Desiccant Dehumidification Performance Lessons

摘要

Desiccant dehumidification is primarily a non-residential end-use technology that can be important to certain commercial businesses such as restaurants, hotels, grocery stores and hospitals; in public buildings such as courthouses, jails, and auditoriums; and in manufacturing sectors such as pharmaceuticals and microelectronics. This rigorous case study presents the results of the field test and the performance evaluation of a typical, commercially available, two-wheel gas-fired desiccant air conditioner. Field-measured performance is compared with the manufacturer's specifications, with predictions made using DOE-2 hourly modeling, with all-electric technologies, and with the theoretical limits of the technology. Comparisons were made between the manufacturer's published data, the manufacturer's site test data taken at the time of installation, the collected field data, the computer model, and theoretical best-case performance. The desiccant unit as installed delivers less cooling and dehumidification capacity than the manufacturer's rating, and much less than it would if the equipment design were optimized and the installation were commissioned. While the measured energy efficiency at peak load conditions is better than rated, the data show clearly that this rating is not representative of long-term field performance.