Expert: James Ball - 10/6/2008

Question
QUESTION: I currently have an oil furnace and was going to add a wood/coal burning furnace to help with oil costs. i am going to disconnect the oil furnace completely. I believe that the chimney flu size is approx. 8" x 8". Is size of the flu need to be bigger or is something that should be ok.

ANSWER: Hello Joe, you can not reduce (and should keep the same size all the way to the top, cross section of a 6" is 28 or an 7x7 is 49) of the collar or the stove (outlet pipe). You can not run both oil and wood/coal in the same flue (sounds like you are removing the oil. I would also reline all the way to the top and insulate that liner. I would have a local Certified Chimney Sweep (www.csia.org, there you can look up by zip code to find one near you) take a first hand look at what you have.
hope this helped
James Ball


---------- FOLLOW-UP ----------

QUESTION: What do you mean re line and insulate. There is an existing flu, in chimney block, that has been bricked also.

Answer
Welcome back Joe, a "re lining with insulation" means to insert a Stainless Steel tube into your existing chimney flue and before you do wrap an insulating blanket of ceramic wool with foil backing. this will contain all the exhaust of the wood stove and help keep the exhaust gases hot to get more out of the chimney.
James