The role of underfloor heating in a sustainable future
The UK’s largest-ever underfloor-heating installation, undertaken by Warmafloor uses some 60 km of pipe. The work was undertaken for Airbus in the wing-equipping area of its aerostructures assembly and manufacturing centre in North Wales.
considers how increasing awareness of the importance of renewable energy adds to the importance of underfloor heating.Demand for underfloor heating systems has grown massively in recent years. Given the increased focus on energy saving, linked to concerns about global warming and rising fuel costs, it is no surprise that savings in running costs of up to 50% attract specifiers and end users more than ever before. But this is by no means the only reason for the sustained high level of demand. Of equal importance are how this type of heating relates to other forms of heating technology and control and its ability to harness energy from the ground and boreholes. Continuing growth
To put interest in underfloor heating (UFH) within the commercial sector into some type of context, it is helpful to note that companies like Warmafloor have, since the late 1990s, seen a 25% year on year increase in demand — and there are no signs of the pace slowing. UFH has become the norm for large industrial and commercial premises and has been installed in numerous high-profile buildings, including the Government offices at Portcullis House in London, the Scottish Parliament building, Greenwich Museum, the Imperial Museum of the North, the British Museum and Canary Wharf. Embedding coils of pipe within the floor (be it within a screeded or timber floor) provides an efficient water-transfer system which can be used both for heating and cooling simply by passing warm/cool water through the pipes. Because the entire floor area can be utilised and because warm air rises, only low-temperature heat input is needed to achieve comfortable ambient temperatures within a building. This applies irrespective of ceiling heights since underfloor heating creates a ‘warm-feet, cool-head’ heat gradient which concentrates heat at living level rather than using large amounts of energy to heat unoccupied space at high level. In tandem with the comfort and energy benefits, underfloor heating leaves walls free from surface-mounted equipment, reducing maintenance requirements and providing real versatility in the way in which a space is utilised. Inherent growth
The inherent efficiency of underfloor heating is today complemented by developments in appliance technology. Heat pumps, condensing boilers and solar panels are natural partners for underfloor systems — but are much less attractive when linked to traditional wall-mounted radiators, warm-air systems and the like which demand higher energy inputs.
| Underfloor heating has become the norm for large commercial and industrial premises and has been installed in numerous high-profile buildings — such as the Great Court at the British Museum. |
Many of these modern heat sources are, in effect, the Aston Martins of heating but a top-of-the-range car is no good without the right tyres. If the heat source is the Aston Martin, the coils of underfloor heating pipe installed in buildings are the tyres. They maximise the efficiency and performance of the appliances linked to them. The ability of underfloor heating to achieve comfort levels with much lower energy input than alternatives also provides the opportunity to make use of sustainable heat from boreholes or from other geothermal technologies. Borehole water is typically around 12°C — and that’s enough, with minimal additional energy, to provide warmth through an underfloor-heating installation in the winter months. Not only is this energy efficient heat but it is also highly sustainable since the water is returned to the ground after circulation. Exactly the same principle applies with heat from ground-source heat pumps, using coils embedded a metre or so down below soft or hard landscaped areas. Cooling
As well as providing an economic means of heating, the same water, at about 12°C, can be used to cool a building in the summer months and so offset internal temperature rises resulting from, for example, solar gain. The need for expensive air conditioning can be avoided in many buildings, and the only additional cost required to benefit from both heating and cooling, through underfloor pipe circuits, is an upgraded control package. Choice of underfloor heating pipe can also, in itself, add significantly to the sustainability credentials of any project. Arguably the best option is polybutylene pipe. Polybutylene is produced from crude oil by refining and polymerisation. The polymer is extruded to create the finished pipe. The environmental impact of the production process, in terms both of energy usage and emissions is markedly less than is the case for alternative metal pipe systems and many other plastics. Comparisons between polybutylene and other materials used for pipe manufacture indicate that plastics such as polybutylene have less environmental impact, in terms of soil, water and air pollution. Recycling polybutylene is possible because the molecular structure of the material is not altered at all by the production process. Polybutylene pipe can be recycled and converted back to granular form ready for re-use in the production of other plastics-based products. At Warmafloor we already recycle installation offcuts which are granulated and returned to the manufacturer for re-use. Natural choice
Given the ability to use inherently sustainable materials, the low energy requirement of underfloor heating systems, their ability to maximise the potential of heating appliances and heat in the ground, these green credentials alone can be expected to maintain the pace of growth in market demand. Add the associated maintenance and energy-cost savings into the equation and it is evident that underfloor heating is the natural choice in a world which, increasingly, must combine environmental concerns with practical commercial realities. Mike Lamb is managing director of Warmafloor (GB) Ltd.