WO2007016666A2

WO2007016666A2 - Condensate removal apparatus and method

Info

Publication number: WO2007016666A2
Application number: PCT/US2006/030247
Authority: WO
Inventors: Steve Hampton
Original assignee: Little Giant Pump Company
Priority date: 2005-08-02
Filing date: 2006-08-02
Publication date: 2007-02-08
Also published as: EP1913316A2; EP1913316A4; WO2007016666A3; US20070028640A1

Abstract

A coupling assembly (108) and associated method is provided for an air conditioning system (100). The coupling assembly is configured for coupling an indoor coil section (104) of the air conditioning system to a condensate drain line (119). The coupling assembly has a conduit (110) that is attachable at one end to the indoor coil section. Also, a pump (112) is enclosed within the conduit that has a suction port (116) and a parallel discharge port. The suction port is operably connected to a condensate collection member (120) of the indoor coil section and the discharge port (118) operably connected to the condensate drain line. Preferably, the coupling assembly also has a switching circuit (200) controlling operation of the pump in relation to rate at which condensate is pumped.

Description

CONDENSATE REMOVAL APPARATUS AND METHOD

Field of the Invention

The present embodiments as claimed relate to the field of liquid pumping, and more particularly but not by way of limitation, to a condensate removal system for the removal of condensate from a wall mounted unit of an air conditioner.

Background

In the field of air conditioning, there are systems in which one portion of an air conditioning unit is disposed in a building to be cooled, while another portion of the unit is disposed external to the building at some convenient remote site. The inside portion is often mounted on an interior room wall.

A refrigerant can be passed from the exterior condensing unit to the interior air handling system, in which a fan circulates ambient air over a heat exchanging coil to condition the ambient air. In the process, humidity in the ambient air can condense, which therefore must be properly disposed of to prevent growth of mold and damage that can occur from water leakage onto normal indoor building materials.

Some attempted solutions require the condensate collected by the interior unit to flow by gravity to an interior drain or to an outside outlet. However, frequently the location of the wall mounted unit does not permit reliance on gravity to effectively evacuate the condensed water. A condensate pump can be used to dispose of the condensation, but in most air conditioning systems installation space is not available to accommodate a condensate pump. _ _

In other attempted solutions a condensate pump is supported in ductwork serving to house refrigerant lines between the interior and exterior units. However, this approach tends to limit the space available for the refrigerant lines. Also, since ductwork installations usually incorporate a vertical condensate discharge from the pump, there is a potential problem of water leakage flowing into the control electrical circuitry of the pump. That is, condensate can leak from a break in the tubing or from the connection to the pump.

Another disadvantage of other attempted solutions occurs when the placement of the entry boot to the ductwork must be disposed at some distance from the wall unit. This arrangement requires that condensate flow either partially or totally by gravity from the interior wall mounted unit to the condensate removal conduit in the ductwork.

It is to the resolution of the disadvantages associated with other attempted solutions that the present embodiments are directed.

Summary of the Invention

Embodiments of the present invention are generally directed to a condensate removal system having a condensate pump supported in a support conduit designed to mount to the side of a wall mounted air conditioner unit. Accumulated condensate is pumped directly from the air conditioner unit to an appropriate condensate drainage location.

In some embodiments as condensate is detected in a condensate collection pan, the condensate pump is activated and the condensate is pumped by a straight coupling assembly. The invention can be interfaced with a straight section of conduit as may be necessary, or the collection conduit can be attached to an elbow - -

on the ductwork containing the refrigerant lines that interconnect the interior and exterior units.

In some embodiments a coupling assembly is provided for an air conditioning system. The coupling assembly is configured for coupling an indoor coil section of the air conditioning system to a condensate drain line. The coupling assembly has a conduit that is attachable at one end to the indoor coil section.

Also, a pump is enclosed within the conduit that has a suction port and a discharge port that are disposed in parallel planes. The suction port is operably connected to a condensate collection member of the indoor coil section and the discharge port operably connected to the condensate drain line. Preferably, the coupling assembly also has a switching circuit controlling operation of the pump in relation to a rate at which condensate is pumped.

In some embodiments a method is provided for removing condensate from an air handler. The method includes providing a coupling assembly having a conduit enclosing a pump with parallel suction and discharge ports; connecting the pump suction port to a condensate collection member of the air handler; connecting the pump discharge port to a first segment of a drain line; connecting one end of the conduit to the air handler; and pumping condensate from the condensate collection member to the drain line. Preferably, the method also includes providing a switching circuit controlling operation of the pump in relation to the rate at which condensate is pumped.

In some embodiments a condensate removal system is provided for a ductless air conditioner having a condensate collection member disposed to collect condensate from a heat exchanging member, and means for pumping the . condensate from the collection member to a distant drainage location with a minimal static head loss.

These and various other features and advantages which characterize the embodiments of the present invention will become apparent upon reading the following detailed description and upon reviewing the associated drawings.

Brief Description of the Drawings

FIG. 1 is an isometric and partially cutaway depiction of an air conditioned living space employing embodiments of the present invention. FIG. 2 is a diagrammatic depiction of a portion of the indoor coil section of

FIG. 1 having a coupling assembly constructed in accordance with embodiments of the present invention.

FIG. 3 is an elevational view of the coupling assembly partially cutaway and connected to the indoor coil section and a horizontally disposed condensate drain line.

FIG. 4 is an exploded isometric view of a pump utilized in the coupling assembly of the present embodiments.

FIG. 5 is an isometric view of an alternative pump utilized in the coupling assembly of the present embodiments. FIG. 6 is a view similar to FIG. 3 but wherein the coupling assembly is connected to a vertically disposed condensate drain line.

FIG. 7 is an enlarged detail view of a portion of FIG. 6. FIG. 8 is a flowchart depicting steps of a method for PUMP CONTROL in accordance with embodiments of the present invention. Description

Referring to the drawings in general, and particularly to FIG. 1 which depicts a living space equipped with a ductless split-system air conditioning system 100. The air conditioning system 100 shown is typical of the type generally referred to as a mini split system having an outdoor coil section 102 and in this case two indoor coil sections 104. The outdoor coil section 102 has a compressor and a heat exchanger coil connected by discharge and return lines to another heat exchanger coil in each of the indoor coil sections 104. In a cooling mode the compressor and coil in the outdoor section act to condense a refrigerant by expelling heat from the refrigerant. The condensed refrigerant then travels to the coil in the indoor section 104 where it is expanded, thereby absorbing heat. Air forced over the coil in the indoor section 104 can thereby direct refrigerated air into the living space, as indicated by arrows 106. In a mini split heat pump system a reversing valve is provided to reverse this cycle in order to heat the living space with the same forced air flow.

While the discussion that follows is directed to a mini split system with an indoor evaporative coil, the skilled artisan will readily recognize that the present embodiments are not so limited but may equivalently be utilized in other room conditioning systems such as but not limited to chiller systems with one or more air handlers, evaporative cooler systems, and the like.

As the indoor coil section 104 is cooled, atmospheric moisture condenses on the surface area of its heat exchanger coil and forms a liquid condensate. The condensate must be effectively removed from the living space in order to prevent adverse conditions such as water damage and bacteria growth. As indicated in FIG. 1, it is usually most economically feasible to mount the refrigerant lines and electrical wires that run between the indoor and outdoor coil sections onto the exposed surface of walls in the living space. The present embodiments contemplate a coupling assembly for connecting to the indoor coil section 104 and providing an enclosed raceway for the plumbing and wiring, as well as for a condensate drain line to a suitable indoor or outdoor drain location.

FIG. 2 diagrammatically depicts a portion of the indoor coil section 104, and shows a coupling assembly 108 that is constructed in accordance with the present embodiments. The coupling assembly 108 has a conduit 110 that, as shown in FIG. 3, is attachable at one end thereof to an enclosure of the indoor coil section 104. The coupling assembly 108 also has a pump 112 enclosed within the conduit 110.

FIG. 4 shows a pump 112 that is suited for use in the present embodiments and that is commercially manufactured by the assignee of the present application. Advantageously, the pump 112 has a fluid reservoir 111 with an inlet 114 for collecting a volume of condensate from the indoor coil section 104 and placing it in fluid communication with a suction port 116 of the pump 112. The pump 112 also has a discharge port 118 that is disposed in a parallel plane to that of the suction port 116.

FIG. 5 shows an alternative pump 112 that is likewise suited for use with the present embodiments and which is manufactured by the assignee of the present application with an integrally formed reservoir 111; in other words, having a unitary component construction of the pump 112 housing and the reservoir 111. An inlet to the reservoir 111 is shown which is in fluid connection with the pump suction port 116 (not shown in FIG. 5). - -

By disposing the suction and discharge ports 116, 118 in parallel relation, and preferably making them substantially coplanar, the coupling assembly 108 provides a straight coupling member of a compact size that is aesthetically pleasing to the user of the living space. By making the conduit 110 attachable directly to the indoor coil section 104, the distance from the indoor coil section 104 to the suction side of the pump 112 is minimized. In other words, this permits attaching the pump 112 directly to the indoor coil section 104. This eliminates the concerns associated with other attempted solutions that require adequate gravity feeding of the condensate to the pump 112, which often results in pumping failures caused by cavitation.

The unitary direction of flow from the suction to the discharge side of the pump 112 furthermore minimizes the head loss through the pump 112, especially when the downstream condensate drain line is entirely horizontal. This arrangement is shown by the attachment of a horizontal conduit 113 to the conduit 110 in FIG. 3 that encloses the condensate drain line 119. The unitary direction of flow is also advantageous where it is desirable to route the downstream condensate drain line 119 vertically, such as shown in FIG. 6 by the attachment of a vertical conduit 115 and transitioning elbow 117. In either case, in the present embodiments any condensate leak in a connection or tubing will drain harmlessly past and not onto the pump 112 motor and control electronics..

Referring back to FIG. 2, the indoor coil section 104 has a condensate collection member, such as a collection pan 120, disposed beneath (in relation to gravity) the heat exchanger coil 122. As mentioned, the indoor coil section 104 has a fan (not shown) that passes ambient air over the heat exchanger coil 122. As this occurs, cooling of the ambient air causes its humidity to condense on the heat _o

- 8 -

exchanger coil 122. The condensate collection pan 120 is positioned to capture the condensate as it drips from the heat exchanger coil 122. Accumulated condensate is pumped directly from the condensate collection pan 120 via a drain conduit 124.

The pump suction port 116 is connected (or directly connected to the reservoir 111 inlet) to the drain conduit 124, and as mentioned above is preferably directly connected thereto in order to minimize the volume of accumulated condensate between the condensate collection pan 120 and the pump 112. The pump discharge port 118 is connected to the condensate drain line 119 that terminates at an appropriate drainage location, such as an indoor drain or an outdoor location.

The straight-length of the coupling assembly 108 permits the user complete freedom of design in laying out the conduit that runs between the indoor coil section 104 and the outdoor coil section 102. For example, the coupling assembly 108 is readily adapted to be connected either to the horizontal conduit 113 of FIG. 3 or to the elbow 117 of FIG. 6. The horizontally disposed orientation of FIG. 3 advantageously permits the condensate drain line 119 to be disposed in a plane that is substantially parallel to a plane defined by accumulated condensate in the condensate drain pan 120. This orientation, and the coplanar disposition of the suction and discharge sides of the pump 112, provide conditions resulting in a minimal pumping head requirement. This affords the opportunity of using a relatively reduced-size pump in comparison to other attempted solutions employing a vertical discharge or a right-angle oriented discharge pump.

In any event, the conduit provides an aesthetically pleasing cover for routing the refrigerant lines 132 and electrical wires 136 between the indoor and outdoor coil sections 102, 104, as well as for routing the condensate drain line 119 . .

to an appropriate drainage location. As best seen in the enlarged view of FIG. 7, the coupling assembly 108 defines a passage 134 extending continuously therethrough that is sized for these purposes.

The coupling assembly 108 also preferably has control circuitry that monitors the effectiveness of condensate removal and implements corrective actions accordingly. For example, FIG. 7 shows a float switch 140 disposed in the reservoir 111 that signals the amount of accumulated condensate in the reservoir 111 in relation to an observed condensate level. At a predetermined first (low) level the pump 112 is advantageously de-energized in order to save wear-and-tear on the pump 112. At a predetermined second (normal) level the pump is energized to drain the condensate. At a predetermined third (abnormal) level an alarm condition exists, such as might be associated with a runaway coil section condition or a fan failure condition. FIG. 8 is a flowchart depicting steps in a method 200 for PUMP CONTROL performed by a switching circuit of the control circuitry in accordance with the present embodiments.

The method 200 begins in block 202 where a default condition of de- energizing the pump 112 is implemented. In block 204 the float switch 140 is monitored for its condensate level signal. In block 206 it is determined whether a predetermined high level of condensate has accumulated in the reservoir 111. If no, then control loops back to block 204; otherwise, control passes to block 208 where the pump 112 is energized to pump condensate from the reservoir 111 to the distant drain location.

In block 210 it is determined whether the pumping has lowered the condensate level to a predetermined low level. If yes, then control returns to block 202 to de-energize the pump 112; otherwise, control passes to block 212 where it is .

determined whether the condensate level has risen past the expected normal level to an alarm level. If yes, then an alarm can be signaled in block 214; otherwise control returns to block 210. Optionally, if the alarm condition exists for a predetermined dwell time then the indoor coil section 104 can also be de- energized, as shown in block 218, to prevent the anticipated likelihood that a condensate overflow condition might exist.

Generally as described, the present embodiments contemplate a condensate removal system for an air conditioner having a condensate collection member disposed to collect condensate from a heat exchanging member, and means for pumping the condensate from the collection member to a distant drainage location with a minimal static head loss. For purposes of the present embodiments and meaning of the attached claims, the term "means for pumping" expressly encompasses a coupling assembly that is directly attachable to the air conditioner, and that has a pump with suction and discharge ports that are disposed in parallel planes, and preferably are substantially coplanar. The term "means for pumping" thus expressly does not encompass previous attempted solutions that require a remote attachment to the air conditioner, or that dispose the suction and discharge ports in non-parallel planes. As described, the advantageous parallel suction and discharge arrangement of the present embodiments provides unlimited flexibility in routing the conduit that encloses the drain line 119. For example, the present embodiments even permits routing the conduit vertically from the indoor coil section 104 as shown in FIG. 1, which would not be possible with a right-angle arrangement of the suction and discharge planes. The parallel suction and discharge arrangement furthermore permits connecting the pump 112 directly to the coil section regardless of the drain line 119 orientation, and affords routing the drain line 119 entirely horizontally in order to pump the condensate with an absolute minimum head loss.

It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and function of various embodiments of the invention, this detailed description is illustrative only, and changes may be made in detail, especially in matters of structure and arrangements of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, the particular elements may vary depending on the particular application without departing from the spirit and scope of the present invention.

In addition, although the embodiments described herein are directed to an evaporative coil section, it will be appreciated by those skilled in the art that the claimed subject matter is not so limited and various other liquid systems can utilize the present embodiments without departing from the spirit and scope of the claimed invention.

Claims

- -Claims:

1. A coupling assembly for an air conditioning system, the coupling assembly configured for coupling an indoor coil section of the air conditioning system to a condensate drain line, the coupling assembly comprising: a conduit that is attachable at one end to the indoor coil section; and a pump enclosed within the conduit having a suction port and a substantially parallel discharge port, the suction port operably connected to a condensate collection member of the indoor coil section and the discharge port operably connected to the condensate drain line.

2. The coupling assembly of claim 1 wherein the pump comprises a reservoir for collecting a volume of condensate in fluid communication with the suction port.

3. The coupling assembly of claim 2 wherein the pump comprises a housing that is formed integrally with the reservoir.

4. The coupling assembly of claim 2 further comprising a switching circuit controlling operation of the pump in relation to an amount of condensate in the reservoir.

5. The coupling assembly of claim 4 wherein the switching circuit operably energizes the pump when an amount of condensate in the reservoir exceeds a first predetermined amount. W - -

6. The coupling assembly of claim 5 wherein the switching circuit operably de-energizes the pump when the amount of condensate in the reservoir is less than a second predetermined amount.

7. The coupling assembly of claim 6 wherein the switching circuit operably signals an alarm when the amount of condensate in the reservoir exceeds a third predetermined amount.

8. ^" The coupling assembly of claim 1 wherein the discharge port is adapted for operably connecting directly to the condensate drain line that is operably disposed substantially parallel with a plane defined by accumulated condensate in the condensate collection member.

9. The coupling assembly of claim 1 wherein the conduit defines a passage extending continuously from the one end to an opposing end and is sized for routing the condensate drain line and at least one of an electrical lead and a fluid-bearing conduit to the indoor coil section.

10. The coupling assembly of claim 1 wherein the conduit defines a substantially straight member.

11. A method for removing condensate from an air handler, comprising: providing a coupling assembly having a conduit enclosing a pump with suction and discharge ports disposed in substantially parallel relation to each other; connecting the pump suction port to a condensate collection member of the air handler; connecting the pump discharge port to a first segment of a condensate drain line; connecting one end of the conduit to the air handler; and pumping condensate from the condensate collection member to the condensate drain line.

12. The method of claim 11 wherein the providing step is characterized by the pump having a reservoir for collecting a volume of condensate at the pump suction port.

13. The method of claim 12 wherein the providing step is characterized by a switching circuit controlling operation of the pump in relation to an amount of condensate in the reservoir.

14. The method of claim 13 wherein the providing step is characterized by the switching circuit energizing the pump in relation to an amount of condensate in the reservoir.

15. The method of claim 14 wherein the providing step is characterized by the switching circuit de-energizing the pump in relation to the amount of condensate in the reservoir.

16. The method of claim 15 wherein the providing step is characterized by the switching circuit signaling an alarm in relation to the amount of condensate in the reservoir.

17. The method of claim 16 wherein the providing step is characterized by the switching circuit de-energizing the air handler in relation to the amount of condensate in the reservoir.

18. The method of claim 11 wherein the providing step is characterized by the conduit defining a passage extending continuously from the one end to an opposing end and sized for routing the condensate drain line and at least one of an electrical lead and a fluid-bearing conduit to the air handler.

19. The method of claim 11 wherein the pumping step is characterized by pumping the condensate through a second segment of the drain line that is disposed non-parallel to the first segment.

20. A condensate removal system for an air conditioner, comprising: a condensate collection member disposed to collect condensate from a heat exchanging member; and means for pumping the condensate from the collection member to a distant drainage location with a minimal static head loss.