Investing in a New Chimney – What to Know
If you are installing a new wood-burning appliance, a chimney is needed for venting purposes. Whether building a new masonry chimney or installing a factory-built chimney, it is important that the flue is the size recommended by the manufacturer of your fireplace or wood stove. The following are some specifics to consider when investing in a new chimney, to help you make the best decision for your home:
The single biggest mistake that can be made with a chimney is placing it on an outside wall where it is exposed to outdoor elements to a much greater extent than if it only protruded through the rooftop. If your goal is to have a chimney that functions optimally, place your chimney within the structure of your home.
The reason an outside chimney is not the best choice has to do with something called the “stack effect,” which prevents the chimney from having the needed draft to pull combustion materials up and out of your home. When the weather is cold, warm air in the home rises in the same way that hot exhaust fumes raise in a chimney. With the stack effect, a slight low pressure area is created in the lower part of the house and a slight high pressure exists in the house’s higher levels. In the midst is a neutral plane with neutral pressure.
If you have an outside chimney and there is no fire in the wood stove or fireplace, the house begins to operate as though it were the chimney. It will pull cold, odorous air down the flue and into your home, due to the stack effect.
If your chimney is installed within the house envelope the negative pressure low does not have a negative effect. Instead, the air in the chimney flows gently upward even without a fire burning. The warmth inside the home that surrounds the chimney creates the needed draft.
Another benefit of placing your chimney on the inside is that you will be able to light kindling easier with less smoking. What people often have to do when their chimney is built or installed on the outside is light a rolled up newspaper like a torch and hold it up through the damper so that the cold column of air in the chimney will be dispersed and stop pushing downward toward the fireplace or stove.
For a high-performance chimney used for a stove or fireplace that provides heat as opposed to serving as a pure decorative feature, insulation is a must. The type of insulation you need depends upon the type of chimney you have.
Another important consideration is to ensure that your chimney meets building safety codes, this includes installing the correct lining. Liners are arguably the most important component of your chimney system so make sure to ask your chimney professional about the choices for liner installations.
When you use your chimney, the materials expand and contract when it’s cold. The movement wears on joints, structural material, and seals. The best way to maintain your chimney is to have an annual chimney inspection, in addition to contacting a professional when problems arise. When needed, also have your chimney cleaned by a chimney technician.
Northeastern Chimney, Inc.
37 Cody Street, West Hartford, CT 06110