Modeling and Validation of Building Thermal Performance of the 2007 Santa Clara University Solar Decathlon House Available to Purchase

Sustainability is an issue of great importance in the building and energy sectors. In the United States, about 40% of total energy use is in buildings, 30% of raw materials are used in buildings, 30% of waste outputs come from buildings, 30% of greenhouse gas emissions are attributed to buildings, and 12% of potable water consumption occurs in buildings. Thus, there is a great necessity for the rapid deployment of highly sustainable buildings that are aesthetic and reliable. Solar houses are highly sustainable and can be designed to be reliable by using streamlined technologies, providing as much power as needed, and by minimizing the energy usage within the building. The US DOE Solar Decathlon offered a great opportunity to test these criteria which were at the same time the fundamental elements taken into consideration when designing the Santa Clara University (SCU) solar house in 2007 [1]. In this research the SCU solar decathlon solar house energy and thermal performances were analyzed. The energy and thermal loads were modeled using EnergyPlus™ software which helps to perform detailed modeling of the energy and thermal performances of buildings. The conditioned space of the building consists of two rectangular shaped zones, the living room and the bedroom, which together are approximately 45ft along the east-west direction and 11ft wide. Wood framing with R-19 insulation, made from recycled jeans, was used for the walls. The roof and the floor are constructed of a bamboo wood frame with foam insulation. Daylighting was maximized through active windows (i.e. electro-chromic), energy efficient appliances were incorporated along with solar thermal air conditioning, heating and hot water. Performance parameters for the mechanical systems were developed from conventionally available technologies and the control set-points were based on DOE Solar Decathlon 2007 (SD07) guidelines [1]. The thermal energy design decisions for the house were based largely on a combination of the solar decathlon contest requirements and that technologies were sustainable and commercially available. The house was tested in Washington DC in October 2007 during the competition and performed excellently well ranking at the top in the following categories: energy balance, thermal comfort, and hot water. Data collected during the event provide the unique opportunity of validating the simulated energy and thermal performances of the house with weather file created from the real-time weather data. The created weather file is used to run new simulations of the SCU SD07 house, from these results we can assess the accuracy of the simulation program used. If accuracy is high enough, annual simulations are executed to demonstrate how the house would perform under extreme climatic conditions in different regions.