The main benefits of Underfloor Heating (UFH), when compared to conventional radiator heating systems, can be summarised as follows:
- Floors without carpets become comfortable and cosy when heated by modern hydronic means. Materials such as tiles, marble, and natural stones, which would normally be cold to the touch, become pleasantly warm with heated
- Heat is concentrated at floor level, where it is needed and with minimum temperature gradient; in fact, modern radiant floors achieve the closest temperature distribution profile to the theoretical
- Floor heating provides an even air temperature across the room and therefore all round comfort; the cooler air at low level and local hot spots, associated with radiator systems, is
- Heat transmission from the heated floor more nearly matches the percentage radiant/convective mix that is lost from the human body, resulting in better balanced heat transfer between the person and the heated
There are a number of factors that make UFH the most appropriate energy efficient form of heating, including:
- Floor heating does not create the strong convective currents associated with natural and forced convection heat emitters, as it provides a more uniform temperature and air pressure within the indoor space, resulting in reduced heat losses for natural air infiltration (air change rate).
- More than 50% of the floor heat emission is in the form of radiant transfer, which heats bodies, objects and the internal building fabric surfaces without directly warming the air. This heat exchange increases the room’s mean radiant temperature MRT, which implies that a lower air temperature, in comparison to convective systems, will apply when determining an equivalent Operative Temperature. A value of 1 to 2oC reduction in room air temperature is commonly quoted for UFH, when compared to radiators, for use in heat loss
- The low flow water temperature, usually between 35 and 50oC, makes this form of heating highly suitable for coupling to energy efficient heat sources, such as: condensing boilers, heat pumps, solar panels and heat recovery
- UFH, with solid floor construction, provides a large thermal storage capacity giving rise to steady energy demands and therefore reduced boiler
- The use of sophisticated controls like the range of weather compensators and tN4 thermostats, will further reduce running
In general, figures between 5% and 50% are often quoted for energy savings when compared to traditional radiator and warm air heating systems. Actual savings will depend on many factors - however, buildings with high floor to ceiling dimensions tend to produce the greater savings due to reduced air temperature gradients.
Heat placement “spot heating” is more easily achieved with radiant heating. Individual rooms or spaces within a room can be controlled to differing temperatures with radiant heat emitters which, in most instances, would be impossible to achieve by convective means.
Redecoration, maintenance and cleaning costs
UFH has a long maintenance free life with just the manifold and its fitments exposed. The embedded pipe, to comply with European Standards, is manufactured to realise a life expectancy exceeding 50 years. While redecoration costs are reduced due to:
- Rooms are more easily decorated without any obstructions caused by heat emitters.
- There is no wall discolouration, which is often associated with radiator/convector
- There is no possibility of accidental or intentional damage to the heat emitter.
- No risk of damage to floor covering due to leaking radiator valve connections.
- Nothing to clean or paint with significant reduction in maintenance
Space allocation and aesthetics
- Placement of furniture is not limited by location of the heat emitters and net useable floor area is increased; in fact freedom of room layout is more or less
- There are no unsightly radiators or other heat emitters, or exposed pipe runs and pipe
- The size and style of curtains are not restricted by under window radiators.
- The system can be totally invisible and vandal proof to occupants with the addition of the 084e Discreet
Health and safety
The reasons for choosing UFH could be justified for some people solely on health and safety grounds. The advantages of not having an exposed hot surface in nursing homes, primary schools, hospitals and other public buildings is readily apparent.
- The floor surface temperature is designed to be less than 29oC, way below the 43oC touch temperature that is stipulated by guidance standards, for rooms that may be occupied by young children and/or the elderly. If not using UFH, the requirement is normally achieved by the installation of relatively expensive low surface temperature radiators operating on a standard boiler water flow temperature of around 70 to 80o Alternatively, conventional radiators operating on reduced water temperatures with radiators being oversized to achieve the required heat output. In both instances the actual cost differential, when compared to an UFH installation, is considerably reduced.
Other health and safety benefits include:
- Floor heating reduces relative humidity levels especially at floor level. This helps inhibit the growth in population of house dust mites, high humidity levels are required by the mite for its survival, it is a known contributor to the increased proliferation of asthma and other
- Because convective currents are weak, there is a general reduction in the circulation dust and other
- There is no risk of an occupant being injured by potentially hazardous wall projections or dangerous hot
Some floors get wet/damp periodically such as floors in bathroom areas, shower and wet rooms, kitchens and areas around the outside of swimming pools. With UFH these floors will dry up rapidly. Radiant Control Ltd can provide thermostat controls to accurately control minimum/maximum floor surface temperatures in addition to room temperatures.
The plastic pipe in UFH will not resonate or amplify sound, this is a common problem for conventional systems utilising metal pipe work where noise can be transmitted around the entire system.