Self-Regulating Underfloor Heating

By Chris Hayes
Country Specification Manager - Roth UK LTD

The 'Self-Regulating Effect' of under floor heating - what does it mean?
In a heating system with low heating surface temperatures, e.g. underfloor heating, a physical effect that regulates the power output comes into play before any technical control devices.

The self-regulating effect of the underfloor heating takes place independently of control systems and at the same time as the room temperature changes. This creates the basis for a comfortable room climate.

Basically, the following applies:

The power output of a heating surface in the room is almost proportional to the temperature difference between the heating surface temperature and the room temperature.

In a residential building insulated in accordance with the current building regulations, the floor temperature with underfloor heating is on average around 22°C during the heating period. Since the temperature difference between the surface of the floor and the room is very small, the power output of the underfloor heating is reduced significantly when the room air temperature rises.

If, for example, the room air temperature rises from 20° C to 21° C with a floor surface temperature of 22° C due to solar radiation in the room, the heat emission is reduced by half. Conversely, lowering the room temperature results in an increase in power output.

An individual room control reduces the difference between the heating/cooling surface temperature and the temperature of the room. The smaller this temperature difference is, the better the self-regulating effect comes into its own. This means that the self-regulating effect achieves its greatest effect in combination with individual room regulation. This was proven by Dresden University of Technology as part of a larger study on the subject of energy saving in individual room control systems.

ROTH UK LIMITED is commited to helping designers, installers and users of underfloor heating system to maximise efficiency and create more sustainable system.