Here HVR editor Paul Braithwaite gives his editorial comment on heat pumps.
Heat pumps have been used in the UK since the 1950s, or thereabouts.
But it is only recently that they seem to have come into their own - although the air conditioning
industry saw their potential way back. It used heat pumps in its systems and, consequently, stole a march on other manufacturers.
Today, the heating world has changed.
There is legislation to consider, worries about the ever-increasing cost of fossil fuels, and concern about the environment. In the current economic climate, most bosses in the commercial sector are more worried about staying in business than how green their firms are. Many householders are struggling to pay mortgages, so environmental concerns go out the window.
Don't get me wrong, a heat pump system costs more than one with a condensing boiler, but there are grants - although not enough in my opinion.
There is a fairly long payback period, but this is becoming shorter by the day. All of this means the heat pump is back in favour here.
The rest of Europe has embraced the technology. Continental Europe has, traditionally, been less sceptical than the British.
I have been writing more and more about heat pumps in the past couple of years. But I am surprised at the increasing number of case studies in which heat pumps are the primary source of heating and hot water. And the more I hear, the more I realise the potential of the equipment.
All three variants - air, water and ground source - of the heat pump have their advantages and
disadvantages for a particular application, but all have a coefficient of performance (COP) of at least 3.5 (3.5kW of energy for every 1kW of electricity). The condensing boiler has efficiencies of about 90%.
Further, heat pumps can be used in conjunction with other renewables, and we have the ability to control the different technologies as they come together. There is no reason why, for instance, a care home should not use the heat pump to heat the rooms, while during the summer a solar thermal unit supplies nearly all the hot water needed. The heat pump would be the back-up, and would supply the hot water when the sun doesn't shine.
There are other initiatives. Mitsubishi, for instance, has linked with Thermoscreens to introduce a heat pump air curtain. I am sure there is more technological crossover to come. Indeed, the heat pump solution is being used in more and more new homes to provide comfortable underfloor heating.
The heat pump is tried and tested and, Tony Bowen of The Heat Pump Association insists, there is more to come.
As the technology continues to improve, then so will the COP. Already, some manufacturers are
beginning to quote more than the 3.5:1 ratio. For the heat pump, there is only one way to go - and that is up. But manufacturers must play their part.
Training is essential, otherwise installers will go the way they have always gone.
While it is the commercial sector that is leading the charge - an industry source estimates a £300M spend in 2007 - as far as the heat pump is concerned, it is the emerging domestic sector that has the greatest potential.
But it also has training issues that need to be resolved fairly rapidly if installers are to offer heat pumps as well as condensing boilers. The industry is already addressing this. As Bowen says in his interview, the Microgeneration Certification Scheme was set up for just this reason.