Residential - Tips & tricks - Back-up heater fuel

Everyone’s aware of environmental issues these days. So to help you stoke your fall fires in a way that’s as “green” as possible, here’s some useful information about fuels used by back-up heaters, and the impact they have on the air we breathe.

Heating with wood is far from being innocuous. The smoke it releases into the atmosphere contains a hundred contaminants that poison the environment – carbon monoxide (CO), volatile organic compounds (VOC), fines particles, mononitrogen oxides (NOx), polynuclear aromatic hydrocarbons (PAH), dioxins, furans and more. In Quebec alone, residential heating with wood accounts for nearly half the amount of fine particles emitted and one quarter of all VOC emissions each year. In addition to contributing to the greenhouse effect and winter smog, these airborne particles constitute a major health hazard, especially in the case of cardiorespiratory illnesses, as they can penetrate deeply into airways due to their very small size. Some substances are recognized carcinogenics.

But it’s not all bad news when it comes to burning wood for heat. It is, after all, a renewable source of energy, and it’s ecofriendly when burned efficiently. According to Environment Canada, pollution caused by woodsmoke can be greatly reduced by using EPA-certified (US Environmental Protection Agency) equipment designed to produce a minimum amount of polluting particles into the outdoors as well as within the house. These use two different methods of burning wood: advanced combustion and catalytic combustion. Advanced combustion provides a second combustion zone in which the pollutants contained in the smoke are burned off before leaving the stove or fireplace. Catalytic combustion directs combustion gases toward a catalytic filter where the pollutants are destroyed. This system is generally more efficient, but the filter must be replaced regularly.

EPA-certified fireplaces and wood stoves produce less smoke and fewer pollutants than traditional ones. According to Environment Canada, they emit only 2 to 5 grams of pollutants per hour, compared to 25 to 50 grams per hour for non-certified appliances. What’s even more interesting is that a traditional wood stove operating for nine hours emits as many fine particles into the atmosphere as a certified stove operating for 60 hours! Certified fireplaces are also more energy efficient. Due to a more thorough combustion, they burn up to 33% less firewood and produce up to 20% more heat than traditional fireplaces. The result is a reduction in wood being harvested from forests, lower heating costs and less pollution. For the sake of the environment and your bank account, look for the CSA (Canadian Standards Association) sticker, which too is an indication that the stove or fireplace pollutes less.

To fully reduce the amount of harmful particles escaping from your fireplace or wood stove, even with one that is EPA-certified, there are certain procedures that need to be followed. But before you buy, choose the smallest one that can meet your needs: it will burn wood more efficiently and produce less pollution. Never burn wood that is green or “wet.” Avoid household waste, plastics, treated or painted wood, or coated paper, as they produce a lot of toxic fumes when burned. Use dry wood that’s split into small pieces to maximize flammable surfaces as well as provide the cleanest possible combustion. Keep the flames alive and make sure the fire does not smoke for a long time after having been lit or revived; a smouldering fire is very bad for the environment. From time to time, go outside to check the smoke escaping from the chimney. Excessive, black or foul-smelling smoke indicates poor combustion. Do not shut your stove or fireplace’s air registers when the combustion chamber is full, as the fire needs oxygen to burn properly; otherwise, you’ll get pollution inside as well as outside the house.

If you’re concerned about deforestation, there are synthetic logs on the market made of compressed wood waste. You may find these to be a more acceptable compromise, environmentally speaking. They also produce less creosote due to their low humidity level. Furthermore, they make less smoke, which means fewer fine particles into the air than traditional wood logs, and produce more heat, burn longer, and because they are made from recuperated industrial waste, burning them instead of wood logs helps in the fight against deforestation. On the other hand, producing them generates greenhouse gases – but so does cutting real logs.

Natural and propane gas
Although natural and propane gas produce much less carbon monoxide and fewer particles than wood, they do come from non-renewable fossil fuels. Their extraction, refining, transportation and combustion affects the environment and results in greenhouse gases being emitted into the atmosphere. Furthermore, according to Natural Resources Canada, they release large amounts of water vapour into the air. But there are energy-efficient gas fireplaces on the market that burn less energy and produce a lower amount of greenhouse gases. A well-tuned and properly maintained gas fireplace also makes for the most efficient combustion.

In Quebec, thanks to hydroelectric power, electric fireplaces do not involve emissions that directly contribute to atmospheric pollution. This makes them the most environmentally efficient appliances. But in terms of energy output, they produce the least amount of heat. They’re usually chosen for the ambiance they create.

Pellet fireplaces and stoves emit fewer polluting particles than do traditional wood-burning appliances, mostly because the sawdust from which the pellets are made contain much less water that do wood logs. As logs burn, their water content contributes to pollution; but pellet stoves and fireplaces transform approximately 80% of their fuel into heat. What’s more, their fuel is made from recuperated industrial sawdust, which would otherwise end up in the dump. But because nothing’s perfect, it must be pointed out that during their manufacture, energy is consumed and polluting particles are emitted. For an environmentally friendly appliance, look for one that is EPA certified.

Original article by Jacqueline Simoneau, Translated by John Woolfrey