Wood Burning Fireplace: Energy Efficiency Loser.
Great Appeal
People can have a Love-hate relationship with their wood burning fireplace. There is a lot of loving and hating going on right about now, because cooler weather has come and there are about 35 million fireplaces in the U.S. Whether we are hanging the Christmas stockings with care or trying to get rid of the big limb that fell out of the fir tree, we use our fireplaces for a wide variety of reasons.
Too often, we love the idea of having a fireplace in the home to feel a close connection between our home and all those great, cozy, fireplace pictures that can be seen in most any home magazine. On the other hand, we hate the idea of needing to clean out the ashes before setting the fire for the family Thanksgiving dinner.
Realizing the old wood burning fireplace is not a very efficient heater.
Before we can begin to keep warm beside our cozy fireplace, we need to realize a wood burning fireplace is probably the least efficient appliance in the home. 9o% of the heat it creates from burning wood, goes right up the chimney. A fireplace pulls 4 to 10 times as much air out of the room as it needs to keep the fire burning. Even when the fireplace is just sitting there, looking cozy without a fire, warm air from the room is being sucked up the chimney.
Furthermore, the smoke from a wood burning fireplace contains methane, carcinogens, carbon monoxide, and a bucket full of other toxic gases. And when conditions are not right, a backdraft can occur and send smoke and soot back into the house. Plus, when efficiency is considered, let's not forget about cutting, splitting, hauling, and storing our wood supply.
Realizing the fireplace is not a high efficient, clean heating source will help us have a more successful relationship with this household appliance.
Downdraft
Fireplaces are losers because:
Simply stated, they are losers because, they allow a direct, open connection between the inside of the home and the outside of the home.
What happens when you light up the fireplace on a cold winters evening? You roll up a wad of newspaper, grab some kindling, add a few sticks of maple to the grate and then carefully add a match.
You open the damper and the heavy, cold outside air pushes its way down the chimney and into the room.
With the cold air coming down the chimney, the first draft created is a reverse draft.
The paper burns and begins to light the kindling which spills smoke and all the toxic stuff, back into the house.
More paper is added to create more heat so the air in the chimney will begin to warm up and reverse the reverse draft. Smoke begins to draw up the chimney.
The ceiling fan in the bathroom is turned on as Junior begins a shower, the rangehood fan is turned on as a pot of stew is added to a burner, and the clothes dryer, that is in the utility room, is drying a load of clothes.
The three exhaust fans over power the chimney draft and smoke once more is drawn into the house. Even more paper is added to the fire and the kid is told to get out of the shower.
To help with the draft, a window near the fireplace is cracked open letting in even more cold air, but the smoke and toxic gases are persuaded to return to the chimney.
The chimney warms up and a strong draft is created which draws the smoke up the chimney along with about 450 cubic feet of conditioned air every minute.
Feeling the cool air from the open window, the window is closed and the air it was providing is now pulled from seal plates, around heating registers, holes in heating ducts, window frames, and under doors.
With the fire well established, the damper is closed down to control the rate of burn, it is now that the fireplace will burn most efficiently, returning a whooping 20% of the heat generated back to the house.
Is this energy efficient?
A spark screen is added to the front of the fireplace, and the heat returned drops to about 12%.
The final insult:
The kids are tucked into bed, the doors and windows are checked, and the damper on the fireplace is closed down a little more. It's been a long day.
The fire has died down and your turning in for the night. As you fall to sleep, the fire is providing very little heat, but the chimney has become a freeway for removing heated air from the house. The freeway continues, like rush hour in Atlanta, until the fire dies down enough to let the chimney cool, allowing, once again, the heavy cold air to reverse the draft and enter the home.
With cold air now entering the room, the fire takes a second breath and flares up for just a minute. Smoke sneaks into the house and with laser accuracy heads directly for the smoke detector.
You throw the covers off with visions of a burning house racing through your mind and charge into the living room where you find the slight red glow of a few amber's sitting gently in the fireplace. As the smoke detector continues to warn of impending destruction, you are reminded that the fireplace maybe a bigger loser than you thought. At the moment, the love-hate relationship with a wood burning fireplace is heavy on the hate.
Thanks for stopping by, hope you'll come back soon, but I won't leave the light on for you...
