CHIMNEYS

The following info is courtesy of our buddy, Charlie Hanft at The Hearth & Patio Shop in Tucker, Georgia. You can reach Charlie at (770) 934-8646, if you have any questions. He’s a good guy and will be happy to help you out.

When a fireplace operates well it gives all of us a feeling inside that’s hard to describe. Might have something to do with folks sitting around in caves out of the weather hoping they were protected from creatures with bad intentions. On the other hand, when your fireplace starts acting up, it can prove a focus of ill will and colorful language.

Fireplace problems range from the simply annoying to life threatening. What follows are a few ideas which you might find helpful in the following areas of "Life with a Fireplace:" Maintenance, Safety, Troubleshooting and Efficiency.

Operation and Maintenance:

Start a fire with a small amount of newspaper or other fire starter, NOT a flammable liquid. The kindling should ignite in less than half a minute. Too much fire starter might flash quickly and throw smoke into the room. A chimney establishes "draw" slowly as heat in the firebox warms air in the chimney. If your chimney draws well but puffs smoke into the house when you start your fire, place a piece of crumpled newspaper on top of the laid firewood and ignite it just before you ignite the kindling under the firewood.  Cracking a window in the room may help.

When starting a fire, even with a gas log lighter, it’s important to have enough small kindling (each about 2 fingers in width) to burn long enough for larger logs to catch.

Use seasoned wood!!! Hardwoods are best but pine is O.K. with a HOT chimney, i.e., one that is well heated by a burn in progress. Unseasoned ("green") wood will waste heat in the process of creating steam from water in the green material and will never become a hot fire to warm the little cockles of yo’ heart which is what fireplaces are all about.

Always keep a screen in front of the fire. Embers are subject to popping out at the worst times and you need a screen to avoid damage to life and limb. SCREENS or GLASS DOORS are a MUST!!!

As a general rule, have your fireplace cleaned once for each cord of wood burned. More often, perhaps, if you burn a lot of pine or other soft timber.

During cleaning, your fireplace should absolutely be visually inspected for signs of breakdown in the construction materials.

A hot chimney collects less creosote (partially combusted wood products carried by smoke that plates out on inner surfaces of the chimney).

Seasoned wood burns hotter.

Safety:

As mentioned, always keep screen or glass protection in front of an active fire. Complete coverage of the opening is important. Embers need only a small opening to escape.

Don’t close the damper down, even just a little, cause there’s a good chance smoke won’t be completely drawn out of the firebox up the chimney.

Get a carbon monoxide alarm. An alarm could be a lifesaver. This is especially true with most gas logs which need venting about as much as a wood fire. Spillage of these gasses is much harder to detect than wood smoke – by the time you realize you’ve got a carbon monoxide problem from your physical symptoms IT MAY BE TOO LATE. So called "unvented logs," though cleaner burning, require this safeguard also.

On prefabricated fireplaces don’t close glass doors on an active fire until you are assured the doors are tested for that model fireplace. Absent proper doors, the fire could run too hot with the doors closed with the possibility of eventually causing a house fire.

Prefab fireplaces are, when properly installed, safe for wood fires.

Chimney fires are due to ignition of excessive creosote buildup. They are intense and hard to stop. The only way to stop a chimney fire is to deprive it of oxygen by blocking the flue with the damper. Smoke bomb suppressants can help smother the fire and should be kept at hand. In any event, call your fire department as soon as possible.

Troubleshooting:

Smoke spillage: If the damper is fully open and smoke spills in the room you might want to check the following:

• Is the fire too big too soon? If a fire gets too big too quickly, the chimney’s "draw" may not be able to keep up.

• Should the fire be smaller?

• Could the fire be pushed back a little?

• Are any competing draft devices or fans running? For example, house fans, bathroom fans, kitchen exhaust fans, clothes dryers, house vacuums, other fireplaces.

• Is the fireplace opening too large for the flue? A 10 to 1 ratio is about the max.

• Is the fireplace opening exceptionally tall leaving less area above the fire box itself to hold smoke? This holding area is called the smoke dome.

• Is the chimney tall enough? The top should be at least 24" above the roof’s ridge.

• Is the flue centered in the fireplace or off to one side?

• Is your chimney flue straight or offset? How much offset?

• Is your fireplace multi-sided?

• Is there no chimney cap to dampen the impact of gusty winds in the fire box?

• Are fans in the room causing turbulence by the fireplace?

• Is there a heated portion of the house – anywhere in the house – which is taller than the chimney … a room addition, perhaps?

• At what level of the heated house is the fireplace? Higher is hotter, lower is a more difficult location in which to draw air.

Some of the above are easily changed and some are not. Most single factors are only part of a solution. You’ll probably do well to obtain the services of an experienced professional.

In multi-fireplace homes where one chimney has two or more flues, one cold chimney may draw in smoke from another fireplace which is being used….the house is supplying make-up air the easiest way it knows how! Sealing damper caps mounted at the top of the chimney may be a good solution here ($150 to $250 depending on size). The cap is operated from below with a thin stainless steel cable.

Odors from a cold fireplace can also result from air being pulled into the house through that chimney. A sealing damper cap helps here as well. Especially dirty fireplaces sometimes have a slight odor nearby resulting from being open to the room as opposed to air coming down the chimney. A good cleaning and/or fireplace deodorant could help. A glass door may help with local odors but not with downdraft odors.

Water Leaks:

• Masonry fireplaces leak at the roof flashing (fix the flashing) or through the chimney structure itself (this needs inspection and can be costly). Remember to keep the cement crown of the chimney in good condition. Water can enter cracks and damage a chimney quickly.

• Prefab fireplace leaks are generally due to rainpan, pipecap or sidewall damage. The rainpan is the metal top which overlaps the entire wooded chimney. It sometimes is pushed down to form a bowl which collects water. It needs resecuring or replacing. The pan collar which connects the rainpan to the pipecap could require new caulk. If needed, a replacement pan should usually not exceed $100 in materials.

Efficiency:

It can now be revealed ... a fireplace is nothing more than a ventilator! Its primary job is to exhaust smoke from the home. With this smoke goes most of the heat your fire is working so hard to produce … along with a surprisingly large amount of heated house air. The replacement air enters the house from outside – where it’s cold! This results in poor efficiency to the point of negative efficiency when considering the house as a whole. PLEASE DON’T PLAY WITH THE DAMPER IN AN EFFORT TO CORRECT THINGS. IT WON’T!!!

That being said, some things help a little, some more.

• Glass doors can safely reduce excessive air loss but do so while cutting the infrared (radiant) heat to the room which is the only heat a fireplace offers without heat exchangers.

• Heat exchangers can be added to throw warmed room air cleanly back to the room. They vary in size and cost ($100 to $500) but do not always meet expectations, especially in large rooms with high ceilings and a lot of glass as in windows.

• Some fireplaces, masonry or prefab, have built in heat exchangers. They vary in effectiveness but all are better when the open front has a glass door.

• Reflecting devices and firebacks can increase the throw of radiant heat to a room but limit your expectations here. The front must be left open and protected with a screen.

• Outside air vents are mostly ineffective but will work when the fireplace front is closed tightly thereby forcing the fireplace to pull air in through the vents to the outside.

• The best efficiency with wood heat results from using well designed, costly equipment such as air tight stoves and inserts. Well designed equipment allows for terrific heat transfer even without fans and minimal use of ambient air. Costs can reach mid teens up to $2000. If you elect to go with used equipment, obtain the services of an experienced installer.

• Vented gas inserts also boast similar effectiveness and costs.

• Unvented gas logs are excellent at heating ($250 - $600) but here an objective and knowledgeable seller is an absolute must. There is much to consider. In a nutshell: with no house air exhausted and all heat produced retained in the home, efficiency is high. The downside is, products of combustion, good and bad, are delivered to the living space. For this reason, proper installation and a carbon monoxide detector are a must. This product isn’t right for all situations. GET THE ADVICE OF AN EXPERT!!!

A final note of caution. If you’re adding heating equipment to your home, be sure to let your insurance carrier know. Some insurance companies exempt damage from such equipment unless they’ve been notified of its existence and proper installation.

Like you learned in kindergarten, DON’T PLAY WITH FIRE!!! If handled safely, however, a crackling fire on an autumn day goes a long way toward enjoyment of family and home.