Underfloor heating

When you’re weighing up the benefits of any product, a good place to start is with people who use it. So, although the straw poll we conducted at Sentric Design office may not be statistically significant, it did suggest that when it comes to efficiency, underfloor heating appears to be a mixed bag. That’s why we thought it might be useful to examine the pros and cons and see whether it offers any opportunities to make energy savings. 

The Pros

First things first, there are two types of underfloor heating. One uses electric matting or wires that are either installed under your floors or are set inside tiles or concrete screed. The other is water fed underfloor heating where hot water is fed around pipes in a subfloor.

Although underfloor heating is more frequently installed in new houses, it is possible to add it to an older house, in which case, choosing the electric kind is likely to be a lot less hassle. Underfloor heating can be thermostatically controlled on a room-by-room basis so you don’t waste energy heating rooms you’re not using. You can also install it where it’s likely to be most effective. For example, it could be used to maintain an ambient temperature in a tiled kitchen or bathroom. However, it may not be the best way to heat a conservatory where warmth is easily lost through walls of glass.

You can install underfloor heating with all sorts of flooring, including vinyl, laminate, stone and ceramic. The latter two are ideal because they are better conductors and will hold the heat for longer. Underfloor heating will even work under carpet although it’s wise to keep it to 1.5 tog, otherwise it could actually absorb most of the heat before it enters the room.

Choose electric underfloor heating and it can be powered from the national grid, by solar panels or a wind turbine and you can run water fed systems from a conventional boiler, solar panels or a heat pump. Using renewable energy sources obviously means you’re maximising on the efficiency of your system, reducing your fuel bills and eliminating carbon emissions.

So far, so good. But now let’s look at the downside.

Cons

Well, it may come as no surprise that one drawback to underfloor heating is the British weather. It’s just so unpredictable. And whereas you can pop the gas central heating on when you’re a bit chilly and you’ll feel the effect in minutes, underfloor heating takes time to warm up and you’re paying for energy without seeing an immediate benefit. You really need to keep an eye on tomorrow’s weather forecast so you know whether to put the heating on early or perhaps overnight.

Of course, if you’re on Economy 7, during the winter months you could give your underfloor heating a two or three-hour blast on cheaper rate electricity then, a bit like a storage heater, it will emit heat during the day. Remember, if you’re heating ceramic or stone floors they’re likely to emit heat for longer but, even so, you may need to switch on the heating again before evening.

Like any other heating system, underfloor will be most efficient when your home is well insulated and draught free. What’s more, if your installer is worth their salt they’ll make sure that either an electric or water fed system is well insulated on the sub-floor to increase efficiency.

Finally, it’s critical to remember that underfloor heating works in a different way to conventional heating systems. It produces radiant heat that provides an even, ambient temperature, lowering the heat loss from your body and allowing you to feel warmer at a lower temperature. However, if you crank up the heat as you would with a conventional system, you’ll soon find that any potential savings simply melt away.

The verdict

Well, some sources claim that given a well-insulated house, with an energy efficient boiler or power source, effective and efficient installation and a competitive gas or electricity tariff, you could achieve energy savings of 10-15%. These claims are far from undisputed though, and if you take any of the above factors out of the equation, the jury is certainly still out on whether underfloor heating is any more efficient that more conventional heating systems.