I am considering my options for a renovation project which will require substantial changes to my central heating and domestic hot water system. I was considering going a thermal store with a biomass boiler (wood pellet) and solar thermal, to supply:
- domestic hot water
- high temperature water for radiators
- low temperature water for underfloor heating
While researching these options I've discovered that underfloor heating needs carefully controlled water temperature. Installation guides for floor coverings make explicit requirements about how the materials are commissioned with respect to the underfloor heating.
So I assume that the underfloor heating system, when used in conjunction with a thermal store has some method of modifying the available water, mixing hot with cooler if hot is too hot? If this assumption is correct what part of the system manages this and where does the mixing occur?
Yes, this is supposedly possible with a thermal store. Quoting from a manufacturers' website:
The Thermal Store can be used to capture energy from a variety of heat sources, such as solar, heat pumps, biomass and CHP, and is capable of providing hot water at varying temperatures to suit different heat emitters within a building. For example the Thermal Store can supply an underfloor heating system that may require 40°C, radiators requiring 70°C and hot water at 55°C, all from the same unit.
Yes, qualified engineers would be involved in the commissioning of such a system. However, there's an amount DIY in designing the system in the first place and I may take on some of the installation work myself (e.g. laying the pipework for the underfloor heating).
I'm seeking understanding in how such a system balances the temperature requirements.