Terrill, Trevor (2015-08). A Long-Term Building Study of Energy Usage and Thermal Comfort in Religious Facilities. Master's Thesis.
Buildings represent a large portion of total US energy usage. Religious facilities, which consume a significant percentage of the total floorspace and energy usage in the commercial sector, have generally not been the focus of efficiency studies or building energy audits. Religious facilities are characterized by unique patterns of occupancy and energy use. This thesis presents the results of a long-term, in-depth energy study of architecturally similar church buildings in different climates in an effort to identify energy efficiency opportunities in religious buildings. A clear relationship between energy use and climate is evident, with HVAC and lighting systems consuming the majority of energy in the buildings. HVAC usage in the buildings show the expected pattern of increased electricity for cooling in the summer and natural gas for heating in the winter, with overall building performance comparing favorably to similar religious facilities. The energy savings from implementing temperature setbacks were experimentally verified and quantified. An analysis of faulty operational settings and equipment in HVAC systems reveal the large energy saving potential from correcting faulty conditions. The increased energy consumption of condenser units with higher outdoor temperatures is quantified experimentally. Analysis on building occupancy and lighting reveal the infrequent, yet consistent use of the building. The majority of lighting is condensed in the meeting areas and hallways. Due to the infrequent usage of the building, the energy and cost saving potential of occupancy based lighting control is limited. Two separate experimental instances demonstrate the limited energy savings associated with occupancy based lighting control. An analysis of thermal comfort reveals the overall comfort conditions of the building and main meeting areas. During winter and summer months, the buildings are often uncomfortable to many occupants, possibly from insufficient preconditioning or from occupancy during unexpected time periods. An analysis of comfort, through monitoring of CO2 levels throughout the building, highlights the need for additional outdoor air during space conditioning.