Wood burning fireplace inserts. What you need to know.

Photo by: The Rockland Insert By Jotul

With heating oil at $4.00 a gallon many homeowners are considering to, at least partially, heat their homes with good ole Maine firewood at a fraction of the heating costs. The pay back time for investing in an EPA clean burning wood burning fireplace insert is usually less than two years. Here is how to get started. 

Determine if the chimney is up to code.  Start with your local fire department. Any installer should perform a site review (ask about any fees) to inspect the flue and to ensure that the unit you select will fit both your fireplace and your heating requirement.  

My installer says I have to reline my flue?  Likely true. New EPA stoves are so efficient that there is little heat lost up the flue which also means that the stoves cannot heat up that oversized fireplace flue to create draft and to keep the gases that are going up the flue above the condensation (creosote forming) temperature.  This is why there is a new code requirement stating that oversized flues must be resized before a new appliance can be installed.

What fits?  You need a lot of good measurements. Measure the opening size of the fireplace (height & width) plus the depth of the firebox, rear width and the rear height at the distance that the insert sits into the firebox.  The other issues to be addressed are the location of mantle, top trim and side trim and the distance the manufacturer lists for clearances.

What are my choices?  Some units fit flush to the fireplace opening, some are bay window designs others are extended onto the hearth. Units can be cast iron enameled or steel with brass or pewter trim. Many styles and sizes are available.

What can I expect from an insert?  EPA wood burning approved insert are 75% + efficient (open fireplaces are 10-20%). The bigger the firebox the more heat it can produce and the longer it will hold a fire. Many burn 6-10 hours on a single full charge of wood.

The cost?  You purchase the insert or firebox plus a set of panels to fit around the unit and cover the fireplace opening. Most units sold by industry leaders like Vermont Castings, Jotul, Hearthstone, Lopi, and Morso having list prices starting at $2000. Installation w/ stainless steel reline can add $1000. or more depending on the chimney height and roof accessibility.

What is the pay back?    Using the Smithers method for estimating, one cord of wood equals 140 gallons of No. #2 fuel oil.  If you typically use 1000 gallons of oil a season and with the current price running around $4.00 your total seasonal heating costs equals $4000.00.  Firewood, cut, split and delivered green at $230 a cord, times the estimated usage of 6.5 cords equals $1495.   Oil   $4,000.00 or Wood  $1,495.00  Annual Saving $2,505.00

If you are late ordering firewood you will be charged a premium for wood that is already seasoned but even at $300 a seasoned cord your heating costs will be less than half that of fuel oil. Don’t burn green, wet wood! It’s a bad BTU value, it’s bad for your chimney and it’s bad for the environment!

Comments (0)
If you wish to comment, please login.