Autocad Design Service for Underfloor Heating

If needed we can also produce a CAD drawing for the loop layout for a small charge.

Normally the hand sketch, project information and the instructions are enough for most customers.

Underfloor Heating Single Room Pack Instructions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PE-rt Adhesive Aluminium (0.2mm) Adhesive PolyePthEy-lret ne-rt

Unit 1

79 Friar Street

Worcester

WR1 2NT

Tel: 01905 616 928

Fax:01905 611 240

E-mail: info@underfloorheatingsystems.co.uk

Website: www.underfloorheatingsystems.co.uk

1. General Information

Read this entire document first!

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Pipe distance for concrete floor is c/c 200 mm to c/c 300 mm and for timber suspended floors

c/c 200 mm.

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Pipe to be 100 mm from the walls. Always go with flow to the cold spots first. See sketch for

typical layout.

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Max loop length is 100 m. Also we recommend two people for fitting the pipe, one person that

holds the coil and another person to clip the pipe into the insulation.

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Fix the pipe to the insulation with the clips provided. You need approximate 1 to 2 clips per

metre of pipe.

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The control unit should always be located near or in the room it is serving.

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The room thermostat controls the pump when boiler is on.

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Try to use all the pipework supplied. The pipe is marked every metre so you know when it is

time to go back to the control unit.

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Pipe is normally not laid under Kitchen and Utility units.

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To fit the pipe to the control unit, cut the pipe end squarely using the plastic pipe cutter. Reround

the pipe end with the calibration tool provided, place the nut over the pipe, then the olive

and finally push in the insert into the pipe and then attached to the control unit.

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If the pipe is kinked when bending, the pipe should be straightened and rearranged so that the

location of the kink remains in a straight length.

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Prevent people from walking over the pipes, keep tools etc away from the pipes.

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Fill the system as instructions provided. Do not fill from the boiler filling loop.

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It is important to purge the pipework from the boiler to the control unit, to avoid air being

introduced into the underfloor heating system.

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Hardwood timber flooring must be conditioned before fixing.

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Screed or chipboard flooring should be laid immediately after the pipe laying to protect the

pipe.

Maximum heat output for underfloor heating systems are 100 W/m

 

2 for concrete floors and 70 W/m2

for timber suspended floors. For any underfloor heating system to work efficiently the property needs

to be built to current building regulations. Carpet and underlay should not exceed 2.5 Tog.

If you are using the single room pack for a Conservatory, note that it will extend the time you can use

the Conservatory for, not to keep it at 20 degree C all year as the heat losses are higher than 100

W/sqm in a Conservatory. Usually, this is also the case with radiators.

Condensing boilers are very efficient with underfloor heating. For combination boilers it is

recommended to check with the manufacturer if the boiler can be fitted with a

secondary pump.

We recommend a minimum of 50 mm of Polyurethane insulation for the underfloor heating system.

This is very high quality insulation and can be used for both concrete and timber suspended floor

constructions.

1. General Information (continued)

Note we do not supply the insulation. Any builder’s merchant will have Celotex or Kingspan insulation

in stock. The quote is based on clipping the pipe direct to the insulation board. We do supply pipe

clips. We recommend 65 mm of screed on top of the insulation for concrete floors, for timber

suspended floors see this document.

The screed must be allowed to dry for a minimum of 4 to 6 weeks before the heating is operated. As

the system is used for the first time, the mixing valve must be set to minimum setting to let the

moisture in the screed to dry out. The temperature should be increased by two degrees every day

until the mixing valve is set at 45°C. Floorboards must have moisture content lower than 7 % before

they are installed. We do not recommend floorboards thicker than 25 mm, see website link under

technical for more information about floorboards. Always check with the manufacturers of any floor

finish that it will work with underfloor heating.

For stone and ceramics tiles it is recommended that flexible adhesives and grout are used. Avoid

underlays for carpet with felt and rubber crumb type. With Vinyl check the vinyl floor manufacturer

that it works with underfloor heating. Laminate flooring should have an expansion gap for movement.

2. Designing the Installation

Below are guidelines on how to design your UFH installation.

Before you commence your installation take time to design your pipe layout to use the maximum

amount of pipe but be careful to make an allowance for the location of the control unit. Set the

pipework in 100mm from all walls/edges.

As the temperature of the UFH system is controlled by the Blending Valve in the Control Unit,

reducing the pipe centres does not increase the room temperature but does reduce the heat up time.

Use the chart below along with the area of your room to determine the optimum pipe spacing. The

spacing is described as c/c; this is the distance between the centreline of the pipes.

Room Size Coil c/c Blending ValveTemperature

25 m2 100 m 300 mm 48

20 m2 100 m 200 mm 45

15 m2 100 m 150 mm 44

If the room is smaller than 15m2 it is still recommended to use as much pipe as possible. But,

normally c/c 150mm is the minimum spacing.

We recommend setting the water temperature at 45°C for screeded floors, which can be increased to

48°C if larger pipe centres are used to achieve a maximum floor temperature of 29°C.

If a timber floor finish or floating floor is proposed set the Blending Valve to achieve a maximum floor

temperature of 27°C to avoid shrinkage of the timber boards.

A typical pipe layout is illustrated below:

3.

Installation

The Compact UFH System is pre-assembled to allow speedy and simple installation for extensions

and conservatories. The control unit comes complete with wall fixing kit and the pump is pre-wired in

conjunction with a flow temperature thermostat. There is also a mains connection point and

removable

link for connection of a room stat (supplied) if desired.

The control unit has integral ball valves for connecting/isolating the primary heating system, an

adjustable thermostatic blending valve and Grundfos 5 metre circulating pump all secured to a fixing

bracket with anti-vibration mountings for silent operation. 1/2” female tappings are provided with

compression adaptors for connecting the UFH pipework.

Before beginning the installation check that there are no missing items. Refer to

the pack contents list below.

List of items included in the Compact UFH System:

• 100 m 16×2 Multilayer pipe

• 200 no. pipe clips

• 2 no. 16×2 pipe adapters

• Tools – 1 no. Pipe Cutter and 1 no. Calibration Tool

• 1 no. 240v Room Thermostat

• Pre-assembled control unit

3. Installation – Preparation

After checking that all the components are included in the packaged it is time to prepare for the

installation of the underfloor heating pipe.

Make sure that the floor is level and clean and the

room is empty. Next install your floor insulation (not

supplied). We recommend a minimum of 50 mm highdensity

(Polyurethane) insulation. Such as Celotex or

Kingspan. High density insulation’s have better

insulation properties and allow the use of pipe clips.

These brands can be bought from most builders

merchants. The clips need the high-density

insulation to stay in place. If Polystyrene is used,

then a lightweight mesh e.g. ref D49 needs to be

installed on top of the insulation and the pipe tied to

the mesh.

Note, some insulation board manufacturers recommend that you tape the joints to prevent screed

ingress, which can form cold bridges.

3. Installation – Installing the Control Unit

The Compact UFH System is designed for wall fixing and ideally should be

mounted in a horizontal position with the electrical connection box uppermost.

However, it can also be mounted vertical to pump up or down if desired.

Provision should be made to vent air to protect pump from cavitation.

The unit must not be floor mounted or in any position that inclines the pump shaft

vertical. Refer to the pump installation leaflet enclosed.

Choose the location for the unit ensuring adequate clearance and

accessibility

for pipework and any subsequent maintenance. This is particularly important

if

enclosed within a cupboard space for example.

Locate the unit on the wall and mark the hole fixing positions through the

bracket.

Take care to protect any electrical equipment and cables during handling.

When connecting the pipe to the manifold use the cutter supplied to cut the pipe square then

calibrate the cut end to round the pipe ready to accept the compression adaptor. As the adaptor has

integral ‘O’ rings it is not essential to use further sealant such as PTFE tape.

3. Installation – Pressure Testing

Before connecting the unit to the primary circuit it is recommended to pressure test the system.

This can best be achieved by connecting mains pressure hose to the red ball valve and a hose or

bucket to the blue ball valve on the control unit. Open both valves fully & fill the system to purge

all traces of air from the system.

After all the air has been removed it is recommended to pressure

test the system with 6 bar pressure for 24 hours. We recommend maintaining

the system under pressure whilst screeding.

Note

 

 

,

if there is a risk for the air temperature dropping below freezing, then you must protect the pipes

and control unit from freezing. It is always recommended to lay screed on top of the pipes as soon as

they have been pressure tested.

3. Installation – Screeding

We recommend 65 mm of screed on top of the insulation. All installation work must comply with

current Building Regulations. Note that the screed drying time can be up to 4 to 6 weeks

before the underfloor heating system is operated.

The mixing valve needs to be set at minimum temperature when commissioning

the system. Rapid heating of the screed can cause cracking so increase the

temperature by 2 to 3 degrees every day to gently raise the floor temperature to

the desired setting.

3. Installation – Wiring

All wiring should be undertaken by a qualified installer and conform to

IEE

regulations.

To comply with IEE regulations, the pump on the unit is provided with

an earth connection via the connection box.

Connect the Control Unit to a mains fed switched spur fused at 3

amps.

If fitting a room thermostat position in accordance with

the manufacturer instructions and remove the link between terminal

SF &

L as indicated on the wiring diagram.

All wiring should be undertaken by a qualified installer and conform to

IEE regulations.

3. Installation – Connection to the Primary Heating Circuit

After the pipe installation and pressure testing it is time to connect the control unit to the primary

heating

circuit. To avoid ‘starving’ radiators ‘down line’ of the Under Floor Heating system we recommend

connecting the control unit to the 22mm main primary circuit of your heating system, as close to the

boiler as possible.

3. Installation – Operating Principles

When the primary heating circuit is on and the heating water temperature has reached approximately

43°C and the room thermostat is calling for heat, the pump will activate and feed the under floor

heating loops.

The blending valve will maintain the temperature of the heating loop by continually blending the flow

from the boiler with the cooler return flow from the underfloor heating loop.

The heat output can be adjusted with the control knob on the blending valve to suit different floor

structure and comfort levels.

The room thermostat will switch the pump off when the selected room temperature is reached.

When the primary heating is off and the room stat is calling for heat, the pump will continue to run

until the heating loop temperature falls to approximately 30°C. when it will automatically switch off.

3. Installation – Settings

The thermostatic blending valve has a temperature setting range between 35°C and 60°C as shown

below:

Min 35°C

1 40°C

2 44°C

3 48°C

4 50°C

5 54°C

6 58°C

Max 60°C

Initial setting of the thermostatic blending valve (after the heat up/screed drying period) should

provide the following temperatures at the flow pipe control unit. Screeded floors 40-48°C Timber

floors 55-60°C

These initial settings can then be adjusted to provide comfort. A maximum floor

surface temperature of 29°C should not be exceeded (wet areas such as bathrooms, 35°C) as this will

lead to feelings of discomfort. With timber floor finishes including strip laminate products the

maximum floor temperature of 27°C should not be exceeded as this may result in excessive material

shrinkage.

4. Pump/Control Valve Assembly

The Compact UFH

System is designed for wall fixing and ideally should be

mounted in a horizontal position with the electrical connection box uppermost.

However, it can also be mounted vertical to pump up or down if desired.

5. Commissioning

1) Screed or chipboard flooring should be laid immediately after pipelaying to protect the pipe.

2) Concrete screed floors must be cured before any heat is applied, a general rule of thumb is to

allow 1 day per 2 millimetres of screed.

3) Timber floor with drymix infill can have heat applied immediately, the drymix must be dried

completely before laying the flooring.

4) Hardwood timber flooring must be ‘conditioned’ before fixing.

5) It is important to purge the pipework from the boiler to the control unit, to avoid air being

introduced into the underfloor heating system.

6) Initially start the system with the thermostatic valve set at min (35

 

 

°

c).

7) Increase the setting by 2

 

 

° per day, up to a maximum of 48° for concrete floors, max 65°

for

timber floors.

NOTE. When first starting up the system it may take 12-24 hours for the heating effect to

become apparent!

Joists

Insulation

Pipes at 200mm

Centres

Flooring Drymix

The Underfloor Heating system can be fitted in both concrete and timber suspended floors. See

picture above. For other floor constructions please contact us and we will explain installation

procedure, for example you can also do a floating floor.

In concrete screeded floors, the screed acts to diffuse the heat across the surface providing an even

temperature at the floor surface.

Normally a concrete slab is laid over DPM. A 20 mm thick piece of insulation is fixed to the perimeter

walls, to a height to include the depth of floor insulation and screed.

Whilst the edging insulation may be on show it is covered by wall plastering and skirting boards. We

do not supply the edging strip. Use 20 mm Celotex.

Floor insulation is laid to the whole area, joints are taped to prevent the ingress of screed between

the insulation boards. The floor is now ready for the underfloor heating pipework installation.

We recommend a minimum of 50 mm Polyurethane insulation. If there is not enough space for 50 mm

insulation, 30 mm is recommended, but always check that you apply to current building regulations.

We recommend Polyurethane as it out performs Polystyrene and it’s greater density allows for use of

clip fittings.

If you use Polystyrene insulation it is recommended that you install wire mesh D49 on top of the

insulation and tie the pipe with cable ties to the mesh.

The pipe is laid at 200 – 300 mm centres dependent upon design. Care must be taken to protect the

pipework whilst laying the screed. Finally the floor finish is laid.

Always check with the manufacturer of any floor covering that it can be used for underfloor heating.

Timber suspended floors do not conduct heat as efficiently as screeded floors. This means that the

heat output is less.

Some manufacturers use heat emission plates to try and achieve an even temperature on the floor.

This is a very expensive way of installing underfloor heating in timber suspended floors and at the end

of the plate the temperature is not going to be very high. Clearly there should be a cheaper solution

that works without using the very expensive plates. After all, the first floor is usually timber

suspended and on the first floor less heat is usually required. Also note that the first floor is

supplemented by heat from the ground floor.

Our underfloor heating system is very simple and easy to install in timber suspended floors. The

system is based on thousands of installations that are now working with total satisfaction.

Between the joists, a 50 mm Polyurethane insulation board is cut for a tight fit. See picture above. It

is advisable to use scrap battens from building site to support the insulation from below.

The pipe is then clipped on the insulation with our special clips. Then the floor boards are laid on top

of the joists. Be careful not to leave too much air space between the insulation boards and floor

boards (25 mm is recommended). The joists need to be notched where needed for pipe runs.

For ground floor timber suspended or buildings 20 year or older we recommend;

To get the timber suspended floor to act as a screed floor and to give out more heat, the air gap

between the insulation and the floor boards should be filled with a lightweight screed mix. This infill is

normally also required if you are mixing timber suspended floor and concrete floor on the same floor

level.

We recommend the infill for all properties that are not built to current building regulations. The mix

consists of 10:1 sand/cement mix or 8:1 Lytag lightweight mix on top of the insulation, with enough

water to hold the mix together. The additional load imposed on the floor by the mix is approximate 18

kg/sqm. Note that the mix is not intended as load bearing, merely as a heat conductor. The thickness

of the mix should be 25 mm with the pipe included in it.

8. Floor Types

Timber Suspended Floor Between Joists

The Drymix is needed for Ground Floor, older buildings and if concrete floor and timber suspended

floor are on the same floor. For First Floor applications when property is built to current building

regulations an air gap is fine, still good to use the drymix as will give out more heat.

Concrete Floor with Staples

1. General Information (continued)

Water Underfloor Heating Installations

We now have water underfloor heating installers all over the UK.