Know your chimney

Modern, efficient appliances need modern, efficient chimneys. The selection, location and installation of the chimney is at least as important as the type of wood-burning appliance you choose. A properly designed and installed chimney will give many years of reliable service and will allow your appliance to perform properly. An effective chimney is an important part of any successful wood burning system. Many of the reported problems with the performance of wood burning appliances can be traced to chimney deficiencies of various kinds. Knowing how chimneys work is not only necessary in selecting the correct chimney and designing the installation, but is useful in the day-to-day operation of the appliance.

Chimneys operate on the principle that hot air rises because it is less dense than cold air. When a chimney is filled with hot gas, that gas tends to rise because it is less dense than air outside the house. The rising hot gas creates a pressure difference called draft which draws combustion air into the appliance and expels the exhaust gas outside. The hotter the gas compared to the air outside, the stronger the draft.

To learn more contact your local certified chimney installer and remember to check local codes.

Use a certified chimney sweep

Wood burning systems must operate under a variety of conditions during each heating season, and these different conditions create the need for a number of maintenance tasks. Chimney cleaning is usually needed more often in the spring and fall. On the other hand, wood burning appliances operate closer to their maximum heat output during the coldest winter months, creating stress on internal components. Many of the modern wood heaters have internal components that can wear out because of their exposure to high temperatures. These components can be replaced.

One of the best ways to ensure that your wood heating system gets the maintenance it needs to be safe and effective is to hire a fully-trained professional chimney sweep. A professional sweep will clean the system top to bottom and report any problems to you. The sweep might suggest that it is time to replace the flue pipes, catalytic combustor, or door gasket and will probably be able to do the work for you when the time comes. Your wood heating retailer may also offer sweeping and maintenance services.

Catalytic Retrofits for 6" and 8" flue size

In the mid 80's there were at least 15 catalytic retrofit manufacturers in the United States. However, with the coming of new EPA-certified wood burning stoves, retrofit were sold less and less. Most of these manufactures are gone today, but I know of one one model is still sold today.
The Cat-1000, as it is called today, can still be purchased by contacting Woodman's Parts Plus. They manufacture a retrofit that fits in a 6" or 8" flue size. This catalytic retrofit has been around for many years.

Catalytic retrofits have been tested by several independent testing laboratories over the years.
Results showed the that some catalytic retrofits decreased Burn rate KG/hr by 50.8% and Particulate emissions by 49%, while increasing Thermal efficiency by 9.2% when used on a pre-phase I, non-catalytic wood burning stove.

For more information on the Cat-1000, contact Woodman's Parts Plus:

Woodman's Parts Plus
P.O. Box 186
587 Pine River Pond Road
East Wakefield, NH 03830

(603) 522-8216 or woodmanspartsplus.com

Cycles of firing

Don't expect perfectly steady heat output from the fire. Wood fires burn best in cycles. A cycle is the time between the ignition of a load from charcoal and the consumption of the load back to a coal bed.
Each cycle should provide between four and eight hours of heating, depending on how much wood was used and how much heat is needed.
Plan the firing cycles around your household routine. If someone is home to tend the fire, use a short firing cycle. If you must be away from the house during the day, use the extended firing cycle.

(see 6-16-08 posting)

Health effects of wood smoke

Smoke may smell good, but it's not good for you. If you are healthy, you are not usually at major risk from smoke. Still, it's a good idea to avoid breathing smoke if you can help it.

Smoke is made up of a complex mixture of gases and fine particles produced when wood and other organic matter burn. The biggest health threat from smoke comes from fine particles (also called particulate matter or PM).

These microscopic particles can get into your eyes and respiratory system, where they can cause health problems such as burning eyes, runny nose, and illnesses such as bronchitis. Fine particles also can aggravate chronic heart and lung diseases—and are linked to premature deaths in people with these chronic conditions.

Some people are more susceptible than others:
If you have heart or lung disease, such as congestive heart failure, angina, chronic obstructive pulmonary disease, emphysema or asthma, you may experience health effects earlier and at lower smoke levels than healthy people.
Older adults are more likely to be affected by smoke, possibly because they are more likely to have chronic heart or lung diseases than younger people.
Children also are more susceptible to smoke for several reasons: their respiratory systems are still developing; they breathe more air (and air pollution) per pound of body weight than adults; and they're more likely to be active outdoors.
How to tell if smoke is affecting you: Smoke can irritate the eyes and airways, causing coughing, a scratchy throat, irritated sinuses, headaches, stinging eyes, or a runny nose. If you have heart or lung disease, smoke might make your symptoms worse.

Protect yourself! It's important to limit your exposure to smoke—especially if you may be susceptible. Follow the guidelines we have provided in this Web site for using your wood stove and fireplace efficiently and safely.

For additional information on the health effects of wood smoke, visit http://www.airnow.gov/index.cfm?action=smoke.smoke2

Also, the State of Washington's Department of Ecology has published a useful booklet entitled, Health Effects of Wood Smoke (PDF)


(15pp, 206k)

Catalytic wood stove - Operation Don'ts

Don't burn trash, treated wood, particle board, plywood, or other fuels (such as coal, kerosene, or lighter fluid) unless they are listed on your stove's permanent label. Trash produces fly ash. Treated wood, particle board, and plywood contain chemicals that, when burned and inhaled, are hazardous. Burning other fuels may poison your catalyst or damage your stove. Cardboard, foil, and plastic may block exhaust flow through the catalyst, causing smoke to spill into your room. Don't operate your stove in the catalyst bypass mode after the catalyst has reached the recommended temperature (350 to 600°F). At this point, your catalyst should be working for you (to produce more heat using less firewood) and for the environment (destroying smoke and the cancer-causing pollution in the smoke).

Don't over fire your stove, especially when the catalyst is engaged. Avoid catalyst temperatures near or above 1600°F. This is another reason to use a catalyst temperature monitor. Catalysts can be damaged or destroyed by prolonged high heat. If temperatures are above 1600°F, switch to bypass mode and allow the catalyst to cool down to about 1000°F before resuming normal catalytic operation. Don't open the ash pan while catalyst is engaged because this will lead to overheating.