Air-Conditioning Heating Directory

Posts Tagged ‘Under’

Under floor Heating (UFH) is a highly efficient comfort conditioning system because:

•  The distribution of warmth (the heat energy) is from the floor level upwards

•  The wall or ceiling mounted heat emitters are eliminated

•  The heat distribution is uniform through out the space and cold pockets are thus eliminated

Types of UFH systems

There are two main types of under floor heating technologies depending on the source of heat. i.e.

•  Electrical heater element type (in cable or mat form)

And,

•  Warm water circulating pipe type (hydronic)

Under different situations and requirements each type has its own applications.

Which is suitable for my home?

Examples of situations where electrical heater elements are better suited are;

•  When the subfloor is already high to embed a piped system

•  In an existing building where the finished floor level does not permit raising further to embed pipes

•  When cheap or excess electrical energy is available in the building (say for example through solar PV panels or wind turbines)

•  When a high back pressure rated warm water circulating pump (necessary for hydronic systems) cannot be incorporated in the system.

On the other hand the embedded pipe system is better suited for you when:

•  Cheap warm water is available from your existing or retrofitted hot water boiler.

•  When zoning and a condensing boiler is used in your home heating system.

•  In geothermal heat pump installations

•  When adequate clearance is available above sub floor to embed the heater piping.

•  When solar water heating is available

•  When better energy economy is sought

What ever is your choice, under floor heating (UFH) provides you with individual room temperature control, avoid obtrusive and ungainly terminal heating equipment and affords much less maintenance.

Consider these well in advance!

Some important points to keep in your mind when considering a UFH system are;

•  A particular product is designed for a specific type of installation and therefore the manufacturers’ guidance must be sought and adhered to. For example pipes suited for screed embedded UFH is not suited generally in under wooden floor installations and vise versa.

•  Whether it is a solid or wooden floor the under side of the heaters must be well insulated with an adequate layer of insulation and also reflective insulation foil doubling as a vapor barrier to prevent condensation (if a damp proof membrane is not available below subfloor).

•  If your building exists and is with solid floors the pipe or the mat is generally laid on the floor and finished with timber, laminate or any other type of tiles. The level of the finished floor will be raised .This will in turn necessitate the lifting of the doors, skirting boards etc.

•  In the case of electrical heating elements you will find heating mat (which is in effect heater elements attached to a flexible mat) can be laid on the surface rather than embedding in the screed. This has the added advantage of maintaining the element/cable spacing for uniform heat distribution.

•  In tiled floors the heater elements or the pipes may be embedded in the adhesive which is generally flexible.

•  Suspended wooden floors pose a different situation altogether. Generally the pipes or cables may be mounted between joists (clipped or clamped to under side) with adequate insulation and foil vapor barrier below. All joints must be well sealed with sealant tape. Though views may differ on timber floor insulation, as moisture is detrimental to timber (which is a good insulator but absorbs moisture easily) a vapor sealant and insulation (depending on the floor design “U” value) is prudent. Further it should not be forgotten that the timber floor will be exposed to two different temperatures on either side which may warp the material unless adequately insulated.

•  Another technique used to suspend pipes or cables under timber floors is to lay a masonry filling under the timer work embedding the heaters. This is however slow and labor intensive process and accordingly expensive. The masonry filler will be heavy too and unless you are sure of the floor strength this method is not advisable.

•  The third method for timber floors is to fix an aluminium plate to support the heater elements from under .This is tedious and costly in terms of material as well as labor.

Evaluation of all pros and cons for the type of installation best suited for your application and the purse is a must prior to finalization. Another aspect you must consider is whether your new under floor heating installation will qualify for any SEI grant aid schemes.