This Small Business Innovation Research Phase II project seeks to discover and prove chemical additives for lithium bromide(LiBr)-water vapor absorption chillers that will significantly improve absorption rates compared to currently available additives. Current state of the art absorption chiller technology uses performance additives to increase rates of vapor absorption in order to reduce absorber size and cost. An additive meeting this goal will enable absorption chillers to be built with significantly smaller copper tube heat exchangers, resulting in reduced first costs. This in turn will allow for increased market share for absorption chillers in the air conditioning industry, and significantly enhance the competitiveness of this non-chlorofluorocarbon(CFC) alternative technology. Candidate additives will be selected based on a chemical catalysis mechanism describing their activity. Absorption rate enhancement activity will be determined using a falling film test absorption machine. Chemical stability will be verified by calorimetry and long term thermal exposure tests. In Phase II, field tests of selected additives will be performed using production machines. This technology has commercial applications in any new designs of LiBr-based absorption chillers, as well as similar chillers currently in service worldwide.