A systematic approach to improving thermosyphon SDHW model performance

A systematic procedure is used to calibrate a computer model of a thermosyphoning, solar domestic hot water heating system with a tank-in-tank heat exchanger using data from an indoor solar simulator experimental performance test. Excellent agreement with the experimental collector useful energy gain and the energy delivered during a draw is achieved by ensuring that the model gives an accurate prediction of the temporal history of both the system flow rates and temperatures. The calibrated simulation model is then compared to two additional one-day outdoor tests. Simulation accuracy is greatly improved and confidence in an annual performance prediction is increased.