Development and Validate an Occupant-Centric Control of An Integrated Air and Domestic Hot Water System for Residential Buildings

New York State has over 750,000 residential units with inefficient HVAC and domestic hot water supplies. The potential for energy saving through occupancy control of ventilation and hot water system varies from 5% to 20%. In this study, we investigated the energy saving of occupancy control for an integrated air and domestic hot water system that could meet all the heating, cooling, and ventilation requirements for a single-family residential unit. We first collected the outdoor weather data, and air temperature and heating load or each room of a lab-based house equipped with this system at Syracuse University. Then, we built the thermal resistance-capacitance (RC) network model of this residential unit. It contained four thermal zones with a living room, two bedrooms and a bathroom. Next, we implemented the room occupancy profiles to each room for occupancy control. The occupancy control enabled the ventilation system work to meet the temperature set point only when the room was occupied. The measured and simulated results showed that the there was around 13% heating and 35% cooling energy reduction compared to the energy consumption with the conventional fiexed point control. The total cost for this occupancy control system was about $212 and the payback period was about 0.25 years.The future work includes implementing the occupancy control for this system with hot water usage in actual residential unit to further test the performance.