THIS is good news for the environment of course - using ground or air source energy can typically reduce carbon emissions by between 40 per cent and 50 per cent compared with gas and between 55 per cent and 65 per cent compared with oil.

With the Energy Performance of Buildings (Scotland) Regulations Act coming into force on 4 January 2009 requiring the majority of new buildings in Scotland to be given an energy rating from A to G and an Energy Performance Certificate, specifiers are increasingly looking at ground and air source systems with heat pumps to help them deliver energy efficient solutions.

However, the benefits of these systems are not always being fully maximised because there remains a persistent trend amongst some specifiers to match heat pumps with radiators or other conventional heat emitters - eliminating much of the energy efficiency potential of an installation.

Ground and air source energy systems by definition use low flow and return temperatures - typically the return temperature of a ground source loop is 5∫C. This is simply not compatible with radiator systems because the energy required by the heat pump to increase this temperature sufficiently for the radiators to achieve the required output negates much of the savings made by the system in the first place.

Added to this is the common practice of having to oversize radiators when using a heat pump simply in order to deliver the performance required.

Instead, it is underfloor heating which should be paired with ground or air source energy systems wherever possible. Underfloor heating systems can be designed to run with flow temperatures as low as 40∫C compared with 80∫C for radiators, minimising the energy used by the heat pump and achieving average COP (Coefficient of Performance) levels of around 4.2 for a ground source heat pump and 3.8 for an air source version.

Added to this, is the fact that underfloor heating is more efficient overall than a radiator based scheme - even with a conventional heat source it can save approximately 15 per cent on annual heating costs and with a ground source heat pump, this increases to more than 25 per cent.

With energy prices still high and likely to remain a key focus for clients in the future, I believe it is vital that specifiers design systems which fully exploit the real strengths of the new renewable heat sources and avoid compromising their performance by mismatching them with unsuitable heating systems.

Of course, underfloor heating also has aesthetic benefits over radiators with no visible heat emitters on show or to distract from the interior design scheme and greater comfort levels - an underfloor heating system from a company like REHAU delivers constant, steady warmth into the occupied area of a home or commercial premises with no hot or cold spots.

For further information on REHAU’s underfloor heating and ground source energy systems, please call our Glasgow Sales Office on: 01698 503700, go to our website at www. rehau.co.uk or visit us on stand 1145 at the forthcoming EcoBuild exhibition at Earls Court.