HOME Boilers – what kind is best?

Boiling issues

The cost of fuel is rising fast Replacing your boiler could help

In the home
Andy Wilson

The exceptionally cold weather at the end of 2010 demonstrated to many householders two non-negotiable realities about home heating: Heat output has to be able to meet demand, but equally, it has to stay around long enough to do some good.
My earlier articles on energy in the home (available on mayonews.ie) have concentrated on how heat can be retained in houses and plumbing systems by measures like draught-proofing, insulation work and the lagging of pipes. I have also mentioned the benefits of replacing inefficient open fires with solid-fuel stoves (particularly those with tightly-sealed doors).

Be sure
While this latter suggestion is nearly always beneficial, it’s generally not such a good idea to rush out to replace existing central heating boilers with something different. If your house is cold, it may be due to poor retention of heat in the building, poor plumbing configuration or inappropriate energy usage, and not be the fault of the boiler at all. So sort out these issues first, have the boiler serviced, and if it still doesn’t do the job, consider the alternatives. Nine times out of ten, the boiler is fine.

Boiler types
So what if the boiler does need changing? Do you choose a new boiler that runs off oil, gas, coal, turf, wood pellets or wood? The answer lies in what you can get hold of, and what you expect to be able to get hold of in the future.
Oil is going to get very scarce someday, and when it does it will also become unaffordably expensive, but in the meantime it’s still quite a convenient fuel and can easily be stored in large volumes.
The boilers themselves are also very affordable, so even if you had to switch to something else in six or seven years’ time, it wouldn’t be the end of the world. Similar arguments could be put for gas and coal, and also turf (hand cut or processed briquettes) bearing in mind all these fuels are finite and one day supply will become problematic.

Pellet Practicalities
Wood pellets have become popular in recent years but contrary to common perception, aren’t necessarily that sustainable, as many are imported from Eastern Europe (and even from as far away as South America) and rely completely on oil-driven ships and road freight networks to deliver them to the consumer.
Where pellets have been produced in Ireland, generally they have been a by-product of the construction industry and its former high demand for construction timber and composite boards. However, if virgin trees have to be cut down solely to provide the raw materials for pellets, it begs the question, why not simply use the wood for fuel instead, and save all the energy used in the manufacture of the pellets?     A research project I was involved in a few years ago (the Mayo Energy Audit) found that County Mayo could meet over one third of its total domestic heating requirements from wood produced in sustainably managed deciduous forests and woodland, in combination with a smaller area of coniferous plantation.  The only problem is, most of this woodland has yet to be planted!  The most viable system was identified as medium-term rotation coppicing, whereby relatively slow-growing deciduous trees are coppiced on an 8-20 year cycle.* What is definitely not a good choice for coppicing is hybrid (biomass) willow, as it is very fussy in terms of suitable soils, demands heavy doses of artificial fertilisers in order to maintain yields, and requires specialist harvesting machinery. The only type of willow worth planting is the native grey or bog willow, on waterlogged ground where nothing else will grow.

The final word was going to be on stoves and solar heating, but I’ve run out of space so I’ll cover that in the next article instead. Last bit of advice - if you have a central heating boiler or any form of gas appliance in the house, install a carbon monoxide detector. Now.

The Westport Sustainability Group is running a one day workshop on ‘Coppicing for Fuel Production’ on March 5. For details email westport@sustainability.ie or phone 087 6714075.