WO2015187392A1 - Détection d'encrassement de filtre et système de notification - Google Patents

Détection d'encrassement de filtre et système de notification Download PDF

Info

Publication number
WO2015187392A1
WO2015187392A1 PCT/US2015/032220 US2015032220W WO2015187392A1 WO 2015187392 A1 WO2015187392 A1 WO 2015187392A1 US 2015032220 W US2015032220 W US 2015032220W WO 2015187392 A1 WO2015187392 A1 WO 2015187392A1
Authority
WO
WIPO (PCT)
Prior art keywords
filter
gas
sensing system
sensing
condition
Prior art date
Application number
PCT/US2015/032220
Other languages
English (en)
Inventor
William Sherman
Richard Green
Original Assignee
Cleanalert, Llc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US14/296,872 external-priority patent/US9183723B2/en
Application filed by Cleanalert, Llc filed Critical Cleanalert, Llc
Priority to CA2950289A priority Critical patent/CA2950289C/fr
Publication of WO2015187392A1 publication Critical patent/WO2015187392A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/0084—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours provided with safety means
    • B01D46/0086—Filter condition indicators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/32—Responding to malfunctions or emergencies
    • F24F11/39—Monitoring filter performance
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/18—Status alarms
    • G08B21/187—Machine fault alarms
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F15/00—Details of, or accessories for, apparatus of groups G01F1/00 - G01F13/00 insofar as such details or appliances are not adapted to particular types of such apparatus
    • G01F15/12—Cleaning arrangements; Filters
    • G01F15/125—Filters

Definitions

  • Embodiments described and claimed herein relate to monitoring and detection of clogging in a gas filter, which is utilized in a gas conduit attached to a gas blower, the latter having a motor for producing a first gas flow.
  • gas flow refers to the movement of gas, which can be air confined to a space
  • gas filter refers to a filter positioned in such a way that gas flows through it.
  • HVAC Heating, Ventilation, and Air Conditioning
  • a blower having a motor for producing a first gas flow, moves air in the gaseous phase through one or more gas conduits (ducts) to different locations within a building before it exits the duct through a vent. After entering a duct through a HVAC system's air intake, air flows in response to a blower.
  • Typical blowers have a motor that rotates a fan having a plurality of blades, in order to pull air through a duct in a direction that can be thought of as moving from upstream to downstream.
  • HVAC systems use filters to remove dust, dirt, contaminants, and other undesired particles that adversely affect air quality so they are not delivered past a certain location within the duct, and do not exit through a vent.
  • Filters limit the progress of undesired particles through a duct, for example by physical restriction in which the small size of openings in a filter keeps particles from progressing through and past it, or by electrostatic attraction that hold particles to a filter.
  • a filter collects undesired particles, it becomes discolored and dirty.
  • a dirty filter does not substantially affect flow of air through a duct, over time, the accumulation of undesired particles produces clogging in a filter, which substantially decreases air flow in the building, and causes dust and dirt to accumulate inside the duct system and on the blower fan blades, all of which potentially reduces the quality of air in a building and adversely affects the performance of the HVAC system. Consequently, filters in systems such as HVAC systems, as well as automobiles, must be changed periodically.
  • the heated sensor is kept at a temperature higher than the unheated sensor by a fixed number of degrees. If air flow velocity is greater, then more energy is dissipated away from the heated sensor. Accordingly, a measurement of the voltage required to maintain the temperature difference between the two sensors indicates the amount of air flowing through the duct where the sensors are located.
  • filter condition can be determined based on voltage readings, or similar properties having a relationship to air flow through a duct.
  • filter condition is determined as a function of measurable properties or conditions within a duct
  • differential pressure sensors which respond to a pressure drop that occurs from the upstream side of a filter compared to the downstream side.
  • This restriction produces a corresponding pressure on the upstream side of the filter.
  • air passing through the filter also produces pressure on the downstream side.
  • pressures are measured using sensors and methods that are known to those having ordinary skill in the art.
  • the differential pressure from the upstream side of the filter to the downstream side will usually be relatively small.
  • the restriction on air that passes through the filter tends to decrease pressure on the upstream side. Further, because less air passes through a clogged filter, this tends to correspond to an increase in pressure on the downstream side.
  • Multi-speed blowers differ from single-speed blowers and two-speed blowers, the latter of which use a two-speed motor, e.g., one speed for summer cooling and another speed for winter heating. Multi-speed blowers are capable of operating at any of a number of different speed settings. Many blowers require a period of time to stabilize and reach a consistent operating speed. For example, some blowers require approximately 60 seconds for this to occur.
  • Multiple embodiments and alternatives disclosed herein relate to a sensing system for monitoring a gas filter's condition.
  • Applications include various kinds of air handling systems.
  • One purpose of the multiple embodiments and alternatives is for determining when a gas filter should be changed based upon its level of clogging, where such filter is used with a HVAC system or other type of gas conduit attached to a gas blower, having a motor for producing a first gas flow.
  • the embodiments and alternatives disclosed herein compensate for and generally help to avoid the potentially compromising effects on accuracy and efficiency due to changes in blower speed, which have the potential to either mimic a clogged filter, or hide the effects of a clogged filter.
  • FIG. 1 illustrates a portion of a conventional HVAC system in which clogging of a gas filter is monitored, according to multiple embodiments and alternatives.
  • FIG. 2 illustrates a portion of a conventional HVAC system, in which clogging of a gas filter is monitored, according to multiple embodiments and alternatives.
  • FIG. 3 is a cross-sectional view of a sensing tube as illustrated in FIG. 1, according to multiple embodiments and alternatives.
  • FIG. 4 is a circuit diagram depicting a sensing tube of the type illustrated in
  • FIG. 3 according to multiple embodiments and alternatives.
  • FIG. 5A is a flow chart related to calibrating a sensing system for use in monitoring a gas filter, according to multiple embodiments and alternatives.
  • FIG. 5B-5C is a flow chart concerning monitoring of a gas filter using a sensing system, according to multiple embodiments and alternatives
  • FIG. 6 is a graph that plots sensor voltage level against the level of cleanliness of a gas filter in a HVAC system, according to multiple embodiments and alternatives.
  • FIG. 7 is a block diagram representing a sensing system and notification system, according to multiple embodiments and alternatives.
  • FIG. 8 is a chart illustrating flow of information from a sensing system to a notification system by which alert messages and notification reports are produced, according to multiple embodiments and alternatives.
  • FIG. 9 shows a portion of a registration module used in setting up communication between a sensing system and a notification system for sending of messages and reports, according to multiple embodiments and alternatives.
  • FIG. 10 shows a portion of a registration module used in setting up communication between a sensing system and a notification system for sending messages and reports, according to multiple embodiments and alternatives.
  • FIG. 11 represents a database, configured for storing status data as part of a notification system, according to multiple embodiments and alternatives.
  • FIG. 12 provides an example notification report, according to multiple embodiments and alternatives.
  • FIG. 1 is a simple diagram showing a portion of a gas conduit 10 having blower 11 that pulls air in a direction indicated by arrow 12.
  • Gas filter 14 is positioned within duct 10.
  • Sensing system 15 generally consists of sensing tube 16 and support base 17.
  • sensing tube 16 has an inlet 25 that ambient air from outside duct 10 flows into, and an outlet 27 providing fluid communication with the interior of duct 10.
  • sensing tube 16 may be positioned at least partially within, or flush with, duct 10.
  • it comprises a cylindrical tube with openings at both ends (inlet 25 and outlet 27, respectively), which enable blower 11 to pull ambient air into duct 10.
  • sensing system 15 is incorporated with a duct at a position downstream relative to filter 14. Consequently, air entering duct 10 passes through filter 14 before it flows past the position of sensing tube 16 in the interior of duct 10.
  • sensing system 15 is incorporated with the duct at a position upstream relative to filter 14, meaning that air entering duct 10 will flow past sensing tube 16 before progressing through and past filter 14.
  • sensing system 15 is attached to duct 10 by forming a hole in the wall of the duct appropriately sized to accommodate sensing tube 16.
  • Support base 17 is also mounted to the external wall with mounting screws so as to maintain operable contact with sensing tube 16, including its various hardware and software components as described herein.
  • FIG. 2 illustrates an alternative means for sensing the condition of a filter, which involves taking a pressure differential across filter 14.
  • differential pressure sensor 20 comprises a differential pressure sensor support base 19, first tube 21 positioned upstream relative to filter 14, and second tube 23 positioned downstream.
  • tube 21 has the same components arranged as those of sensing tube 16. Tube 21 and tube 23 thus are arranged to measure differential pressure across filter 14, using techniques as are known to persons of ordinary skill in the art.
  • processor 29 which acts as a controller, and which can be physically integrated with support base 17 or differential pressure sensor support base 19, respectively.
  • processor 29 includes one or more general or special purpose microprocessors, or any one or more processors of any kind of digital computer, including ones that sense conditions, and perform various calculations as further discussed herein.
  • Processor 29 further includes, or is communicatively coupled to, computer readable storage medium such as, for example memory, which may optionally include read-only memory (ROM), random access memory (RAM), non-volatile RAM (NVRAM), optical media, magnetic media, semiconductor memory devices, flash memory devices, mass data storage device (e.g., a hard drive, CD-ROM and/or DVD units) and/or other storage as is known in the art.
  • processor 29 includes, or is communicatively coupled to, memory having computer readable and executable program instructions, rules, and/or routines (any set of which may be referred to herein generally as "Instructions") which, when executed by processor 29, cause it to perform the steps as described herein.
  • processor 29 is coupled to complementary components, for example user interface screens, key pads, light indicators, and/or dip switches (these are not shown) responsive to operator input to allow user control of the sensing system.
  • components such as screens, key pads, and light indicators are integral with support base 17 or 19, respectively.
  • Some embodiments utilize a dip switch configured for setting the sensing system to upstream mode or downstream mode, and / or switching between such modes depending on where a person chooses to install sensing system 15 in relation to filter 14 (see FIG. 1).
  • sensing tube 16 further includes an outer plate 24, preferably formed of an insulator, for separating an interior space 22 of sensing tube 16 from the interior of duct 10.
  • heater 28 is electrically coupled to heated sensor 30, both of which, along with unheated sensor 32, are positioned in the interior 22. Sensors 30, 32 and heater 28 are connected via wires 33 to an electronic circuit, which can be external to interior 22. Alternatively, wireless connection is provided as known to persons of ordinary skill in the art.
  • plate 24 further comprises a thermal insulating material 26.
  • sensing tube 16 is positioned partially within duct 10, such that one of its openings serves as an inlet 25 for ambient air, while the other serves as an outlet 27 in fluid communication with duct 10. Air flowing through sensing tube 16 dissipates energy from the space around both of sensors 30, 32, thus lowering the temperature at each sensor location.
  • sensing tube 16 is comprised of other features, for example interior 22 may be potted with thermally conductive epoxy (not shown), and heater 28, heated sensor 30, and unheated sensor 32 are affixed to an interior surface of plate 24 by techniques and methods known to persons of ordinary skill in the art, for example by soldering or with a suitable adhesive such as epoxy.
  • heated sensor 30 is a thermistor, which is thermally sensitive to changes in temperature of ambient air flowing through interior 22. It will be noted that maintaining a temperature difference of no more than 5° C provides significant advantages to the present embodiments, because less power is consumed to maintain such a difference than a system that requires, for example, a 50° C temperature difference between the two sensors.
  • unheated sensor 32 remains at the temperature of ambient air flowing into and through sensing tube 16.
  • heater 28 increases and maintains the temperature of heated sensor 30 to a predetermined level, e.g., 3° C - 5° C above the temperature of ambient air flowing through sensing tube 16.
  • sensing system 15 is positioned downstream from filter 14, as shown in FIG. 1, then the effect of clogging in filter 14 generally pulls a greater volume of ambient air through sensing tube 16. This is because clogging of filter 14 tends to restrict air flow through the filter, resulting in a lesser volume of air downstream of filter 14 being pulled by blower 11. Consequently, a higher volume of ambient air is pulled through sensing tube 16, with corresponding increase in air velocity. Therefore, heater 28 supplies more voltage to maintain the fixed temperature difference, as the movement of greater volumes of air through sensing tube 16 dissipates more energy. Thus, the voltage required varies with, and is an indicator of, the clogging in filter 14.
  • sensing system 15 is positioned upstream from filter 14, these relationships are essentially reversed.
  • filter 14 being positioned between blower 11 and sensing tube 16, the extent of filter clogging tends to limit the amount of ambient air that contacts sensors 30, 32. As a result, less energy is dissipated, and voltage needed to maintain a fixed temperature difference is reduced.
  • FIG. 4 is a circuit diagram depicting a sensor of the type illustrated in FIG. 3, in connection with a clogging detector for a gas filter.
  • Heated sensor 30, and unheated sensor 32 are represented by S2 and SI, respectively.
  • Voltage required for maintaining a predetermined temperature difference between sensors 30, 32, as discussed above, is transmitted as sensor output of flex circuit 35 (which in some embodiments comprises a thermal insulator 26).
  • flex circuit 35 is electrically coupled to sensing system controller input, including a signal amplifier of the type as is known to persons of ordinary skill in the art. Because flex circuit 35 transmits a signal representing voltage for maintaining the temperature difference between sensors 30, 32, this value is indicative of the extent of clogging of filter 14. Alternatively, in systems that utilize differential pressure sensors, this output is indicative of pressure drop across filter 14, as a function of clogging.
  • blower speed is another variable that may affect the volume of air passing through a filter. If all other factors are equal, then a higher blower speed produces more air flow through a duct generally, and through air (i.e., gas) filters positioned in the duct in particular. Consequently, there is a potential that changes in blower speed will mimic the effects of a clogged filter, or will hide the effects of a clogged filter. This could occur in several ways. One is when the blower is turned off.
  • multi-speed blowers and variable air volume blowers (hereafter referred to together as "multi-speed blowers") automatically change speed in response to demand, for example to 50%, 80%, or 100% of the motor's capacity, in order to promote more efficient operation.
  • a blower motor may operate at less than 100% on a mild day because it promotes efficiency to cool the building gradually. Consequently, even when there has been no appreciable change in filter condition over time, readings taken at an operating speed of 50% will differ from ones at 80%, or 100%, and such differences can potentially mimic filter clogging that does not exist, or hide filter clogging that actually does exist.
  • variable-speed blowers which, in some cases, are capable of having a rotational speed of the blower motor that is continuously and infinitely controlled at very small interval adjustments of, for example, a variance of 1-2% in blower speed.
  • FIG. 5 provides a flow chart showing various steps for promoting detection accuracy, according to multiple embodiments and alternatives. The steps relate to validating a measurement obtained during a monitoring event, either by determining that the gas blower was on, or verifying that the blower was at a stable operating speed, when a particular measurement was obtained, and/or verifying that the blower was operating at the same speed when a particular measurement was obtained relative to the blower speed at the time of a previous measurement. Such validation helps to prevent changes in blower speed from adversely affecting filter clog detection. Discussion is provided regarding calibration (FIG. 5A) and monitoring (5B to 5C) of filter 14, in a HVAC system in which sensing system 15 is positioned downstream of the filter.
  • calibration occurs either when a new filter is installed, or when an existing filter is cleaned.
  • Steps 100 to 130 are for initiating the calibration process and for confirming that sensing system 15 is powered-up in order to obtain readings.
  • the teachings and principles described herein regarding FIGS. 5A-5C are directed to sensing system 15, but can be adapted to sensor 20 in differential pressure systems, as well.
  • a user obtains a value for the clean filter corresponding to zero air flow and/or to air flow when the blower is operating.
  • a user turns the blower fan on, for example by increasing or decreasing temperature setting at a thermostat (not shown).
  • a user then waits a sufficient period of time, for example 60 seconds, to ensure that the blower has stabilized to operating speed.
  • the steps for obtaining a value for zero air flow involve taking a plurality of readings and calculating an average of the readings, as shown at steps 140, 150.
  • a plurality of readings are obtained over a relatively short period of time, for example ten seconds, and then averaged.
  • obtaining a value means calculating the average value for all readings in a sample during a particular monitoring event.
  • an average of the values obtained from several monitoring events is also used in some embodiments.
  • Steps 160 to 210 depict obtaining readings for a clean filter with the blower operating.
  • values obtained during calibration are stored in memory, as are subsequently obtained values during monitoring, as explained in more detail below.
  • sensing system 15 transitions to standby mode (220) until the next scheduled monitoring event occurs.
  • a schedule of monitoring every twenty-four hours conserves energy and promotes efficiency compared to a schedule of every hour.
  • sensing system 15 in which sensor voltage level (needed to maintain the predetermined temperature difference between sensors 30 and 32, respectively) is compared to a clog threshold value, which is stored in memory.
  • a clog threshold value which is stored in memory.
  • various optional checks and tests are provided at steps 255 to 280, for example checking the battery (255) and providing an indication if the battery is low (258).
  • step 260 proper sensor operation is checked (260) after applying power to sensing system 15 and enabling sensor voltage level detection. If voltage is detected at step 260, it indicates that the sensing system has passed this check (270). The sensing system will then proceed to step 290 to obtain readings. If voltage is not detected, then a failure flag is set at step 275. Optionally, the sensing system requires only one such failure before transitioning to alarm mode (280). In this way, indicator means include, but are not limited to, various kinds of alarms in the form of audible, visual, text, LED, and light cues. Alternatively, the sensing system is configured to require a predetermined number of attempts to detect voltage at step 260 before this transition.
  • alarm and indicator means are coupled to various means as are known to persons of ordinary skill in the art for transmitting signals to a remote location, including but not limited to via internet, via text message sent to a mobile device capable of receiving text messages (i.e. ,short message service format (SMS) or multi-media service format (MMS)), radio-frequency transmission, satellite transmission, or other similar methods.
  • SMS short message service format
  • MMS multi-media service format
  • sensing system 15 then obtains readings (290), which are used to first determine whether blower 11 is on or off. Upon powering up the sensing system, an initial sensor voltage reading is obtained followed by at least one additional reading within about five seconds.
  • the sensing system is programmed to monitor on an accelerated schedule once it determines that the blower is off, rather than waiting until the next monitoring opportunity according to a normal schedule.
  • An accelerated schedule is repeated at different and more frequent intervals than the normal schedule, and continues until an indication is received that blower 11 is on, or until a predetermined maximum number of times to run the accelerated schedule has occurred.
  • sensing system 15 calculates an average of a plurality of readings in order to obtain a value. For example, the number of readings may be sixty-four in about a ten second period, or some other number of readings within a given period of time.
  • sensing system 15 determines whether the predetermined number of readings has been obtained. Minimum and maximum readings are determined, as well, and the timing of each one stored at step 305. With each reading, a reading counter is incremented until the appropriate number of readings has been obtained, at which point the reading counter is cleared at step 310.
  • Sensing system 15 compares readings obtained during the particular monitoring event to determine whether blower 11 was operating at a stable speed when the readings were obtained, or whether it was in the process of starting or stopping (320). For example, if the maximum and minimum readings at step 305 differ by more than a predetermined set amount then it indicates that blower 11 was not operating at a stable speed during the entire period (e.g., ten seconds) when those readings were obtained. This may be due to the fact that blower 11 was in the process of starting up, or shutting down. In both cases, the speed of blower 11 typically will change within a relatively short period of a few seconds. In any case, such a value is discarded (325), and present monitoring ends (330) pending the next monitoring event according to an accelerated schedule (325).
  • sensing system 15 if sensing system 15 is configured to maintain a 5° C temperature difference between heated sensor 30 and unheated sensor 32, then a difference of about 0.250 volts or greater between the minimum and maximum readings would cause the sensing system to discard the sample (325). Conversely, if that difference is less than or equal to about 0.250 volts, then sensing system 15 considers the readings to be valid, and the sample and its value are not discarded (340). If a blower starts up at the instant a monitoring event begins, or while a monitoring event is ongoing, then the blower will be running fastest when the last readings are obtained.
  • sensing system 15 compares (not shown in FIG. 5) the value obtained during a monitoring event to the value for zero air flow obtained at calibration and stored in memory. If the averages are substantially identical, for example within, about ⁇ 0.50 volts, this indicates that blower 11 is off. This prompts an accelerated schedule to be initiated, if not already started due to readings at step 320.
  • blower 11 was on when the readings were obtained, and not in the process of starting up or shutting down (320), and that a sufficient number of readings were obtained (340), then a sequence generally provided at steps 350 - 390 occurs next. From prior monitoring events, at least one known valid value is stored in memory, indicating voltage needed to maintain the predetermined temperature difference at a particular blower speed (360) for a particular filter condition. If many monitoring events occurred consecutively without a change in blower operating speed, then an average of the most recent of such values (up to a predetermined number) is stored.
  • this difference will either represent a rise in measured voltage, or a drop in measured voltage.
  • the voltage measured at the time of calibration was 2.0 volts, and a clog detection threshold of 0.150 volts above the clean filter value, i.e., 2.150 volts.
  • 2.1 volts is a stored value representing an average of values from the most recent valid monitoring events (referred to as S, below).
  • next monitoring event obtained a value of 2.38 volts (represented for discussion purposes as X, which is 0.280 volts greater than the S value), that would be a significant difference over both the clean filter value at calibration and the average of the most recent valid monitoring events (S).
  • sensing system 15 is configured in some embodiments to proceed to a next monitoring event, without triggering alarm mode, and without recalculating the clog threshold, and without factoring the 2.38 volts into the average of values for the most recent valid monitoring events. Instead, the sensing system proceeds to the next monitoring event.
  • value is 2.4 volts (Y), which is again a significant upward movement. If the sensing system is configured to evaluate for fan speed change after three consecutive nonzero air flow values representing dynamic shifts in the value, then the sensing system still would not take any action in terms of these values. Instead, the sensing system would proceed to the next monitoring event.
  • the sensing system uses this average for both calculations at step 390. Specifically, the clog threshold would increase from 2.150 volts to 2.550 volts, and the average of values from the most recent monitoring events would increase from 2.1 volts to 2.5 volts.
  • step 400 values are obtained and stored in memory with respect to averaged samples, and the values are compared to a clog threshold stored in memory.
  • this threshold may be set at 0.150 volts above or below a stored value of a clean filter based on calibration readings. If it is determined at step 400 that the average of the readings obtained is greater (or less, depending on the upstream/downstream position of the sensing system) than this clog threshold, then a clog counter is incremented at step 420.
  • step 430 if the clog counter has consecutively exceeded the clog threshold a predetermined number of times, for example three times, then system 15 activates an alarm or a similar signal at step 460, which may include one or more visual or audible indications. If, however, it is determined at step 400 that the average is less than or equal to the clog threshold, or if the clog counter has not exceeded the maximum number of times that is set (430), then sensing system 15 returns to its normal schedule as indicated by step 405. In such case, power to the sensing system is discontinued to at step 410 (until the next scheduled monitoring event) and transition is made to standby mode (440).
  • processor 29 By programming processor 29 with appropriate Instructions to compare readings and values, and discard certain values while using others, as described herein, it removes the need to have separate sensors detecting either the speed of the motor attached to blower (11) or of the air flow in duct 10, or both. Further, it enables sensing system 15 to determine the condition of filter 14 without requiring substantially high temperature increases between sensors 30 and 32, respectively.
  • a graph plots sensor voltage level against the level of cleanliness (i.e., in terms of the absence of dirtiness and / or clogging) of a gas filter in a HVAC system.
  • a clog threshold is determined between points B and C. In some embodiments, that threshold is responsive to the stable operating speed of a blower at the time when voltage readings are obtained.
  • information about filter condition or the status of the detector is conveyed visually at sensing system 15 itself, or as an audible signal emanating from sensing system 15, or both.
  • a flashing green status light on a front panel 18 of sensing system 15 may be employed to indicate Normal Operation of the sensing system.
  • flashing is by switch means prompting a light emitting diode (LED) to alternate between an illuminated state and a non- illuminated state.
  • a flashing red light may be employed to indicate Clogged Filter.
  • a flashing yellow light may be employed to indicate Low Battery.
  • a continuous red light may be employed to indicate Sensor Failure, for example if no voltage reading is detected.
  • visual indications are provided with a LED integrated within sensing system 15 and controlled by processor 29, and which is visible through an opening of a panel (not shown) of the sensing system 15.
  • an audible signal is employed, in the form of an alarm sound which is arranged to occur if a particular threshold is exceeded as at step 400.
  • sensing system 15 is capable of operating as a stand-alone detector. However, it may also be configured to connect to the Internet as a component of a notification system. Various methods including those described here can be selected for this purpose.
  • sensing system 15 further comprises a networking module 105, which facilitates connection to the Internet and in some embodiments does so via wireless networking technology such as through radio frequency transmission.
  • pathways and protocols for connecting sensing system 15 to notification system 110 are not limited to specific embodiments described below. Rather, multiple options exist for doing so, and are known in the art, including but not limited to standard cable connectors such as RJ-45 providing ethernet connections for network communication.
  • data and information from sensing system 15 may be exchanged as packets across a network according to one or more of several optional protocols as selected by a user, e.g., Transmission Control Protocol/Internet Protocol (TCP/IP).
  • TCP/IP Transmission Control Protocol/Internet Protocol
  • sensing system 15, which includes module 105 is battery-powered or, alternatively, may be powered by connection to a standard electrical outlet via a suitable power adapter.
  • a wireless router 102 as an access point, as in Fig. 8, it is advisable to test the Internet connection and locate the wireless router suitably to limit obstruction due to walls, floors, ceilings, and objects in the signal path.
  • notification system 110 Information related to the condition of gas filter 14 is transmitted from sensing system 15 to a notification system 110 for storage and processing, and in some embodiments notification system 110 is cloud-based. As described below, under certain conditions communications are generated from such information, and transmitted to a recipient (Alert Messages) or made available over a web server (Notification Reports). As with cloud computing in general, such a configuration allows for the computing activity to be transitioned from the local sensing system 15 to a remote hosted server or servers thereby gaining efficiencies due to the distribution of hardware and software resources and functions to the remote notification system. Often, the at least one server further comprises a processor 29, which stores the computing application or applications along with their respective Instructions, which execute upon the information transmitted from sensing system 15.
  • FIG. 7 is a block diagram which further depicts the flow of information occurring within the components of sensing system 15, according to various options and embodiments herein.
  • the block associated with sensing tube 16 depicts the sensing tube within which is positioned sensors 30, 32, and from which voltage readings are obtained for purposes of maintaining the predetermined temperature difference discussed above, for example in connection with FIG. 3 and FIG. 4.
  • the block associated with processor 29 further depicts software the processor executes, including Instructions for making the step 400 comparison based on values stored in memory. Module 105 is then involved with providing digital output via a network as further described herein.
  • processor 29 and module 105 are involved in the flow of communication, and in this sense share a connection, but the scope of embodiments is not limited to and does not otherwise require the module 105 to be located within processor 29.
  • the digital output initiated by module 105 involves signals being transmitted, as distinct from the visual and auditory output emanating from front panel 18, as also depicted in block form in FIG. 7.
  • sensing system 15 is set up to remain in standby mode for long durations, conserving power. Its activity is initiated periodically at selected intervals to monitor for alarm triggers, which by way of non-limiting examples may include Clogged Filter, Low Battery, and Sensor Failure. If no such alarm triggers are detected, the sensing system then returns to standby mode until the next interval.
  • alarm triggers which by way of non-limiting examples may include Clogged Filter, Low Battery, and Sensor Failure. If no such alarm triggers are detected, the sensing system then returns to standby mode until the next interval.
  • sensing system 15 is configured with a "SEND" button that, when manually depressed, the system transmits its information to notification system 110.
  • connection between sensing system 15 and notification system 110 occurs via wireless router 102, which is also referred to herein as an "access point.”
  • wireless communication is accomplished via radio frequency transmissions, according to or consistent with IEEE 802.11, e.g., with module 105 of sensing system 15 transmitting through access point 102 at a frequency of 2.4 GHz (gigahertz).
  • access point 102 for connecting module 105 to the Internet is a wireless WiFi® router, which in turn is connected to Internet service by a conventional cable modem (not shown).
  • Such routers and modems are commonly known to persons of ordinary skill practicing in the pertinent field, and their use generally requires a subscription with an Internet Service Provider.
  • Transmitted information from sensing system 15 is processed by the notification system 110 for determining whether an alarm trigger exists, and if so generating and sending an Alert Message.
  • the notification system 110 comprises a web server 112 or servers for which the host has obtained a subscription with an Internet Service Provider, by which the web server(s) 112 connects to other servers.
  • an Internet Service Provider by which the web server(s) 112 connects to other servers.
  • IEEE-compliant gateways, bridges, and other hardware as known to persons of ordinary skill in the art are employed for wireless transmission from sensing system 15 to notification system 110 via the Internet.
  • sensing system 15 when sensing system 15 is manufactured, it is assigned a unique Media Access Control address, hereafter referred to as a "MAC Identifier" specific to that sensing system.
  • MAC Identifier enables the connection from module 105 of sensing system 15 via access point 102 to one or more cloud-based servers 112 providing database storage and processing functions, and which include at least one processor 129.
  • Server 112 is involved with transmitting Alert Messages and Notification Reports (as further described herein), containing information about the status of a gas filter in proximity to and monitored by a particular sensing system 15 identified by its MAC Identifier.
  • a MAC Identifier is incorporated within the address associated with sensing system 15, according to conventional addressing and communication protocols, enabling the server 112 to recognize and communicate with sensing system 15, and otherwise providing a basis on which server 112 (or, servers) should accept and process data transmissions from sensing system 15.
  • the network is configured for access point 102 to connect to a network, which can be through a modem connection, or over a wireless local area network (WLAN), or through other similar means.
  • the system is configured so that the act of connecting sensing system 15 with access point 102 results in the assignment of an internet protocol (IP) address to sensing system 15, as known in the art.
  • IP internet protocol
  • Some embodiments include a step of registering each particular sensing system 15 configured for communication with server 112. Registering is generally accomplished over the Internet with an account that one logs into and into which one or more MAC Identifiers is input.
  • a registration module a user is directed to first enter profile information, such as user name and company name and contact information, and which may also include a field for payment information according to a specific user account.
  • FIG. 9 depicts a series of options provided by the registration module, one of which is an "Add Monitor" option 122.
  • a user would input identification data such as the sensing system's serial number and MAC Identifier, so that data can later be stored and processed specific to that particular sensing system unit.
  • registration also may include specifying the language and content for alert messages which are to be generated and sent, and their form of delivery, e.g., text messages, email, or both. According to which form(s) of delivery is specified, a user will then enter a phone number(s) in space 123 for alert messages by text (SMS or MMS), or e-mail address(es) in space 124 for alert messages by email, or both. Additionally, as further shown in FIG. 10, the registration module directs a user to input what type of alert messages shall be sent for various alarm triggers, again by way of non-limiting examples, for any or all of Clogged Filter, Low Battery, and Sensor Failure, and to input the quantity and frequency with which an alert message will be sent following the detection of one of those conditions.
  • form(s) of delivery e.g., text messages, email, or both.
  • the registration module directs a user to input what type of alert messages shall be sent for various alarm triggers, again by way of non-limiting examples, for any or all of Clogged Filter
  • the frequency and content of Alert Messages may also be established at registration. Generally, registration is performed for each individual sensing system 15 that will communicate via the notification system 110. As desired, the setup for any given sensing system may be edited at any time with use of the "Edit Messages" option 119 in FIG. 9.
  • the notification system 110 is configured to send an
  • sensing system 15 through its module 105 connects to access point 102, providing for transmission of signals representing information about a condition detected by the sensing system to notification system 110 on a periodic basis as selected. Signals corresponding to values are transmitted to and stored in database 131.
  • FIG. 11 depicts the organization and content of database 131 in an embodiment. The content stored in each row of database 131 correlates to a particular sensing system matching a particular MAC Identifier as shown in space 127.
  • step 400 involves reading a value of the voltage required for maintaining the above-mentioned predetermined temperature difference, and comparing it to a clog threshold stored in memory of sensing system 15. If it is determined at step 400 that the average of readings obtained is greater (or less, depending on the upstream/downstream position of the sensing system within the gas conduit) than the clog threshold, a clog counter is incremented at step 420. At step 430, if the clog counter has consecutively exceeded the clog threshold a predetermined number of times, for example three times, in operation sensing system 15 transmits a signal representing that finding to notification system 110 for storage and further processing by server 112.
  • a binary system in which a first number represents a determination of an alarm trigger and a second number represents the absence of an alarm trigger. For example, “1" is used to indicate a positive finding consistent with a Clogged Filter at step 430; otherwise, the numeral "0" is used to indicate no such finding.
  • non-numeric forms of information could be employed, provided they are discernible to machine readable and executable instructions. For example, the word “good” could be used instead of "0,” or the word “clogged” instead of the number "1.” At each monitored interval, one or the other of these values is inserted under "Clog Status" column 128 as part of the aforementioned database.
  • the use of "1" and “0” values provides status data, in which the status data is populated into a database 131 of server 112 for storage and processing.
  • the use of "0" and “1” values minimizes server time and conserves bandwidth on the notification system.
  • processor 129 query database 131 represented in FIG. 11. For example, with respect to column 128, labeled "Clog Status,” in some embodiments the query Instructions are programmed to differentiate between “0" and “1” values. Processor 129 in turn interprets "1" to represent that an identified filter was clogged at a particular date and time noted on the right of the figure.
  • the MAC Identifier shown in box 127 is associated with a specific sensing system 15, and each sensing system is positioned proximal to an individual filter, the position of which is known and, therefore, the location of which is able to be tracked when practicing these embodiments.
  • the sensing tube 16 must be sufficiently close to the filter so that the amount or velocity of ambient air from outside duct 10 flowing through inlet 25 of the sensing tube affects the voltage read by the sensing system.
  • the MAC Identifier matches the status data which has been queried to the particular sensing system(s) 15 which reported a Clogged Filter condition to point out the location of the subject filter. Likewise, the same would be true of pointing out filter location for other alarm triggers, e.g., Low Battery and Sensor Failure.
  • the identification of a "1" during the query results in an Alert Message informing that the filter matched to the identified sensing system 15 is clogged or has encountered some other alarm trigger according to columns which are configured.
  • the Alert Message can be worded according to how a user desires, in connection with FIG. 10. For example, a user may desire for the Alert Message to also state that filter service is needed, or to place a time limit on when the filter must be changed.
  • Notification system 110 is configurable to send Alert Messages to a variety of devices or destinations, non-limiting examples of which are a cellular telephone, an email account accessed via personal computer or tablet, and a printer.
  • devices or destinations non-limiting examples of which are a cellular telephone, an email account accessed via personal computer or tablet, and a printer.
  • the act of transmitting the Alert Message itself may employ various base transceiver stations, towers, gateways, and other components for wireless connection, which are known in the art.
  • users may also arrange for online accessing and reviewing of filter information obtained from sensing system 15 in the form of Notification Reports.
  • This type of access may require a separate subscription, which allows a user to log into a dedicated web page and access information stored on server 112.
  • user-specific accounts may be setup at https://www.cleanalertwifi.com or a similar type of webpage.
  • FIG. 12 provides an example Notification Report.
  • a Notification Report provides additional information beyond stating that a filter is clogged, or a battery has little remaining charge, or that the sensing system is not transmitting voltage readings or otherwise functioning properly.
  • Notification Reports make additional filter status information available periodically according to selected data points.
  • One example of such information is the time until service is needed (clean or replace the gas filter).
  • Notification Reports can be more tailored to the unique environment of a particular filter, than a manufacturer's standard recommendation of 3 months, for example.
  • the Notification Report may provide more specific information related to the condition of a filter.
  • the thermostat temperature setting also affects filter life, in that a higher temperature setting in winter with the heater on forces the HVAC system to run longer, causing the filter to become clogged in a shorter amount of time. The same may be true when the thermostat is set to very low temperatures in hot summer months with the air conditioning on.
  • a "1 " in the "Clog Status” column 128 indicates the existence of a 100% clog. This initiates the status of "Clogged” as shown in the "Status” column 134 of FIG. 12.
  • a "1" in the "Battery” column 126 of the database represented in FIG. 11 indicates a low battery, and may serve as the basis for reporting in a Notification Report the status of "LOW” as shown in the "Battery” column 133 of FIG. 12
  • a dial (not shown) is provided with a setting in the middle, reflecting the level of clogging when the filter should be changed according to factory recommendations.
  • the user would have the option of adjusting the dial toward the "less often” (i.e., less often than factory recommendation schedule), or alternatively, toward “more often.”
  • it would alter the point at which a "clogged” filter is sensed. This, in turn, would alter the point at which a "1" appeared in column 128 of FIG. 11, and at which a value of "100%" appeared in column 132 of FIG. 12.
  • voltage readings are saved based upon initial differential pressure (a pressure drop that occurs across the filter from the upstream side compared to the downstream side) at calibration, and then compared to later voltage readings.
  • initial differential pressure a pressure drop that occurs across the filter from the upstream side compared to the downstream side
  • later voltage readings At the middle setting of the dial, an alarm trigger would result when differential pressure rises to two times the initial differential pressure at calibration, based on voltage readings.
  • the networking module 105 transmits a representation of the numerical percentage which is processed according to Instructions on second processor 129, and represented as numbers shown in column 132 of the FIG. 12 notification report.
  • Notification Reports are generally accessible online.
  • a user may access a Notification Report for a sensing system corresponding to a particular MAC Identifier by logging onto the Internet with a computer, a tablet, an intelligent phone, and the like then inputting a predetermined web page according to a specified Uniform Resource Locator (URL), and specifying the particular MAC Identifier(s) associated with the registered account for which information is desired.
  • URL Uniform Resource Locator

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

L'invention concerne un système de détection d'encrassement de filtre de gaz pour surveiller les performances et l'état d'un filtre en fonction d'indicateurs d'accumulation de crasse et d'autres particules sur un filtre placé dans un conduit de gaz, dans lequel un système de notification fournit des alertes et des rapports lorsque le volume d'encrassement atteint un seuil prédéterminé.
PCT/US2015/032220 2014-06-05 2015-05-22 Détection d'encrassement de filtre et système de notification WO2015187392A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA2950289A CA2950289C (fr) 2014-06-05 2015-05-22 Detection d'encrassement de filtre et systeme de notification

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US14/296,872 US9183723B2 (en) 2012-01-31 2014-06-05 Filter clog detection and notification system
US14/296,872 2014-06-05

Publications (1)

Publication Number Publication Date
WO2015187392A1 true WO2015187392A1 (fr) 2015-12-10

Family

ID=54767185

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2015/032220 WO2015187392A1 (fr) 2014-06-05 2015-05-22 Détection d'encrassement de filtre et système de notification

Country Status (2)

Country Link
CA (1) CA2950289C (fr)
WO (1) WO2015187392A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3885022A1 (fr) * 2020-03-24 2021-09-29 Sensirion AG Surveillance de l'état d'un filtre

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100017151A1 (en) * 2008-07-21 2010-01-21 International Business Machines Corporation Detecting A Fouled Air Filter In A Computer Equipment Enclosure
US20100099193A1 (en) * 2008-10-20 2010-04-22 Industrial Technology Research Institute System and method for monitoring and controlling quality of culture water and integrated water quality analyzer thereof
US20100313748A1 (en) * 2009-06-15 2010-12-16 Middle Atlantic Products, Inc. Method and system for smart air filter monitoring
US20130197829A1 (en) * 2012-01-31 2013-08-01 William Sherman, III Filter clog sensing system and method for compensating in response to blower speed changes

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100017151A1 (en) * 2008-07-21 2010-01-21 International Business Machines Corporation Detecting A Fouled Air Filter In A Computer Equipment Enclosure
US20100099193A1 (en) * 2008-10-20 2010-04-22 Industrial Technology Research Institute System and method for monitoring and controlling quality of culture water and integrated water quality analyzer thereof
US20100313748A1 (en) * 2009-06-15 2010-12-16 Middle Atlantic Products, Inc. Method and system for smart air filter monitoring
US20130197829A1 (en) * 2012-01-31 2013-08-01 William Sherman, III Filter clog sensing system and method for compensating in response to blower speed changes

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3885022A1 (fr) * 2020-03-24 2021-09-29 Sensirion AG Surveillance de l'état d'un filtre

Also Published As

Publication number Publication date
CA2950289A1 (fr) 2015-12-10
CA2950289C (fr) 2022-08-30

Similar Documents

Publication Publication Date Title
US9183723B2 (en) Filter clog detection and notification system
US9186609B2 (en) Filter clog sensing system and method for compensating in response to blower speed changes
US9920947B2 (en) Networked filter condition indicator
EP3862743A1 (fr) Dispositif de mesure, système et procédé de mesure d'une concentration de masse de particules de poussière
CN108779925B (zh) 用于空气过滤器管理的系统、方法及计算机程序产品
US7178410B2 (en) Clogging detector for air filter
US9349279B2 (en) Systems and methods for compensating for sensor drift in a hazard detection system
AU2014229103B2 (en) HVAC system remote monitoring and diagnosis
US20090165644A1 (en) Air Filter Apparatus with Self-Contained Detachable Programmable Clogging Indicator
CN108700853B (zh) 根据控制器配置详情来自动推断装备详情的系统
US11579601B2 (en) Methods and devices for a building monitoring system
US9631833B2 (en) Climate control systems, and methods relating thereto
US9437094B2 (en) Non-radioactive ionizing smoke detectors and methods for use thereof
CN102519118A (zh) 空调清洁度自动提醒的方法和装置
US20110295524A1 (en) Determining apparatus and determining method
EP3467605B1 (fr) Procédé de surveillance d'un système de régulation de la température associé à une armoire électrique
CN101097226A (zh) 空气过滤器监视器
WO2023236566A1 (fr) Procédé et appareil de rappel de saleté pour condenseur de climatiseur, climatiseur et support de stockage
CA2950289C (fr) Detection d'encrassement de filtre et systeme de notification
US20220290886A1 (en) Filter Monitoring Device, Air Flow System and Corresponding Methods
US20190083917A1 (en) Smart air filter apparatus and system
CN106442249B (zh) 粉尘检测装置
US9488723B2 (en) Method and system of controlling a drive-thru operation of a quick-service restaurant
KR101947157B1 (ko) 공기조화기의 제어방법
CN106290098B (zh) 粉尘检测装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15803184

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2950289

Country of ref document: CA

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15803184

Country of ref document: EP

Kind code of ref document: A1