Richard Harvey, Commercial Director at Wolseley, looks at the considerations for installers as demand for underfloor heating jobs increase.
The UK’s underfloor heating (UFH) market has grown significantly over the last five years and currently accounts for 7.7% of the UK’s heating systems, according to AMA Research.
With the industry expected to grow between 4% and 6% in the next four years, installers need to prepare themselves to take on more UFH work.
While UFH benefits from stability in residential homebuilding’s and the renovation sector, homeowners are moving towards the hidden heating system in favour of more interior space. Removing traditional radiators allows homeowners to make use of their additional space by providing them with an option to have large open plan areas with more furniture.
While UFH is up to 25% more efficient than the traditional radiator, if used with a condensing boiler running from a heat pump, wet systems can be up to 40% more efficient. Heat pumps are also great for maximising overall efficiency and power for UFH, and while the systems still work with conventional gas and oil boilers, the required running temperature sits between 35-45°C, almost half of that required for traditional radiators.
An increase in smart technology is also driving the market. With a 3G, 4G, or WiFi connection, homeowners can control underfloor heating remotely, increasing convenience, comfort, and savings.
Prices for UFH vary depending on the area of the UK and the size of the project. Although wet systems are 30% more expensive than traditional radiators, the long-term monetary benefits are far greater.
Homeowners can expect to pay up to £2,800 for every 100m2 in newbuild properties. For retrofit residential projects, installation costs are usually higher. For example, according to BuildIt, in an average Victorian terrace with a downstairs floor area of around 60m2, a bespoke LoPro10 system from Nu-Heat would come in somewhere in the region of £4,500.
While no particular training is required to fit UFH, installers are expected to brush up on their existing skills to ensure the project is completed correctly.
Upskilling on floor screeding is highly useful. Poorly screeded floors can create an uneven dissipation of heat and cracking, or collapsing of the floor itself – an extremely costly and disruptive problem to correct.
Although most suppliers offer basic training for their first installation, there is also a range of online training courses available that focus on theory and the practical elements of design and installation.
To the floor
For an installer, it’s important to consider the floor of the building prior to installation as it can affect the heat output. Although UFH is generally suited for ground floor rooms, there are systems that suit all floor types.
Solid wood floors aren’t really suitable for underfloor heating as it’s harder for heat to transfer through. Laminate flooring though is much better than natural wood as it’s less likely to expand when exposed to different temperatures.
If a homeowner has timber flooring, the UFH should have a temperature restriction of 27°C and an expansion gap, while carpet must have a thermal resistance of less than 2.5 tog.
Pipework and air
In terms of pipework, it’s crucial that all elements are measured carefully and correctly in order to reduce the risk of under or over ordering, and even compromising the performance of the system altogether.
Before fitting the pipes, installers should remember to factor in the heat source, as it’s crucial that the spacing between the pipes is 20cm for heat pumps and 30cm for traditional heating.
It’s also important that the system circulates warm water properly, while also ensuring there aren’t any traces of air in the system or pipes. If air does get trapped, it can reduce the impact of heat, leaving some areas of the room colder than others.
Installers are advised to wait ten minutes until the system is full of water before bleeding the ports, as it stops any air from getting into the system. After that, valves can then be vented individually, draining off the waste and closing each valve, gradually flushing the pipes to refill the system.
Thermostats and heating zones
Homeowners with UFH are able to create multi-zone heating temperatures with a digital programmable thermostat and mobile device. But to ensure this works correctly, it’s critical that the zones and positioning of each are mapped out to match the occupant’s lifestyle, as this will mean that the pipework layout and wiring centre will support each zone and manual input.
It’s also recommended that homeowners have multiple thermostats to reduce unoccupied rooms being heated.
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