* Optimum Chimney Height
* Fireplace Opening & Flue Sizes
* Installing inserts & stoves
* Getting Enough Air
* Occasional Problems
* Just Can't Wait?
Far and away the most common complaint with fireplaces is smoking. Usually the smoking can be categorized as preexisting, new, or intermittent. Although smoking can be caused by a variety of reasons, you can generally figure out the problem with just a little detective work, starting with the chimney.
Chimneys are actually quite simple in theory. A chimney is just a column of air that, being warmer than the air above it, tends to rise and draw air (or a fire's smoke) in at the bottom to replace the air going out the top.
Why I am smoking up the room ?
In the beginning of every Fall Season we get calls about smoke problems. Here is what you need to do to fix the problem and you need to do this every time the system is cold for a period of time.
You need to reverse the flue.
Cold air is heavy and pushes down.
Hot air is light and takes force to push the cold air out of the chimney.
Follow these simple steps:
1- Use a starter log or fire starter products.
2- Keep the stove or fireplace doors and dampers open.
3- Build up a good hot fire with no smoke just heat.
4- You are now starting to reverse the flue, keep the heat going up the chimney. The chimney needs to have hot air raising to start the draw. Do not close it until it's hot.
5- Keep the dampers wide open.
The fire should not be smoking. No smoke, no creosote. Keep the fire burning hot. The flue tempeture should be around 400 - 450 degrees. That's HOT
Optimum Chimney Height:
Preexisting conditions usually are caused by not following the basic rules of chimney construction. A chimney should project at least 2 - 3 feet above any point within 10 feet of the chimney. To take an extreme case as an example, if a chimney on a one story addition is within 10 feet of the three story main house, your chimney would have to be at least 18 feet above the one story roof (8 feet for each of the two higher stories plus 2 feet). The taller the chimney, the stronger the draft. Sometimes a short chimney may not have enough draft even though it follows the 3-2-10 rule, but the addition of a few feet will solve a smoking problem.
Fireplace Opening & Flue Sizes:
For a fireplace that always smokes, the first thing to check is the relationship between the area of the fireplace opening and the area of the flue. The opening should be no more than 10 times the area of the flue. For example, a 33"W x 29"H opening is 957 sq. in. A 10" x 10" flue would be large enough at 100 sq. in., but an 8" x 10" flue would be too small at 800 sq. in. To test whether decreasing the opening size would eliminate the smoking problem you can use a piece of sheet metal or a row of bricks to reduce the opening.
Installing a wood stove:
We install many stoves into your existing fireplace every year. However, we are going to recommend you install a full lenth insulated stainless steel liner for the stove. The reason for the liner being installed is two fold. First is to reduce the flue size to match the size of the stove to your installation. Improve the draft. If the flue is too big it will not draft. Second is safety. A full lenth fully insulated liner simply puts the exhaust outside the home and not into the smoke chamber. It's just a matter of time and you will have a problem.
Installing a liner to your chimney is to prevent chimney problems. The threat of chimney fires or carbon monoxide poisoning from a deteriorating masonry chimney can be reduced with the installation of a stainless steel chimney liner. According to the NFPA National Fire Protection Agency, clay flue tiles within a chimney should be replaced if they are cracked, broken or missing. The most efficient and cost effective way to reline a chimney is with a stainless steel liner.
Getting Enough Air:
An extremely airtight house can also cause a smoking fireplace. Newer houses, particularly, often will not let in enough air to replace the air drawn out by the chimney. Open a window or door close to the fireplace to see if this stops the smoking. If it does, add a vent to bring combustion air to the fireplace or leave a door or window cracked while burning. Many new houses have fireplace vents built in. Look in or near the fireplace to see if there is a closed air inlet vent in yours.
New smoking problems with a fireplace that previously drew fine are easy to trace. Look for obstructions at the top of the chimney. A cap may have a clogged screen, or trees may now be blocking the exit. If you have not had your chimney swept recently, a buildup of creosote could be the culprit.
Birds, squirrels, raccoons, or other animals can also block a chimney. Often you will hear them in the chimney, but the best solution is to install a chimney cap to avoid the problem before it happens. A cap also protects your chimney from deteriorating from the weather.
If critters have already moved into your chimney, seek removal assistance from someone trained in the area, as bites, rabies and other problems can result from attempting to do this work yourself (see Nuisance Wildlife Removal in the yellow pages of your phone book). Just call " Dublin City Chimney Sweeps."
Intermittent smoking problems are often the hardest to trace, but here are some things to look for. If your house is moderately airtight, other appliances can draw enough air to cause the fireplace to smoke. Running kitchen or bathroom exhaust fans, or a furnace coming on can create the negative pressure needed to pull smoke from a fireplace. As with airtight homes, you will need to get more air to the fireplace either by cracking a window or door, or adding a fireplace vent.
Sometimes smoking can be cause by wind overcoming the draft and pushing smoke down the chimney. The siting of a house in relation to a hill, other buildings, or trees can cause wind to veer down a chimney. Short of cutting down trees or moving the house, you can try one of the chimney caps specially designed to protect against downdrafts.
Just Can't Wait?
Finally, intermittent smoking can be caused by an overeagerness to have a fire. If the temperature difference between the air in the chimney and the air outside is not enough, the chimney will be slow to draw. The solution? Try holding a piece of lit newspaper up the chimney to help warm the air column.
Converting a prefab or zero clearance fireplace to produce more heat.......
1. Purchasing a fireplace insert that BOTH fits and is approved for use in pre-fab fireplace. If possible it would have to be a fully lined and insulated chimney all the way to the top with new astainless liner and connected directly to stove.
2. You can always rip out the ENTIRE assembly, firebox and chimney and replace with new metal chimney and stove or built-in high efficiency fireplace.
You cannot take just any stove and place it in front of your fireplace and pipe it up into the chimney. It must be an stove approved for such use. This is because of two reasons
first: The chimney in many prefabs is not tested with anything other than the open fireplace and is not as heavy duty.
second: There is wood just inside the walls a few inches from your fireplace. Proper clearances for a stove in front and its pipe will not always meet the required clearances to meet current fire codes.
Can it be done? Maybe, but not always recommended....... We can look and give you advise.
If you see this little guy is living in your chimney, you need to call us now. Don't wait. The damage he can do is unbelievable.