Groundwork

Survey

It is strongly recommended that a ground survey is carried out to identify any service/utility pipes or other underground obstacles in the area, before any groundwork commences.

Groundwork considerations

All groundwork should be carried out with the proper safety considerations appropriate to the depth of any trench work being carried out. Shuttering should be considered on steep sided trenches where people will be working.

Groundwork contractors

An experienced groundwork contractor should be used for trench work. Services can be obtained from:

Bemand Contracts Ltd, Holloway Common Farm, Hampton Charles, Tenbury Wells, Worcestershire WR15 8PY Telephone 01885 410338
Website: www.bemandcontracts.com

Consideration should be given to settlement of the backfilled earth.

Borehole contractors

Specialist borehole contractors will be required for vertical collector installations. Contractors are normally able to drill the borehole and supply, fill and install the collector ready for connection by the installer. The collector must be filled before being lowered into the bore hole. The contractor should be able to provide a geological survey of the area before drilling commences.

Borehole services can be obtained from:

WB & AD Morgan Ltd, Presteigne Industrial Estate, Presteigne, Powys LD8 2UF Tel: 01544 267980 Website:www.findingwater.co.uk

Ground loop connections

Pipework connecting collectors to the appliance should be buried to a depth of between 800mm and 1,200mm. It must also be insulated in accordance with the recommendations made in the insulation section. The maximum permitted bend diameter for 40mm PEM pipe is 1m.

Where possible collector pipework should be run in the longest single lengths possible to reduce the number of connections in the system. The connections in 40mm PEM pipe or compact collectors can be made using ultrasonic welding equipment or using compression fittings.

Suitable fittings are available from:

Uponor Housing Solutions Ltd, Snapethorpe House, Rugby Road, Lutterworth, Leicestershire LE17 4HN Tel: 01455 550355

George Fischer Alprene, P.O. Box 2932, Coventry CV2 2YZ Tel: 024 7653 3800

Philmac, Diplocks Way, Hailsham, East Sussex BN27 3JF Tel: 01323 847323

Plasson UK Ltd, Parbrook House, Natts Lane, Billinghurst, West Sussex RH14 9EY Tel: 01403 782782

Care should be taken to ensure that all connections remain clean and free from debris and all pipe ends must be capped when not in use. It is also important to ensure that pipe cuts are fully deburred. It is recommended that hose pliers are used to make clean pipe cuts.

A fluid leak test should be made on all connections between the heat pump and the ground loop.

It is recommended that external pipework is marked to ensure that the correct connections are made at the heat pump.

Ground loop testing and filling

The collectors should be pressure tested with air before filling. A 40mm PEM pipe loop system should be tested to a pressure of 3-4 bar over a period of 2 hours. Compact collectors should be pressure tested at 3-4 bar for a minimum of 3-4 hours.

Care should be taken when disconnecting from the ground loop. Ensure that the pressure is reduced fully before disconnection.

After filling the system with the required concentration of heat transfer fluid the filling pump should be run for an hour to ensure that all the air has been purged from the system.