Assuming we’re not going to be at the point of only heating one room anytime soon, how do we heat the whole house? Traditionally I’d have said easy – just radiators. The hot water can come from our wood-fired range, topped up with Solar hot water and our emergency Gas boiler. But I’ve always had a hankering for underfloor heating, so I thought I’d have a look and see whether it was possible , and economically sensible.
The efficiency figures are impressive – “wet” underfloor heating is 30% more efficient than radiators (you can also get electric underfloor heating but it is 30-40% more expensive to run than the hot water – “wet” – systems, so we won’t be considering those).
Wet systems work by running warm water through a network of pipes either under the floor or under the floor covering. The water only has to be about 50C, so it’s much easier to run with renewable sources than radiators are. You’ll also get back all the wall space usually dedicated to radiators, and benefit from not having your heating source trapped behind a sofa or right underneath a window.
I’ve always thought it’d be something you’d only fit if you were building new or replacing all the floors, but there are now systems that will fit on top of your existing floor, under your floor covering. This makes fitting them to an existing house a much more manageable proposition. You just need to ensure that suspended ground floors are insulated and that you don’t have too insulating a floor covering – make sure it is less than 1.5 tog.
How much will it cost? If you’re doing a whole house it’ll probably come in at between £12-16/sqm – about the price of a decent carpet, ro about the same price as a radiator system. So you probably wouldn’t do it to replace a perfectly good central heating system, but if you need all-new heating it should definitely be considered. They should last 25-50 years so it’ll be a good investment!
Other resources
- Channel4 – a great discussion of all the options and issues.
- Myson – Manufacturer, will lots of great technical information on what’s possible, prices etc. Check out their great Technical Guide.
- Polypipe – Manufacturer, includes details of their Overlay low-profile over-floor system.
- SelfBuildABC.co.uk – great article on all the issues.
- Borders Underfloor Heating – a supplier with diagrams of all the fitting methods for each floor type.
Gentle Descent 