The wood heating controversy

Is it an environmentally responsible way to heat... or not?

Many people are re-considering wood heating. With oil and gas being a non-renewable resource, not to mention the uncertainties of yoyo prices, it just makes sense. Depending on where you live, wood may be plentiful - and if you own the land, it's free. It's renewable – and if you replace downed trees with new ones, it's carbon neutral. Sounds great...

But is it environmentally friendly?

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First the downside

When the combustion of wood is complete, only carbon dioxide (CO2) and water are emitted into the air. Unfortunately, that's not generally the case. More often smoke results from the incomplete combustion of wood - through inefficient appliances and poor burning habits.

Wood smoke is a fairly toxic substance. There are fine microscopic particles in smoke - specks so small they can lodge deep in your lungs. These tiny particles of soot can be detrimental for those with heart disease and can trigger asthma attacks, so sensitive populations such as children, the elderly, those with heart disease or asthma are of concern. Even if your doors and windows are closed, the smoke particles will still find their way into your home.

Results obtained between the winter of 1999 and the summer of 2002 in the residential area of Montreal, Quebec, Canada - where wood heating is significant - indicate that wood combustion contributes to the deterioration of ambient air quality. Concentrations of certain pollutants can be five times higher in winter than in summer.

The controversy over wood heating has created conflict in some communities - to the point of becoming quite a divisive issue.

The good news

The internal design of wood stoves has changed entirely since the US Environmental Protection Agency (EPA) issued standards of performance for new wood stoves in 1988. EPA's mandatory smoke emission limit for wood stoves is 7.5 grams of smoke per hour (g/h) for non-catalytic stoves, and 4.1 g/h for catalytic stoves. The new energy efficient stoves burn wood about 90 per cent cleaner and one-third more efficiently than the older conventional appliances. However, despite federal regulations, it's said that up to 90 percent of the estimated ten million indoor wood stoves in the US fail to meet emission requirements.

If you have an older non-certified wood stove, consider purchasing a cleaner, more efficient stove.

The use of wood burning boilers is growing dramatically. Although they are thought by many to be a "dirty" way to heat, in January 2008 the US Environmental Protection Agency's new guidelines for outdoor wood boilers went into effect, and manufacturers have started making cleaner burning wood boilers.

Lisa Rector, a senior policy analyst with NESCAUM, the Northeast States for Coordinated Air Use Management, which represents air quality agencies in six states, said in 2008, "Just three years ago there were about 150 thousand outdoor wood boilers in the US. Today there are a quarter of a million" and she predicts the number will soon double."If sales trends continue there would be half a million in place in 2010."

The new, cleaner burning wood boilers are considerably more expensive but consider this - in one case we read of, a neighbor questioned a homeowner about his new boiler, "When are you going to get this thing running?" The furnace had been up and running for almost a week and they didn't even know it was operating.

It's not just the technology - it's also up to you

Manufacturers have developed more efficient stoves and boilers but poor burning practices are part of the problem. Homeowners sometimes toss green, moist wood into their fires, along with rubbish and newspapers.

Properly dried wood (six months minimum) will burn with less smoke than damp wood. The Environmental Protection Agency recommends wood that has been air-dried at least a year.

According to woodheat.org, the way you manage the fire in your wood stove or wood burner has a big effect on how much smoke you make. "When things are going well, this is what you should see:

• When wood burns it should be flaming until only charcoal remains. If there are no flames, something is wrong
• If there are firebricks in the firebox, they should be tan in color, never black
• Steel or cast iron parts in the firebox should be light to dark brown, never black and shiny
• With seasoned wood, correct air settings and proper loading arrangement you should expect instant ignition of a new load of wood - the bottom pieces should be flaming by the time the door is closed
• If the appliance has a glass door with airwash, it should be clear
• If the appliance has a glass door without airwash, it will be hazy, but should never be totally black
  

  

• The exhaust coming from the top of the chimney should be perfectly clear or white with steam. A plume of blue or gray smoke indicates that you have a problem"

Having wood the right length and range of size makes it easier to build clean burning fires.

Seasoned wood looks dark, or gray when compared to green wood - but if you split a piece of seasoned wood - it's WHITE on the inside. It's brittle, or gnarly. It has cracks running through each piece, and a lot of little cracks on the inner rings.

Unseasoned wood has a wet, fresh looking center, with lighter (drier-looking) wood near the edges or ends which have been exposed since cutting. When firewood is very fresh, the bark will be tightly attached. Hardwoods take longer to dry - especially oak.

Check local regulations

We think wood heating can be cost effective and environmentally friendly if the homeowner is responsible in their choices.

There's no doubt that choosing wood heating probably makes more sense in the countryside than for urban areas. But before you invest in an energy efficient wood stove, fireplace insert, or outdoor wood burning boiler, check out your local bylaws.

Bylaw control strategies can include:

• Limits on total emissions from wood heating appliances
• Incentives or impose disincentives to limit emissions including financial assistance strategies to encourage change-out of non-certified wood burning appliances
• Restriction on some fuels
• Regulations regarding installation of wood burning appliances and non-certified appliance removal
• No burn days

Finally, some recommendations from the US Environmental Protection Agency (EPA):

• Use a properly installed, vented EPA certified wood stove
• Have the wood stove cleaned and inspected annually
• Use safe, efficient wood burning practices
• Never burn household garbage or cardboard. Plastics and the colored ink on magazines, boxes, and wrappers produce harmful chemicals when burned
• Never burn coated, painted, or pressure-treated wood because it releases toxic chemicals when burned
• Never burn ocean driftwood, plywood, particle board, or any wood with glue on or in it. They all release toxic chemicals when burned
• Never burn wet, rotted, diseased, or moldy wood
• Only bring into your home the amount of wood needed for a day to reduce the chance of allergy-causing mold spores circulating indoors