Simulation of High Thermal Mass Passive Solar Buildings

Thermal characteristics of a high thermal mass, passive solar, zero-heating house located in Hockerton, UK were investigated using building thermal energy simulation software SUNREL and EnergyPlus. Simulation results from both programs show that the accuracy of the predicted zone air temperatures depends on solar losses and inter-zone solar transfers in various thermal zones. SUNREL does not explicitly calculate losses and transfer between zones. As such, predicted air temperatures of the zones largely depend on user-defined solar transfer and loss fractions. EnergyPlus determines losses and inter-zone solar transfers based on the optical properties of external fenestration and transparent surfaces between zones. Depending on the massiveness of the building, annual simulations have to be carried out for a period longer than a year using the same weather data to eliminate the error associated with the thermal accumulation in the mass during the initial period of the simulation.