Insulating Chimney

[Robby]

I have double wall, black chimney that connects my boiler to the wall thimble. About 30" long. The boiler room gets excessively hot, actualy hotter than the pumps and controls are designed for. I insulated three sides of the boiler, cut down heat. Now I would like to insulate the 3' of double wall, 8" chimney. Any reason I should not?

Robby

 

[Gooserider]

I have double wall, black chimney that connects my boiler to the wall thimble. About 30" long. The boiler room gets excessively hot, actualy hotter than the pumps and controls are designed for. I insulated three sides of the boiler, cut down heat. Now I would like to insulate the 3' of double wall, 8" chimney. Any reason I should not?

Robby

I seem to recall that the double wall manufacturers say that you aren't supposed to insulate because the pipe is intended to be able to dissipate heat to the surrounding air. Insulation could cause the pipe to overheat... I would definitely say it's a question that should be directed to the manufacturer tech support dept.

Have you insulated all the pipes and so forth? (other than the pumps, obviously) I'd suspect that more of your heat problem could be coming from the plumbing than from the stack...

Gooserider

 

[flyingcow]

I agree with GS. Not a good idea to insulate the pipe, unless manufacturer say its ok, but i'd still be concerned. I used to be in the tin knockin' business installed a lot of exhaust pipe, stack pipes, etc. Don't ever recall insulating stacks after the install. I have installed insulated stacks, but those were few and far between. Extremely expensive stuff.

look into insulating your plumbing as GS pointed out.

Give a list of equipment, a few pics would work well also.

Sounds like some sort of ventilation is in order, t-stat controlled exhaust fan? Or just a t-stat controlled damper to outside air? is your boiler running ok? Enough make up air for combustion? Huffing and puffing?

 

[Robby]

Good Morning,

All the lines are insulated with fiberglass wrap, then foam pipe insulation. The two pumps are in a corner with insulated wall across the front, temps are lower for them. The specs say air temp should not be over 120F. I frequently get over that. I do vent into attic space. I think the gable vent sizes can be increased, that may help some. I also have a screened vent from exterior close to boiler for air intake. Draft seems to be fine. I heat a 1400 gal tank beside boiler building for storage, and on warm days a prolonged burn gets the indoor temp real high.

Thanks for input, I "kinda" thought that if chimney pipe made to be insulated, it would have been.

Robby