Glossary of Terms
Absorptive cooling
An advanced cooling system using natural gas instead of electricity to drive the refrigerant cycle. The reduced electrical load during peak cooling times of the day lessens demand charges from the utility and reduces reliance on the utility grid. Hybrid systems can use either a conventional electrical compressor or a natural-gas-fired, engine-driven compressor. There are several efficiency levels of absorptive chillers, measured as COP (Coefficient of Performance) – the refrigerant effect output divided by the heat input. Single-effect units have efficiencies of 60% to 80%, and often use industrial waste heat as their energy source. Double-effect units can have a COP of 1.0. This technology also has other benefits: no CFC refrigerants, low maintenance, and low repair costs. The technology is not, however, as well developed or field proven as conventional electrical compressors. Absorptive cooling systems range in size from 3ton to 1700 ton capacity.
