EMISSIONS AND ENVIRONMENTAL IMPACTS FROM CHILLERS

The impacts of air conditioning and refrigeration systems on stratospheric ozone are primarily linked to release of ozone-depleting refrigerants. Their contributions to global warming stem both from release of refrigerants and from emission of greenhouse gases by associated energy use. Because the energy-related component has a higher or dominant warming impact, phaseout of the refrigerants in current use with less efficient options will have the opposite effect to that intended, namely to increase net greenhouse gas emissions. Integrated assessment of ozone depletion, global warming, and atmospheric lifetime provides essential indications in the absence of ideal refrigerants, namely those free of these problems as well as safety, stability, compatibility, cost, and similar burdens. This paper examines the trend in refrigerant losses from chiller use. It documents both substantial progress in release reductions and the technical innovations to achieve them. It contrasts the impacts of current hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants with alternatives and with the chlorofluorocarbons (CFCs) they replaced. The paper also summarizes thermodynamic and environmental comparisons of options to show that phaseout decisions based on chemical composition alone, without regard to attributes of individual substances, may result in greater environmental harm than benefit.