Occupancy Based Heating/Cooling for Low Energy Affordable Housing in Hot-Humid Climates

This study investigates the energy saving potential of occupancy based heating/cooling in affordable houses in hot and humid climates. For this purpose, a Habitat for Humanity (HFH) house located in Bryan, Texas is modeled as the base case. The energy performance of this house is then improved by applying a new HVAC design strategy i.e. partial conditioning (reuse of air) using an incremental four step approach. First, the base-case house is modified into an atrium house by converting the transitional spaces (i.e. corridors, hallways and entrance) into a central atrium. Second, the house is divided into zones and temperature setbacks are applied during the unoccupied hours of each zone. Third, the atrium of the house is used as a return plenum of the house. Fourth, the air returning from the occupied zones is sent to the unoccupied zones before it is dumped into the atrium. In this study, EnergyPlus is used with Radiance and TRNSYS programs for more accurate calculation of daylight and slab-on-grade heat transfer respectively. Results shows that partial conditioning strategy provides 24% additional savings to the atrium house and 28% overall savings to the base case HFH house while successfully meeting the setpoints.