A heat transfer system and method for controlling heat transfer to and from a container having thermal insulation disposed with respect to said container or compartment so as to inhibit the flow of heat into and/or out of the compartment, said insulation comprising a polymeric material having closed cells therein wherein said cells are formed from and/or contain a haloalkene according to Formula IA: where each R is independently Cl, F, H, or CF3, provided that the total number of carbon atoms is either 3 or 4, R′ is (CR2)nY, Y is CF3 and n is 0 or 1; and a heat transfer system for adding and/or removing heat from the compartment or container by use of a heat transfer fluid comprising a haloalkene Formula IB: where each R is independently Cl, F or H R′ is (CR2)nY, Y is CF3 and n is 0 or 1.