Expert: James Ball - 1/27/2010

Question
QUESTION: I purchased a Napoleon 1101 insert which calls for a 6" chimney liner. The installer said he could not get past some mortar and would have to go to a 5" liner. Could the mortar be chipped off or do you think he may be cutting corners? Is this safe? And could I have a smoke issue when I open the insert door? I had the chimney inspected by a chimney pro, he said he would use a 6" insulated liner with the same insert. Thanks, James

ANSWER: Hello Lynne you can not down size that unit, you must use a 6" insulated SS 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 they should be able to help.
Hope this helps
James


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

QUESTION: Hi James, Please explain why I must use the 6" liner recommended by Napoleon instead of a 5" liner. I need to convince the installer who insists that a 5" liner is ok. I'm worried about,
1. Back draft when opening the door
2. Voiding the warranty
3. efficiency of the unit
4. Safety
and anything else you could add would be helpful
Thanks again James, Lynne


Answer
Welcome back Lynne, by reducing a 6" into a 5" liner you have all ready choked off the draft.  If you have a 6" solid flue (wood, pellet, coal) it can not be down sized to a 5". this is NFPA 211 2006 code 12.4.4* (1) the cross sectional area of the flue shall not be less that the cross
sectional area of the appliance flue collar unless specified by the manufacturer. most liners and stove manufacturers require an insulated Stainless Steel liner
if you wantit email me your email address and I will send it to you.
I only do insulated SS liners for solid fuel. Or I do not do them
contact your local building department that liner may require a building permit also.
for some reason this guy is fighting you on this I would not be comfortable with that either it maybe time for a new sweep like I listed in my last post.
Keep me posted
James