Underfloor Heating
No1 for Underfloor Heating
Buy online using our secure e-commerce system
Unit 11F
Carcroft Enterprise Park
Carcroft, Doncaster
South Yorkshire
DN6 8DD
Phone: 01302 727182
Fax: 01302 728634
Search: Advanced Search


Underfloor Heating1 - Buy Online Underfloor Heating1 - Get Information
Site by Underfloor Heating 1 - UFH
Copyright © 2004 - 2009
Revel (UK) Limited T/A Underfloor Heating 1

Underfloor Heating Project Example - New House Build

There are commercial companies that will design, supply and even install your wet underfloor heating but that option is expensive. Installing it yourself isn’t very difficult and any competent do-it-yourselfer, with some building and plumbing know-how and the help of this website should have no problem installing wet underfloor heating. Buying your equipment from ufh1 will save you money. Install it your self and your savings will be hundreds of pounds. You might be considering electric under floor heating. Heating systems running off electricity are generally easier and less expensive to install however the running costs will be considerable higher when compared to a wet underfloor heating system connected to a condensing boiler or heat pump. This web site is designed to help you do design and install your own wet underfloor heating system. If you feel we have missed anything or have any suggestions please let us know using the email address on the website.

Design and calculations of wet Underfloor Heating

The design and calculations for a wet underfloor heating system in a solid floor should be conducted in accordance with BS EN 1264 and the details given on these pages are based upon this standard. The design of an underfloor heating system in a new build is a straightforward process consisting of 5 main steps:

Calculating the capacity of an under floor heating system

Calculating the output of a radiant floor heating system correctly involves:

It is necessary to obtain the following information about each of the zones to be heated:

Some of these are described below.

Maximum hourly losses or thermal load of Wet Underfloor Heating

These should be calculated, just as you would for any other heating system, using preferably a proprietary software package or data taken from SAP rating our other reliable source. For an underfloor heating system the criteria is slightly different and this can result I lower heat losses than would be calculated for a radiator system. As more than 50% of the floor heat emitted is radiant transfer this heats bodies, objects and the building fabric without heating the air. This feature of under floor heating increases the rooms mean radiant temperature (MRT) which means a lower room temperature can be used without loss of comfort.

The same comfort will be experienced with a design temperature of 20°C when compared to a radiator system with a design temperature of 21°C because of the heat radiated from the walls, floors and the very fabric of the room. Consequently a 1°C reduction in normal room air temperature is used. For bathrooms, wet areas, and walk in wardrobes we recommend a design temperature of 23°C. This is to compensate for the reduced floor area, added ventilation and the fact you will often use these rooms with little or no clothing.

Air Changes

When compared to radiator and forced convection heating systems wet underfloor heating creates weaker convective currents. This in turn creates a more even temperature and pressure within the heated space. This fact enables a lower air rate change to be used.

Floor Losses

The floor is the equivalent of the radiator. When turned on, the floor will always be warmer than the room temperature. Consequently downward losses from the floor should not be included when sizing underfloor heating coils. Floor losses will only need to be included when sizing the boiler, heat source and distribution pipework. Downward losses should be limited by insulating the floor slab and perimeter edge.

High Ceilings

Because water underfloor heating does not produce the same convective gradients as radiator heating no additions are required to compensate for high ceilings.

Addition for Intermittent Heating

Underfloor heating should be designed to operate at a constant temperature during the day with a night or unoccupied setback of approximately 3°C. This ensures the room warm up periods is reasonably short and no adjustments to the heat loss calculation are required.

Heat output for Wet Underfloor Heating

The formula for working out the floor capacity to heat the room is as follows:

Total Room Heat Loss (W)/ Active Floor Area (m²)

So for a room with heat losses of 1257W and a heated area* of 14.5m² the heat output required is 1257/14.5 = 86.68 W/m²

* Heated area is that available to under floor heating. Sterile areas should not be heated e.g. under fridges, freezers, cupboards, baths and sanitary ware, and anywhere else you do not want under floor heating or where you may required to drill and fix into the floor.

Most rooms in new build properties will require a design heat flow of between 50-70 W/m²

Possible exceptions where floor heat emission required can exceed 100W/m² are:

Floor surface temperature

BS EN 1264 floor heating and floor surface temperature. Floor surface temperature is critical to comfort, as well as to heat output. BS EN 1264 gives guidelines on the maximum values for floor temperatures.

Please click here to continue shopping

Electric Underloor Heating Kits

Ultra-thin mat heating system is an up-to-date kind of electric underfloor heating. It does not require the installation of a screed, because it can be easily laid into thin (8-10mm) under tile adhesive layer. It is applicable for all types of premises and can be easily installed both on a new surface or on the existing floor in case of repair works, especially when it is highly important to keep low thickness of the floor construction. Mats are manufactured and tested in full conformity with IEC (International Electrotechnical Commission) Global Quality Standards.

Electric Underfloor Heating Mat kit includes: heating mat, thermostat with temperature sensor, fixture elements, and corrugated tube for temperature probe placement. Double insulation undergoes special processing, which makes it flame-resistant and infusible. Foil-coated shielded jacket ensures mechanical and electrical protection of the cable. Only high-quality polymers of leading world manufacturers are used.

Kit comes complete with RS110 Temperature contoller - Electric Underfloor Heating Kits 110 room temperature controller complete with remote floor temperature sensor. Provides simple on/off controls of floor heating system based on floor temperature. Convenient display with LED 'on' status display. Room thermostat 110 is designed to maintain the specified constant temperature.