COST EFFECTIVE OPERATION OF HVAC SYSTEM UNDER THERMAL DISTURBANCE

Varying cooling load requirements in HVAC system become a major concern to many consumers because of the additional cost of electricity. The cooling load variation of HVAC system usually occurs when the domestic house door is frequently kept open for prolonged durations, which is particularly important in hot seasons. The present study, addresses a comparison of energy consumption due to the thermal disturbance during domestic house door keep opened for various duration when the Variable Frequency Driver (VFD) and ON/OFF controllers are installed in HVAC system. The experiments are carried out in two identical houses during six warm days in a hot season where the outdoor temperatures have similar patterns throughout the days. The energy response of HVAC system is analysed incorporating the thermal and the electricity consumption data because of the change of the indoor temperature during opening of the house main door. The cost analysis is carried out and it is extended to include several repeats of door opening durations. It is the first time demonstrated that the energy consumption for HVAC system increases dramatically when the house main door is kept opened for several times in a day. The energy consumption and additional cost increase significantly for the case when the period of the main door opening is extended. In this case, VFD A/C controller unit achieves more energy savings than that of ON/OFF A/C controller unit.