How Long Does Underfloor Heating Take To Warm Up?
Unlike a traditional central heating system with a combi boiler, pump and radiators, an underfloor heating system takes considerably longer to reach the desired temperature. With a traditional heating system that uses a gas boiler and a pump for example, the water is heated instantly or ‘on-demand’ and then pumped directly to the radiators.
With this system, it can take only a few minutes to begin heating up, reaching the desired temperature within all rooms in the house within about 15 minutes. For underfloor heating, it can take up to 4 hours or more to reach a comfortable room temperature and this is due to several different reasons.
Factors that affect how long it takes for an underfloor system to heat up
How long underfloor heating takes to warm up can depend on a number of factors including whether the subfloor is insulated or not. Also, the type of floor and floor covering can have a major bearing on how long it takes for the system to deliver an acceptable room temperature. Some factors will depend on the type of underfloor heating system installed, such as whether it is electric or water. One overwhelming aspect to take into consideration regarding how long it takes to heat a home in general, might come down to home insulation affecting areas such as windows, cavity walls and the loft.
Underfloor heating that has been installed on a concrete floor without insulation will lose a large proportion of heat to the floor below the heating pipes or wires. Heat travels in all directions so most of the heat will be totally wasted and because of this it could take up to 8 hours for the heat to finally dissipate into the room above. To prevent this, special insulation boards made from high-grade polystyrene or polyurethane foam are available from heating trade suppliers, which need to be laid beneath the UFH pipework or heating cables when the system is being installed.
The type of floor covering that is laid on top of your underfloor heating system can also affect the time it takes for heat to filter through into rooms. The best type of floor covering with an underfloor heating system is stone or ceramic tiles because they have a very high heat transfer level. A polished screed or resin floor surface also has a very high heat transfer rate. Solid wood and engineered wood, such as laminated veneer, together with vinyl and linoleum all have a high heat transfer level. Rugs and carpets offer the least heat transfer.
How long does underfloor heating take to cool down is determined by the rate of heat loss. Heat can be lost through poor insulation in walls and perished rubber seals in windows and doors. Wooden sash and casement windows are notorious for draughts and should be inspected regularly and then refurbished if necessary. It is essential to keep heat loss to a minimum. One way to ensure your rooms reach the desired temperatures is to install a smart thermostat in each room.
A traditional central heating system is usually set on a timer, which is programmed to switch on and switch off as required. A thermostat will then regulate the room temperature. The resting temperature is calculated with the heating system turned off. This is the typical temperature between heating on and heating off.
With an underfloor heating installation, the heating is very rarely switched off. Instead, it is controlled by a smart thermostat that keeps the internal areas of the property at a constant temperature. This works out to be a much more economical and efficient way to heat your home.
Estimate underfloor heating heat up times
Underfloor heating heat-up times will vary depending on the type of system and whether it is electric or water. The table below indicates some average heat-up times relevant to different floor coverings together with wattage per square metre.
|Un-insulated concrete||2-4 hours||1 hr 30 mins - 3 hrs|
|Concrete with 10mm Insulation||1 hours||45 mins|
|Concrete with 10mm Insulation & 25mm Screed||2 hours||90 mins|
|Un-insulated Timber Substrate||1 hours||45 mins|
|Timer Substrate with 10mm Insulation||30 mins||20 mins|
Underfloor heating might appear to take a long time to heat up when compared to traditional central heating systems but because they are kept switched on they are actually more efficient. By keeping the UFH system switched on, you don’t have to experience the long wait for the system to heat up each time and the heat in the floor is more likely to remain fairly constant.
An underfloor heating system is quite versatile as it can be powered by a traditional gas combi boiler, an oil boiler or LPG boiler. It can also be connected to an air source, water source or ground source heat pump, delivering even cheaper and low-carbon energy. More information about electric underfloor heating systems, including DIY installations, is available together with several different water underfloor heating types of installation.