Improved model for solar heating of buildings

Abstract

A considerable future increase in the global energy use is expected, and the effects of energy conversion on the climate are already observed. Future energy conversion should thus be based on resources that have negligible climate effects; solar energy is perhaps the most important of such resources. The presented work builds on a previous complete model for solar heating of a house; here the aim to introduce ventilation heat recovery and improve on the hot water storage model. Ventilation heat recovery reduces the heat loss due to ventilation, as expected. Here, a recovery efficiency of 0:5 is used, although a more realistic number is perhaps 0:7. The improved hot water storage model increases the exergy of the storage tank by assuming a vertical temperature distribution. Further improvements are possible by introducing a simple thermocline tracking algorithm, effectively allowing for variable volumes of the temperature zones in the hot water storage tank. Currently, the model does not allow for very good temperature control; this is due to a lack of freedom in the control inputs.