By Dave Cromarty, retired forester and Landcare facilitator
At this time of year as we struggle to stay warm, we might ponder how to minimise our carbon footprint with our household heating. During winter, space heating and water heating are a big component of most household carbon emissions so how can we reduce this impact?
The answer, of course, depends largely on whether you already have household heating installed or whether you are planning a new house or replacing space and water heating appliances. If you’re building a new home or replacing aged infrastructure, then insulation and house design are important in allowing you to make good use of the low winter sun angles and isolate parts of the house you aren’t using at various times of the day.
To minimise household emissions, renewable energy sources are the obvious choice – wood heating for space heating and solar or combined solar & wood heating for your hot water system. In the days of open fires and old inefficient wood heaters, smoke was regarded as a drawback to wood heating, particularly in towns and suburbs, but we have come a long way with modern systems if they are well maintained. Remember the old advertising for “clean” electrical heating? Householders could rest assured that there were no emissions coming from their home heaters – the emissions were all occurring at some distant coal fired power station. Now of course, we are more aware that we all share the same global atmosphere.
It is often asked how firewood is better than fossil fuels given that they both emit CO2 when burnt. The answer lies in the fact the carbon in wood is already in circulation. Within a relevant time frame, unutilised trees and dead wood will die, burn, decompose or be consumed by termites. All these processes emit CO2 or methane and so, by sourcing energy from firewood, we are able to keep the fossil fuel carbon in the ground and out of the atmosphere.
Of course, a lot of people are put off by the trouble of getting, splitting and carrying firewood supplies and keeping the fire burning efficiently. This is particularly relevant with our ageing population. In Europe where they have well established sawmills with secure access to forest resources, oil heaters are being replaced with pelletised sawdust as a fuel. The pellets are handled in bulk and feed directly and automatically into a basement furnace which heats both the house and the water. Perhaps this technology is our next big leap into renewables at the household level.