Advice about insulation on the heat duct.

[Rogerius]

Hi All,

We are planning to install the new FP30 (Pacific) soon. Looking at the 6" ducts received with the heat transfer kits, I'm questioning if will not be a good idea to have those bare duct insulated instead to radiate heat. Make sense? If yes, what kind of insulation as I assume need to be for high temp? Any recommendation?
Thanks for any advice.

 

[begreen]

You could use type B vent pipe to reduce heat loss a bit.

 

[webby3650]

You could use type B vent pipe to reduce heat loss a bit.

One of the discontinued SBI fireplaces required B vent.

 

[Rogerius]

See in the picture the flex pipe which I've got. So, if I don't insulate this pipe with something I see the temp inside the chase raising up. But with what kind of insulation.

 

[begreen]

Is this 6" round flex? This will work, use metal tape to seal.

(broken link removed)

 

[Rogerius]

Is this 6" round flex? This will work, use metal tape to seal.

(broken link removed)

I don't think this will work. Checking the spec of this insulation I see has the flame spread rating less then 25, which is the same as gypsum sheathing. As no drywall is accepted in proximity of the fireplace I don\t think this will be accepted as well. Maybe I'm wrong but this is my interpretation here.

 

[begreen]

Not sure flame spread rating is applicable here. This is what is typically used on warm air ducts. However, you could get 15' of chimney liner insulation and use that instead.

 

[Drewman]

I posed a similar questions to my installer. I questioned about heat loss and efficiency of air movement, as my remote ducts are going down to the basements I wanted the best chance at pulling the heat down. He understood and decided to use type B vent. I am unable to provide hard data that this helps but it does give me peace of mind knowing I did about all that could be done. Post some pictures of the install and finished product! We love ours!

Which FP 30 are you going with, square, arch, or arch + craftsman surround?

 

[Rogerius]

We bought the FP30 with rectangle door, type B no surround. The quote for chimney and install was ridiculous for a new constructions so we will install ourselves. Unfortunately the winter is in full blast here so we'll start once the weather will permit.

About insulation, I see HD has 1" Ceramic Fiber Insulation which is rated to 2300F and the spec is saying non-combustible. The size will wrap perfect the 6" duct.

(broken link removed)

 

[Drewman]

We bought the FP30 with rectangle door, type B no surround. The quote for chimney and install was ridiculous for a new constructions so we will install ourselves. Unfortunately the winter is in full blast here so we'll start once the weather will permit.

About insulation, I see HD has 1" Ceramic Fiber Insulation which is rated to 2300F and the spec is saying non-combustible. The size will wrap perfect the 6" duct.

(broken link removed)

I do like the clean lines of the rectangle door! Ours was ridiculously priced as well...
That fiber looks appropriate, but I am not professional just a do it yourselfer.

 

[billb3]

Hi All,

We are planning to install the new FP30 (Pacific) soon. Looking at the 6" ducts received with the heat transfer kits, I'm questioning if will not be a good idea to have those bare duct insulated instead to radiate heat. Make sense? If yes, what kind of insulation as I assume need to be for high temp? Any recommendation?
Thanks for any advice.

Won't insulating them minimize radiation ?

 

[ddddddden]

...About insulation, I see HD has 1" Ceramic Fiber Insulation which is rated to 2300F and the spec is saying non-combustible. The size will wrap perfect the 6" duct.

(broken link removed)

Nice to know that HD carries this insulation, but ~ $10 / ft is about the same price as a kit with all the trimmings.

FireFlex Insulation Wrap 1/2in - 3in to 6in liners (25ft) https://www.amazon.com/dp/B009KUWDWE/?tag=hearthamazon-20

Of course, if you need to buy the chimney pipe too, you can get the whole mess in one kit.

FireFlex 316Ti Flexible Chimney Liner Tee Kit - 6in x 15ft with 1/2" Insulation Kit https://www.amazon.com/dp/B076JQ8ZJ6/?tag=hearthamazon-20