Danfoss Pre sales Heat Collector Installation guide

Brand: Danfoss

Model: Pre sales Heat Collector

Type: Installation guide

MAKING MODERN LIVING POSSIBLE

DANFOSS HEAT PUMPS

Installation Guide

Heat Collector

Your ground loop system has been designed

to meet the energy requirements of your home

and should not be modied. The ground loop

consists of one or more continuous lengths

of polyethylene pipe laid at in the trenches.

Precisely how you lay your loop depends on

the land you have available and the digging

equipment you will be using. For optimum

eciency, your trench should be dug to a

depth of a minimum of 1m. If the ow and

returns are in the same trench the ground loop

pipes should be horizontally separated by at

least 1m. Neighbouring trenches should be

separated by at least 1 m.

The minimum bending diameter [please refer

to the manufacturers specications] must be

exceeded, anything less than this and the

pipe will be damaged. A narrow single pipe

trench can be dug as long as a m separation

is maintained.

In the case of a multi-loop system, you must

ensure that your trenching begins and termi-

nates at the same point, i.e. at the location of

the man-hole chamber.

All holes through walls where pipes pass

through should be sealed after installation.

Choose a suitable position in your house, utili-

ty room or integral garage for your heat pump.

The position should be chosen so that the

excavation work for the ground loop outside is

as close to the heat pump as is practicable.

The ground loop constitutes a hydraulic circuit

just like your internal heat distribution circuit.

Any air caught in the loop during operation

will collect at the highest point in the circuit.

Ensure that the loops are installed on ground

that is sloping away from the house or if the land

is at that a fall is created within the trenches.

If this is not possible air bleed points must be

installed at the highest points in the loops.

In planning the layout of the ground loop take

care to avoid any services such as water mains

or foul drains. Should this be unavoidable and

the ground loops come within 1 m of any such

services then the ground loops and/or the

services should be insulated.

Avoid laying the ground loop closer than

1 m from the footings of the house and any

retaining walls. This of course excludes

the nal insulated part of the loop.

Installation Guide Heat Collector

VIBMA102

Please read the whole of this guide carefully before starting the job as there are materials and

equipment that you will need to complete the work successfully.

A pressure test pump capable of

achieving 10 bar pressure.

Compatible connections to connect

the pressure test pump to the

polyethylene pipe.

Pipe end caps.

Pipe end stieners.

A water butt.

Equipment

that you will need

Pre installation

considerations

Planning

the ground work

System with a horizontal

ground loop

It is not advisable to use any mechanical joints

on any buried ground heat exchanger loops.

If your system uses multiple ground heat

exchanger loops you will need a manifold to

connect the loops together. If this cannot be

accommodated next to the heat pump we

recommend that this is sited in a man-hole

chamber so that the mechanical joints can

be inspected at any time. The ow and return

headers from the manifold to the heat pump

should be sized according to the ground

loop and heat pump model. To ensure proper

operation of the system it is essential that

the header pipe diameter has been specied

according to the system pressure drop. If in

doubt please seek advice.

Bleed point construction.

Manual air bleed

Paving stone cover

Cylindrical Sleeve

(Ø 300 mm)

Ø 22 mm pipe

Couplings

Typical single ground loop layout.Example of multi-loop system layout.

Installation Guide Heat Collector

VIBMA102

Pressure testing

the ground loop

Installing the

ground loop

When you are ready to lay your ground loop

carefully roll it out from its coil. It is advisable

to do this before your trenching is started

to allow the pipe to relax. Please ensure that

the pipe does not get kinked as this will need

either repairing or replacing.

If there is a large stone or rock at certain points

along the bottom of your trench a shallower

depth or a reduced horizontal separation can

be accepted for a short length. Dependant

on the make up of the ground it is advisable

to lay sand in the bottom of the trench to

help protect the pipe and give good thermal

contact for the ground loop. A further 100 mm

of sand should be laid over the pipe after the

pressure test has been carried out.

Lay your ground loop in the trenches and take

the ends of the loops into your house leaving

1.5 m exposed above oor level. This is a good

time to place your insulation over the pipe

ends. Cap o or tape up the ends of the open

pipes to prevent debris ingress.

Power is required on site to pressure test the

ground loop. You must pressure test the loops

before back lling the trench.

Fit a pipe stiener into both ends of

the loop.

Fill the loop with clean water. You should

let the water run through the loop for at

least 10 minutes after it rst emerges

from the end of the pipe. This will allow

any trapped air and debris to be purged

from the loop.

Fill the pressure test pump with water

and connect to the loop ensuring a good

air tight seal.

Pump water through the loop until you

get a small ow out of the open end of

the loop.

Fit an end cap to the open end of the

loop. Secure tightly.

The test pressure must be 1.5 times the

operating pressure. Take care to follow the

instructions supplied with the pressure

If a duct is being laid prior to the ground loop

being installed this must be of the type that

has a long radius bend to accommodate the

minimum bending diameter of the pipe. Alter-

natively loop tails can be brought in through a

common hole. All inlet methods should allow

for the insulation in addition to the pipe dia-

meter. After the loop system has had its nal

pressure test carried out use a suitable sealant

to close any gaps.

The initial pipe run from the heat pump down

to the bottom of the trench must be insulated

for at least 1m from the building to avoid frost

damage. The insulation used should have a

wall thickness of at least 13 mm.

Passage of pipes through exterior wall.

Exterior wall

Seal

Foundations

Sleeve

Wall cavity

HDPE/MDPE

header pipe

Insulation for

1 m either side

Danfoss Heat Pumps UK

3 Parkwood Business Park

Parkwood Business Park

Sheeld

S3 8AL

Phone: 0114 270 3900

Fax: 0114 275 1398

Email: info[email protected]

www.uk.heatpumps.danfoss.com

Danfoss assumes no responsibility for any errors found in the catalogues, brochures and any other printed material. Danfoss retains the right to make changes to their products, including products that have already

been ordered, without prior notice, as long as these changes can be carried out without changing predetermined specications. All trademarks in this material belong to respective companies. Danfoss and the

A single ow and return, insulated, pressure

tested and capped o at the position of the

heat pump is required before installation can

take place. All ground loops connecting to

the manifold must be of equivalent length to

ensure equal ow rates.

The chamber should be sized according to

the number of ground loops feeding into it.

Plan the exact position of the manifold and

man-hole chamber carefully to avoid the need

to bend the connecting pipes sharply. All pipe

work above ground and that less than 1m

below should be insulated as previously speci-

ed. The ow and return from the manifold

to the heat pump must be pressure tested for

integrity as per the ground loops.

tester. If there is still some air trapped in

the loop this might take some time to

bleed out.

Record start pressure.

Visually inspect the loop for leaks.

When the pressure falls, the loops are

to be pumped up to the test pressure

again. This is to be repeated until the test

pressure is constant.

Record the pressures at 5 minute inter-

vals. After 20 minutes, check whether the

pressure has fallen. If the pressure has fallen,

the leak must be repaired, after which it is to

be again pumped up to the rest pressure.

Repeat the above until the pressure is

constant at 1.5 times the operating pressure

20 minutes from the last pumping.

After completion of the pressure test remove

the ttings but do not try to retrieve the pipe

stieners. Repeat for each loop.

Lake water heat pumps extract the solar energy

stored in lake water through a collector loop

that is lowered to the bottom of the lake. The

hose is laid on the bottom of the lake or water-

course, with weights holding it securely in

place. The principles of loop spacing, pressure

testing, header pipe and manifold installation

are the same as for ground loops. Man-hole

chambers should be installed at a suitable

point above the water table.

Systems using

pond or lake loops

Manholes chambers for

ground loop manifolds

Installation Guide Heat Collector

VIBMA102

Back lling.

1 m

Sand back ll

Backll hand

compacted

Backll

mechanically

compacted

0.3 m

0.1 m

Note:

When digging and working in trenches

local health and safety regulations must

be applied.

As a rule trench walls should be supported

as the work progresses and this is a manda-

tory requirement for all excavations greater

than 1.2 m deep.

If in doubt please seek specic local guid-

ance appertaining to trenching, excavations

and earthworks.

After a successful pressure test you can now

backll the trenches taking care to ll

around the loops with sand as recom-

mended. Loops should be capped after

testing to prevent dirt getting into the

system.

Danfoss Pre sales Heat Collector Installation guide

Danfoss Pre sales Heat Collector Installation guide

Danfoss Pre sales Heat Collector Installation guide

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