Ask the Energy ExpertCan My Fireplace Help Lower My Heating Bill?
By Bob Hysong, Community Relations Representative
Q. Can using my fireplace help lower my heating bill?
A. If you consider your fireplace as a form of supplemental heat, similar to a space heater, it may reduce the kilowatt-hours (kwhs) you use. Electric bill savings will depend on the type of fireplace you have, how you use it, and how you maintain it when it's not in use.
For people who have the time, the inclination, and access to free or low-cost firewood, a fireplace may help reduce your overall seasonal heating costs. That may not mean it costs you less in the long run, but we won't try to quantify the value of your time and equipment.
The advantages of a fireplace are not to be taken lightly: supplemental heat when your heating system is stressed or inadequate (i.e. severe cold weather), emergency heat during a winter power outage, the comfort and ambience of a cozy hearth, etc.
However, a traditional, open fireplace also has shortcomings to keep in mind:
(1) A fireplace can seldom provide all the heat your home requires, and is one of the most inefficient heat sources you can use.
(2) Fires need oxygen to burn. This usually comes from room air that has already been warmed, unless your fireplace can draw cold, unconditioned air from outdoors.
(3) Fireplaces are most efficient when burning very hot. Lower temperature fires, such as glowing embers, draw conditioned air right up the flue, removing more warmth than they add. A slow, overnight burn can accentuate heat loss, generally at its worst 3 a.m. — 6 a.m.
(4) If a flue is left open with no fire burning, you can lose up to 8% of your home heat every day.
(5) Fireplace heat is usually directional, meaning if you face the fire your front side is warm, and your back side is cool. Direct comfort benefits are limited.
(6) Firewood is plentiful at the beginning of winter. Both your supply and interest may dwindle as winter lingers. By mid-February you may be using conventional heat more than you think, and your kwh use will increase, perhaps by as much as 2,500 kwhs per month — roughly $135 — when you run out of wood.
If you're convinced that your fireplace is heating your entire home, and your furnace shouldn't be running, this is easy to test. Turn your furnace "off" at the breaker, not "down" at the thermostat. If your house remains a comfortable temperature throughout, you know the fire is doing all the work. This is seldom the case.
Q. How can I make my fireplace more efficient?
A. Here are some suggestions:
(1) If you never use your fireplace, plug and seal the chimney flue, preferably above the roof, to keep out both water and air. The seal should cover the top of the chimney and be made of waterproof galvanized steel or aluminum.
(2) Keep your fireplace damper closed unless a fire is burning; otherwise it's just a wide open window. Check the seal on the flue damper and make it as snug as possible. (Be sure to open the damper before starting your next fire!)
(3) When using the fireplace, reduce heat loss by opening dampers in the bottom of the firebox (if provided) or open the nearest window slightly. Lower your heating system thermostat.
(4) Add caulking around the fireplace hearth, careful to use a product designated for this use.
(5) Use tempered glass fireplace doors and an air exchange system that blows warmed air back into the room.
(6) Consider installing a fireplace insert, a popular way to improve the efficiency of an open fireplace.
Q. What is a good alternative if I get tired of cutting wood and want to replace my wood heating system?
A. Many members have asked themselves this question recently. They foresee that their wood cutting days are numbered, want to keep energy bills low, and want an alternative that offers the convenience wood heat lacks. In light of recent rebates and tax credit incentives, the system many of them have chosen is a ground source heat pump. High efficiency and low operating costs have lured them away from the wood pile as rebates make ground source heat pump systems more affordable.
There are many types of wood heating systems in addition to traditional open fireplaces. They all become more attractive when temperatures and wind-chill factors linger in single digits, as they have this winter.
For more comprehensive information about wood system options, responsible wood burning practices, and wood burning safety, visit the Hearth, Patio & Barbecue Association at www.hpba.org. You may also wish to consult a web resource such as About.com. Type "heating with wood" into the search field to find a wealth of information. We're happy to help you sort through your choices and determine how using wood heat systems may impact your electric bill — for better or for worse.
Contact Bob Hysong or any Member Services Representative about energy use and rebate topics. Call 800.392.3709, ext. 233, 272, 334, 4732, 4733.
Sources for some information contained in this article include the U. S. Dept. of Energy and the Rural Missouri News Service.