, sump trap 902 may trap a volume of flush water in the toilet bowl of the dual-trap toilet that may create a water spot in the toilet bowl. Between flush cycles, the water spot depth 926 may be defined by a first water spot line 916 and a second water spot line 918. In some embodiments, water spot depth 926 may be greater than or equal to 40, 50, 60, 70, 80, or 90 mm. In some embodiments, water spot depth 926 may be less than or equal to 40, 50, 60, 70, 80, or 90 mm. In some embodiments, water spot depth 926 may be greater than or equal to 50 mm and less than or equal to 60 mm. In some embodiments, between flush cycles, connecting portion 906 may contain a volume of positively pressurized air that applies an upward pressure on the water spot, resulting in a greater water spot depth 926.

[0122] Sump trap 902 may be fluidly coupled to the toilet bowl via a sump inlet that is centered at a sump inlet center-point 928 that is positioned along flow path 900. In some embodiments, an inlet diameter 924 of the sump trap outlet may be greater than or equal to 50, 60, 70, 80, 90, or 100 mm. In some embodiments, inlet diameter 924 may be less than or equal to 60, 60, 70, 80, 90, or 100 mm. In some embodiments, inlet diameter 924 may be greater than or equal to 60 mm and less than or equal to 70 mm. [0123] First upstream weir 904 may form a first arced shape that is centered at a first center-point 912. Similarly, lower trap 908 may form a second arced shape that is centered at a second center-point 914. A first radius 930 of the first arced shape may be the distance from the center of flow path 900 through first upstream weir 904 to first center-point 912. A second radius 932 of the second arced shape may be the distance from the center of flow path 900 through lower trap 908 to second center-point 914. In some embodiments, first radius 930 may be greater than second radius 932. In some embodiments, first radius 930 may be less than second radius 932. In some embodiments, first radius 930 and second radius 932 may be equal.

[0124] In some embodiments, first radius 930 may be greater than or equal to 40, 50, 60, 70, or 80 mm. In some embodiments, first radius 930 may be less than or equal to 40, 50, 60, 70, or 80 mm. In some embodiments, first radius 930 may be greater than or equal to 50 mm and less than or equal to 70 mm.

[0125] In some embodiments, second radius 932 may be greater than or equal to 20, 30, 40, 50, 60, or 70 mm. In some embodiments, second radius 932 may be less than or equal to 20, 30, 40, 50, 60, or 70 mm. In some embodiments, second radius 932 may be greater than or equal to 20 mm and less than or equal to 70 mm.

[0126] Between flush cycles, lower trap 908 may contain a volume of water. As mentioned above, between flush cycles, connecting portion 906 may contain a volume of positively pressurized air. The volume of pressurized air may exert a downward pressure on the volume of water that is held in lower trap 908 between flush cycles. This downward pressure may cause an upstream water level 920 of lower trap 908 to be offset by an offset distance 934 from a downstream water level 922 of lower trap 908. In some embodiments, offset distance 934 may be greater than or equal to 2, 3, 4, 5, 10, 15, or 20 mm. In some embodiments, offset distance 934 may be less than or equal to 2, 3, 4, 5, 10, 15, or 20 mm. In some embodiments, offset distance 934 may be greater than or equal to 4.75 mm and less than or equal to 5.25 mm.

Trapway diameter dimensions

[0127] In order to optimize the flow of air and water during flush cycles, a dual-trap toilet may have trapway that varies in diameter at different locations along the trapway. The interface may have an upper end that couples to a lower end of the connecting tube and may have a lower end that couples to the trapway. The lower end may couple to the trapway at a location between the sump trap and the lower trap, such that positively-pressurized air may be delivered, through the interface, to the area of the trapway between the water in the sump trap and the water in the lower trap. The lower end may couple to an upper wall of the trapway above the first upstream weir and/or to an upper/outer wall of the connecting portion. A diameter of the trapway may be measured at any of the trapway components referred to above and may, in some embodiments, differ from one or more other components at any of the trapway components referred to above. When trapway diameter is referenced, it may be understood to refer to a diameter of a circular trapway and/or to a diameter in at least one direction of an elliptical and/or irregularly-shaped trapway.

[0128] FIG. 10 shows trap diameter dimensions for a trapway for a dual -trap toilet, in accordance with some embodiments. Specifically, FIG. 10 shows a flow path 1000 for a dualtrap toilet trapway. In some embodiments, the trapway may have a variable diameter at different locations along flow path 1000. The trapway diameter at each location along flow path 1000 may be the length of a straight line from one side of the trapway boundary to the opposite side of the trapway boundary that passes through flow path 1000.

[0129] Location 1002 may be a sump trap outlet into the trapway. The cross-section of the sump trap outlet may be approximately “D”-shaped. In some embodiments, the cross- sectional area of the trapway at location 1002 may be greater than or equal to 15, 20, 25, 30, 35, 40, 45, 50, or 55 cm². In some embodiments, the cross-sectional area of the trapway at location 1002 may be less than or equal to 65, 60, 55, 50, 45, 40, 35, 30, or 25 cm². In some embodiments, the cross-sectional area of the trapway at location 1002 may be between about 20-25, 25-30, 30-35, 35-40, 40-45, or 45-50 cm². In some embodiments, the cross-sectional area of the trapway at location 1002 can be about 34, 34.5, 35, 35.5, 36, 36.5, or 37 cm².

[0130] In some embodiments, the cross-section of the sump trap outlet may comprise additional or alternative shapes. In some embodiments, at its widest point, the width of the sump trap outlet may be greater than or equal to 50, 60, 70, 80, 90, or 100 mm. In some embodiments, at its widest point, the width of the sump trap outlet may be less than or equal to 60, 60, 70, 80, 90, or 100 mm. In some embodiments, at its widest point, the width of the sump trap outlet may be greater than or equal to 60 mm and less than or equal to 70 mm. [0131] Location 1004 may be a downstream end of a sump trap. The diameter of the trapway at location 1004 may be greater than, less than, or equal to the diameter of the trapway at location 1002.

[0132] Location 1006 may be a peak of a first upstream weir. In some embodiments, the diameter of the trapway at location 1006 (and/or at one or more locations further downstream) may be greater than or equal to 52, 56, 60, 64, 68, 72, or 76 mm. In some embodiments, the diameter of the trapway at location 1006 (and/or at one or more locations further downstream) may be less than or equal to 52, 56, 60, 64, 68, 72, or 76 mm. In some embodiments, the diameter of the trapway at location 1006 (and/or at one or more locations further downstream) may be greater than or equal to 63 mm and less than or equal to 67 mm. In some embodiments, the diameter of the trapway at location 1006 (and/or at one or more locations further downstream) may be greater than or equal to 61 mm and less than or equal to 69 mm. In some embodiments, the diameter of the trapway at location 1006 (and/or at one or more locations further downstream) may be about 65 mm.

[0133] In some embodiments, the trapway may have a funnel-like shape between location 1002 and location 1006. In other words, the cross-sectional area of the trapway may gradually narrow between location 1002 and location 1006. This form factor may aid in the passing of solid waste.

[0134] Location 1008 may be an upstream end of a lower trap. In some embodiments, the diameter of the trapway at location 1008 may be greater than or equal to 42, 46, 50, 54, 58, 62, or 66 mm. In some embodiments, the diameter of the trapway at location 1008 (and/or at one or more locations further downstream) may be less than or equal to 42, 46, 50, 54, 58, 62, or 66 mm. In some embodiments, the diameter of the trapway at location 1008 (and/or at one or more locations further downstream) may be greater than or equal to 52 mm and less than or equal to 56 mm. In some embodiments, the diameter of the trapway at location 1008 (and/or at one or more locations further downstream) may be greater than or equal to 50 mm and less than or equal to 58 mm. In some embodiments, the diameter of the trapway at location 1008 (and/or at one or more locations further downstream) may be about 54 mm.

[0135] Location 1010 may be a lowermost point of the lower trap. In some embodiments, the diameter of the trapway at location 1010 may be wider than a diameter of the trapway at location 1008 and/or may be wider than a diameter of the trapway at one or more points downstream from location 1010 (e.g., locations along a second downstream weir). In some embodiments, a widened diameter of the trapway at location 1010 may reduce clogging at that position in the trapway. In some embodiments, the diameter of the trapway at location 1010 may be greater than, equal to, or less than a diameter of the trapway at one or more upstream locations (e.g., locations 1002-1006).

[0136] Location 1012 may be a peak of a second downstream weir. In some embodiments, the diameter of the trapway at location 1012 may be greater than or equal to 30, 40, 50, 60, or 70 mm. In some embodiments, the diameter of the trapway at location 1012 may be less than or equal to 30, 40, 50, 60, or 70 mm.

[0137] Location 1014 may be location downstream of the peak of the second downstream weir. In some embodiments, location 1014 may be offset from location 1012 by an offset distance of at least 5, at least 10, at least 20, at least 30, at least 40, or at least 50 mm. In some embodiments, the diameter of the trapway at location 1014 may be greater than the diameter of the trapway at location 1012. In some embodiments, the diameter of the trapway at location 1014 may be less than the diameter of the trapway at location 1012. In some embodiments, the diameter of the trapway at location 1014 may be equal to the diameter of the trap way at location 1012.

[0138] Finally, location 1016 may be a trapway outlet. The trapway may be fluidly coupled to a drainage pipe that connects to a sewer system at location 1016. In some embodiments, the diameter of the trapway at location 1016 may be greater than or equal to 50, 60, 70, 80, 90, or 100 mm. In some embodiments, the diameter of the trapway at location 1016 may be less than or equal to 60, 60, 70, 80, 90, or 100 mm. In some embodiments, the diameter of the trapway at location 1016 may be greater than or equal to 60 mm and less than or equal to 70 mm.

Interface between the trapway and the connecting tube

[0139] The tank of a dual-trap toilet may house a container that is configured to hold a portion of the flush water in between flush cycles. In some embodiments, a connecting tube that is configured to provide flow communication between the container and the trapway may be positioned inside the container. The dual-trap toilet may have an interface between (or included as part of) the connecting tube that is positioned and shaped to optimize flow of air and water during flush cycles. The interface may have an upper end that couples to a lower end of the connecting tube and may have a lower end that couples to the trapway. The lower end may couple to the trapway at a location between the sump trap and the lower trap, such that positively-pressurized air may be delivered, through the interface, to the area of the trapway between the water in the sump trap and the water in the lower trap. The lower end may couple to an upper wall of the trapway above the first upstream weir and/or to an upper/outer wall of the connecting portion.

[0140] FIG. 11 shows an interface between a connecting tube and a trapway of a dualtrap toilet, in accordance with some embodiments. Specifically, FIG. 11 shows a portion 1100 of a dual -trap toilet comprising an interface 1102 between a connecting tube outlet 1104 and a trapway 1106. Connecting tube outlet 1104 may be fluidly coupled to a connecting tube that is positioned within a container that is housed in a toilet tank of the dual-trap toilet. The toilet tank may also couple to the toilet bowl via a flush valve outlet 1110 that is adjacent to connecting tube outlet 1104.

[0141] Interface 1102 may couple to trapway 1106 at a location between a sump trap and a lower trap of trapway 1106. In some embodiments, an upstream portion of the lower end of interface 1102 may couple to trapway 1106 at a first point 1112 on an upper wall of trapway 1106 above first upstream weir 1108. A downstream portion of the lower end of interface 1102 may couple to trapway 1106 at a second point 1116 that is downstream of first point 1112. In some embodiments, second point 1106 may be defined by a first line 1118 and a second line 1120. First line 1118 may be a vertical line that intersects first point 1112. First line 1118 may intersect a lower portion of the trapway wall at a third point 1114. Second line 1120 may be a horizontal line that intersects third point 1114. Second point 1116 may be located along second line 820 on a side of the trapway wall that is opposite to third point 1114.

Exemplary Embodiments

[0142] Below is an enumerated listing of certain embodiments. In some embodiments, any one or more of the features of any one or more of the embodiments below may be combined with any one or more of the other embodiments, even if the dependencies of the embodiments do not explicitly indicate that the embodiments may be combined in such manner. In some embodiments, any one or more of the features of any one or more of the embodiments below may be combined with any one or more features or aspects otherwise disclosed in this application.

1. A toilet assembly, comprising a toilet tank to hold flush water; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, wherein the upper end of the container contains a first portion of pressurized air when the toilet assembly is between flush cycles, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, and the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway, and the trapway contains a second portion of pressurized air when the toilet assembly is between flush cycles, wherein a volume of the first portion of pressurized air is less than or equal to 30% of a volume of the second portion of pressurized air.

2. The toilet assembly of embodiment 1, wherein, between flush cycles, the first portion of pressurized air is positioned above flush water in the container.

3. The toilet assembly of any one of embodiments 1-2, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in one or both of the first portion of pressurized air and the second portion of pressurized air.

4. The toilet assembly of any one of embodiments 1-3, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in one or both of the first portion of pressurized air and the second portion of pressurized air. 5. The toilet assembly of any one of embodiments 1-4, wherein, between flush cycles, the first portion of pressurized air and the second portion of pressurized air are pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

6. The toilet assembly of any one of embodiments 1-5, wherein the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

7. The toilet assembly of any one of embodiments 1-6, wherein the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

8. The toilet assembly of any one of embodiments 1-7, wherein the connecting tube comprises a backflow preventer.

9. The toilet assembly of any one of embodiments 1-8, wherein the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet.

10. The toilet assembly of any one of embodiments 1-9, wherein the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound a vacuum chamber of the container.

11. The toilet assembly of embodiment 10, wherein the inner wall bounds an inner chamber of the container.

11. The toilet assembly of embodiment 10 or 11, wherein a vertical distance between a top surface of the connecting tube and an inner surface of the upper end wall is greater than or equal to 10 mm and less than or equal to 35 mm.

12. The toilet assembly of any one of embodiments 1-11, wherein an internal diameter of the connecting tube is greater than or equal to 12 mm and less than or equal to 20 mm. 13. The toilet assembly of any one of embodiments 1-12, wherein, between flush cycles, a vertical distance between a top surface of the connecting tube and a water level in the toilet tank is greater than or equal to 45 mm and less than or equal to 55 mm.

14. A toilet assembly, comprising: a toilet tank to hold flush water; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway, and the trapway contains pressurized air when the toilet assembly is between flush cycles, wherein the pressurized air in the trapway exerts force on water in the lower trap such that an upstream water level in the lower trap is lower than a downstream water level in the lower trap by an offset distance of greater than or equal to 15 mm between flush cycles.

15. The toilet assembly of embodiment 14, wherein, between flush cycles, the container comprises pressurized air positioned above flush water.

16. The toilet assembly of any one of embodiments 14-15, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in the pressurized air in the trapway.

17. The toilet assembly of any one of embodiments 14-16, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in the pressurized air in the trapway. 18. The toilet assembly of any one of embodiments 14-17, wherein, between flush cycles, the pressurized air in the trapway is pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

19. The toilet assembly of any one of embodiments 14-18, wherein the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

20. The toilet assembly of any one of embodiments 14-19, wherein the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

21. The toilet assembly of any one of embodiments 14-20, wherein the connecting tube comprises a backflow preventer.

22. The toilet assembly of any one of embodiments 14-21, wherein the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet.

23. The toilet assembly of any one of embodiments 14-22, wherein the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound a vacuum chamber of the container.

24. The toilet assembly of embodiment 23, wherein the inner wall bounds an inner chamber of the container.

25. The toilet assembly of embodiment 23 or 24, wherein a vertical distance between a top surface of the connecting tube and an inner surface of the upper end wall is greater than or equal to 10 mm and less than or equal to 35 mm.

26. The toilet assembly of any one of embodiments 14-25, wherein an internal diameter of the connecting tube is greater than or equal to 12 mm and less than or equal to 20 mm. 27. The toilet assembly of any one of embodiments 14-26, wherein, between flush cycles, a vertical distance between a top surface of the connecting tube and a water level in the toilet tank is greater than or equal to 45 mm and less than or equal to 55 mm.

28. A toilet assembly, comprising: a toilet tank; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, wherein the container comprises an inner chamber and a vacuum chamber, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, and the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway, and during a flush cycle, the toilet assembly flushes a volume of flush water, wherein: a first portion of the volume of flush water is stored in the tank prior to the flush cycle; a second portion of the volume of flush water is stored in the vacuum chamber prior to the flush cycle; a third portion of the volume of flush water is stored in the inner chamber prior to the flush cycle, wherein the third portion is greater than or equal to 40% of the volume of flush water.

29. The toilet assembly of embodiment 28, wherein the first portion is less than or equal to 20% of the volume of flush water.

30. The toilet assembly of any one of embodiments 28-29, wherein the second portion is less than or equal to 40% of the volume of flush water. 31. The toilet assembly of any one of embodiments 28-30, wherein, between flush cycles, the container comprises pressurized air positioned above flush water in the vacuum chamber.

32. The toilet assembly of any one of embodiments 28-31, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in pressurized air in the trapway.

33. The toilet assembly of any one of embodiments 28-32, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in pressurized air in the trap way.

34. The toilet assembly of any one of embodiments 28-33, wherein, between flush cycles, pressurized air in the trapway is pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

35. The toilet assembly of any one of embodiments 28-34, wherein the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

36. The toilet assembly of any one of embodiments 28-35, wherein the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

37. The toilet assembly of any one of embodiments 28-36, wherein the connecting tube comprises a backflow preventer.

38. The toilet assembly of any one of embodiments 28-37, wherein the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet. 39. The toilet assembly of any one of embodiments 28-38, wherein the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound the vacuum chamber.

40. The toilet assembly of embodiment 39, wherein the inner wall bounds the inner chamber.

41. The toilet assembly of embodiment 39 or 40, wherein a vertical distance between a top surface of the connecting tube and an inner surface of the upper end wall is greater than or equal to 10 mm and less than or equal to 35 mm.

42. The toilet assembly of any one of embodiments 28-41, wherein an internal diameter of the connecting tube is greater than or equal to 12 mm and less than or equal to 20 mm.

43. The toilet assembly of any one of embodiments 28-42, wherein, between flush cycles, a vertical distance between a top surface of the connecting tube and a water level in the toilet tank is greater than or equal to 45 mm and less than or equal to 55 mm.

44. A toilet assembly, comprising: a toilet tank to hold flush water; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, the trapway comprises a sump trap, a first upstream weir, a connecting portion, a lower trap, and a second downstream weir, the first upstream weir comprises a first arced shape arcing about a first center-point; the lower trap comprises a second arced shape arcing about a second center-point; the connecting portion forms a central arced path between the first upstream weir and the lower trap, wherein the central arced path extends laterally away from the first upstream weir and then extends laterally back toward the lower trap; a first line extending through the first center-point and the second center-point is offset from a second line by at an offset distance of greater than or equal to 60 mm, wherein the second line is tangent to the central arced path and parallel to the first line; and the connecting tube is coupled to the trapway at a position between the sump trap and the lower trapl and provides flow communication between the container and the trap way.

45. The toilet assembly of embodiment 44, wherein the second line is tangent to the central arced path at a location that is closer to the first upstream weir than to the lower trap.

46. The toilet assembly of any one of embodiments 44-45, wherein the first arced shape has a larger radius than the second arced shape.

47. The toilet assembly of embodiment 46, wherein the first arced shape has a radius of greater than or equal to 50 mm and less than or equal to 70 mm.

48. The toilet assembly of any one of embodiments 44-47, wherein the second arced shape has a radius of greater than or equal to 20 mm and less than or equal to 70 mm.

49. The toilet assembly of any one of embodiments 44-48, wherein, between flush cycles, the container comprises pressurized air positioned above flush water.

50. The toilet assembly of any one of embodiments 44-49, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in pressurized air in the trapway.

51. The toilet assembly of any one of embodiments 44-50, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in pressurized air in the trap way. 52. The toilet assembly of any one of embodiments 44-51, wherein, between flush cycles, pressurized air in the trapway is pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

53. The toilet assembly of any one of embodiments 44-52, wherein the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

54. The toilet assembly of any one of embodiments 44-53, wherein the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

55. The toilet assembly of any one of embodiments 44-54, wherein the connecting tube comprises a backflow preventer.

56. The toilet assembly of any one of embodiments 44-55, wherein the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet.

57. The toilet assembly of any one of embodiments 44-56, wherein the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound a vacuum chamber of the container.

58. The toilet assembly of embodiment 57, wherein the inner wall bounds an inner chamber of the container.

59. The toilet assembly of embodiment 57 or 58, wherein a vertical distance between a top surface of the connecting tube and an inner surface of the upper end wall is greater than or equal to 10 mm and less than or equal to 35 mm.

60. The toilet assembly of any one of embodiments 44-59, wherein an internal diameter of the connecting tube is greater than or equal to 12 mm and less than or equal to 20 mm. 61. The toilet assembly of any one of embodiments 44-60, wherein, between flush cycles, a vertical distance between a top surface of the connecting tube and a water level in the toilet tank is greater than or equal to 45 mm and less than or equal to 55 mm.

62. A toilet assembly, comprising a toilet tank to hold flush water; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir; and the connecting tube is coupled to the trapway via an interface located at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway, wherein an upper end of the interface couples to the connecting tube and a lower end of the interface couples to the trapway, wherein a first edge of the lower end of the interface is located on an upper wall of the trapway directly above the first upstream weir.

63. The toilet assembly of embodiment 62, wherein a second edge of the lower end of the interface is located on the upper wall of the trapway at a position having a same height as the first upstream weir.

64. The toilet assembly of any one of embodiments 62-63, wherein a wall of the interface is tangent to the upper wall of the trapway at the first edge of the lower end of the interface.

65. The toilet assembly of any one of embodiments 62-64, wherein the lower end of the interface is wider in at least one direction than the upper end of the interface. 66. The toilet assembly of any one of embodiments 62-65, wherein the lower end of the interface is wider in a first direction than in a second direction.

67. The toilet assembly of any one of embodiments 62-66, wherein, between flush cycles, the container comprises pressurized air positioned above flush water.

68. The toilet assembly of any one of embodiments 62-67, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in pressurized air in the trapway.

69. The toilet assembly of any one of embodiments 62-68, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in pressurized air in the trap way.

70. The toilet assembly of any one of embodiments 62-69, wherein, between flush cycles, pressurized air in the trapway is pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

71. The toilet assembly of any one of embodiments 62-70, wherein the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

72. The toilet assembly of any one of embodiments 62-71, wherein the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

73. The toilet assembly of any one of embodiments 62-72, wherein the connecting tube comprises a backflow preventer.

74. The toilet assembly of any one of embodiments 62-73, wherein the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet. 75. The toilet assembly of any one of embodiments 62-74, wherein the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound a vacuum chamber of the container.

76. The toilet assembly of embodiment 75, wherein the inner wall bounds an inner chamber of the container.

77. The toilet assembly of embodiment 75 or 76, wherein a vertical distance between a top surface of the connecting tube and an inner surface of the upper end wall is greater than or equal to 10 mm and less than or equal to 35 mm.

78. The toilet assembly of any one of embodiments 62-77, wherein an internal diameter of the connecting tube is greater than or equal to 12 mm and less than or equal to 20 mm.

79. The toilet assembly of any one of embodiments 62-78, wherein, between flush cycles, a vertical distance between a top surface of the connecting tube and a water level in the toilet tank is greater than or equal to 45 mm and less than or equal to 55 mm.

80. A toilet assembly, comprising a toilet tank to hold flush water; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, wherein the trapway is wider at the a lowermost point of the lower trap than at the second downstream weir; and the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trap way. 81. The toilet assembly of embodiment 80, wherein the trapway is wider at a lowermost portion of the lower trap than at an upstream end of the lower trap.

82. The toilet assembly of any one of embodiments 80-81, wherein the trapway is wider at the first upstream weir than at an upstream end of the lower trap.

83. The toilet assembly of any one of embodiments 80-82, wherein the trapway is equal in diameter at the first upstream weir than at the lowermost point of the lower trap.

84. The toilet assembly of any one of embodiments 80-83, wherein the trapway is wider at the first upstream weir than at the lowermost point of the lower trap.

85. The toilet assembly of any one of embodiments 80-84, wherein the trapway is narrower at the first upstream weir than at the lowermost point of the lower trap.

86. The toilet assembly of any one of embodiments 80-85, wherein, between flush cycles, the container comprises pressurized air positioned above flush water.

87. The toilet assembly of any one of embodiments 80-86, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in pressurized air in the trapway.

88. The toilet assembly of any one of embodiments 80-87, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in pressurized air in the trap way.

89. The toilet assembly of any one of embodiments 80-88, wherein, between flush cycles, pressurized air in the trapway is pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure. 90. The toilet assembly of any one of embodiments 80-89, wherein the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

91. The toilet assembly of any one of embodiments 80-90, wherein the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

92. The toilet assembly of any one of embodiments 80-91, wherein the connecting tube comprises a backflow preventer.

93. The toilet assembly of any one of embodiments 80-92, wherein the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet.

94. The toilet assembly of any one of embodiments 90-93, wherein the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound a vacuum chamber of the container.

95. The toilet assembly of embodiment 80-94, wherein the inner wall bounds an inner chamber of the container.

Conclusion

[0143] In some embodiments, dual-trap toilets described and/or shown herein may share any one or more characteristics in common with dual-trap toilets described, shown, and/or referenced in PCT publication no. WO2022046876A1, in PCT publication no.

WO2022051331A1, and/or in PCT application no. PCT/US2021/060307 (filed Nov 22, 2021), the entirety of each of which is hereby incorporated by reference.

[0144] Any one or more characteristics of any of the embodiments (including claims) described, shown, and/or referenced herein may be combined, in whole or in part, with any one or more characteristics of any one or more other embodiments (including claims) described, shown, and/or referenced herein. [0145] The foregoing description, for the purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the techniques and their practical applications. Others skilled in the art are thereby enabled to best utilize the techniques and various embodiments with various modifications as are suited to the particular use contemplated.

[0146] Although the disclosure and examples have been fully described with reference to the accompanying figures, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosure and examples as defined by the claims. Finally, the entire disclosure of the patents and publications referred to in this application are hereby incorporated herein by reference.

Claims

1. A toilet assembly, comprising a toilet tank to hold flush water; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, wherein the upper end of the container contains a first portion of pressurized air when the toilet assembly is between flush cycles, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, and the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway, and the trapway contains a second portion of pressurized air when the toilet assembly is between flush cycles, wherein a volume of the first portion of pressurized air is less than 30% of a volume of the second portion of pressurized air.

2. The toilet assembly of claim 1, wherein, between flush cycles, the first portion of pressurized air is positioned above flush water in the container.

3. The toilet assembly of any one of claims 1-2, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in one or both of the first portion of pressurized air and the second portion of pressurized air.

4. The toilet assembly of any one of claims 1-3, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in one or both of the first portion of pressurized air and the second portion of pressurized air.

5. The toilet assembly of any one of claims 1-4, wherein, between flush cycles, the first portion of pressurized air and the second portion of pressurized air are pressurized at a pressure greater than or equal to 0.5 cm of water above atmospheric pressure and less than or equal to 5 cm of water above atmospheric pressure.

6. The toilet assembly of any one of claims 1-5, wherein the first upstream weir is positioned above a highest point of a trapway inlet by an offset distance of greater than or equal to 2 inches.

7. The toilet assembly of any one of claims 1-6, wherein the first upstream weir is positioned at point that, between flush cycles, is vertically higher than a water seal of the toilet bowl by a distance of greater than or equal to 0.2 inches.

8. The toilet assembly of any one of claims 1-7, wherein the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet.

9. The toilet assembly of any one of claims 1-8, wherein the container comprises a continuous side wall, an upper end wall, and an inner wall that together bound a vacuum chamber of the container.

10. The toilet assembly of claim 9, wherein the inner wall bounds an inner chamber of the container.

11. The toilet assembly of claim 9, wherein a vertical distance between a top surface of the connecting tube and an inner surface of the upper end wall is greater than or equal to 10 mm and less than or equal to 35 mm.

12. The toilet assembly of any one of claims 1-11, wherein an internal diameter of the connecting tube is greater than or equal to 12 mm and less than or equal to 20 mm.

13. The toilet assembly of any one of claims 1-12, wherein, between flush cycles, a vertical distance between a top surface of the connecting tube and a water level in the toilet tank is greater than or equal to 45 mm and less than or equal to 55 mm.

14. A toilet assembly, comprising a toilet tank to hold flush water; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, and the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway, and the trapway contains pressurized air when the toilet assembly is between flush cycles, wherein the pressurized air in the trapway exerts force on water in the lower trap such that an upstream water level in the lower trap is lower than a downstream water level in the lower trap by an offset distance of greater than or equal to 15 mm between flush cycles.

15. The toilet assembly of claim 14, wherein, between flush cycles, the container comprises pressurized air positioned above flush water.

16. The toilet assembly of any one of claims 14-15, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in pressurized air in the trap way.

17. The toilet assembly of any one of claims 14-16, wherein, re-filling the toilet tank with water to end a flush cycle, increased pressure is created in the pressurized air in the trapway.

18. A toilet assembly, comprising a toilet tank; a flush valve assembly positioned in the toilet tank; a toilet bowl; a trapway in flow communication with the toilet bowl; a container positioned in the toilet tank, wherein the container comprises an inner chamber and a vacuum chamber, and a connecting tube extending from an interior of the container to the trapway, wherein: the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, and the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway, and during a flush cycle, the toilet assembly flushes a volume of flush water, wherein: a first portion of the volume of flush water is stored in the tank prior to the flush cycle; a second portion of the volume of flush water is stored in the vacuum chamber prior to the flush cycle; a third portion of the volume of flush water is stored in the inner chamber prior to the flush cycle, wherein the third portion is greater than or equal to 40% of the volume of flush water.

19. The toilet assembly of claim 18, wherein the first portion is less than or equal to 20% of the volume of flush water.

20. The toilet assembly of any one of claims 18-19, wherein the second portion is less than or equal to 40% of the volume of flush water.

21. The toilet assembly of any one of claims 18-20, wherein, between flush cycles, the container comprises pressurized air positioned above flush water in the vacuum chamber.

22. The toilet assembly of any one of claims 18-21, wherein, upon discharging water into a flush valve core to initiate a flush cycle, reduced pressure is created in pressurized air in the trap way.

23. The toilet assembly of any one of claims 18-22, wherein, upon re-filling the toilet tank with water to end a flush cycle, increased pressure is created in pressurized air in the trapway.