The advantages and disadvantages of underfloor heating

Whilst underfloor heating is regularly associated with high-end hotels and luxury homes, it is become more common in new homes in the UK.

Advantages

One of the main attractions of underfloor heating is that it frees up space in your house. It removes the need for radiators and other heating appliances that generally take up a lot of room. By moving your heating system underground you allow yourself the luxury of utilising more of the floor space in your home.

Another appeal of underfloor heating is that it heats rooms much more efficiently than traditional methods, such as radiators. The reason for this is that radiators work by heating up the air around them. As radiators are almost always positioned at the side of a room, they end up only heating the air in their immediate vicinity. After the radiator has heated this area, the majority of the heat will escape upwards and won’t go far when it comes to heating the rest of the room. Underfloor heating on the other hand heats the room evenly from below. This means that almost all the heat that is produced will go directly into heating the room in which it is installed.

As radiators are largely inefficient at warming the room that they are in, they need to operate at a higher temperature in order to achieve the desired results. Underfloor heating however, heats rooms much more efficiently. As a result of this they can operate at much lower temperatures and still be easily as effective at maintaining an intended level of warmth. This can save you money on your energy costs, as you will not need to use as much energy in order to get the same outcome.

Disadvantages

The biggest disadvantage to underfloor heating is its installation cost in retro fitting situations. As the system needs to be located beneath a room for it to work, it can often require quite extensive work to put into place. It is important to work out whether the savings you will make from heating your home more efficiently, will be enough to offset the cost of having the underfloor heating system put down in the first place. Though the ascetics of not having radiators can be appealing.

Another disadvantage to having an underfloor heating system is that it can often take longer to heat a room than more traditional methods. This is because they operate at lower temperatures than other options such as radiators. One way to get around this problem is to have your underfloor heating set to a regimented timer and having a fall back temperature rather than letting rooms become cold. By doing this you will ensure that your home has always heated up by the time you want it to.

Types of underfloor heating

There are two main different forms of underfloor heating. You can either choose electric underfloor heating or water underfloor heating.

Electrical underfloor heating

This form of underfloor heating uses a large system of wires that will be placed under the floor in the room you wish to heat. Some people opt to go for heating mats that can be laid to cover a large portion of the room, whereas others go with a system of individual wires that can reach all parts of a room. The heating mats tend to be a bit more affordable as they can be mass-produced in a variety of shapes and sizes.

The lines themselves tend to be positioned on top of a layer of insulation and can generally go underneath most types of flooring.

One advantage of electrical underfloor heating is that the wires are a lot easier to install than the pipes required for water underfloor heating. This means that it often doesn’t cost as much to install and can sometimes even be put in place by yourself.

One disadvantage of electrical underfloor heating is that it is generally more costly to run than water underfloor heating, this depends on whether you have a cheap electricity supplier. This means that if you are planning on putting it into your home, it may be wise to try and restrict it to smaller areas such as bathrooms.

Water underfloor heating

Water underfloor heating systems are made by constructing an extensive system of pipes that will cover the majority of your floor. These pipes will be linked to your home’s boiler and water will be pumped through, much like it would be pumped through a radiator.

One big advantage of having a water-based underfloor heating system is that it requires a lower water temperature to heat the room that it is in. This is because water underfloor heating systems can warm a room more evenly than a radiator can. As a result these underfloor heating systems are more energy efficient and cost a lot less to run than traditional heating methods. This enables use of heat pumps as they have  a lower temperature flow than gas boilers.

The disadvantage to choosing a water-based underfloor heating system is that pipes are a lot more expensive to install than electric wiring. This means that installation costs are often a lot higher for these types of underfloor heating systems. In addition to this, it is not advisable to attempt to install a water-based underfloor heating system without assistance from a trained plumber.

As the work required to install a water underfloor heating system is so extensive, it may not be possible to put into every property.

How to install underfloor heating systems

Of the two types of underfloor heating systems; electric and water-based, only electric systems can be self installed. This does offer an easy way to save some money as your installation costs will be minimal. However, although you may be able to lay the wiring yourself, you must still contact a qualified electrician before attaching the wires to your mains supply.

When installing these systems, the most important thing to remember is that you must place the wiring over the top of any insulation. If you fail to do this, then you will not feel any of the heat being generated as it will be insulated from reaching the room.

It is important to note that some systems will only work with certain floor types. This means that your options may be limited depending on what flooring you have in place.

When installing a water-based system, you should not attempt to install it yourself. You will need a large amount of piping, and in some cases the level of the floor will need to be lifted to allow room for the system underneath.

How much does underfloor heating cost?

The answer to this question can vary greatly depending on what type of underfloor heating system you choose and on how extensively you decide to install it.

For electrical underfloor heating, prices can range from anywhere between £90 per square metre for the heating pads, or £120 per metre for the individual wiring. You will also need to spend money on insulation and electrician fees.

If you decide to go for a water-based underfloor heating system then you will be paying a lot more money. The cost for the whole system will undoubtedly run into thousands of pounds by the time all is said and done.

How much does underfloor heating cost to run?

Underfloor heating systems can be more energy efficient than other forms of central heating, saving you money on gas and electricity. But these running cost savings are unlikely to offset the installation costs of these systems, particularly if they’re supplementing an existing heating system.

• Electric systems cost less than 10p per square meter to run at full power for six hours.

• Electric underfloor heating in a standard-sized 3.5 square meter bathroom, run for two AM hours and two PM hours, will cost £3.16 a month to run.

• An electric system in a 10m2 lounge, run four hours a day, will cost £10.80 a month in electricity.

• Water-based underfloor systems are 25% more efficient than radiators when run from a traditional boiler because they use water heated to a lower temperature – 50°C as opposed to 70°-90°.

Is underfloor heating right for you?

Underfloor heating is not likely to save you much money, even when it comes to your energy bills. On average it is estimated that underfloor heating will save you around twenty pounds per year on gas or electricity. This means it is definitely a choice made for reasons other than budget.

One situation where underfloor heating is an exceptionally good idea, is when building a new house, or even a new room. As you will need to install electricity and piping under the floor anyway, it is not likely to cost you much more to install it and once you do it is unlikely you’ll regret it.

Of course the main appeal of an underfloor heating system is comfort. The even distribution of heat across the room is a feature that cannot be understated. It also works exceptionally well with stone floors. This is because the stone floor will remain warm even if a window is open, unlike the heat from a radiator which will disperse given the slightest of drafts.

One more thing to consider is the space saving aspect. Underfloor heating removes clutter and lends your home to a more minimalist, tidy appearance.

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Personally I have put underfloor heating on my ground floor. Due to retrofit costs and disruption I have not put underfloor heating on the first floor instead I have instead installed radiators, but I have sized these radiators so they will work on a delta 30, this will enable me to put install an air source heat pump.

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Jeff Culkin MCIPHE RP RHP

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