Abstract: A refrigerant recovery and recharge device and a method to recharge oil to refrigeration equipment is disclosed. The refrigerant recovery and recharge device comprises a valve block which is adapted to establish fluid communication between the device and refrigeration equipment and a recharge path adapted to recharge oil to the refrigeration equipment through an outlet in the valve block. The device further comprises at least a first oil container and a second oil container and the valve block comprises a valve with a first inlet and a second inlet. The first oil container is in fluid communication with the first inlet and the second oil container is in fluid communication with the second inlet to recharge oil to the refrigeration equipment. The method for recharging oil recharges oil either from the first oil container or the second oil container in dependence of the type of fuel used in the vehicle.

Abstract: A valve apparatus includes a valve main body provided with a first inlet and outlet, a valve chamber to which a valve port is open, and a second inlet and outlet connected to the valve port. A valve shaft having a valve body portion for opening and closing the valve port is provided in the valve chamber. A relief valve is provided within the valve body portion to relieve a pressure of the valve chamber to the second inlet and outlet when a fluid pressure of the refrigerant within the valve chamber becomes a predetermined pressure or more in a fully closed state in which the valve port is closed by the valve body portion, thereby to automatically relieve a fluid within a valve chamber without causing a cost increase and an enlargement of size.

Abstract: A heat transfer composition comprising trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), carbon dioxide (R-744) and a third component selected from difluoromethane (R-32), 1,1-difluoroethane (R-152a), fluoroethane (R-161), 1,1,1,2-tetrafluoroethane (R-134a), propylene, propane and mixtures thereof.

Abstract: The invention relates to the use of 1,1,1,2-tetrafluoroethane for increasing the miscibility of 2,3,3,3-tetrafluoropropene with a lubricating oil, and in particular with a polyalkylene glycol oil. In this regard, the invention provides heat-transfer compositions and also equipment and processes using these compositions.

Abstract: A method of servicing an aircraft cooling system comprises connecting a refilling container containing a two-phase refrigerant to a refrigerant connection provided in a cooling circuit of the cooling system, supplying refrigerant from the refilling container into the cooling circuit of the cooling system, and operating a condenser disposed in the cooling circuit so as to liquefy gaseous refrigerant flowing through the cooling circuit.

Abstract: A method of servicing an aircraft cooling system comprises connecting a refilling container containing a two-phase refrigerant to a refrigerant connection provided in a cooling circuit of the cooling system, supplying refrigerant from the refilling container into the cooling circuit of the cooling system, and operating a condenser disposed in the cooling circuit so as to liquefy gaseous refrigerant flowing through the cooling circuit.

Abstract: A refrigerant recovery unit is provided that can recover and recharge refrigerant. The unit is further configured with a pair of service hoses and a refrigerant control circuit operable to receive and transport the refrigerant between the hoses and the storage vessel and to process the refrigerant to substantially remove contaminants from the refrigerant. A fluid connector is provided in fluid communication with the hoses to enable the refrigerant to flow between the hoses and to establish a closed loop through the refrigerant control circuit, and a controller is operatively connected to the refrigerant control circuit and configured to control a flow of the refrigerant through the refrigerant control circuit and through the fluid connector.

Abstract: A servicing device and method for operating a servicing device for vehicle air-conditioning systems in particular for the self-cleaning thereof, the servicing device is equipped with an emptying device and a filling device for the drawing off of the refrigerant/compressor oil mixture from the refrigerant circuit system of a vehicle air-conditioning system and for the refilling of the vehicle air-conditioning system with refrigerant and compressor oil. A vacuum pump is used for the residual emptying of the refrigerant circuit system of the vehicle air-conditioning system and/or of the servicing device. An at least partially evacuated flushing agent tank is connected directly or indirectly via a connecting line with at least one of the high pressure servicing connection connectors of the servicing device and/or the subsequent pressure hoses and/or the switchover valve block and that a fluidic further connection takes place to the refrigerant reservoir which is under increased refrigerant pressure.

Abstract: An air conditioner is provided. The air conditioner may include a compressor, a condenser, an evaporator, a receiver storing a portion of a refrigerant passing through the condenser, an accumulator receiving refrigerant stored in the receiver and refrigerant passing through the evaporator to separate gas refrigerant from refrigerant introduced therein and supply the gas refrigerant to the compressor, and a bypass line supplying refrigerant from the receiver to the accumulator. The receiver and the accumulator may be integrally formed or provided as separate parts coupled each other. An outlet end of the bypass line may be connected to an upper portion of the accumulator. Such an arrangement may prevent refrigerant from flowing backward from the accumulator into the receiver.

Abstract: A composition based on 3,3,3-trifluoropropene and ammonia, and to the use thereof, especially as a heat transfer fluid. A heat-transfer composition including the composition based on 3,3,3-trifluoropropene and ammonia and also one or more additives chosen from lubricants, stabilizers, surfactants, tracers, fluorescers, odorant agents and solubilizers, and mixtures thereof. A process for heating or cooling a fluid or a body by means of a vapor compression circuit containing a heat-transfer fluid, said process successively including evaporation of the heat-transfer fluid, compression of the heat-transfer fluid, condensation of the heat fluid and depressurization of the heat-transfer fluid, in which the heat-transfer fluid is a composition based on 3,3,3-trifluoropropene and ammonia.

Abstract: A pressure and prevacuum testing system for an AC system in a vehicle includes an air pressure source for pressurizing a cooling circuit of the AC system to a predetermined high pressure threshold and a vacuum source for prevacuuming the cooling circuit either to a predetermined prevacuum low pressure level or for a predetermined time period. The system also includes a pressure gauge for operatively measuring a pressure level in the cooling circuit. A controller is operatively connected to the air pressure source, the vacuum source and the pressure gauge. The controller compares the pressure level as measured by the pressure gauge to the predetermined high pressure threshold during a pressurized test of the cooling circuit and to the predetermined prevacuum low pressure level during a prevacuum test of the cooling circuit to determine if leaks are present in the cooling circuit.

Abstract: A method of charging or recharging an air conditioning wherein an initial amount of refrigerant is introduced, followed by additional introductions of refrigerant during injection pulses. The pulse periods are adjusted dynamically during the charging/recharging process based on feedback obtained after each pulse related to how much refrigerant was transferred during the previous pulse. Also, a system for implementing the above-mentioned method.

Abstract: An apparatus and method providing a refrigeration servicing system that comprises a clean refrigerant source, a recovery circuit and a flushing circuit. The recovery circuit can be configured to recover refrigerant from a cooling system. After recovery cycle is completed, the flushing circuit that is coupled to the recovery circuit can flush clean refrigerant through the recovery circuit. A housing can be provided and configured to house the refrigerant source, the recovery circuit and the flushing circuit.

Abstract: A convertible refrigerant recovery, recycle, and recharge unit, comprising a control valve array, a vacuum pump, an oil separator, an oil-less compressor, and one or more storage tanks. The vacuum pump and the oil separator are in flow communication with the control valve array, the oil-less compressor is in flow communication with the oil separator, and the storage tanks are in flow communication with said oil-less compressor. The control valve array receives refrigerant from a refrigerant containing device wherein the oil-less compressor draws the refrigerant into said the storage tanks. The unit is compatible with a plurality of refrigerant types without cross-contamination of the refrigerant due to the oil-less compressor and conversion cycle whereby the vacuum pump is activated to remove residual refrigerant from the unit. A refrigerant identifier sensor is in flow communication with the system and can detect contaminants and selectively open and close the storage tanks.

Abstract: An apparatus for recovering refrigerant (230) from an air conditioning system includes a collector for connecting hydraulically a high pressure branch and a low pressure branch, provided in the air conditioning system, with a fluid feeding duct of the fluid into the apparatus. The apparatus also has an evaporator arranged to separate the refrigerant from impurities, through an evaporation of residual liquid fractions of the refrigerant obtaining a purified refrigerant that rises towards an upper part of the evaporator, from impurities that are concentrated in a lower part of the evaporator.

Abstract: Refrigerant processing equipment is provided. The refrigerant processing equipment may include: a vacuum pump; an outlet for draining vacuum pump lubricating oil from the vacuum pump; a fluid container; and a conduit configured to provide a fluid connection between the outlet and the container. A method for draining oil from a vacuum pump from refrigerant processing equipment is provided. The method may include connecting an outlet for oil on the vacuum pump with a container; and providing a valve between the outlet and the container to selectively provide fluid communication between the outlet and an the container.

Abstract: A method for converting a refrigerant recovery unit from use with a first refrigerant to use with a second refrigerant includes the steps of opening, with a controller, solenoids along a refrigerant path to remove residue of the first refrigerant into a holding vessel, operating a vacuum pump, as indicated by the controller, to further remove the residue of the first refrigerant from the refrigerant path, introducing, via the controller, an amount of the second refrigerant into the refrigerant path, determining, with a refrigerant identifier, a purity of the second refrigerant in the refrigerant path. A kit is also provided to convert the refrigerant recovery unit for use with the first refrigerant to the second refrigerant.

Abstract: A method for operating a closed circuit vapour compression refrigeration system is disclosed. The system may operate with supercritical pressure on a high pressure side, and includes at least one compressor, at least one heat rejector, at least two in parallel connected heat absorbers, at least one variable expansion means up flow of each heat absorber and at least one control unit for controlling the variable expansion means, connected to a set of sensors. The flow rate of the refrigerant through each of the variable expansion means, is controlled by the control unit, coordinating the flow of refrigerant through each of the variable expansion means to maintain a control parameter within a set range. Any surplus charge resulting from the control is buffered on a low pressure side of the system. Furthermore a refrigeration system based on a closed vapour compression circuit is described.

Abstract: Distributed nodes, such as intelligent register controllers, of a heating, ventilating and/or air conditioning (HVAC) system wirelessly communicate with each other on a peer-to-peer basis, forming a network, and collectively control the HVAC system, without a central controller. The intelligent register controllers collectively control the amount of conditioned air introduced into each region. Each node may base its operation at least in part on information about one or more (ideally all) of the other nodes.

Abstract: The invention relates to a composition comprising (E)-1,1,1,4,4,4-hexafluorobat-2-ene as a mixture with at least one hydrocarbon, hydrofinorocarbon or fluoroolefin compound having a boiling point less than or equal to 42° C., and also to the use of this composition as a heat transfer fluid.

Abstract: A closed loop geothermal system has a fluid circulation loop that includes in series: a heat pump, a ground loop heat exchanger, a tank flow center and a circulation pump. The tank flow center includes a tank, a first valve, a second valve and a tank bypass line all mounted in a common housing. The tank may include a refill inlet that opens through a top surface of the housing. A cap may be attached to close the refill inlet. The tank flow center has the regular geothermal operation configuration, a system flush configuration, and a refill configuration. The tank flow center may be elevated above the circulation pump a distance to produce a water column that is greater than a minimum cavitation avoidance head pressure for the circulation pump.

Abstract: A method of measuring weight of the refrigerant recovered and a device for refrigerant recovery and recharge device is disclosed. A connection is established between the refrigerant recovery path and refrigerant recharge path. Refrigerant is filled in the refrigerant recovery path and the refrigerant recharge path. Once the refrigerant occupies the all components of the refrigerant recovery and recharge device, weight of the refrigerant storage tank is measured. The weight of the refrigerant storage tank is measured once before the recovery of the refrigerant from the refrigeration equipment and once after recovery of the refrigerant from the refrigeration equipment. Difference in the weights measured before recovery and after recovery is calculated to a get the amount of refrigerant recovered.

Abstract: Disclosed herein is a method for producing heating comprising condensing a vapor working fluid comprising (a) E-CF3CH?CHF and (b) at least one tetrafluoroethane of the formula C2H2F4, in a condenser, thereby producing a liquid working fluid; provided that the weight ratio of E-CF3CH?CHF to the total amount of E-CF3CH?CHF and C2H2F4 in the working fluid is from about 0.01 to 0.99. Also disclosed herein is a heat pump apparatus containing a working fluid comprising (a) E-CF3CH?CHF and (b) at least one tetrafluoroethane of the formula C2H2F4; provided that the weight ratio of E-CF3CH?CHF to the total amount of E-CF3CH?CHF and C2H2F4 in the working fluid is from about 0.01 to 0.99.

Abstract: Operation of a refrigeration system can be improved by adding a novel refrigerant composition comprising a mixture of activated long chain fatty acids with a polar heat transfer fluid. Activation is preferably accomplished by blending a mixture of the oils and the heat transfer fluid in a vessel containing a catalyst. Contemplated improvements can include, among other things, a reduction in power consumption, a reduction in evaporator coil condensation, or a reduction in leakage of operating fluid.

Abstract: Disclosed herein is a method for producing cooling comprising evaporating a liquid refrigerant comprising (a) E-CF3CH?CHF and (b) at least one tetrafluoroethane of the formula C2H2F4; provided that the weight ratio of E-CF3CH?CHF to the total amount of E-CF3CH?CHF and C2H2F4 is from about 0.05 to 0.99, in an evaporator, thereby producing a refrigerant vapor. Also disclosed herein is a method for replacing HCFC-124 or HFC-134a refrigerant in a chiller designed for said refrigerant comprising providing a replacement refrigerant composition comprising (a) E-CF3CH?CHF and (b) at least one tetrafluoroethane of the formula C2H2F4; provided that the weight ratio of E-CF3CH?CHF to the total amount of E-CF3CH?CHF and C2H2F4 is from about 0.05 to 0.99.

Abstract: Provided is an air conditioner. The air conditioner including a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an expansion device includes a supercooling device for supercooling a refrigerant condensed in the outdoor heat exchanger or the indoor heat exchanger, an injection passage through which the refrigerant passing through the supercooling device is introduced into an injection inflow part of the compressor, a bypass passage extending from the injection passage to a suction part of the compressor to bypass the refrigerant, and a passage opening/closing part disposed in at least one of the injection passage and the bypass passage to selectively block a flow of the refrigerant.

Abstract: A refrigerant charging method includes installing, cooling, confirming, and moving steps. In the installing step, a refrigeration device is installed on site. In the cooling step, a container is cooled to 31° C. or below using a cooling medium. In the confirming step, it is confirmed that the container has reached 31° C. or below. In the moving step, the refrigerant is moved to the intended charging space from the container upon confirming that the container has reached 31° C. or below via the cooling step. When moving the refrigerant from the container to the intended charging space, first, refrigerant that is in a gas phase within the container is moved into the intended charging space, whereupon refrigerant that is in a liquid phase within the container is moved into the intended charging space.

Abstract: A method of adding refrigerant to an air conditioning system. The method includes measuring a first pressure inside of the air conditioning system and a second pressure inside of a container that holds refrigerant being added to the air conditioning system. The method also includes comparing the difference between the two measured pressures to empirical data in order to determine how long to pulse additional refrigerant into the air conditioning system. In addition, an apparatus configured to add refrigerant to an air conditioning system.

Abstract: A part replacement method for replacement of a part of a refrigeration cycle apparatus includes a refrigerant circuit in which a flammable refrigerant is circulated and a container connecting device for controlling the refrigerant such that the refrigerant is allowed to flow out of the refrigerant circuit. The method includes a refrigerant recovery step of allowing the refrigerant to flow out of the refrigerant circuit through the container connecting device, a pressure reduction step of connecting a pressure reducing device to the container connecting device to reduce a pressure in the refrigerant circuit until the pressure in the refrigerant circuit reaches a set pressure or a setting time is reached, and a part replacement step of removing the part from the refrigerant circuit by heating to replace the part.

Abstract: A part replacement method replaces a part of a refrigeration cycle apparatus including a compressor, a heat source side heat exchanger, an expansion device, a heat exchanger related to heat medium, and first and second refrigerant flow closing devices. The first and second refrigerant flow closing devices control a flow of a refrigerant into and out of an outdoor unit accommodating the compressor and the heat source side heat exchanger. The method includes a pump-down step of closing the first refrigerant flow closing device, allowing the refrigerant in a pressure reduction section to flow into the outdoor unit and reducing a pressure in the reduction section until a set pressure or time is reached, a flow closing step of closing the second refrigerant flow closing device, and a part replacement step of removing the part from the refrigerant circuit by heating to replace the part.

Abstract: A refrigerant recovery and recharge device is configured to be connected to refrigeration equipment. The device includes a filter configured to filter refrigerant and removal contaminants in recovered refrigerant. The filter includes a fuse configured to indicate when the filter should be replaced.

Abstract: The invention relates to a service unit for vehicle air-conditioning systems, which is provided with an emptying and filling device for removing the coolant or a coolant/compressor oil mixture from a vehicle air-conditioning system and replenishing the vehicle air-conditioning system with coolant and optionally with compressor oil. The device can include at least one tank for coolant and a vacuum pump for generating a negative pressure in the vehicle air-conditioning system emptied of coolant or coolant/compressor oil mixture for a subsequent intake of coolant and optionally compressor oil into the vehicle air-conditioning system to be replenished. A chimney-like gas-collecting chamber having upper and lower openings can be arranged inside the service unit and is otherwise sealed off from the surrounding atmosphere.

Abstract: A refrigerant additive supply device can include an outer rigid container, an inner flexible bag positioned in the outer rigid container and defining a space therebetween where the inner flexible bag contains an additive without a refrigerant, a valve in fluid communication with the inner flexible bag, an actuator operably coupled to the valve, and a propellant sealed within the space, where the inner flexible bag has a device pressure that allows flow of the additive into a refrigerant circuit when the actuator is depressed. Other embodiments are disclosed.

Abstract: The invention provides a heat transfer composition comprising: (i) trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)); (ii) a second component selected from difluoromethane (R-32), propene (R-1270)propane (R290) and mixtures thereof; (iii) a third component selected from pentafluoroethane (R-125), 1,1,1,2-tetrafluoroethane (R-134a), and mixtures thereof; and optionally (iv) a fourth component selected from fluoroethane (R-161), 1,1-difluoroethane (R-152a) and mixtures thereof.

Abstract: Heat transfer compositions and methods including (a) HFC-32; (b) HFO-1234ze; and (c) either or both of HFC-152a and/or HFC-134a.

Abstract: The invention relates to a composition comprising: a heat-transfer fluid comprising from 15% to 30% ammonia and from 70% to 85% 2,3,3,3-tetrafluoropropene; and a lubricant oil comprising a polyalkylene glycol. The invention also relates to the use of ammonia for increasing the miscibility of 2,3,3,3-tetrafluoropropene with the polyalkylene glycol, and vice versa.

Abstract: A system is provided and may include a refrigeration circuit having a condenser, a first sensor producing a signal indicative of a detected condenser temperature of the condenser, and processing circuitry in communication with the first sensor. The processing circuitry may determine a derived condenser temperature independent from information received from the first sensor and may compare the derived condenser temperature to the detected condenser temperature to determine a charge level of the refrigeration circuit.

Abstract: A refrigerant charging method for an air conditioning device in which carbon dioxide is used as a refrigerant includes a connecting step and a refrigerant charging step. In the connecting step, a cylinder containing the refrigerant is connected to a space in the air conditioning device intended to be charged by the refrigerant. A heater is interposed between the cylinder and the air conditioning device. In the refrigerant charging step, the refrigerant is moved to the intended charging space from the cylinder, via the heater. In the refrigerant charging step, further, the refrigerant that has exited the cylinder is heated by the heater so that a specific enthalpy of the refrigerant when it enters the intended charging space will be 430 kJ/kg or higher.

Abstract: A method for determining a level of refrigerant charge in a vapor compression system having a compressor, a condenser, an expansion device and an evaporator operatively connected in serial relationship in a refrigerant flow circuit having a refrigerant, includes receiving information indicative of at least one of a compressor torque or compressor current; and determining whether the refrigerant charge is within a defined tolerance or whether the refrigerant is to be added or recovered in response to the receiving of the information.

Abstract: Compositions, methods and systems which comprise or utilize a multi-component mixture comprising: (a) HFC-32; (b) HFC-125; (c) HFO-1234yf and/or HFO-1234ze; (d) HFC-134a. In certain non-limiting aspects, such refrigerants may be used as a replacement for R-404A.

Abstract: A renewal method of an air-conditioning unit for vehicle in which an air-conditioning unit using a former refrigerant disposed in a frame mounted on a vehicle is renewed to an air-conditioning unit using an alternative refrigerant, the renewal method including a removal step of: a removing the existing air-conditioning unit from the frame; an assembly step of disposing the new air-conditioning unit, which is configured so as to be capable of fitting in the frame, in the frame; and a filling step of filling the alternative refrigerant into the new air-conditioning unit. The circulating amount of refrigerant in the new air-conditioning unit is increased so as to be larger than that in the previous air-conditioning unit, and the heat exchange capacity per unit volume of each of the indoor heat exchanger and the outdoor heat exchanger is made larger than that before the renewal.

Abstract: The invention provides a heat transfer composition comprising (i) a first component selected from trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), cis-1,3,3,3-tetrafluoropropene (R-1234ze(Z)) and mixtures thereof; (ii) carbon dioxide (R-744); and (iii) a third component selected from propylene (R-1270), propane (R-290), n-butane (R-600), isobutane (R-600a), and mixtures thereof.

Abstract: The invention provides a heat transfer composition comprising (i) a first component selected from trans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), cis-1,3,3,3-tetrafluoropropene (R-1234ze(Z)) and mixtures thereof; (ii) carbon dioxide (R-744); and (iii) a third component selected from 2,3,3,3-tetrafluoropropene (R-1234yf), 3,3,3-trifluoropropene (R-1243zf), and mixtures thereof.

Abstract: Refrigerant charging systems and methods of use are described herein. A refrigerant charging system may include a conduit, a valve releasably connectable to the outlet portion and coupled to a first end of the conduit; and a disconnect coupler fitting connected to a second end of the conduit. The disconnect coupler fitting may include a control structure positioned in a hollow body that, during use, allows refrigerant flow to the refrigerant circuit. The control structure may include one or more openings that allow controlled leakage of fluid from the refrigerant charging assembly when the refrigerant charging assembly is disconnected from at least the refrigerant service unit.

Abstract: An apparatus and methodology are provided for advantageously increasing heat transfer between the evaporator/oil separator (“accumulator”) and condenser of a refrigerant recovery/recycling system, to increase the efficiency of the system and to simplify the system. Embodiments include a refrigerant recovery/recycling device comprising a compressor having a suction inlet and a discharge outlet; an accumulator fluidly connected to a refrigerant source and to the compressor suction inlet; a recovery tank fluidly connected to the compressor discharge outlet; and a heat exchanger for transferring heat from the recovery tank to the accumulator, for raising the temperature of the accumulator and lowering the temperature of the recovery tank.

Abstract: An air conditioning system has a controller and a receiver located between an indoor and outdoor units. The receiver serves as an auxiliary reservoir for refrigerant. The controller generates signals to adjust the amount of refrigerant to be stored in this reservoir as a way of adjusting the amount of refrigerant flowing in the system during various modes of operation. By increasing or decreasing the amount of refrigerant in the receiver, the controller may achieve or maintain a desired level of performance and/or efficiency.

Abstract: An air conditioner refrigerant circuit performs a cooling operation in which an outdoor heat exchanger functions as a condenser of the refrigerant compressed in a compressor and an indoor heat exchanger functions as an evaporator of the refrigerant condensed in the outdoor heat exchanger. Further, an outdoor expansion valve is disposed at a position that is at once downstream of the outdoor heat exchanger and upstream of a liquid refrigerant communication pipe in the refrigerant flow direction in the refrigerant circuit in the cooling operation, and shuts off the refrigerant flow. A refrigerant detection unit is disposed upstream of the outdoor expansion valve and detects the amount or the amount-related value of refrigerant accumulated upstream of the outdoor expansion valve.

Abstract: Provided is a method for selecting a lubricant and a refrigerant for use in a vapor-compression refrigeration device such that the combination of the lubricant and refrigerant produces a fluid system having a lubricant-rich phase and a refrigerant-rich phase, yet exhibits miscible-type properties.

Abstract: A process and system for storing and recovering a secondary refrigerant such as carbon dioxide in a secondary loop refrigeration system after a shutdown of the primary refrigeration system using ionic liquids is described. The process eliminates the release of the secondary refrigerant into the environment and the need to recharge the secondary loop after a shutdown of the primary refrigeration system.

Abstract: An air conditioner includes a first flow rate regulator for controlling an amount of refrigerant supplied into a receiver, a second flow rate regulator for controlling an amount of refrigerant introduced from the receiver into a gas/liquid separator, a first detection unit for detecting an amount of refrigerant stored in the receiver, and a control unit for controlling an opening degree of the first or second flow rate regulator, based on information of at least one of the amount of refrigerant detected by the first detection unit and an amount of refrigerant circulating in the air conditioner.