A UNIQUE APPROACH TO IAQ AND CHILLER EFFICIENCY

摘要

Most colleges are faced with the challenge of both reducing energy cost and maintaining acceptable IAQ standards. Focusing on just one of these issues can result in additional problems with the other. Emory University in Atlanta, Georgia has developed a unique approach to focusing on both problems simultaneously. Maintaining acceptable indoor air quality standards requires delivering the correct mix of properly treated outside air and re-circulated air. Proper moisture removal of both air streams requires chill water to be delivered to the AHU at a temperature and flow rate that insures proper leaving coil conditions. New standards requiring higher levels of outside air can place higher loads on the air handling apparatus and if not properly dealt with will result in unacceptable leaving coil conditions. Emory's approach to the problem is to monitor chiller performance using a web based chiller efficiency monitoring program called Chiller-Check as well as monitoring AHU performance to insure proper moisture removal and adequate leaving coil conditions. The chillers are logged three times a week using a PDA. The data is then sent to a website which analyses the data and identifies efficiency problems. Loss of efficiency can result in loss of capacity, which may result in leaving water temperatures higher than required for proper air treatment. Air handlers are inspected periodically to insure proper air and water flow, coil surface condition, and that control systems are working properly. When chillers operate efficiently and deliver design water temperatures, and AHU's are properly maintained, energy costs and IAQ problems are both reduced.