A composition including between 4 and 6 wt. % of difluoromethane, between 2.5 and 3.5 wt. % of pentafluoroethane, and between 91 and 93.5 wt. % of tetrafluoropropene. The use of the composition as replacement for R404A, R452A, R22, R134a, R245fa, R152a, R422, R502, R407A, R407F, R407C, R1234yf or R1234ze. A heat-transfer composition including the composition and at least one additive chosen from nanoparticles, stabilizing agents, surfactants, tracing agents, fluorescent agents, odorous agents, lubricants, and solubilizing agents.

A heat source unit and a refrigeration cycle apparatus that are able to reduce damage to a connection pipe when a refrigerant containing at least 1,2-difluoroethylene is used are provided. An outdoor unit (20) that is connected via a liquid-side connection pipe (6) and a gas-side connection pipe (5) to an indoor unit (30) including an indoor heat exchanger (31) and that is a component of an air conditioner (1) includes a compressor (21) and an outdoor heat exchanger (23). A refrigerant containing at least 1,2-difluoroethylene is used as a refrigerant. A design pressure of the outdoor unit (20) is lower than 1.5 times a design pressure of each of the liquid-side connection pipe (6) and the gas-side connection pipe (5).

The present invention relates to a composition comprising HFO-1234yf, or trans-HFO-1234ze, or a mixture thereof; HFC-32; and HFC-152a, HFO-1243zf, or a mixture thereof, wherein said composition is selected from the group consisting of: (I) a first composition, wherein said HFO-1234yf or trans-HFO-1234ze or a mixture thereof is at least 56 weight percent of said first composition; (II) a second composition, wherein said HFC-32 is at most 29 weight percent of said second composition; (III) a third composition, wherein said HFC-152a is at least 56 weight percent said third composition; (IV) a fourth composition, wherein said HFC-32 is at least 56 weight percent of said fourth composition; (V) a fifth composition comprising trans-HFO-1234ze, HFC-32, and HFC-152a, HFO-1243zf, or a mixture thereof; and (VI) a sixth composition, wherein said HFO-1243zf or mixture thereof with HFC-152a is at most 20 weight percent of said sixth composition.

In accordance with the present invention refrigerant compositions are disclosed. The compositions comprise HFC-32, HFC-125, HFO-1234yf, HFC-134a, and CO.sub.2. The refrigerant compositions are useful in processes to produce cooling and heating, in methods for replacing refrigerant R-410A or R-22, and in refrigeration, air conditioning or heat pump systems. These inventive compositions are non-flammable and match cooling performance for R-22 and R-410A within 15%. Additionally, these compositions may serve as replacements for R-404A, R-507, R407A, R407C and/or R-407F in refrigeration, air conditioning or heat pump systems. The compositions as described herein have unexpected flammability properties.

An air conditioning unit capable of performing a refrigeration cycle using a small-GWP refrigerant is provided. A refrigeration cycle apparatus (1, 1a to 1m) includes a refrigerant circuit (10) including a compressor (21), a condenser (23, 31, 36), a decompressing section (24, 44, 45, 33, 38), and an evaporator (31, 36, 23), and a refrigerant containing at least 1,2-difluoroethylene enclosed in the refrigerant circuit (10).

There is provided a refrigeration cycle apparatus in which good lubricity can be achieved when a refrigeration cycle is performed using a refrigerant having a sufficiently low GWP. The refrigeration cycle apparatus contains a refrigerating oil and a refrigerant composition containing a refrigerant containing trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), and 2,3,3,3-tetrafluoro-1-propene (R1234yf).

High power of a compressor that compresses a mixed refrigerant containing at least 1,2-difluoroethylene is achieved. A compressor (100) employs an induction motor (70) as a motor that drives a compression unit (60) that compresses a mixed refrigerant containing at least 1,2-difluoroethylene, and thus, high power is enabled at comparatively low costs.

High efficiency of a compressor that compresses a mixed refrigerant containing at least 1,2-difluoroethylene is achieved. A compressor (100) includes a motor (70) that has a rotor (71) including permanent magnets (712) and thus is suitable for a variable capacity compressor in which the number of rotations of the motor can be changed. In this case, it is possible to change the number of rotations of the motor in accordance with an air conditioning load in an air conditioner (1) that uses a mixed refrigerant containing at least 1,2-difluoroechylene. It is thus possible to enable high efficiency of the compressor (100).

A heat exchange unit is provided with which, even if a flammable refrigerant is used, the likelihood of the refrigerant reaching an electric component unit is reduced. An outdoor unit (20) constitutes a portion of an air-conditioning apparatus (1), and is connected to an indoor unit (30) via a liquid-side refrigerant connection pipe (6) and a gas-side refrigerant connection pipe (5). The outdoor unit (20) includes an outdoor housing (50), an outdoor heat exchanger (23) disposed inside the outdoor housing (50) and in which a refrigerant flows, a liquid-side shutoff valve (29) connected to the liquid-side refrigerant connection pipe (6), a gas-side shutoff valve (28) connected to the gas-side refrigerant connection pipe (5), and an outdoor electric component unit (8) disposed inside the outdoor housing (50). The refrigerant is a flammable refrigerant containing at least 1,2-difluoroethylene. When the outdoor unit (20) is in its installed state, the lower end of the outdoor electric component unit (8) is positioned above the liquid-side shutoff valve (29) and the gas-side shutoff valve (28).

An air conditioning apparatus 1 includes a compressor (321), an indoor heat exchanger (242) that is a use-side heat exchanger that exchanges heat with first air (F1), an outdoor heat exchanger (323) that is a heat-source-side heat exchanger that exchanges heat with second air, a refrigerant, a first duct (209), and a casing (230). The refrigerant contains at least 1,2-difluoroethylene, and circulates in the compressor (321), the indoor heat exchanger (242), and the outdoor heat exchanger (323) to repeat a refrigeration cycle. The first duct (209) supplies the first air (F1) to a plurality of rooms in an interior. The casing (230) includes a use-side space (SP2) that is connected to the first duct (209) and that accommodates the indoor heat exchanger (242). The casing (230) is configured to allow the first air (F1) after heat exchange with the refrigerant at the indoor heat exchanger (242) to be sent out to the first duct (209).