Energy Saving Hydronic Underfloor Heating Controls from Amuheat

The basis of any well-designed heating system is to provide an affordable and comfortable environment for the occupants, so it is worth thinking more along the lines of heating the occupants and not the building. Also, heating systems should have suitable controls to achieve comfort conditions and maintain economic operation.

Traditional hydronic underfloor heating designs incorporate a single room thermostat which serves only as a high limit device in the room it is installed in with no consideration to other rooms throughout the home.

Different rooms gain temperature for different reasons - for example from the solar gains in a south-facing lounge, or from the heat given off when there's cooking in the kitchen. Without a thermostat, the hydronic underfloor heating system cannot recognize the changes in these rooms and may continue to provide heat, leading to overheating.

Hydronic underfloor heating is also different to normal heating in that it requires to be in operation continuously through winter as traditionally hydronic underfloor heating systems have relatively slow response times. Energy wastage occurs during no or low demand periods where the boiler is on at regular intervals to maintain the heat when the occupants do not need it.

The result of poor heating control systems is that the customer is faced with huge heating bills. A better alternative would be to install modern thermostatic controls for inside the home, to monitor the internal conditions in each zone and thus regulate the temperature much more effectively.

To further reduce running costs and to have realistic heat up and cool down response times, rather than the system being switched off, the temperature is reduced by about 4°C during the night or during periods when the home is unoccupied. This is called set back because the system is turned down not off. Set-back can be achieved in two ways.

Individual Programming
A programmable room thermostat can be installed in each zone. They give individual time and temperature control, alternating between daytime and set back temperatures. This is an ideal solution for a system with a small number of zones but it can be an onerous duty to have to programme each of a large number of zones.

Centralised Programming
When using multiple zones, the system becomes more economical and easier to set-up if non programmable setback thermostats are used and the Set-Back times programmed centrally. Set-Back times can be programmed using a timer module connected to the manifold wiring centre or remotely via a conventional programmer located anywhere in the home. All the thermostats will then operate using the same timings, although it is possible to manually override this by changing the position of the switch on the side of the thermostat. When the system switches over to Set-Back mode, the extra circuit is activated. This has the effect of causing the Set-Back Thermostat to think the room is 4°C warmer than it is. The Set-Back Thermostat will then call for heat at 4°C below the temperature set on the dial. When the central programmer reverts back to normal operating mode, the extra circuit is de-activated and the Set-Back Thermostat reverts to calling for heat at the original room setting.

Speedfit hydronic underfloor heating can operate with almost any type of heat source, including combination boilers, heat pumps and solar storage. The choice of controls depends on the system being installed, the building it is being installed in and the needs of the occupants.