The heat transfer composition of low gwp

The present invention is based, in part, (a) about 17% to about 40 wt% of HFC-32; (b) from about 51% to about 83 wt% of tetrafluoropropene; and (c) from about 0 wt% more about 9% less CO The amount of component (c), in particular of the composition in the low or medium temperature cooling system capacity, efficiency, discharge temperature, discharge pressure, or one or more energy consumption, composition and / or refrigerant does not contain a component (c) it is to improve in comparison with R-404A. .FIELD 1