Presents the results of an experimental evaluation of enhancing the dehumidification performance of a heat pipe heat recovery unit by incorporating a liquid desiccant dehumidification function. A commercial heat pipe thermal recovery unit with an indirect evaporative cooling feature was modified by incorporating a liquid desiccant contacting/recirculation loop on the supply-air side. Two liquid desiccants, lithium chloride (LiCl) and triethylene glycol (TEG) solutions, were tested in this device. The cooling capacity of the heat pipe with desiccants increased 20% to 40%. The cooling performance of the heat pipe system using TEG was about 10% less than when using LiCl. The efficiency of the dehumidification operation was estimated to be only on the order of 40% to 50% of the equilibrium dehumidification potential because of less-than-optimum gas/liquid contact. Further research and development could improve this performance into the 80% to 90% range. The outcome suggests that the liquid-desiccant-enhanced heat pipe device could be a viable system for preconditioning ventilation air.

KEYWORDS: year 1995, calculating, desiccants, heat pipes, ventilation, dehumidifying, performance, heat recovery, unit air conditioners, lithium chloride, testing, cooling, efficiency, experiment, comparing.