A common component in many temperature control systems is the thermostat that controls the power of the heating radiators and convectors. Often, the control strategy of these thermostats is proportional or nearly proportional, which means that the control signal (for example the opening of a control valve) is proportional to the control error.
In this paper, the possibility of saving energy and improving control performance by thermostats that use signals from measurable indoor disturbances, so called feedforward control, is discussed. By means of a number of computer simulations based on an identified state space model of a small building, it is shown that such a thermostat often reduces energy consumption as well as improves control performance (smaller temperature variations). It is also shown that the performance of the new thermostat depends on the frequency of disturbances. It is also discussed what hardware is needed for the implementation of the thermostat, how to measure the indoor disturbances, and how to calculate the transfer function of the dynamic feed-forward compensator.