Wood-burning fireplace: loser of energy efficiency.

great appeal

People can have a love-hate relationship with your wood-burning fireplace. There’s a lot of love and hate going on right now, because cooler weather has arrived and there are about 35 million chimneys in the US. Whether we’re hanging up the Christmas stockings carefully or trying to get rid of the big branch that fell from the spruce, 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 cool and cozy fireplace pictures you see in most home magazines. On the other hand, we hate the idea of ​​having to clean up the ashes before starting the fire for the family Thanksgiving dinner.

Realize that the old wood burning fireplace is not a very efficient heater.

Before we can start warming up by our cozy fireplace, we need to realize that a wood-burning fireplace is probably the least efficient appliance in the home. 90% of the heat generated by burning wood goes up the chimney. A fireplace blows 4 to 10 times more air out of the room than it needs to keep the fire going. Even when the fireplace is sitting there, looking cozy without a fire, the warm air in the room is being sucked up the fireplace.

Additionally, smoke from a wood-burning fireplace contains methane, carcinogens, carbon monoxide, and a bucketful of other toxic gases. And when conditions aren’t right, a draft can occur and send smoke and soot back into the house. Also, when considering efficiency, let’s not forget to cut, split, transport and store our wood supply.

Realizing that the fireplace is not a clean, high-efficiency heat source will help us have a more successful relationship with this appliance.

downdraft

Chimneys are losers because:

In short, they are losers because they allow a direct and open connection between the interior and exterior of the house.

What happens when you turn on the fireplace on a cold winter night? Roll up a wad of newspaper, grab some firewood, add some maple sticks to the grill, and then carefully add a match.

• You open the damper and cold, heavy air from outside comes down the chimney and into the room.
• With cold air coming down the chimney, the first draft created is a reverse draft.
• The paper burns and starts to ignite the firewood spilling smoke and all the toxic stuff back into the house.
• More paper is added to create more heat so that the air in the chimney starts to heat up and reverses the reverse draft. Smoke begins to rise up the chimney.
• The ceiling fan in the bathroom turns on when Junior starts taking a shower, the stove fan turns on when a pot of stew is added to a burner, and the clothes dryer, which is in the utility room, is drying a load of laundry. . .
• The three exhaust fans overcome the draft of the chimney and the smoke re-enters the house. Still more paper is added to the fire and the boy is told to get out of the shower.
• To help with the draft, a window near the chimney is opened to let in even more cool air, but smoke and toxic gases are coaxed back up the chimney.
• The chimney heats up, creating a strong draft that pushes smoke up the chimney along with about 450 cubic feet of air conditioning every minute.
• Sensing the cool air from the open window, the window closes and the air it provided is now drawn from the sealing plates, around heating registers, holes in heating ducts, window frames, and below of the doors.
• With the fire well established, the damper closes to control the rate of burning, this is when the chimney will burn most efficiently, returning a whopping 20% ​​of the heat generated back into the house.

Is this energy efficient?

A spark screen is added to the front of the fireplace and the heat return drops to about 12%.

The final insult:

The children are put to bed, the doors and windows are checked, and the fireplace damper is closed a little more. It has been a long day.

The fire has been extinguished and you are returning to spend the night. While you sleep, the fire provides very little heat, but the fireplace has become a highway to get hot air out of the house. The freeway continues, like rush hour in Atlanta, until the fire is out enough to allow the chimney to cool, once again allowing cold, dense air to reverse flow and enter the house.

Now that cold air enters the room, the fire takes a second breath and burns for only a minute. Smoke sneaks into the house and with laser precision is aimed directly at the smoke detector.

You throw back the covers with visions of a burning house running through your mind and run into the living room where you find the faint red glow of some ambers sitting gently on the fireplace. As the smoke detector continues to warn of impending destruction, you are reminded that the chimney may be more of a loser than you thought. At the moment, the love-hate relationship with a wood-burning fireplace is fraught with hate.

Thanks for stopping by, I hope you come back soon, but I won’t leave the light on for you…