Abstract
Commercial hot water heating accounts for approximately 0.78 Quads of primary energy use with 0.44 Quads of this
amount from natural gas fired heaters. An ammonia-water based commercial absorption system, if fully deployed,
could achieve a high level of savings, much higher than would be possible by conversion to the high efficiency nonheat-pump
gas fired alternatives. In comparison with air source electric heat pumps, the absorption system is able to
maintain higher coefficients of performance in colder climates. The ammonia-water system also has the advantage
of zero Ozone Depletion Potential and low Global Warming Potential. A thermodynamic model of a single effect
ammonia-water absorption system for commercial space and water heating was developed, and its performance was
investigated for a range of ambient and return water temperatures. This allowed for the development of a
performance map which was then used in a building energy modeling software. Modeling of two commercial water
heating systems was performed; one using an absorption heat pump and another using a condensing gas storage
system. The energy and financial savings were investigated for a range of locations and climate zones in the
southern and south central United States. A follow up paper will analyze northern and north/central regions. Results
showed that the system using an absorption heat pump offers significant savings.
