Two CHP systems at the University of Maryland are introduced in this paper, which contain both liquid and solid desiccant units recovering exhaust heat from separate prime movers. The desiccant units dry the outdoor air and supply this air to the existing rooftop units on the Chesapeake building in the place of the outdoor air that would otherwise have been drawn in. In terms of installation complexity, the liquid desiccant is more complicated because it needs a pumped heat recovery loop and cooling tower. The performance comparison between the two units is complicated by the differences in waste heat medium and supply present in both systems, but as the systems are currently set up, the liquid desiccant is more effective at reducing the total enthalpy of the process air, whereas the solid desiccant system is better at providing pure dehumidification. This paper presents and discusses the performance of the systems as installed and suggests performance improvement measures.

Units: Dual