Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

The keys to underfloor understanding

The topic of underfloor heating (UFH) is becoming more commonplace in today’s market, with end-users increasingly recognising the benefits.

This now provides installers with an extra option to increase the scope of work on offer and extend business opportunities with clients.

Care with conservatories

Uponor applications manager Neil Young says that while underfloor heating systems are straightforward to install in conservatories, it is important to follow some simple guidelines to ensure that they provide years of comfort and satisfaction in the home. If there is one specific area of installations that requires some carefully prepared instructions, then a conservatory UFH construction is it.

Mr Young explains: “Conservatory constructions typically have high heat losses compared with the main building structure; wherever possible you should minimise the heat load required. The lower the U-value the better; walls, roofs and floors all matter and insulation should be installed in the floor construction. I would advise using a quality product at least 50 mm thick.

“It is also advisable to insulate the floor and wall interface, as this will reduce heat losses to outside walls. Air tightness of the construction will also have an effect; joints and junctions of walls, roofs and floors should be adequately sealed.”

In addition to heat losses, the floor construction will determine how effectively your system transfers heat energy, Mr Young says. A high mass floor construction, ie screed floor, offers the path of least resistance and is capable of emitting more heat than timber suspended floors - always use a screeded floor construction with insulation.

Installing the floor insulation layer between the floor slab and screed reduces heating reaction times and increases the system’s potential heat output. When it comes to laying the system, some careful planning will avoid any potential pitfalls. The conservatory pipe loop(s) should not be shared by adjoining rooms, as this will compromise one or both rooms’ output and make one of the rooms either too hot or cold.

Your conservatory underfloor heating system circuits should be designed with extra capacity (should it be required). They should not be the index circuit. If in doubt, install an extra loop and make them shorter.

Also, higher heat loads typically require higher water temperatures compared with the rest of the building. Ideally, the conservatory underfloor heating system should be served by its own manifold with its own water temperature controls.

Finally, consider the pipe layout pattern used, suggests Mr Young. Your underfloor heating designer should be able to advise the best layout for your conservatory. Some provide additional heating where it’s required, others a more even temperature throughout.

The final flooring type will also affect the system’s efficiency. “I would use a thin solid floor finish within a conservatory, such as ceramic floor tiles, as they offer minimal resistance to heat transfer and absorb solar energy during sunny days,” says Mr Young.

While correctly planned and installed conservatory UFH systems can be effective, Mr Young urges installers to make customers aware of the differences between UFH within a conservatory and the main building. “Be realistic. You wouldn’t expect indoor lounge air temperatures in your conservatory during the depths of winter, but a well-installed and thought-out system will be effective.

“Informing customers of the external factors that can influence a system’s efficacy will help them understand the differences and manage their expectations in advance,” Mr Young adds.

Under control

Michelle Fleming of Thermoboard - Wavin’s underfloor heating division - offers guidance to installers regarding UFH controls, stressing that UFH systems offer a greater level of controllability to the homeowner than many alternative forms of heating. But this benefit can only be enjoyed if the installer is able to fully optimise the system at the commissioning stage.

To optimise the system, it is best to select the thermostat, control centre and manifold together, ensuring each component is able to operate at its most efficient when combined with the other elements of the system, continues Ms Fleming.

As a manufacturer offering all these system components, Thermoboard designs all of them to work to the utmost efficiency when combined in a single system, she adds.

As you complete installation, the manifold will need to be balanced correctly to allow the fine tuning of heat outputs. Fortunately, modern manifolds are now available that offer much simpler balancing at the twist of a hand.

Once in use, zoning for control is simple, as UFH systems are designed with multiple individual circuits of heating pipes. Individual or combined circuits can be zoned and controlled by a thermostat, which accurately measures the air and/or floor temperature, says Ms Fleming.

The system response to the individual thermostats is specific - the manifold will only allow more heated water through the circuits in the relevant zone - not the entire system.

The range of controls on offer ensures the method of control can match a homeowner’s specific needs. Modern thermostats offer holiday modes or boost buttons, for example.

Owners of larger properties or holiday homes could opt for a networked system, which allows users to control thermostats centrally rather than individually. Such a system can also incorporate control of the radiator system and hot water, if required, in a single control centre, and can be controlled remotely from a computer.

Wireless thermostats are another option, which offer no disruption to existing walls during installation as no wiring is required between the room thermostat and the boiler.

For the installer, they eliminate the common problem of cross wiring. They also offer flexibility down the line, as the thermostats can easily be re-sited and re-enrolled to the control centre if the homeowner’s needs change over time, allowing heating zones to be easily reconfigured.

Electric avenue

Over the past few years there’s been a rise in the amount of underfloor heating being installed in new and retrofit projects. But electric heating is also highly suitable for use with underfloor systems, says Heatrae Sadia head of marketing Jon Cockburn.

Since the economic downturn, many homeowners have been upgrading their houses rather than moving. These improvements include building extensions and conservatories, for which an underfloor system and electric boiler arrangement can provide an excellent heating solution, he says.

Particularly appropriate for applications where the current central heating boiler may not have the capacity to cope with any increased demand placed on it to heat the extension, it will also usually be less disruptive than expanding an existing system, Mr Cockburn continues.

As well as the obvious benefits of underfloor heating of warm floors and comfortable room temperatures, the minimalist look is still very much in vogue. Many householders like the fact that an underfloor system removes the need for radiators, which some believe can spoil the appearance of a room.

The underfloor heating manifold can also be incorporated within a box, which can then be placed within an internal wall of an extension or conservatory. The arrangement is then linked up to the electricity supply and the water pipes which run under the floor.

One of the key environmental initiatives of the previous government was the decarbonisation of the UK electricity grid and the indications are that this is set to continue under the coalition. Therefore, the future of electricity in this country should be looking both clean and bright.

The government is also heavily promoting the use of electric cars as viable alternatives to petrol and diesel-fuelled vehicles, with more re-charging points being made available.

However, it is a shame that the government’s enthusiasm for electric power does not transcend to the heating sector. This underlines the fact that government policy is not ‘joined up’, but from a development point-of-view this could result in innovation in electric equipment being stifled - particularly for UK manufacturers. This would be unfortunate, as many believe such appliances could provide an excellent alternative to our dependence on gas.

There is much to be positive about in terms of the future and now is the time for our industry and the government to embrace both the opportunities and technologies available, Mr Cockburn concludes.