A COMPARISON OF PASSIVE SOLAR AND MECHANICALLY DRIVEN EARTH-TO-AIR HEAT EXCHANGERS FOR COOLING BUILDINGS

摘要

The research presented compares a fully passive solar driven geothermal air-conditioning strategy to an active forced air driven geothermal air-conditioning system; in either case ambient air propagates through the Earth-to-Air Heat Exchanger (EAHE) for the purpose of chilling our Solar Energy Research Testing Facility (SERTF) building, located in Bennington Nebraska. The all passive system employs two techniques namely EAHE and solar chimney. This full scale demonstration is then used to evaluate the performance of the coupled system (i.e. EAHE coupled with solar chimney) for the two cases, first: passive solar driven air flow, second: mechanically driven forced air flow, 24 hours per day. The system performance is evaluated through assessing the maximum air flow rate (CFM) and cooling (in Btu/hr, kWatts, and tons) that the system can provide to the building during hot summer time for each case study. Total Cooling Capacity of the system under these two scenarios have been calculated using standardized equations which account for latent and sensible cooling achieved. The experimental results are then compared to building cooling load coefficients generated with a simulation using the TRACE 700 software package. Thermal environmental comfort conditions for human occupancy are also evaluated using American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) standard 55-2004.