Underfloor heating has a range of advantages, some of which are obvious, others less so. It can also be powered by two main sources of energy – electric or hot water.
We shall focus on the hot water systems here becauseI am not a fan of electric heating unless you are able to supply it with renewably sourced current. It also tends to be a retro-fit solution that comes in tile or webbing format. These require insulation underneath but this is not commonly added in sufficient quantities to make it efficient. However if you are desperate for underfloor heating and the added value that it brings to the house and are only looking at small isolated areas then it does become the only viable option.
So to the advantages of underfloor heating with hot water
Freed up wall space
Rather than having radiators cluttering up your walls underfloor heating removes the need for visible and space consuming pipework and rads. This is a great way of creating clean lines through out the the house and minimising dusting.
Warmth where you want it
Our feet are the most psychologically sensitive parts of our bodies to heat. So if our feet feel warm, we feel warm. This means that you can effectively run the system at a lower ambient temperature if needed.
Less risk of damage
Earthquakes aside, underfloor heating is really protected from damage. The chances of being knocked around, leaks etc are much reduced by having the pipes encased in concrete (or similar).
Assuming that the system has been designed correctly, you get as much more even spread of heat in the home by using underfloor heating. Getting the zones and circuits right though does require some knowledge but most companies will do the design for you.
Use of low heat energy sources.
This is growing in importance for water based systems. Some heat sources (Ground and Air Source Heat Pumps most notably) are only good at producing low temperature water. Underfloor heating requires low temperatures rather than hot ones and so they tie in really well with these emerging heat technologies.
The new manifolds have excellent controls for managing different areas of the house independently, so it is easy to get the heat where you want it.
So what about the Cons?
The main ones are around quality of pipes, insulation, design and installation.
Because the system should be fit and forget it is best to use high quality pipes that are free from any underground joins.
The floor must be well insulated and this means that it needs to be insulated under the slab and also at the edges. We would recommend at least 100mm underneath and 50mm at the perimeter.
The design of the system is key as they can operate at different temperatures, so you need to ensure that the heat source is closely matched to the requirements of the heatings layout. The plans are also key to ensure that you have have more pipes around the edges of the room and less in the middle. Some people just fit the same all over the floor rather than having two different levels of pipe concentrations (normally you have pipes half the distance apart on the perimeter).
It is also worth noting that many people run underfloor on the ground floor but not on the upper floors. This can lead to problems with the heat source as radiators want to run at higher temperatures. However, if you are happy to have cooler upstairs then you can run slightly oversized radiators at the lower temperature to obtain a cooler upstairs environment. If you want the same / similar temperatures then you will either need: oversized radiators (and this negates the some of advantages of clean lines etc downstairs); or to run underfloor heating upstairs as well (this is possible); or to have higher temperatures available to conventionally sized radiators. There are solutions to all these scenarios, so for more advice please call the Eco Home Centre.
Installation is important as you must have continuous piping for each circuit (no joins) and the system installed to manufacturers requirements. There are different systems (quick response non screed and the slower in-screed systems) and so you want people who are au fait with these different to ensure that they are installed correctly. The whole system also needs to be fully pressurised and tested before screeding / covering.
So overall, we highly recommend using underfloor heating both in new build and retrofit, but you need to be aware of the potential shortcomings to ensure that you do not suffer from them.