Flue Length

warren · Post by **warren** » Wed. Jan. 01, 2014 3:20 pm

Does anyone know if the length of a flue is as important as if the flue is insulated

carlherrnstein · Post by **carlherrnstein** » Wed. Jan. 01, 2014 3:41 pm

Welcome, I would say that they are both important. The taller the flue the stronger the draft, also the hotter the flue gasses the stronger the draft.

Insulating the chimney will help keep the heat in the flue but, more importantly it reduces the clearance to combustibals.

Wheelo · Post by **Wheelo** » Thu. Jan. 02, 2014 6:23 am

Welcome warren,
I'd say as long as the flue is 3 feet taller than the highest point on the house, you would have a nice draft regardless of insulation. My chimney is over 30 feet, stainless steel and insulated. I have a pretty nice draft. An insulated chimney would hold the temperature of the gasses better all the way to the top, which I feel is critical to burning wood to prevent creosote formation as the gasses cool. Since coal doesn't make creosote, and the flue usually runs much cooler when burning coal, you don't really have to worry as much about a cooler temperature in the flue. Tricky question, I'm sure others that are much more educated and skilled will chime in and give you the answers you are looking for.

Wheelo

rustyrelics · Post by **rustyrelics** » Thu. Jan. 02, 2014 8:43 am

warren wrote:Does anyone know if the length of a flue is as important as if the flue is insulated

flue length is what makes a chimney pull draft when its heated. insulating it holds the heat that much better to enhance it even more. a chimney thats too short and only 10 feet high with insulated pipe, will still not pull as good as a 25 foot chimney of cheap noninsulated pipe. when in doubt add chimney pipe length. don't add a lot of bends and 90 degree angles. keep it straight.