A cryocooler includes: a magnetic shield axially extending along a second-stage cylinder from a second-stage cooling stage outside the second-stage cylinder and disposed separated from a first-stage cooling stage by an axial separation distance, wherein an annular space open to a helium atmosphere is formed between the second-stage cylinder and the magnetic shield, and the axial depth of the annular space is longer than the axial separation distance; and a convection suppression member, for suppressing axial convection of helium gas in the annular space caused by temperature difference between the second-stage cylinder and the magnetic shield, is disposed in the annular space and is of longer axial length than the axial separation distance.

A control method for a refrigerator, comprises sensing a temperature of a storage room; operating a cool air supply means at a cooling power when the sensed temperature of the storage room is equal to or above a first reference temperature; operating the cool air supply means at a delay power, which is less than the cooling power, when the sensed temperature of the storage room is equal to or below a second reference temperature, which is less than the first reference temperature while the cool air supply means is operating at the cooling power; and allowing a control unit to determine a cooling power or a delay power of the cool air supply means according to the temperature of the storage room while the cool air supply means is operating at the delay power, and operating the cool air supply means at the determined cooling power or delay power.

A refrigeration cycle apparatus includes a compressor to compress a working fluid containing 1,1,2-trifluoroethylene. The compressor includes a compression unit which compresses the working fluid, a driving unit which drives the compression unit, a power supply terminal which supplies electric power from an outside of the compressor to an inside of the compressor, and a plurality of lead wires which electrically connects the driving unit to the power supply terminal. Each of the plurality of lead wires is covered with an insulating material having heat resistance of 300 C. or more at least in a part where the lead wires are bundled.

A refrigeration apparatus includes: a casing that houses a compressor therein; a four-way switching valve; an accumulator; a first pipe that causes a refrigerant to flow between the four-way switching valve and a discharge portion of the compressor; and a second pipe that causes a refrigerant to flow between the four-way switching valve and the accumulator. The four-way switching valve, the first pipe, and the second pipe are all made of stainless steel.

A phase change compressor cover may include a first layer configured to provide sound attenuation from undesirable noise produced as a result of operating a compressor and/or thermal isolation of the compressor and a second layer comprising a cavity filled with a phase change material that is configured to absorb heat discharged as a result of operating the compressor and subsequently discharge the absorbed heat onto the compressor in response to discontinuing operation of the compressor to keep the compressor warm and prevent refrigerant migration to the compressor. The phase change compressor cover may be used to substantially envelope the compressor in a heat pump heating, ventilation, and/or air conditioning (HVAC) system.

A direct evaporative cooler includes a liquid delivery system and an assembly of two or more plates. At least one plate of the assembly of two or more plates may include a top surface having a wicking material with an exposed surface for receiving a liquid thereon from the liquid delivery system, and one or more masks lining a portion of the exposed surface. The one or more masks may be impermeable to the liquid thereby preventing the liquid from evaporating through the one or more masks, and the one or more masks may be sized and shaped such that a wick rate of the liquid on the exposed surface exceeds an evaporation rate of the liquid.

An insulating material that tends not to hydrolyze is used to thereby provide a heat pump apparatus having long-term reliability. An electric motor of a compressor is fixed to a sealed container and includes a stator around which a winding wire is wound through intermediation of an insulating material, and a rotor surrounded by the stator. The insulating material is a wholly aromatic liquid crystal polyester (LCP) having a molecular main chain constituted by a monomer including p-hydroxybenzoic acid (PHB) as an essential monomer and a monomer solely including benzene-ring as another monomer via an ester bond. The refrigerating machine oil has a saturated water content of 2% or less at 40 degrees C., a relative humidity of 80%, for 24 Hr. To suppress the explosive decomposition reaction of ethylene-based fluorohydrocarbon, a flame retardant is used to generate chemical species that complement active radicals that cause the decomposition reaction.

A heat pump device includes a compression mechanism for compressing refrigerant, a motor for driving the compression mechanism, a shell housing the compression mechanism and the motor, a discharge muffler located outside the shell, a first pipe connecting the compression mechanism to the discharge muffler, and a thermal insulator (a first thermal insulating material and a second thermal insulating material). The shell and the discharge muffler are spatially located next to each other without being in contact with each other. The thermal insulator is at least partially located in a space where a distance between an outer surface of the shell and an outer surface of the discharge muffler is minimum.

An insulating material that tends not to hydrolyze is used to thereby provide a heat pump apparatus having long-term reliability. An electric motor of a compressor is fixed to a sealed container and includes a stator around which a winding wire is wound through intermediation of an insulating material, and a rotor surrounded by the stator. The insulating material is a wholly aromatic liquid crystal polyester (LCP) having a molecular main chain constituted by a monomer including p-hydroxybenzoic acid (PHB) as an essential monomer and a monomer solely including benzene-ring as another monomer via an ester bond. The refrigerating machine oil has a saturated water content of 2% or less at 40 degrees C., a relative humidity of 80%, for 24 Hr. To suppress the explosive decomposition reaction of ethylene-based fluorohydrocarbon, a flame retardant is used to generate chemical species that complement active radicals that cause the decomposition reaction.

A pipe unit is provided for a refrigerant circuit which performs a vapor compression refrigeration cycle by circulating a refrigerant. The pipe unit includes a pipe body having a liquid pipe through which a liquid refrigerant for the refrigerant circuit flows and a gas pipe through which a gaseous refrigerant for the refrigerant circuit flows; and a heat insulator covering each of the liquid pipe and the gas pipe separately. The liquid pipe and the gas pipe, each of which is covered with the heat insulator, are fixed together to form a single piece. Such partial unitization of the refrigerant circuit allows for reduction in the number of days required for installation of an air conditioner.