Using simulation to validate and optimise the design of a hybrid solar-GCHP system

Detailed TRNSYS simulations are used to validate and optimize the design of a hybrid ground-coupled heating plant including solar thermal collectors in three buildings (187 housing units total). The HVAC system design is constrained by several factors, including pre-existing equipment and funding opportunities for particular options. The TRNSYS simulation uses building loads that were calculated in an earlier stage of the design process with DOE-2. In order to use realistic temperature levels, a global heat exchange coefficient for radiators and floor heating is estimated. The long-term system performance is analyzed for the selected design, which does not follow conventional design rules. The system provides 33% of the total heating load from renewable energy on a yearly basis (average performance over 20 years of operation).