Introduction to Underfloor Heating
Underfloor Heating systems are becoming the most popular form of heating for new build houses in the UK. They produce uncluttered, comfortable spaces with fewer draughts, and work well in combination with efficient condensing boilers.
In both new build and existing dwellings, Honeywell can control underfloor heating in many ways.
If you are considering underfloor heating as an option, you need to be aware of the following factors which could influence your decision.
Advantages
• Even distribution of heat across the room
• Easy to install
• Unobtrusive
• No restriction on the placement of furniture
• Quiet in use
• Very little maintenance is required
• Individual room temperature control
• No risk of contact with hot surfaces
• Fabric temperature of building maintained
Disadvantages
• Long heat up period
• Requires major disruption on existing buildings
• Long cooling down period
• Cannot respond rapidly to quick temperature changes
• Choice of floor finishing requires careful consideration
• Changes of floor finish may affect performance
How does an Underfloor Heating System Work?
Generally speaking, most underfloor heating systems are warm water (wet) systems although electric (dry) systems are available. For wet systems, pipes are buried in screed, or run underneath the floor surface.
Each room will have one or more “loops” of heat-emitting pipe buried in the floor, each loop being run in a serpentine pattern so as to cover the entire floor
area. The two ends of each loop are connected to either a flow or return Manifold, which may have an electric control valve (one for each loop) controlling the water flow.
Traditional wired zone controls can be used to control the actuators, individually or in groups. More modern wireless RF controls may also be used to avoid disturbing the decorations in existing dwellings.
Underfloor heating systems operate by transferring heat from a very large surface, which is only slightly hotter than the room.
Typically, the temperature of the water in the underfloor heating system pipe is 45 – 65oC (compare this to approximately 80oC flow and surface temperature of a radiator system) and this warms the floor to a temperature of 25 – 28oC, which is comfortable to walk on. In order that the whole floor area receives heat, the layout of the pipework should be considered carefully. The supplier of the underfloor pipework will be able to provide details on the best layout for your application.
At the design stage there are a number of points that need to be considered:
• Insulating affects of floor finish e.g. carpets
• Protection of floor finish from cracking
• Accommodation of thermal gains e.g. conservatory
• Location of manifolds
• Zoning requirements
• Boiler/pump position and size
There are several different pipework layouts which can be used. No matter what the layout is, this will not affect the control requirements.
Where can underfloor heating systems be used?
Underfloor heating systems are suitable for both domestic and commercial applications. It has a particular advantage in public areas where exposed hot surfaces can be dangerous.
Gas, oil or solid fuel boilers can be used as the source of heat for any underfloor heating system. Condensing boilers being particularly suited as the operation of underfloor heating systems allows them to operate in their most efficient manner.
Underfloor heating systems can be fitted as complete systems in new or major refurbished properties, extensions to existing houses such as conservatories or single or multiple rooms in a house.
It is possible to combine both underfloor systems with radiator systems. For example, the ground floor could be heated by an underfloor system whilst the 1st floor is heated using a wet radiator system or radiators can be fitted in the bathroom and lavatory in homes where the main system is underfloor heating.
To control underfloor heating systems, Honeywell can offer a wide range of traditional controls and also the more sophisticated Hometronic system, which allows for each room to be individually controlled automatically, amongst numerous other features.