An outdoor unit includes an indication cover including a cover portion on which at least one of a type of refrigerant employed and a caution are marked, the cover portion being disposed so as to cover a hexagonal column-shaped outer circumference of a sealing hexagon nut, a ring portion attached to a gas-side valve which is the refrigerant pipe connection valve, and a joint portion formed so as to be bendable and connecting between the cover portion and the ring portion.

Methods and systems for removing moisture from a refrigerant can utilize a desiccant-based system. The methods and systems can be employed in conjunction with a liquid natural gas (LNG) refrigeration circuit in either an online mode or an offline mode. For example, a system for removing moisture from a refrigerant can include: a refrigerant source; a moisture removal unit containing desiccant; and a refrigeration circuit comprising a refrigerant compressor, a refrigerant condenser, and a heat exchanger that are fluidly connected in a loop, wherein the refrigerant source is fluidly coupled to the moisture removal unit to supply a refrigerant from the refrigerant source to the moisture removal unit, and the moisture removal unit is fluidly coupled to the refrigeration circuit to supply the refrigerant from the moisture removal unit to the refrigeration circuit.

An air conditioning service system includes an accumulator defining an accumulator chamber, a pressure transducer operably connected to the accumulator chamber, a drain valve operably connected to the accumulator chamber, and a controller operably connected to the pressure transducer and the drain valve. The controller includes a processor configured to execute program instructions stored in a memory to determine a volume of liquid drained from the accumulator by: determining a volumetric flow rate of liquid through the drain valve by controlling the drain valve with the controller to an open position for a predetermined period of time; detecting an increased rate of pressure reduction while the drain valve is open; and determining an amount of liquid drained through the drain valve based upon the volumetric flow rate and a total time elapsed between opening the drain valve and the increased rate of pressure reduction.

An air conditioning service system includes an accumulator defining an accumulator chamber, a pressure transducer operably connected to the accumulator chamber, a drain valve operably connected to the accumulator chamber, and a controller operably connected to the pressure transducer and the drain valve. The controller includes a processor configured to execute program instructions stored in a memory to determine a volume of liquid drained from the accumulator by: determining a volumetric flow rate of liquid through the drain valve by controlling the drain valve with the controller to an open position for a predetermined period of time; detecting an increased rate of pressure reduction while the drain valve is open; and determining an amount of liquid drained through the drain valve based upon the volumetric flow rate and a total time elapsed between opening the drain valve and the increased rate of pressure reduction.

Disclosed herein is a method for producing cooling comprising evaporating a liquid refrigerant comprising (a) E-CF.sub.3CH═CHF and (b) at least one tetrafluoroethane of the formula C.sub.2H.sub.2F.sub.4; provided that the weight ratio of E-CF.sub.3CH═CHF to the total amount of E-CF.sub.3CH═CHF and C.sub.2H.sub.2F.sub.4 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-CF.sub.3CH═CHF and (b) at least one tetrafluoroethane of the formula C.sub.2H.sub.2F.sub.4; provided that the weight ratio of E-CF.sub.3CH═CHF to the total amount of E-CF.sub.3CH═CHF and C.sub.2H.sub.2F.sub.4 is from about 0.05 to 0.99. Also disclosed herein is a chiller apparatus for cooling, said apparatus containing a working fluid comprising a refrigerant comprising (a) E-CF.sub.3CH═CHF and (b) at least one tetrafluoroethane of the formula C.sub.2H.sub.2F.sub.4; provided that the weight ratio of E-CF.sub.3CH═CHF to the total amount of E-CF.sub.3CH═CHF and C.sub.2H.sub.2F.sub.4 is from about 0.05 to 0.99.

A variable refrigerant volume system and control method thereof. The variable refrigerant volume system comprises: a compressor (1); a four-way valve (19); an indoor unit; a liquid tube (22), the first end thereof being connected to the indoor unit, the second end thereof being connected to the third valve port of the four-way valve (19), and a condenser (18) being provided on the liquid tube (22); a low pressure air pipe (23), the first end thereof being connected to the indoor unit, and the second end thereof being connected to the fourth valve port of the four-way valve (19); a refrigerant adjustment tank (6), the first port thereof being connected to the liquid tube (22), the second port thereof being connected to the low pressure air pipe (23), and the third port thereof optionally communicating with the liquid tube (22) or the low pressure air pipe (23). The refrigerant adjustment tank (6) provides refrigerant to the variable refrigerant volume system when the system requires more refrigerant, and recycles refrigerant from the variable refrigerant volume system when the system requires less refrigerant. The variable refrigerant volume system can flexibly control a refrigerant recycling amount in accordance with a refrigerant operation situation, thus ensuring system reliability.

Methods, systems and apparatuses are described that are directed to on-site recovery and/or repurposing of refrigerant, where an original refrigerant is converted into a refrigerant different from the original refrigerant. The refrigerant different from the original refrigerant can have relatively lower global warming potential (GWP) than the original refrigerant. The recovery and/or repurposing can be implemented for example in a refrigeration circuit, such as for example in general cooling and/or heating applications, which may be embodied in a heating, venting, and air conditioning (HVAC) system and/or unit, in a transport refrigeration system and/or unit, as well as in commercial, residential and/or industrial cooling and/or heating applications.

Methods, systems and apparatuses are described that are directed to on-site recovery and/or repurposing of refrigerant, where an original refrigerant is converted into a refrigerant different from the original refrigerant. The refrigerant different from the original refrigerant can have relatively lower global warming potential (GWP) than the original refrigerant. The recovery and/or repurposing can be implemented for example in a refrigeration circuit, such as for example in general cooling and/or heating applications, which may be embodied in a heating, venting, and air conditioning (HVAC) system and/or unit, in a transport refrigeration system and/or unit, as well as in commercial, residential and/or industrial cooling and/or heating applications.

An indoor unit includes an air-sending fan, an air inlet through which air of an indoor space is sucked in, and an air outlet located above the air inlet and through which the air sucked in through the air inlet is blown out to the indoor space. A control unit activates the air-sending fan when leakage of the refrigerant is detected. When M [kg] represents an amount of charge of the refrigerant in a refrigeration cycle, LFL [kg/m.sup.3] represents a lower flammable limit of the refrigerant, A [m.sup.2] represents a floor area of the indoor space, and Ho [m] represents a height of the air outlet above a floor surface of the indoor space, the amount of charge M, the lower flammable limit LFL, the floor area A, and the height Ho satisfy a relationship of M<LFL×A×Ho.

An indoor unit includes an air-sending fan, an air inlet through which air of an indoor space is sucked in, and an air outlet located above the air inlet and through which the air sucked in through the air inlet is blown out to the indoor space. A control unit activates the air-sending fan when leakage of the refrigerant is detected. When M [kg] represents an amount of charge of the refrigerant in a refrigeration cycle, LFL [kg/m.sup.3] represents a lower flammable limit of the refrigerant, A [m.sup.2] represents a floor area of the indoor space, and Ho [m] represents a height of the air outlet above a floor surface of the indoor space, the amount of charge M, the lower flammable limit LFL, the floor area A, and the height Ho satisfy a relationship of M<LFL×A×Ho.