01 September 1995
Natural working fluids such as ammonia, hydrocarbons, carbon dioxide, water and air, receive growing attention as sound, long-term replacements for the CFCs and HCFCs that are commonly used in today’s air conditioners, heat pumps and refrigeration equipment. As natural substances they not only pose no risk to the ozone layer, they also present little or no other threat to the environment.
In practice, the application of natural working fluids can be difficult. Some are toxic or flammable and additional costs can be incurred. Furthermore, it is always important to ensure that the efficiency of equipment is not downgraded by using new working fluids, as this could result in other negative environmental consecuences. The challenge in using natural working fluids is to build safe and reliable systems, that are equal to or better than alternative systems in terms of both costs and energy efficiency. Annex 22 of the IEA Heat Pump Programme, “Compression Systems with Natural Working Fluids”, is the international Energy Agency’s response to this challenge. The eight member countries of this Annex aim to stimulate technology development, accelerate application, and expand knowledge an the “naturals”. One element of the work of Annex 22 is to organize workshops in close collaboration with the IEA Heat Pump Centre. These proceedings report on the first one of these,which focused on applications, experiences and developments. The proceedings provide a broad overview of the latest development, and reflect the stimulating exchange of views between market parties, researchers and policy makers necessary to advance the application and applicability of natural working fluids.