The temperature regulation in low-temperature heating systems with a slow power dynamic demands a different approach than conventional heating systems.
Measurements show that the heat demand is essentially dependent on two parameters: the ambient temperature and the solar irradiation. The operation of the controller is based on information about these variables. Taking the large heat capacity of the floor mass into account, it defines the energy demand for a given period. The controller calculates the energy demand for the coming time interval (e.g. 15 min. or 30 min.). Due to the large heat capacity, the required energy can be delivered in terms of "energy pulses". Hence there is no need for an accurate power control, which has been the dominating control strategy until now.
The duration of the "heat pulse" is calculated from the actual source temperature (in the heat store). The controller directly regulates the circulation pump of the floor heating system, eventually a thermal or motor driven valve. This requires very few installations with low costs compared to conventional heating systems.
Multi zone function
The SOLARNOR floor controller is a complete control unit for low temperature floor heating systems. The multi-zone function allows different temperatures and regulation parameters for different living areas independently, based on outdoor temperature and solar radiation through the windows (passive solar heating). The control system consists of the temperature controller and the temperature sensors. Different zones have individual motor driven valves (or pumps). These are opened/closed by the controller, which operates directly on the power supply.