An airtight house is a prerequisite if you want to reap the full benefit of any new heating installation, but this can pose a problem for owners of draughty, older rural properties-and makes bio-mass, in the form of wood-burning, particularly appealing for them.
A log supply from your own woodland allows you to be profligate and perhaps mind less that 45% of your heat is escaping through your unavoidably non insulated walls. At the same time, you can take comfort in the fact that woodburning is much more eco-friendly than it sounds. The Energy Saving Trust says carbon-dioxide emissions go down by 7.5 tons a year when a wood-fuelled boiler replaces a solid (coal) fired system or electric storage heating. A 70kWH boiler suitable for six bedroom family homes can start from £9,500.
Unlike wood-burning stoves (which are also back in fashion) and randomly fed, traditional log fires, boilers need orderly stacking about twice a day and so are best suited to properties or farms where there is always someone around. They’re easily integrated into existing central-heating systems and some allow conventional fuels to cut in if logs run out. Auto-fed log burners are not yet available, so if you want a hands-off approach, you need auto-fed woodchip or commercially made pellets- and you can’t yet chop and change between logs, pellets and chips.
Set in a luxuriant estate, Grade II-listed Gelli Gynan, in Llanarmon-Yn- Lâl, Denbighshire, has lambswool insulation and a state-of-the-art biomass burner with 100kw capacity that can provide heat for the house, workshops, cottage and swimming pool. £3 million through Savills (01952 239500)
Using commercial products will cost you. However, sports-sponsorship executive Rod Kohler, who installed an extra large, high-spec boiler to service his family’s two adjacent Victorian properties, says producing logs from his own woodland isn’t really free either. ‘I’ve had to factor in my time spent at weekends seasoning and chopping the wood, creating somewhere dry to store it and teaching myself about moisture content. It can be a bit of a pain getting the supply going and ensuring you’ll have it every year, and you don’t fully appreciate the amount you’ll get through.’
He adds: ‘But we were spending £350 a month on liquefied petroleum gas (LPG). If we save £4,200 a year, our burner will have paid for itself in six or seven years, and then we’re looking at making a real saving on utilities and being self-sufficient in a future when the cost of LPG can only go up.’
Technology in the wood-burning sector is advancing fast through pressure on commerce and public services to utilise it. Inevitably, this has led to a proliferation of pushy salesmen, so many people now turn to independent consultants to guide them through the forest of promises. Reenergise Consulting Ltd (www.reenergiserenewables.com; 01428 608462) has overseen installations and provided maintenance support for 100 period houses since 2010.
The company’s Tarquin Henderson, whose most recent challenge has been reducing a £19,000 oil bill on a 14th century property, says: ‘There is a misconception that bio-mass is some sort of ecological rape. In fact, we’re taking back our lost relationship with woodland. If there is an environmental “cost”, it’s in the manufacturing of pellets. Quite a lot of pellets are imported, although that might well change.’
As well as British systems, Scandinavian technology is well established and Mr Henderson says Croatia is gaining a reputation for reliability. If you’re thinking of installing wood burners, there are subsidies available, chiefly in the guise of the Renewable Heat Incentive (RHI), which extends to domestic installations this summer, with first payments due in spring 2014 at the indicative tariff of 5.2-8.7p/kWh.
At present, households can claim the Renewable Heat Premium Payment (RHPP), a lump sum of £2,000 payable for boilers installed after May 2013 (£950 for those installed before that date). RHPP recipients will also be able to get RHI if they meet the scheme’s criteria. Until March 2014, a Green Deal assessment is required to qualify for both RHPP and domestic RHI (visit www.gov.uk/green-deal-energy-savingmeasures for details).
It’s also worth asking about local initiatives-63 properties took advantage of a recent Exmoor National Park subsidy of £3,000. Ground-source and air-source heat pumps are eligible for the RHI, too, and reputable suppliers such as Dimplex sometimes have cashback schemes.
Because of the temperatures you can achieve from ambient heat-reliant sources, these are best considered for outbuildings and swimming pools rather than a draughty main residence. You may need to change radiators and find room for an internal hotwater cylinder.
Which wood for biomass?
Hardwoods such as ash, oak, birch and beech have a slower rate of gasification than softwoods. Fir, pine, spruce and larch will generally burn more quickly.
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