The work of Annex 33 “Compact Heat Exchangers in Heat Pumping Equipment” within the International Energy Agency Heat Pump Programme has been completed. The principal goal of the Annex was to identify compact heat exchangers (CHEs), either existing or under development, that may be applied in heat pumping equipment. The aim has been to reduce the possible direct and indirect effects of the systems on the global and local environments by decreasing the working fluid inventory, minimising the environmental impact of system manufacture and disposal, and/or increasing the system performance during the equipment life.
Moreover, to promote and simplify the commercial use of CHEs by heat pump manufacturers, a second goal was to identify, propose and document methods of predicting heat transfer, pressure drop and void fractions in CHEs, while a third goal was to present listings of operating limits etc. for the different types of CHEs.