Select Page

# Flue Size Once Again

Home Forums Public Forums Gas & Gasfitting Flue Size Once Again

• Author
Posts
• #278058
Anonymous

Really is getting complicated, but I haven’t lost my cool, YET.

Plumber consulated with the Building Inspector.

Inspector said 8inch flue pipe.

Chimney people said can’t get it into 8inch chimney.

Connected with supplier outside Philly, confirmed Art with 6inch liner.

The word is “don’t oversize the liner” because this will create a poor draft and allow the combustion gasses to condensate causing acids to collect on the liner.

I would prefer not to use high efficency appliances with thru the wall venting because I’m told the control systems are prone to failure. I know they cost more but that’s not the issue.

Supplier will sell me an aluminum 6inch liner kit for \$100.00 with a 10 year replacement guarantee (\$500.00 for stainless). It’s probably a 2-3 hour job.

Chimney people quotes are nearly \$2,000.00.

If I can find a architect or consultant the building inspector accepts and it costs me \$300.00, I’ll do the work myself and still be ahead of the game. More importantly, I’ll get a better job.

It must be wonderful to have blind faith with the people your dealing with, but somehow I trust you guys more. You’ve got nothing to win or lose and from what I’ve read, only try to be helpful.

So my post question is, does anyone have any recommendations for a chimney consultant in the Westchester County, NY – Fairfield County, CT area?

Thanks & All The Best

• #297604
hj
Participant

The theoretical size can be calculated by adding the areas. Since pi is a constant, it can be disregarded and just use the radius squared portion. 4″ = 4 and 3″ = 2.25. Adding two fours 4 + 4 and two threes + 2.25 + 2.25 gives a figure of 12.5. A seven inch flues’s radius squared is 12.25, which is a little undersized when all units are operating at the same time, but under those conditions, the stack temperature will be at a maximum and will give excellent draft.