One of the key issues when considering underfloor heating is the eventual running cost of the system once it is installed. One of the reasons underfloor heating is becoming more popular is because it proposes to be more energy efficient; reducing carbon emissions and saving money.
Choosing the most suitable system for your particular property, and your lifestyle, can help you make the most of heating while saving money at the same time.
What are the average running costs of underfloor heating?
Wet systems usually cost less to run than electric systems because they are heated via a gas boiler, and gas is currently cheaper per KWh of heat output than electricity.
Handy Heat offer running cost figures for some of their electric underfloor heating products, based on being installed into a well insulated house in line with building regulations, which we can use a rough guide.
They state that the average new building, in the right circumstances would cost approximately £3-4 per square metre per year to heat, therefore a property with 100 square metres could cost as little as £300-400 per year.
They also estimate that in a conservatory where the heating was on at weekends and winter evenings the running cost would be £8 per square metre per year; less than £100 per year for a small conservatory.
Pricing based on much more realistic usage in a standard property by Living Heat Ltd, estimate the running cost for a 4m2 room for both central heating and wet underfloor heating. Their figures suggest that the central heating would cost £496-516 per annum to heat the room, compared with £180 per annum for an underfloor system.
Is it cheaper to run than central heating?
Underfloor heating is cheaper to run than central heating for a number of reasons. A typical central heating system runs at 60-80oC, While a wet underfloor system runs at temperatures around 40-50oC, and some electric systems operate at temperatures as low as 30oC. By working at lower temperatures underfloor heating uses less energy to achieve the same level of heat.
Heat from the radiators is via convection, and the heat quickly rises to the highest level in the room, creating a hotspot at ceiling level. The heating is often turned up higher as a result to ensure a certain level of heat at lower levels in the room.
Much of the heat at the top of the property escapes through the roof and is lost to atmosphere. Underfloor heating emits radiated heat, which is a similar type of heat to that of the sun.
People, objects and furnishings in the room all absorb the heat and act as heat emitters as well. The heat comes from floor level, so not only does it provide an even spread of heat throughout the room, less heat is lost through the roof.
The other effect of radiated heat, because we absorb some of it, is that the temperature can typically run at 2oC lower than a central heating system and still provide the same level of comfort. Running at a lower temperature on the thermostat also makes underfloor heating cheaper to run than central heating.
What variables can affect the cost?
Running costs will be affected by other factors, particularly if the system has been installed into an existing property. All new build houses have to comply with building regulations in terms of insulation properties and energy performance, so underfloor heating will have a chance of working at its most efficient.
In renovations, poor insulation or draughty single glazed windows will reduce the ability of the underfloor heating to sufficiently heat the house.
The type of flooring you use will affect the performance of underfloor heating systems, and you may need to run the system at a higher temperature with certain types.
Stone, concrete or tiles floors are generally the most conductive and transfer the heat easily.
Some carpets and lino floors are thick enough to seriously affect the efficiency of the heating system.
The height and size of the room may also affect your running costs as larger rooms will have more volume to heat and the heating may need to be on longer.
The cost of energy will also have an effect as both gas and electricity prices fluctuate.
Insulation board and edge insulation is very important in helping to reduce running costs. Most new build properties are required to have a downward U-value of 0.25w/m2K.
The U-value is the measure of how much heat loss is allowed to the ground, and when combined with an underfloor heating system the requirement is 0.15w/m2K.
Edge insulation is laid around the perimeter of the system to prevent heat loss into the walls and doors, and also acts as an expansion gap for the screed and flooring to expand and contract with the heat.
How to minimise running costs
Underfloor heating on the market today come with several energy saving features, and you can minimise running costs by using the full functionality of your system.
Most are supplied with a thermostat for each room or zone, so you should set the right temperature for each room rather than maintaining a single temperature throughout the house.
The control unit will incorporate a timer so you can set the times that each zone is heated; take advantage of these settings so you are not heating rooms unnecessarily.
Underfloor heating emits radiant heat, so you can turn the temperature down by a few degrees compared to the setting you may be used to with central heating. You will still feel the same level of comfort due to the benefit of radiant heat.
The heating systems also have a slower cool down time compared to central heating, you may find that you can time the heating to turn off earlier and still feel the residual heat for some time after.
Underfloor heating is growing in popularity in the UK because it provides a feeling of luxury within a home, and promises to have cheaper running costs than conventional heating systems.
Selecting the right system, the right type of flooring, and backing it up with a well insulated property is essential to get the best out of underfloor heating, and realise the best performance.
Once the heating is in place, utilising all of the energy saving features integrated into the system will further enhance the reduced running costs.