HVAC condensate drain pan overflow detection system

Abstract

An air conditioner drain pan overflow detection system includes a plug, a liquid detector and a control circuit. The plug is inserted into an outlet opening of an air conditioner condensate drain pan, and forms a water-tight seal with the outlet opening once inserted into the outlet opening. The liquid detector is disposed on an outer surface of a portion of the plug that is located inside of the air conditioner condensate drain pan when the plug has been inserted into the outlet opening. The control circuit is electrically coupled to the liquid detector, and shuts off an air conditioner unit that releases condensate to the air conditioner condensate drain pan based on a signal output from the liquid detector when the liquid detector detects liquid in contact with the liquid detector on the plug in the air conditioner condensate drain pan.

Description

TECHNICAL FIELD

[0001] This application relates to condensate drain pan overflow detection systems for use with an air cooling system, and in particular to condensate drain pan overflow detection systems that will shut down the air cooling system when the build-up of condensate in the drain pan is detected, the build-up being caused, for example, by clogging of a drainage line of the drain pan.BACKGROUND

[0002] Air cooling systems such as air conditioners and heat pumps typically have heat exchange coils that produce condensate as the system cools the air in a building. The condensate can cause damage to structures within the building, such as dry walls, ceilings, wooden supports, etc. Thus, the condensate is collected in a drain pan usually placed below the heat exchange coils, and is transported away through a drainage line connected to the drain pan. Over a period of time, a blockage can occur in the drain pan or in the drainage line due to debris, algae, mold, etc. The blockage causes the condensate to accumulate in the drain pan, and the drain pan eventually overflows to cause damage to the building. It thus is common (and often required by local building codes) to install an overflow detector, which has a float or electrodes, in the drain pan to detect when condensate is building-up in the drain pan due to a blockage. The overflow detector, upon sensing the build-up of condensate, will send an alarm and / or shut down the air cooling system to prevent the further build-up of condensate and the overflow of condensate (water) from the drain pan.

[0003] Some time is required to install an overflow detector in a drain pan. In particular, if the air conditioner system is a mini-split air conditioner, the wall unit that includes the drain pan needs to be partially disassembled in order to place the overflow detector in the drain pan. One known system provides a liquid detector on a clip that must be installed in the drain pan and attached to a wall of the drain pan.

[0004] Furthermore, upon becoming aware of the alarm, or if no alarm is issued upon becoming aware that the air cooling system is not working, the building occupant (such as the home owner or superintendent of the building) needs to contact a technician to schedule a service call to unclog the drain system (the drain pan and the drainage line). This can result in an extended period of time in which the building does not have air conditioning, which is inconvenient.SUMMARY

[0005] Many air cooling systems are provided with a drain pan having more than one opening that can be connected to a drainage line to ease in the connection of the drainage line to the drain pan. For example, it is known for the drain pan of the wall unit of a mini-split air conditioner to include two openings, one on the left and one on the right, so that the installer can easily choose the best opening for connection to the drainage line based on the structures surrounding the outside of the wall unit and based on any existing drainage lines. An elastomeric plug, for example, a rubber plug, is provided to block the drain pan opening that is not connected to the drainage line.

[0006] The inventor has realized that a liquid detector may be incorporated into the plug that is used to block the drain pan opening that is not connected to the drainage line in an air conditioning system that includes a drain pan. Incorporating the liquid detector into the plug greatly reduces the time required for installing the overflow detection system. An air conditioner drain pan overflow detection system according to one aspect of this disclosure includes a plug, a liquid detector and a control circuit. The plug is configured to be inserted into an outlet opening of an air conditioner condensate drain pan and form a water tight seal with the outlet opening once inserted into the outlet opening. The liquid detector may be disposed on the outer surface of a portion of the plug that is located inside of the air conditioner condensate drain pan when the plug has been inserted into the outlet opening of the air conditioner condensate drain pan. The control circuit is electrically coupled to the liquid detector, and the control circuit is configured to shut off the air conditioner unit that releases condensate into the condensate drain pan based on a signal output from the liquid detector once the liquid detector detects liquid in contact with the liquid detector on the plug in the air conditioner condensate drain pan.

[0007] The inventor also has realized that it is beneficial to send an alarm signal to a remote monitoring site, for example, to a company that is contracted to service the air cooling system, when the clogged condition is detected by the control circuit of the overflow detection system. This can expedite resolution of the clogged condition as appropriate. An air conditioner drain pan overflow detection system according to another aspect of this disclosure thus includes a liquid detector and a control circuit. The liquid detector is configured to be attached to an air conditioner condensate drain pan so as to be located inside the air conditioner condensate drain pan. The control circuit is electrically coupled to the liquid detector and the control circuit is configured to shut off the air conditioner that releases condensate to the air conditioner condensate drain pan based on a signal output from the liquid detector once the liquid detector detects liquid in contact with the liquid detector inside the air conditioner condensate drain pan. The control circuit further includes a wireless transmitter that wirelessly outputs an alarm signal to a monitoring site when the control circuit shuts off the air conditioner unit due to the liquid detector detecting that the liquid is in contact with the liquid detector.

[0008] The foregoing is a summary and thus may contain simplifications, generalizations, and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting.

[0009] For a better understanding of the embodiments, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various exemplary embodiments are described in detail with reference to the following figures in which:

[0011] FIG. 1 illustrates an exemplary embodiment of an air cooling system incorporating a condensate drain pan with outlet openings, one such outlet opening having a plug inserted, the plug having a liquid detector incorporated into it, the liquid detector being electrically coupled to a control circuit.

[0012] FIG. 2 is a perspective view of a part of the FIG. 1 condensate drain pan showing a drainage line connected to a first one of the outlet openings and showing a plug having a liquid detector according to an aspect of the disclosed embodiments and that may be inserted into a second one of the drain pan outlet openings, forming a liquid tight seal with the second one of the drain pan outlet openings.

[0013] FIG. 3A is a side view and FIG. 3B is a cross sectional view (taken along line 3B-3B in FIG. 3A) of a condensate drain pan plug incorporating a liquid detector sensor according to one preferred embodiment.

[0014] FIG. 4A shows the external appearance of a control unit, and FIG. 4B is a block diagram of an exemplary control circuit located within the control unit, and that is used with the liquid detector and coupled between a power supply (source of electric power) and an air conditioning unit having the condensate drain pan.

[0015] FIG. 5 is a flowchart showing processes performed by the control circuit of one embodiment.

[0016] FIG. 6 is a view of an application GUI which shows a mobile device application used to receive information from an HVAC condensate drain pan overflow detection system.DETAILED DESCRIPTION

[0017] In the following description, numerous specific embodiments are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the system and processes of the present disclosure may be practiced without the exact details of these specific embodiments and that numerous variations or modifications from the described embodiments may be possible.

[0018] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, et cetera. In other instances, well-known structures, materials, or operations are not shown or described in detail. The following description is intended only by way of example, and illustrates certain example embodiments. As used herein the term “liquid detector” refers to a sensor having electrically-conductive electrodes which, when liquid is present between and contacting both of the electrodes, completes a circuit so as to output a signal.

[0019] Disclosed herein is an HVAC Condensate Drain Pan Overflow Detection System that includes a liquid detector configured to be attached to a drain pan preferably by being incorporated into one end of a drain pan plug that is inserted into the second (unused) outlet opening of the drain pan. The detector is electrically coupled to a control circuit. The control circuit can be configured to send one or more signals including but not limited to a signal to a switch (a relay) that is disposed between a power source and an air conditioner to shut the air conditioner off when liquid has been detected. According to a preferred embodiment, the signal is sent to the switch only after presence of the liquid is detected by the detector for a predetermined period of time. The predetermined period of time can be set in the factory or can be adjustable at the control circuit. The predetermined period of time can be in the range of, for example, 5 seconds-30 seconds, although other periods greater than 30 seconds are possible. According to one preferred embodiments, the predetermined period of time is set to 10 seconds. The control circuit also is configured to output a signal to the switch to turn the air conditioner back on when liquid is no longer detected by the liquid detector. According to an embodiment, the control circuit also is configured to output a signal to a cellular tower, to a router, and / or to a Wi-Fi or Bluetooth enabled device to notify one or more users and / or to store information in a database indicating that water has been detected by the liquid detector.

[0020] FIG. 1 illustrates an air cooling system 1 including a drain pan 22 with two outlet openings 32, where one of the outlets 32 is attached to a drainage line 20 and the other outlet 32 is closed by a plug 24 that is inserted into the outlet and that forms a liquid-tight seal with the outlet 32 according to an exemplary embodiment of the present invention. FIG. 1 (and FIG. 2) shows the outlets 32 on opposite left and right side walls of the drain pan 22 for ease of illustration; however, many mini-split air conditioner units place the outlets 32 at left and right ends of the same wall (the rear wall) of the drain pan 22. Embodiments of the invention are applicable to drain pans regardless of the locations of the drain pan outlets 32. The air cooling system 1 includes an air conditioner 2 coupled to an air handler 4. The air conditioner 2 circulates and cools a coolant passing through the air conditioner 2. The air handler 4 contains heat exchange coils 6 through which the cold coolant circulates. Warm air is conveyed to the air handler 4 through an inlet duct 12. The warm air is cooled as it makes contact with the exchange coils 6. The cool air is then transported away from air handler 4 through an outlet duct 8. When the warm air is cooled, moisture in the air condenses on the heat exchange coils 6 as liquid droplets or condensate.

[0021] As is common with many air cooling systems, particularly so-called mini-split air conditioners, the condensate drain pan 22 has two outlet openings 32 that can be connected to a drainage line 20 to ease in the connection of the drainage line 20 to the drain pan 22. As shown in FIG. 1, one outlet opening 32 is disposed on the left portion of the drain pan 22 and another outlet opening 32 is disposed on the right portion of the drain pan 22, so that the installer can easily choose the best opening for connection to the drainage line 20 based on the structures surrounding the outside of the wall unit and based on any existing drainage lines. Such air cooling systems typically come with a drainage line 20 connected to one of the outlet openings 32 and with an elastomeric plug, for example, a rubber plug, pre-installed in the other outlet opening 32 to block that unused drain pan outlet opening. According to the present embodiment, the elastomeric plug that is supplied with the air cooling system can be discarded and replaced with the present plug 24 that includes a liquid detector 26, to be described below. In the example shown in FIG. 1 and FIG. 2, the drainage line 20 is attached to the outlet opening 32 disposed on the left portion of the drain pan 22, and the plug 24 is inserted into the outlet opening 32 disposed on the right portion of the drain pan 22.

[0022] In the embodiment shown in FIGS. 1 and 2, the liquid detector 26 is attached to the plug 24 that is inserted into the unused outlet opening 32 on the right side of the drain pan 22. The liquid detector 26 detects an excess level of condensate in the drain pan 22. Usually, the condensate that drips into the drain pan 22 flows away into the drainage line 20 connected to the drain pan 22. However, if a blockage occurs in the drainage line 20, or in the drain pan 22 adjacent to the inlet of the drainage line 20, for example, due to accumulation of debris, algae, mold, etc., the condensate starts to accumulate within the drain pan 22. When the condensate exceeds a predetermined level in the drain pan 22, the liquid detector 26 provided on the plug 24 will detect the high level of condensate, which will result in a signal that is sent through wires 28 that are electrically coupled to a control circuit (to be described below) of a control unit 30, to be received by the control circuit. The control circuit then causes power to be shut off from reaching the air conditioner 2 (to prevent the further production of condensate) and also, optionally, to output an alarm signal / message to one or more locations that the clogged condition has occurred. Preferably the alarm signal / message is transmitted wirelessly.

[0023] FIG. 2 illustrates an embodiment of a liquid detector 26 disposed at the end (tip) of a plug 24, with the liquid detector 26 being configured to detect liquid and send a signal through electrically coupled wires 28 to the connected control unit 30. The plug 24 makes a friction fit with the inside (bore) of an outlet opening 32 of the drain pan 22, and the plug 24 forms a liquid tight seal with the inside (bore) of the outlet opening 32. The plug 24 has a circular cross section similar to the circular bore of the outlet opening 32. The plug 24 is resilient so as to form a water-tight seal with the bore of the outlet opening 32, and the plug 24 thus is made from an elastomeric material such as, for example, rubber. The plug 24 could be made of other materials (or multiple materials) as long as the plug 24 can form a water-tight seal when inserted into a drain pan outlet opening 32. For example, the plug 24 can be made of elastomeric plastics having similar properties to rubber, or even from hard materials such as metal, fiberglass, carbon fiber or hard plastic as long as a plurality of annular soft rubber or plastic elastomer sealing rings are provided on the plug's external circumference or the external circumference of the plug is provided with a soft rubber or plastic elastomer covering that seals against the inside surface of the drain pan outlet opening 32. The plug 24 has a tip or distal end 21 (see FIG. 3B) at which the detector 26 is disposed and a proximal end 23. The distal end 21 of the plug 24 has a cross-section that is smaller than a cross-section of the proximal end 23 of the plug 24. The cross-section of the distal end 21 of the plug 24 also is smaller than a cross-section of the outlet opening 32 so that the distal end 21 is located inside of the air conditioner condensate drain pan 22 (see FIG. 1) when the plug 24 has been inserted into the outlet opening 32 of the air conditioner condensate drain pan 22. The cross-section of the proximal end 23 of the plug 24 is larger than the cross-section of the outlet opening 32 so that the proximal end 23 is located outside of the air conditioner condensate drain pan 22 when the plug 24 has been inserted into the outlet opening 32 of the air conditioner condensate drain pan 22. In addition, a portion of the plug 24 located between the distal end 21 and the proximal end 23 includes ribs 25 that form the water-tight seal with the outlet opening 32. The ribs 25 deform when the plug 24 is inserted into the outlet opening 32 to form a water-tight seal with the outlet opening 32. According to one preferred embodiment, the plug 24 has a total length of about 69 mm, the distal end 21 has a diameter of about 10.8 mm, the ribs 25 have a diameter of about 13.1 mm, and the proximal end 23 has a diameter of about 20.8 mm and a length of about 3.6 mm.

[0024] FIG. 3A is a side view of the plug 24. FIG. 3B is a cross sectional view of this same plug 24. In a preferred embodiment, the plug 24 is made from resilient, electrically insulative material such as rubber. The detector 26 is made of two electrically conductive electrodes 26A and 26B provided at the distal end 21 of the plug 24. Each of the electrodes 26A, 26B is attached to a wire 28. The wires 28 extend through the plug (the rubber plug 24 is molded around the electrodes 26A, 26B and the wires 28) and are attached to a control circuit 80 (see FIG. 4B) within the control unit 30. While FIGS. 3A and 3B show a preferred embodiment for providing a liquid detector in / on the plug 24, it is possible to locate electrodes constituting the liquid detector at other locations on the plug 24 as long as the electrodes will be exposed to liquid (condensate) that collects within the drain pan 22 if the drain pan 22 and / or the drainage line 20 becomes clogged. In addition, less than or more than two electrodes / wires can constitute the detector 26. Multiple detectors 26 also can be provided.

[0025] FIG. 4A shows the external appearance of a control unit 30, and FIG. 4B is a block diagram showing some internal components of the control unit 30. The control unit 30 includes control circuitry 80 that receives a signal from the liquid detector 26 based on whether liquid (condensate) is in contact with the electrodes 26A, 26B of the detector 26. Basically, and as is well known with liquid detectors that employ electrodes, when the level of liquid in drain pan 22 is such that liquid contacts both of the electrodes 26A and 26B, a circuit defined by the electrodes 26A, 26B, the wires 28 and the control circuit 80 is closed so as indicate that there is a clog in the drain pan 22 or the drainage line 20. Based on the signal indicating that liquid has been detected by the detector 26, the control circuit 80 opens a switch 84, which is a high-voltage relay, that is attached between a power supply and the air conditioner unit 2. In particular, the switch 84 is connected between wiring 29 that is connected to a power supply (e.g. the utility power supply) and wiring 27 that is connected to the air conditioner unit 2. When no water is sensed by the detector 26, the control circuit 80 places the switch 84 in the closed state so that the air conditioner unit 2 can operate as normal. As noted above, when water is sensed by the detector 26, the control circuit 80 places the switch 84 in the open state so that the air conditioner unit 2 is shut off and no more condensate is produced.

[0026] The control circuit 80 includes a processor that is programmed or hardwired to function as described herein. The processor 80 is part of a computer chip that includes memory and a central processing unit (the processor 80) that executes one or more programs stored in the memory.

[0027] According to a preferred embodiment, the control circuit 80 does not change the switch 84 from the closed state to the open state immediately upon sensing of liquid by the detector 26. Instead, the control circuit 80 changes the switch 84 from the closed state to the open state only after continuously receiving the water detection signal from the detector 26 for a predetermined amount of time that is greater than zero seconds. The predetermined amount of time can be in the ranger of, for example, 5 seconds to 30 seconds. In one preferred embodiment, the predetermined amount of time is 10 seconds. The predetermined amount of time can be fixed at the factory or programmable (adjustable) by the user of the system. The predetermined amount of time can be less than 5 seconds or more than 30 seconds. Because the plug 24 is located near the bottom of the pan 22 (attached to one of the standard outlet openings 32 of the pan 22), it can be easy for water to splash against the detector 26 even when the drainage line 20 is not clogged. The predetermined delay thus avoids a false signaling of a clogged condition of the drainage line 20 due to splashing of liquid in the pan 22 against the detector 26 on the plug 24.

[0028] According to another aspect of this disclosure, the control circuit 80 also includes a wireless transmitter 82. The wireless transmitter 82 wirelessly outputs an alarm signal to a monitoring site when the control circuit 80 shuts off the air conditioner unit 2 due to the liquid detector 26 detecting that the liquid is in contact with the liquid detector 26. According to some embodiments, the wireless transmitter 82 is a short distance wireless transmitter that communicates with a router located in a building in which the air conditioner drain pan overflow detection system is located. Examples of short distance wireless transmitters are a WIFI transmitter and a Bluetooth transmitter. According to some embodiments, the wireless transmitter is a long distance wireless transmitter that communicates with a cellular communication tower. FIG. 4A illustrates indicators on the outer casing of the control unit 30 showing activation of different forms of wireless transmission such as a WIFI indicator 31A, a Bluetooth indicator 31B and a cellular indicator 31C.

[0029] FIG. 5 is a flowchart showing an exemplary logic structure 500 implemented by the control circuit 80 for automatically communicating the detection of liquid by the detector 26. Upon supply of power to the system, the system begins monitoring in step S502. In step S504, the system continuously receives a monitoring signal S504 from the liquid detector 26. In step S506, the system determines if contact with liquid is made by the detector 26, and either continues monitoring if no liquid is detected or, if liquid is detected, in addition to shutting down the air conditioner unit 2 (by opening the switch 84), sends a communication (such as an alarm or a message) via the wireless transmitter 82 in step S508. The communication can be sent to the home or building owner and displayed on a mobile device that has downloaded an appropriate application (app), or can be sent by email or text message, for example, to the home or building owner or even more preferably to a maintenance technician at a remote location so that, if appropriate, a technician can be sent to the site of the unit in order to unclog the drainage line 20 and / or the drain pan 22. Furthermore, a log of instances of the clogged condition can be maintained, either by the control circuit 80 or at an external location, for example, at the location of the technician. This log of instances is also referred to as a “Failure Tally.” Accordingly, in step S510, the instance (of overflow detection) can be added to the Failure Tally. The Failure Tally can include the time at which the communication was sent (the time at which the clogged condition was detected), the unit that sent the communication and optionally also the duration of the time that the detector continuously detected the liquid.

[0030] Sometimes the liquid in the drain pan 22 will slowly drain from the pan 22, for example, when the drainage line 20 is not completely clogged. In preferred embodiments, when the detector 26 no longer senses liquid in the drain pan 22, the control circuit will close the switch 84, which turns the air conditioner unit 2 back on. By maintaining (storing in memory) the Failure Tally, a technician (or the home / building owner) can review how often the detector 26 detects the occurrence of the clogged condition and then schedule a service call as appropriate.

[0031] FIG. 6 is an exemplary embodiment of a graphical user interface (GUI) 700 for a user to configure device and Wi-Fi information corresponding to one or more air conditioning units and their associated condensate drain pan liquid detectors, such that in some such embodiments the user will be alerted that a particular unit has been shut down due to the detection of liquid by the detector 26 and be given an indication of the type of failure that has occurred based on the duration that the liquid detector has sensed the presence of liquid, the number of repeated detections, the time between detections or some combination thereof.

[0032] The embodiments in which a message is wirelessly sent to a remote location when the control circuit 80 determines that the clogged condition is present can be used with liquid sensors disposed anywhere within the drain pan 22 and is not limited to embodiments in which the liquid detector 26 is provided on the plug 24 that is used to seal the second outlet opening 32 of the drain pan 22 (that is, the outlet opening 32 that is not connected to the drainage line 20).

[0033] This disclosure has been presented for purposes of illustration and description but is not intended to be exhaustive or limiting. Many modifications and variations will be apparent to those of ordinary skill in the art. The example embodiments were chosen and described in order to explain principles and practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.

[0034] Thus, although illustrative example embodiments have been described herein with reference to the accompanying figures, it is to be understood that this description is not limiting and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the disclosure.

Examples

Embodiment Construction

[0017]In the following description, numerous specific embodiments are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the system and processes of the present disclosure may be practiced without the exact details of these specific embodiments and that numerous variations or modifications from the described embodiments may be possible.

[0018]Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, et cetera. In other instances, well-known structures, materials, or operations are not shown or described in detail. The followi...

TECHNICAL FIELD

[0001] This application relates to condensate drain pan overflow detection systems for use with an air cooling system, and in particular to condensate drain pan overflow detection systems that will shut down the air cooling system when the build-up of condensate in the drain pan is detected, the build-up being caused, for example, by clogging of a drainage line of the drain pan.BACKGROUND

[0002] Air cooling systems such as air conditioners and heat pumps typically have heat exchange coils that produce condensate as the system cools the air in a building. The condensate can cause damage to structures within the building, such as dry walls, ceilings, wooden supports, etc. Thus, the condensate is collected in a drain pan usually placed below the heat exchange coils, and is transported away through a drainage line connected to the drain pan. Over a period of time, a blockage can occur in the drain pan or in the drainage line due to debris, algae, mold, etc. The blockage causes the condensate to accumulate in the drain pan, and the drain pan eventually overflows to cause damage to the building. It thus is common (and often required by local building codes) to install an overflow detector, which has a float or electrodes, in the drain pan to detect when condensate is building-up in the drain pan due to a blockage. The overflow detector, upon sensing the build-up of condensate, will send an alarm and / or shut down the air cooling system to prevent the further build-up of condensate and the overflow of condensate (water) from the drain pan.

[0003] Some time is required to install an overflow detector in a drain pan. In particular, if the air conditioner system is a mini-split air conditioner, the wall unit that includes the drain pan needs to be partially disassembled in order to place the overflow detector in the drain pan. One known system provides a liquid detector on a clip that must be installed in the drain pan and attached to a wall of the drain pan.

[0004] Furthermore, upon becoming aware of the alarm, or if no alarm is issued upon becoming aware that the air cooling system is not working, the building occupant (such as the home owner or superintendent of the building) needs to contact a technician to schedule a service call to unclog the drain system (the drain pan and the drainage line). This can result in an extended period of time in which the building does not have air conditioning, which is inconvenient.SUMMARY

[0005] Many air cooling systems are provided with a drain pan having more than one opening that can be connected to a drainage line to ease in the connection of the drainage line to the drain pan. For example, it is known for the drain pan of the wall unit of a mini-split air conditioner to include two openings, one on the left and one on the right, so that the installer can easily choose the best opening for connection to the drainage line based on the structures surrounding the outside of the wall unit and based on any existing drainage lines. An elastomeric plug, for example, a rubber plug, is provided to block the drain pan opening that is not connected to the drainage line.

[0006] The inventor has realized that a liquid detector may be incorporated into the plug that is used to block the drain pan opening that is not connected to the drainage line in an air conditioning system that includes a drain pan. Incorporating the liquid detector into the plug greatly reduces the time required for installing the overflow detection system. An air conditioner drain pan overflow detection system according to one aspect of this disclosure includes a plug, a liquid detector and a control circuit. The plug is configured to be inserted into an outlet opening of an air conditioner condensate drain pan and form a water tight seal with the outlet opening once inserted into the outlet opening. The liquid detector may be disposed on the outer surface of a portion of the plug that is located inside of the air conditioner condensate drain pan when the plug has been inserted into the outlet opening of the air conditioner condensate drain pan. The control circuit is electrically coupled to the liquid detector, and the control circuit is configured to shut off the air conditioner unit that releases condensate into the condensate drain pan based on a signal output from the liquid detector once the liquid detector detects liquid in contact with the liquid detector on the plug in the air conditioner condensate drain pan.

[0007] The inventor also has realized that it is beneficial to send an alarm signal to a remote monitoring site, for example, to a company that is contracted to service the air cooling system, when the clogged condition is detected by the control circuit of the overflow detection system. This can expedite resolution of the clogged condition as appropriate. An air conditioner drain pan overflow detection system according to another aspect of this disclosure thus includes a liquid detector and a control circuit. The liquid detector is configured to be attached to an air conditioner condensate drain pan so as to be located inside the air conditioner condensate drain pan. The control circuit is electrically coupled to the liquid detector and the control circuit is configured to shut off the air conditioner that releases condensate to the air conditioner condensate drain pan based on a signal output from the liquid detector once the liquid detector detects liquid in contact with the liquid detector inside the air conditioner condensate drain pan. The control circuit further includes a wireless transmitter that wirelessly outputs an alarm signal to a monitoring site when the control circuit shuts off the air conditioner unit due to the liquid detector detecting that the liquid is in contact with the liquid detector.

[0008] The foregoing is a summary and thus may contain simplifications, generalizations, and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting.

[0009] For a better understanding of the embodiments, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various exemplary embodiments are described in detail with reference to the following figures in which:

[0011] FIG. 1 illustrates an exemplary embodiment of an air cooling system incorporating a condensate drain pan with outlet openings, one such outlet opening having a plug inserted, the plug having a liquid detector incorporated into it, the liquid detector being electrically coupled to a control circuit.

[0012] FIG. 2 is a perspective view of a part of the FIG. 1 condensate drain pan showing a drainage line connected to a first one of the outlet openings and showing a plug having a liquid detector according to an aspect of the disclosed embodiments and that may be inserted into a second one of the drain pan outlet openings, forming a liquid tight seal with the second one of the drain pan outlet openings.

[0013] FIG. 3A is a side view and FIG. 3B is a cross sectional view (taken along line 3B-3B in FIG. 3A) of a condensate drain pan plug incorporating a liquid detector sensor according to one preferred embodiment.

[0014] FIG. 4A shows the external appearance of a control unit, and FIG. 4B is a block diagram of an exemplary control circuit located within the control unit, and that is used with the liquid detector and coupled between a power supply (source of electric power) and an air conditioning unit having the condensate drain pan.

[0015] FIG. 5 is a flowchart showing processes performed by the control circuit of one embodiment.

[0016] FIG. 6 is a view of an application GUI which shows a mobile device application used to receive information from an HVAC condensate drain pan overflow detection system.DETAILED DESCRIPTION

[0017] In the following description, numerous specific embodiments are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the system and processes of the present disclosure may be practiced without the exact details of these specific embodiments and that numerous variations or modifications from the described embodiments may be possible.

[0018] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, et cetera. In other instances, well-known structures, materials, or operations are not shown or described in detail. The following description is intended only by way of example, and illustrates certain example embodiments. As used herein the term “liquid detector” refers to a sensor having electrically-conductive electrodes which, when liquid is present between and contacting both of the electrodes, completes a circuit so as to output a signal.

[0019] Disclosed herein is an HVAC Condensate Drain Pan Overflow Detection System that includes a liquid detector configured to be attached to a drain pan preferably by being incorporated into one end of a drain pan plug that is inserted into the second (unused) outlet opening of the drain pan. The detector is electrically coupled to a control circuit. The control circuit can be configured to send one or more signals including but not limited to a signal to a switch (a relay) that is disposed between a power source and an air conditioner to shut the air conditioner off when liquid has been detected. According to a preferred embodiment, the signal is sent to the switch only after presence of the liquid is detected by the detector for a predetermined period of time. The predetermined period of time can be set in the factory or can be adjustable at the control circuit. The predetermined period of time can be in the range of, for example, 5 seconds-30 seconds, although other periods greater than 30 seconds are possible. According to one preferred embodiments, the predetermined period of time is set to 10 seconds. The control circuit also is configured to output a signal to the switch to turn the air conditioner back on when liquid is no longer detected by the liquid detector. According to an embodiment, the control circuit also is configured to output a signal to a cellular tower, to a router, and / or to a Wi-Fi or Bluetooth enabled device to notify one or more users and / or to store information in a database indicating that water has been detected by the liquid detector.

[0020] FIG. 1 illustrates an air cooling system 1 including a drain pan 22 with two outlet openings 32, where one of the outlets 32 is attached to a drainage line 20 and the other outlet 32 is closed by a plug 24 that is inserted into the outlet and that forms a liquid-tight seal with the outlet 32 according to an exemplary embodiment of the present invention. FIG. 1 (and FIG. 2) shows the outlets 32 on opposite left and right side walls of the drain pan 22 for ease of illustration; however, many mini-split air conditioner units place the outlets 32 at left and right ends of the same wall (the rear wall) of the drain pan 22. Embodiments of the invention are applicable to drain pans regardless of the locations of the drain pan outlets 32. The air cooling system 1 includes an air conditioner 2 coupled to an air handler 4. The air conditioner 2 circulates and cools a coolant passing through the air conditioner 2. The air handler 4 contains heat exchange coils 6 through which the cold coolant circulates. Warm air is conveyed to the air handler 4 through an inlet duct 12. The warm air is cooled as it makes contact with the exchange coils 6. The cool air is then transported away from air handler 4 through an outlet duct 8. When the warm air is cooled, moisture in the air condenses on the heat exchange coils 6 as liquid droplets or condensate.

[0021] As is common with many air cooling systems, particularly so-called mini-split air conditioners, the condensate drain pan 22 has two outlet openings 32 that can be connected to a drainage line 20 to ease in the connection of the drainage line 20 to the drain pan 22. As shown in FIG. 1, one outlet opening 32 is disposed on the left portion of the drain pan 22 and another outlet opening 32 is disposed on the right portion of the drain pan 22, so that the installer can easily choose the best opening for connection to the drainage line 20 based on the structures surrounding the outside of the wall unit and based on any existing drainage lines. Such air cooling systems typically come with a drainage line 20 connected to one of the outlet openings 32 and with an elastomeric plug, for example, a rubber plug, pre-installed in the other outlet opening 32 to block that unused drain pan outlet opening. According to the present embodiment, the elastomeric plug that is supplied with the air cooling system can be discarded and replaced with the present plug 24 that includes a liquid detector 26, to be described below. In the example shown in FIG. 1 and FIG. 2, the drainage line 20 is attached to the outlet opening 32 disposed on the left portion of the drain pan 22, and the plug 24 is inserted into the outlet opening 32 disposed on the right portion of the drain pan 22.

[0022] In the embodiment shown in FIGS. 1 and 2, the liquid detector 26 is attached to the plug 24 that is inserted into the unused outlet opening 32 on the right side of the drain pan 22. The liquid detector 26 detects an excess level of condensate in the drain pan 22. Usually, the condensate that drips into the drain pan 22 flows away into the drainage line 20 connected to the drain pan 22. However, if a blockage occurs in the drainage line 20, or in the drain pan 22 adjacent to the inlet of the drainage line 20, for example, due to accumulation of debris, algae, mold, etc., the condensate starts to accumulate within the drain pan 22. When the condensate exceeds a predetermined level in the drain pan 22, the liquid detector 26 provided on the plug 24 will detect the high level of condensate, which will result in a signal that is sent through wires 28 that are electrically coupled to a control circuit (to be described below) of a control unit 30, to be received by the control circuit. The control circuit then causes power to be shut off from reaching the air conditioner 2 (to prevent the further production of condensate) and also, optionally, to output an alarm signal / message to one or more locations that the clogged condition has occurred. Preferably the alarm signal / message is transmitted wirelessly.

[0023] FIG. 2 illustrates an embodiment of a liquid detector 26 disposed at the end (tip) of a plug 24, with the liquid detector 26 being configured to detect liquid and send a signal through electrically coupled wires 28 to the connected control unit 30. The plug 24 makes a friction fit with the inside (bore) of an outlet opening 32 of the drain pan 22, and the plug 24 forms a liquid tight seal with the inside (bore) of the outlet opening 32. The plug 24 has a circular cross section similar to the circular bore of the outlet opening 32. The plug 24 is resilient so as to form a water-tight seal with the bore of the outlet opening 32, and the plug 24 thus is made from an elastomeric material such as, for example, rubber. The plug 24 could be made of other materials (or multiple materials) as long as the plug 24 can form a water-tight seal when inserted into a drain pan outlet opening 32. For example, the plug 24 can be made of elastomeric plastics having similar properties to rubber, or even from hard materials such as metal, fiberglass, carbon fiber or hard plastic as long as a plurality of annular soft rubber or plastic elastomer sealing rings are provided on the plug's external circumference or the external circumference of the plug is provided with a soft rubber or plastic elastomer covering that seals against the inside surface of the drain pan outlet opening 32. The plug 24 has a tip or distal end 21 (see FIG. 3B) at which the detector 26 is disposed and a proximal end 23. The distal end 21 of the plug 24 has a cross-section that is smaller than a cross-section of the proximal end 23 of the plug 24. The cross-section of the distal end 21 of the plug 24 also is smaller than a cross-section of the outlet opening 32 so that the distal end 21 is located inside of the air conditioner condensate drain pan 22 (see FIG. 1) when the plug 24 has been inserted into the outlet opening 32 of the air conditioner condensate drain pan 22. The cross-section of the proximal end 23 of the plug 24 is larger than the cross-section of the outlet opening 32 so that the proximal end 23 is located outside of the air conditioner condensate drain pan 22 when the plug 24 has been inserted into the outlet opening 32 of the air conditioner condensate drain pan 22. In addition, a portion of the plug 24 located between the distal end 21 and the proximal end 23 includes ribs 25 that form the water-tight seal with the outlet opening 32. The ribs 25 deform when the plug 24 is inserted into the outlet opening 32 to form a water-tight seal with the outlet opening 32. According to one preferred embodiment, the plug 24 has a total length of about 69 mm, the distal end 21 has a diameter of about 10.8 mm, the ribs 25 have a diameter of about 13.1 mm, and the proximal end 23 has a diameter of about 20.8 mm and a length of about 3.6 mm.

[0024] FIG. 3A is a side view of the plug 24. FIG. 3B is a cross sectional view of this same plug 24. In a preferred embodiment, the plug 24 is made from resilient, electrically insulative material such as rubber. The detector 26 is made of two electrically conductive electrodes 26A and 26B provided at the distal end 21 of the plug 24. Each of the electrodes 26A, 26B is attached to a wire 28. The wires 28 extend through the plug (the rubber plug 24 is molded around the electrodes 26A, 26B and the wires 28) and are attached to a control circuit 80 (see FIG. 4B) within the control unit 30. While FIGS. 3A and 3B show a preferred embodiment for providing a liquid detector in / on the plug 24, it is possible to locate electrodes constituting the liquid detector at other locations on the plug 24 as long as the electrodes will be exposed to liquid (condensate) that collects within the drain pan 22 if the drain pan 22 and / or the drainage line 20 becomes clogged. In addition, less than or more than two electrodes / wires can constitute the detector 26. Multiple detectors 26 also can be provided.

[0025] FIG. 4A shows the external appearance of a control unit 30, and FIG. 4B is a block diagram showing some internal components of the control unit 30. The control unit 30 includes control circuitry 80 that receives a signal from the liquid detector 26 based on whether liquid (condensate) is in contact with the electrodes 26A, 26B of the detector 26. Basically, and as is well known with liquid detectors that employ electrodes, when the level of liquid in drain pan 22 is such that liquid contacts both of the electrodes 26A and 26B, a circuit defined by the electrodes 26A, 26B, the wires 28 and the control circuit 80 is closed so as indicate that there is a clog in the drain pan 22 or the drainage line 20. Based on the signal indicating that liquid has been detected by the detector 26, the control circuit 80 opens a switch 84, which is a high-voltage relay, that is attached between a power supply and the air conditioner unit 2. In particular, the switch 84 is connected between wiring 29 that is connected to a power supply (e.g. the utility power supply) and wiring 27 that is connected to the air conditioner unit 2. When no water is sensed by the detector 26, the control circuit 80 places the switch 84 in the closed state so that the air conditioner unit 2 can operate as normal. As noted above, when water is sensed by the detector 26, the control circuit 80 places the switch 84 in the open state so that the air conditioner unit 2 is shut off and no more condensate is produced.

[0026] The control circuit 80 includes a processor that is programmed or hardwired to function as described herein. The processor 80 is part of a computer chip that includes memory and a central processing unit (the processor 80) that executes one or more programs stored in the memory.

[0027] According to a preferred embodiment, the control circuit 80 does not change the switch 84 from the closed state to the open state immediately upon sensing of liquid by the detector 26. Instead, the control circuit 80 changes the switch 84 from the closed state to the open state only after continuously receiving the water detection signal from the detector 26 for a predetermined amount of time that is greater than zero seconds. The predetermined amount of time can be in the ranger of, for example, 5 seconds to 30 seconds. In one preferred embodiment, the predetermined amount of time is 10 seconds. The predetermined amount of time can be fixed at the factory or programmable (adjustable) by the user of the system. The predetermined amount of time can be less than 5 seconds or more than 30 seconds. Because the plug 24 is located near the bottom of the pan 22 (attached to one of the standard outlet openings 32 of the pan 22), it can be easy for water to splash against the detector 26 even when the drainage line 20 is not clogged. The predetermined delay thus avoids a false signaling of a clogged condition of the drainage line 20 due to splashing of liquid in the pan 22 against the detector 26 on the plug 24.

[0028] According to another aspect of this disclosure, the control circuit 80 also includes a wireless transmitter 82. The wireless transmitter 82 wirelessly outputs an alarm signal to a monitoring site when the control circuit 80 shuts off the air conditioner unit 2 due to the liquid detector 26 detecting that the liquid is in contact with the liquid detector 26. According to some embodiments, the wireless transmitter 82 is a short distance wireless transmitter that communicates with a router located in a building in which the air conditioner drain pan overflow detection system is located. Examples of short distance wireless transmitters are a WIFI transmitter and a Bluetooth transmitter. According to some embodiments, the wireless transmitter is a long distance wireless transmitter that communicates with a cellular communication tower. FIG. 4A illustrates indicators on the outer casing of the control unit 30 showing activation of different forms of wireless transmission such as a WIFI indicator 31A, a Bluetooth indicator 31B and a cellular indicator 31C.

[0029] FIG. 5 is a flowchart showing an exemplary logic structure 500 implemented by the control circuit 80 for automatically communicating the detection of liquid by the detector 26. Upon supply of power to the system, the system begins monitoring in step S502. In step S504, the system continuously receives a monitoring signal S504 from the liquid detector 26. In step S506, the system determines if contact with liquid is made by the detector 26, and either continues monitoring if no liquid is detected or, if liquid is detected, in addition to shutting down the air conditioner unit 2 (by opening the switch 84), sends a communication (such as an alarm or a message) via the wireless transmitter 82 in step S508. The communication can be sent to the home or building owner and displayed on a mobile device that has downloaded an appropriate application (app), or can be sent by email or text message, for example, to the home or building owner or even more preferably to a maintenance technician at a remote location so that, if appropriate, a technician can be sent to the site of the unit in order to unclog the drainage line 20 and / or the drain pan 22. Furthermore, a log of instances of the clogged condition can be maintained, either by the control circuit 80 or at an external location, for example, at the location of the technician. This log of instances is also referred to as a “Failure Tally.” Accordingly, in step S510, the instance (of overflow detection) can be added to the Failure Tally. The Failure Tally can include the time at which the communication was sent (the time at which the clogged condition was detected), the unit that sent the communication and optionally also the duration of the time that the detector continuously detected the liquid.

[0030] Sometimes the liquid in the drain pan 22 will slowly drain from the pan 22, for example, when the drainage line 20 is not completely clogged. In preferred embodiments, when the detector 26 no longer senses liquid in the drain pan 22, the control circuit will close the switch 84, which turns the air conditioner unit 2 back on. By maintaining (storing in memory) the Failure Tally, a technician (or the home / building owner) can review how often the detector 26 detects the occurrence of the clogged condition and then schedule a service call as appropriate.

[0031] FIG. 6 is an exemplary embodiment of a graphical user interface (GUI) 700 for a user to configure device and Wi-Fi information corresponding to one or more air conditioning units and their associated condensate drain pan liquid detectors, such that in some such embodiments the user will be alerted that a particular unit has been shut down due to the detection of liquid by the detector 26 and be given an indication of the type of failure that has occurred based on the duration that the liquid detector has sensed the presence of liquid, the number of repeated detections, the time between detections or some combination thereof.

[0032] The embodiments in which a message is wirelessly sent to a remote location when the control circuit 80 determines that the clogged condition is present can be used with liquid sensors disposed anywhere within the drain pan 22 and is not limited to embodiments in which the liquid detector 26 is provided on the plug 24 that is used to seal the second outlet opening 32 of the drain pan 22 (that is, the outlet opening 32 that is not connected to the drainage line 20).

[0033] This disclosure has been presented for purposes of illustration and description but is not intended to be exhaustive or limiting. Many modifications and variations will be apparent to those of ordinary skill in the art. The example embodiments were chosen and described in order to explain principles and practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.

[0034] Thus, although illustrative example embodiments have been described herein with reference to the accompanying figures, it is to be understood that this description is not limiting and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the disclosure.

Examples

Embodiment Construction

[0017]In the following description, numerous specific embodiments are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the system and processes of the present disclosure may be practiced without the exact details of these specific embodiments and that numerous variations or modifications from the described embodiments may be possible.

[0018]Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, et cetera. In other instances, well-known structures, materials, or operations are not shown or described in detail. The followi...

Claims

1. An air conditioner drain pan overflow detection system comprising:a plug that is configured to (i) be inserted into an outlet opening of an air conditioner condensate drain pan, and (ii) form a water-tight seal with the outlet opening once inserted into the outlet opening;a liquid detector disposed on an outer surface of a portion of the plug that is located inside of the air conditioner condensate drain pan when the plug has been inserted into the outlet opening of the air conditioner condensate drain pan; anda control circuit that is electrically coupled to the liquid detector, the control circuit being configured to shut off an air conditioner unit that releases condensate to the air conditioner condensate drain pan based on a signal output from the liquid detector when the liquid detector detects liquid in contact with the liquid detector on the plug in the air conditioner condensate drain pan.

2. The air conditioner drain pan overflow detection system according to claim 1, whereinthe plug is a solid member that is electrically insulative, andthe liquid detector includes electrically-conductive electrodes disposed on the outer surface portion of the plug.

3. The air conditioner drain pan overflow detection system according to claim 2, whereinthe plug is made from rubber.

4. The air conditioner drain pan overflow detection system according to claim 2, whereinthe plug includes a distal end and a proximal end,the distal end of the plug has a cross-section that is smaller than a cross-section of the proximal end of the plug and smaller than a cross-section of the outlet opening so that the distal end is located inside of the air conditioner condensate drain pan when the plug has been inserted into the outlet opening of the air conditioner condensate drain pan,the cross-section of the proximal end of the plug is larger than the cross-section of the outlet opening so that the proximal end is located outside of the air conditioner condensate drain pan when the plug has been inserted into the outlet opening of the air conditioner condensate drain pan, and a portion of the plug located between the distal and proximal forms the water-tight seal with the outlet opening, andthe electrically-conductive electrodes of the liquid detector are disposed at the distal end of the plug.

5. The air conditioner drain pan overflow detection system according to claim 4, further comprising wires extending from the electrically-conductive electrodes through the plug to the control circuit.

6. The air conditioner drain pan overflow detection system according to claim 4, whereinthe plug includes a plurality of ribs on an outer surface of the plug between the distal end of the plug and the proximal end of the plug.

7. The air conditioner drain pan overflow detection system according to claim 1, whereinthe control circuit changes a state of a switch, which supplies electricity to the air conditioner unit, from a closed state to an open state when the signal output from the liquid detector indicates that the liquid is in contact with the liquid detector.

8. The air conditioner drain pan overflow detection system according to claim 7, whereinthe control circuit changes the state of the switch from the closed state to the open state after the signal output from the liquid detector indicates that the liquid is in contact with the liquid detector for a predetermined amount of time.

9. The air conditioner drain pan overflow detection system according to claim 8, whereinthe predetermined amount of time is adjustable.

10. The air conditioner drain pan overflow detection system according to claim 7, whereinthe control circuit changes the state of the switch from the open state to the closed state when the signal output from the liquid detector indicates that the liquid is no longer in contact with the liquid detector.

11. The air conditioner drain pan overflow detection system according to claim 1, whereinthe control circuit includes a wireless transmitter that wirelessly outputs an alarm signal to a monitoring site when the control circuit shuts off the air conditioner unit due to the liquid detector detecting that the liquid is in contact with the liquid detector.

12. The air conditioner drain pan overflow detection system according to claim 11, whereinthe wireless transmitter is a short distance wireless transmitter that communicates with a router located in a building in which the air conditioner drain pan overflow detection system is located.

13. The air conditioner drain pan overflow detection system according to claim 11, whereinthe wireless transmitter is a long distance wireless transmitter that communicates with a cellular communication tower.

14. An air conditioner system comprising:an air conditioner unit that cools air and generates condensate;an air conditioner condensate drain pan that collects the condensate produced by the air conditioner unit, the air conditioner condensate drain pan having a first outlet opening and a second outlet opening;a drain line connected to the first outlet opening and directing the condensate collected by the air conditioner condensate drain pan out of the air conditioner condensate drain pan; andthe air conditioner drain pan overflow detection system according to claim 1, whereinthe plug of the air conditioner drain pan overflow detection system is inserted into and forms a water-tight seal with the second outlet opening of the air conditioner condensate drain pan, andthe control circuit of the air conditioner drain pan overflow detection system is coupled to the air conditioner unit.

15. An air conditioner drain pan overflow detection system comprising:a liquid detector that is configured to be attached to an air conditioner condensate drain pan so as to be located inside of the air conditioner condensate drain pan; anda control circuit that is electrically coupled to the liquid detector, the control circuit being configured to shut off an air conditioner unit that releases condensate to the air conditioner condensate drain pan based on a signal output from the liquid detector when the liquid detector detects liquid in contact with the liquid detector inside the air conditioner condensate drain pan, whereinthe control circuit includes a wireless transmitter that wirelessly outputs an alarm signal to a monitoring site when the control circuit shuts off the air conditioner unit due to the liquid detector detecting that the liquid is in contact with the liquid detector.

16. The air conditioner drain pan overflow detection system according to claim 15, whereinthe wireless transmitter is a short distance wireless transmitter that communicates with a router located in a building in which the air conditioner drain pan overflow detection system is located.

17. The air conditioner drain pan overflow detection system according to claim 15, whereinthe wireless transmitter is a long distance wireless transmitter that communicates with a cellular communication tower.

18. The air conditioner drain pan overflow detection system according to claim 15, whereinthe control circuit changes a state of a switch, which supplies electricity to the air conditioner unit, from a closed state to an open state when the signal output from the liquid detector indicates that the liquid is in contact with the liquid detector.

19. The air conditioner drain pan overflow detection system according to claim 18, whereinthe control circuit changes the state of the switch from the closed state to the open state after the signal output from the liquid detector indicates that the liquid is in contact with the liquid detector for a predetermined amount of time.

20. The air conditioner drain pan overflow detection system according to claim 19, whereinthe predetermined amount of time is adjustable.

21. The air conditioner drain pan overflow detection system according to claim 15, further comprisinga plug that is configured to (i) be inserted into an outlet opening of the air conditioner condensate drain pan, and (ii) form a water-tight seal with the outlet opening once inserted into the outlet opening, whereinthe liquid detector is attached to the plug.

22. An air conditioner system comprising:an air conditioner unit that cools air and generates condensate;an air conditioner condensate drain pan that collects the condensate produced by the air conditioner unit, the air conditioner condensate drain pan having an outlet opening;a drain line connected to the outlet opening and directing the condensate collected by the air conditioner condensate drain pan out of the air conditioner condensate drain pan; andthe air conditioner drain pan overflow detection system according to claim 15, whereinthe liquid detector of the air conditioner drain pan overflow detection system is attached to the air conditioner condensate drain pan so as to be located inside of the air conditioner condensate drain pan, andthe control circuit of the air conditioner drain pan overflow detection system is coupled to the air conditioner unit.

Images