Abstract

An extensive analysis of thermal dynamics of a solar building with floor heating, conducted through an integrated methodology based on frequency domain techniques showed the relative effects of different amounts of thermal mass and of different types of thermal mass. An accurate building heat balance model is developed through a detailed thermal network with distributed parameter elements and lumped elements, accurate representation of interior radiant exchanges and a floor internal heat source with variable depth within the slab. Frequency domain and finite difference techniques were used to perform analysis of the transient response of the heating system. It is shown that a combined feedback and feedforward controller when used with weather predictions one day ahead can practically provide perfect control. However, the appropriate building transfer functions must be estimated. Various control strategies involving room air temperature and operative temperature control with different thermostat setpoint profiles were investigated and it was demonstrated that control of floor radiant heating based on operative temperature constitutes a preferred approach.