System impact of climate change is small performs efficient heating and / or cooling

The invention, in some heat transfer systems using heat transfer fluids directed to methods and compositions, its heat transfer fluid up to about 15% by weight (a) from about 0 wt% or more HCFO-1233zd, (b ) comprises HFO-1234ze or HFO-1234yf or HFC-125 of up to about 20 wt% more combinations thereof, and (c) than about 0 wt%, from about 65 wt% to less than about 100 wt%, wherein the weight percents being based on the total amount of components in the composition (a) ~ (c). .BACKGROUND