wood burning stoves

An Engineer's Perspective on Heating with Wood and Other Solid Fuels
by Curt M. Freedman, M.S.E.M., P.E. (see resume)
In a blind attempt to stay warm for less money, many people are mistakenly choosing to burn solid fuels such as wood, wood pellets or coal this winter. The alleged popularity and benefit of heating with wood or other solid fuels is simply not justified by the expense, detrimental health impacts of "second hand" wood smoke, fire hazards, and poor heating performance of wood stoves. Newspapers and magazines as well as movies and television that promote the use of wood stoves and fireplaces as being romantic and natural do not responsibly present the detrimental health and safety ramifications of heating with solid fuels nor do they discuss more cost-effective alternatives that would promote improved energy conservation, health and safety.

Interest in energy conservation has increased recently due to the following developments:

a) Increase in natural gas prices caused by increased demand; the Wall Street Journal has reported that the increase in demand can be directly linked to the increased utilization of natural gas for electric power generation.

b) Increase in demand for oil and higher prices caused by the strong global economy;

c) Unrest in the mid-east;

d) Concern for price volatility caused by low domestic oil supplies;

As a licensed professional engineer in the Commonwealth of Massachusetts specializing in energy conservation and a technical advisor for "Burning Issues", (Burning Issues is an advocacy group that promotes cleaner burning fuels) [www.burningissues.org], I have two major concerns over the use of wood for heating (I am not a representative or spokesman for the oil, natural gas or propane industries nor do I have any financial interests in the above industries):

A) There is inadequate economic benefit to burn wood; a modern high efficiency oil, propane or natural gas appliance will out perform a wood or pellet stove.

The availability of split seasoned wood is decreasing and the cost is increasing; in fact, most of the firewood dealers that were contacted in the Springfield Yellow pages were completely out of wood. The energy cost value of wood products is not cheap. Wood at $140/cord is equivalent to oil at $1.53/gallon (I have locked in with my dealer @$.91/gallon) and natural gas $1.12/Therm (I obtain natural gas @ $.65/therm). Wood pellets @ $2.78 per 40 pound bag is comparable to oil @ $1.73/gallon and natural gas @ $1.27/Therm. When one adds the $1,500 to $4,500 initial equipment cost and the ongoing value of a persons time to clean the stoves and load the fuel, an investment in a solid fueled wood or pellet stove may be financially unsound.

B) There can be significant health impacts; a wood stove is 500-1,000 times dirtier than a modern oil burner.

Wood smoke emissions contain fine particulate pollution and can have similar detrimental health effects as tobacco smoke. Experts have documented that the chemical components in wood smoke cause irritation to the respiratory system causing bronchitis, asthma, and sinus infections weakening the immune system resulting in a lower resistance to infectious diseases. I feel that it is time for more responsible energy policies to direct citizens in a more environmentally and economically smarter route on the highway to the 21st Century. I feel that the public should know that returning home in a gas guzzling SUV to their glass enclosed family room heated with a wood stove and a redwood Jacuzzi heated with wood from an 80 year old red oak tree may not be environmentally friendly. I feel that we need to utilize equipment that has comparable emission levels and protects clean air quality standards. I feel we need to more aggressively promote energy & electrical conservation to reduce our emissions from, and consumption of fossil fuels. I do not feel burning formerly healthy hardwood trees is the proper utilization of our forests.

My experience with fine particulate air pollution began seven years ago when my neighbor installed an EPA approved wood stove (with a catalytic converter) that resulted in my normally healthy lungs bleeding from bronchitis and my son being hospitalized. I resolved the problem with my neighbor by investing in a natural gas hydronic heating system for their family room so they could choose to utilize a heating system that releases 1/500th the PM1O and PM2.5 pollution of a wood stove. After this experience, I became an advocate in my community identifying problems with the use of solid fuels and promoted Best Available Technologies or "BATs" utilizing conventional heating equipment.

Within the last few years, after I presented documentation to the Longmeadow Board of Health, the Longmeadow Bertucci's Wood burning Pizza Restaurant converted its wood burning oven to natural gas. The emissions from the wood oven became a nuisance after the wood smoke continued to detrimentally impact the occupants of a nearby commercial office building, including the chairman of the Longmeadow Board of Health, Dr. Robert Rappaport.

There are other very good reasons to utilize conventional fuels:

"Wood smoke is significantly associated with respiratory function decrements in young children with asthma." In Seattle area, "60%-90% of particles in residential neighborhoods ... are from wood burning year round."

-EPA report: "A Summary of The Emissions Characterization and Non-Cancer Respiratory Effects of Wood Smoke," 12/1993.


"Individuals can also help reduce particulate pollution through simple steps such as using energy efficient light bulbs and appliances, maintaining cars properly, insulating homes, and curtailing use of wood stoves for home heating in favor of cleaner fuels."

-NRDC report: "Danger in the air," 1996.

Summary and recommendations:

1) Everyone must know the detrimental effects of secondhand wood smoke; solid fuel appliances should have warning labels as do cigarettes; we all have a right to know of substances that are unhealthful; people will make better fuel use choices if better informed.

2) We should all aggressively implement energy and electrical conservation to reduce fossil fuel emissions in our homes and in our vehicles. Example: additional zones and/or nighttime set-backs will save energy in our homes and reduced highway speeds would improve mileage on our vehicles.

3) It is far better to convert from electric heating to conventional fuels instead of converting from electric to wood;

4) Re-establish the right of every citizen in this country to breath clean air and not be detrimentally impacted by fine particulate pollution; if we were putting Creosote in our water supply there would be a public outcry;

5) Inform the public that during periods of fog or nighttime inversions atmospheric conditions may not allow sufficient atmospheric ventilation to justify using a wood stove or fireplace 24 hours a day. A conventional heating system must also be installed so that cleaner conventional fuels can be utilized when atmospheric conditions do not allow sufficient atmospheric ventilation or when the solid fuel appliance becomes a nuisance to abutters

Substantial scientific evidence has shown that wood smoke can cause and/or contribute to: cardiopulmonary disease, asthma, bronchitis, emphysema and other problems such as eye irritation, sinus infections, and acid reflux.

Fine Particulate Air Pollution Is Not a Small Problem!

"Yes, a lot of people just don't have a realistic choice, and I have no complaint with them. It's the fancy ass spec houses that just have to have that wood fireplace for ornament that I'm peeved about."

"Just for quantitative completeness of the thread, though, even "EPA certified" whoop de doo stoves emit an enormous amount of PM2.5, the worst stuff. And the chemical composition of wood stove PM2.5 (vs. dust PM2.5) is particularly harmful. If you look at the most current EPA certified list (Nov 2014), you see that efficiencies (I guess heating efficiency) are mostly in the range of 63-72 percent, and emissions are in the range of about 1.5 to 6 GRAMS per hour, probably an average for all certified stoves of about 3 or higher. A whole gram of wood smoke particles is a LOT of particles, and that's every hour, for maybe 6-8 months in Truckee for example, and doesn't even count the giant slug of emissions when you light it or when it's not burning perfectly. That's like 35 pounds of wood smoke particles every year, from the best stoves operating perfectly. No wonder we get smoked out when there's an inversion!

I do like the aesthetics of a nice wood fire, it is beautiful and mystical and very primal. But we're long past time to allow wood burning facilities in any new residential construction, period, except on parcels of a minimum or 20 or 100 acres, where it doesn't affect anyone else so much. If you gotta have flame, go gas. A go play outdoors! You don't need to heat the house much when you're out getting some. "

Before a woodstove may be installed in a mobile home, .......... Third, a hard ducting system for bringing outside combustion air directly to the stove's air inlet is required.

Where I'm at now is still in the Pleistocene

assuming proper installation and use (which are probably rarely achieved; and this doesn't count the smoke that billows out during ignition), an EPA "phase 2" wood stove emits only about 1/3 as much smoke as non-EPA stoves. That's still a LOT of smoke anywhere you don't have 20-acre or larger parcels

Additionally, modern stoves with dry wood (even pine!) produce almost no creosote, and use about 1/3 less wood for the same heat output.