HVR Magazine

Braithwaite's Blog by Paul Braithwaite

The editor's chance to air his thoughts about the industry and anything else he'd like to get off his chest.


Contributing to substantial energy savings
07/11/2007 16:51:00
It was only a couple of years ago that one of HVR’s contributors said the condensing boiler with its sophisticated controls had gone as far as it could with regard to energy efficiency. Only better controls would generate more efficiency. Then I, and I suspect you, would have agreed with him.

This prompted a call from Chris Farrell, owner of Zenex, who had invented the gas saver unit which fitted on the top of a condensing boiler and used the heat from the condensate to pre-heat the water flowing into the boiler. The hotter water uses less gas to heat it to the required temperature for central heating or DHW. Since then things have changed radically in the market.

Driven by legislation from a UK government (which I believe knows little about environmental concerns and cares less), and from Brussels (which might care more but is so remote from the people it governs), the building services industry has produced many of the engineers who have been able to innovate to meet and beat the strictures of these tigher laws.

The latest innovation is from Louis Pickersgill and his team at Ravenheat. To me, like many inventions, his heat exchanger is simplicity itself to make. But someone had to have the idea.

The rest of us have been watching the pluming from the boiler for the last few years, possibly not realising how much energy is wasted – not to mention the cost for the environment. Harness that heat – and bingo! – Ravenheat has an invention which cuts fuel bills for the householder and cuts emissions to the environment.

Imagine if all houses could cut emissions and fuel costs by 5%. When the boiler is running for either DHW or central heating, it produces waste heat and Ravenheat’s Energycatcher heat exchanger unit uses this waste to heat ambient water from the mains. As the water heats up it rises (I remember that from my physics lessons) and goes into a tank positioned (obviously) above the boiler. This can then be drawn off to run a bath or a shower or used for the washing up.

Pickersgill says that the waste heat from the boiler will heat a 120 litre tank of water (for a three-bedroomed house) to 60ºC in a couple of hours. He reckons that up to 90% of DHW will be free during the winter saving a householder with a three-bedroom detached house some £110 a year.

The Energycatcher can be used with most condensing boilers but installers should check with the manufacturer because of the hotter water which will be fed into the boiler. The Energycatcher can be used in commercial applications. The unit will fit on to each boiler in a cascade and feed a cylinder, or cylinders, for free hot water for the staff. You can learn more about the Energycatcher in HVR’s December issue.

In the meantime our politicians can get on with what they do best – claiming their allowances – while the building services industry gets on with doing what it does so well – innovation!

I take my hat off (I wear one during the winter) to people like Louis Pickersgill of Ravenheat and Chris Farrell of Zenex who have ability and passion and everyone else in building services who are beavering away to save this planet.

Some 5% less emissions on one condensing boiler may not seem a lot but put those 5%s together with all the other savings the building services industry has managed and it is substantial.