Underfloor Heating Installation tips

There are a number of factors to think about when installing underfloor heating. If you are thinking of installing for the first time, then read the important points below

Pre-Installtion

Before commencing installation the installer should have all the information and components as follows:

Design sheet. The installer should have the design sheet(available from U.F.H company), which shows all the room details, and manifold valve settings.
Pipe layout drawing. This drawing shows the pipe distribution from the manifold and manner in which the pipe should be laid. The drawing also incudes a list of the zones and details such as loop identification, pipe spacing, flow rates and loop lengths.
Materials. The installer should cross-reference the materials and quantities against the materials list/quotation and delivery note.
Special instructions.
Closed installation area. The installer should ensure that other trades are excluded from the area while installation is underway.

Installation of The Manifold

Refer to the “System Components” section for a description of the manifold. Ideally the manifold should be located in an area, which lends itself to allow equal lengths of distribution pipe work. As previously seen the mixing kit that is coupled to the manifold is 381mm in length. The manifold lengths are as follows:

No.of Circuits
Length (mm)
2
320
3
370
4
420
5
270
6
520
7
570
8
620
9
670
10
720
11
770
12
820

Note the above dimensions include the de-aeration end caps and ball valves with thermometers.

Installation Procedure:

Decide on the manifold location ensuring accessibility after construction is complete.
Connect the terminal sets (this incorporates a port for a hose connection and an automatic and manual air vent) to pre-assembled manifold.
Fit the mixing kit to the manifold.
Ensure the brackets are tightened on the manifold and fix securely to the wall using pre-drilled holes on the brackets. Note the manifold should be positioned 300mm to 450mm above the finished floor surface. If there is no wall existing at the time of installation mount the manifold on a temporary structure.
Push fit the Pexal pipe adaptors into each of the outlets on both the flow and return manifolds.
Fit the thermostatic head to the injector valve and secure the immersion probe into the mixing kit.
Fit the safety immersion stat to the mixing kit.
Using the compression fittings connect the pipes to the manifold ensuring the loops are installed according to the design.
Using the balancing key supplied regulate the supply manifold port valves as per the design sheet i.e. “no. of turns”.
After commissioning, fix the thermo-electric actuators to the return manifold.

Installation of The Pipe Loops

Depending on where the highest heat losses occur for a particular zone the pipe loops or circuits can be laid in a number of different patterns or the pipe can be laid at different spacings, i.e. the pipe can be laid at smaller centre-to-centre distances in areas where a high heat loss occurs. Some typical layouts are described below:
Single serpentine pattern –used when one wall represents the major heat loss of the zone. The supply pipe is laid in a serpentine fashion from the outside wall therefore the pipe water temperature is highest at the outside.
Double serpentine pattern – used when two walls are considered the major heat loss of the zone. Again the same principle applies as above however in this case the pipe is laid in an “L” shape along the two external walls.
Triple serpentine pattern – used when three walls are considered the major heat loss of the zone.
Spiral pattern - used when there is an even heat loss throughout the room. The supply pipe is laid along the walls of the room spiralling inward at twice the design spacing. At the centre of the room the pipe continues in an outward spiral and is laid between the supple pipes thus giving the desired pipe spacing.


Installation Procedure:

Ensure the insulation is installed as per the floor construction (see “Structural Requirements” section).
Laying the pipe needs two people. One holds the pipe coil and unrolls it while the second fixes the pipe.
Refer to the pipe layout drawing and install the pipe tracking over the insulation across the direction of the pipe. The tracking should be placed at intervals of approximately 1100mm.
Refer to the pipe layout drawing for the manifold location. Do not cut the loop length form the coil. Run the pipe to the edge of the zone, this length should be insulated.
The pipe is laid at a distance of 100mm from the perimeter. The loop is laid as per the layout-drawing pattern and pipe spacing. On completion the pipe is run back to the manifold location.
The loop of pipe is then cut and its loop identity and length are recorded. The flow and return leg of the loop and its identity should be marked for connection to the manifold.
Carry out the same procedure for each loop.

Heating Solutions Ltd

Solar Panels – Underfloor Heating – Heat Pumps 29 Suil na Habhann, Mill Rd, Limerick, Ireland Tel: 086 3823062; Fax: 061 346011 Email: info@heating-solutions-ireland.com http://www.heating-solutions-ireland.com/