Environmentally friendly heating & green energy

Geothermal space and solar water heating have been used widely in Northern Europe for more than a decade; it is a cheap, technically simple, absolutely reliable long life system which effectively just replaces a central heating gas or oil-fired boiler with a ground source heat pump. A roof-mounted solar collector, which looks similar to a conventional roof light, supplies most of your summer and a proportion of your winter hot water for free. The heat pump utilises underfloor heating, judged by users as the most pleasant form of central heating, so there are no radiators or pipework visible in the house. Most importantly, it is about 70-80% cheaper to run than a conventional condensing boiler using LPG/propane or oil and about 60-70% cheaper than natural gas at present prices. The cost advantage is likely to improve as gas and oil prices rise. Furthermore, since it utilises only off-peak electricty, you will not need either to store oil or bulk gas or remember to order new deliveries so it is safer and cleaner. It is fully automatic and fail-safe and is controlled by room and tank thermostats as in any other system. As part of government incentives to reduce energy consumption and carbon emissions, The DTI (Department of Trade and Industry) and the BRE (Buildings Research Establishment) are encouraging this better technology and subsidising domestic installations (£1200 for GSHP and about £800 for solar thermal) and up to 50% for community projects. You will be much less dependent on fuel price rises.

Geothermal energy means simply taking heat from the ground and pumping it into your building; the ground source heat pump achieves this. For each 1kWh of energy paid for by you, the heat pump collects 4kWh from the ground – hence the huge cost savings. The ground below about 1m maintains a temperature of about 10°C all year round and is a reliable and inexhaustable reservoir of heat provided ultimately from the sun warming the earth. Nothing is burned, so no direct carbon emissions; the only power requirement is the electricity used to operate the heat pump.

The heat pump works exactly like a refrigerator. In a refrigerator, the small heat pump (the apparatus behind the fridge) pumps heat from inside the fridge (thus cooling it down) and dumps the heat into your kitchen via the radiator grill at the back (feel it, it’s warm!). The central heating ground source heat pump is much larger (about the same size and appearance as a boiler) and collects heat from coolant circulating in coils of plastic pipe buried in your garden. This coolant (at 10°C) is cooled by the heat pump to about 0-2°C and the heat is delivered to coolant circulating in the underfloor piping (maintaining its temperature at about 35°C), thus warming the floor and your house. This heat transfer occurs continuously while the heat pump is on (at off-peak electricity times). The underfloor heat is stored in the concrete floor slab and is released slowly over the day and night maintaining an almost constant temperature in the house. The only mechanical parts in the system are the circulation pumps (standard central heating pumps) and the compressor of the heat pump, so the system has a much longer maintenance-free life than any other heating system and so saves significant replacement and maintenance costs too.

This simple technology has now reached high levels of sophistication and efficiency and can easily supply almost all of your hot water requirements in summer and a significant proportion in winter. In an independent DTI survey in a real family house, the solar panel provided an average 68% of total hot water used over a whole year. Any back-up heating via an off-peak immersion heater (the 2nd cheapest water heating) is automatically brought in if there is any shortfall from solar and together the system can provide limitless supplies of hot water. The solar collector on the roof (about 1m2 per resident) consists of a thin stainless steel envelope coated with a heat absorbing surface which collects a high proportion of all radiant energy from the sun. As soon as the water in the collector reaches a pre-set temperature, it is pumped through your hot water cylinder to store the heat. Heat collection occurs even on hazy and thinly overcast days. Fail-safe systems ensure that the collector does not overheat.

We offer a totally integrated solar and ground source central and water heating system which is fully automatic and we recommend it for any new build project, barn conversion or major renovation (since underfloor heating is required). It is possible to fit the system to existing wet underfloor systems to replace the boiler or even (with oversize radiators) to radiator systems – but consult us about this.