The retrofit of dual-duct, constant-volume systems to variable-air-volume systems has become common in recent years. Air-handler measurements can be used to explain the degree to which such retrofits do not provide expected operating savings. A dual-duct constant-volume air handler in a large engineering centre in central Texas that was retrofitted to a variable-air-volume system in March 1991 has been instrumented to monitor temperature and relative humidity at various locations, air flow rate, pressure drop, electric consumption of the fan motor, and runtimes of the hot and chilled-water pumps. The monitored data from the air handler prior to retrofit are presented. Significant differences between design performance and measured hot deck and cold deck temperatures and outdoor air fraction as a function of outdoor temperature were found. The measured data are also compared with the predictions of a partially calibrated simplified systems model based on the TC 4.7 simplified energy analysis procedure (Knebel 1983).
KEYWORDS: monitoring, air handling units, performance, comparing, modernising, dual duct air conditioning, constant volume air conditioning, variable volume air conditioning, measuring, USA, relative humidity, temperature, air flow rate, pressure drop, electricity consumption, fans, motors, heat load, cooling load
Citation: Symposium Papers, Baltimore, MD, 1992
Product Details
- Published:
- 1992
- File Size:
- 1 file , 1.3 MB
- Product Code(s):
- D-17822
