DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   HVAC (http://www.diychatroom.com/f17/)
-   -   insulating and insulated duct runs (http://www.diychatroom.com/f17/insulating-insulated-duct-runs-129386/)

hummer4x4guy 01-09-2012 01:40 PM

insulating and insulated duct runs
 
Greetings all,
New to the DIY chatroom but not to DIY itself.

My latest project I am working on is to remove the hard duct lines 6" round and replace them with insulated 6" round runs. I have one installed so far and works fine.

I wanted to know if there is a specific distance from the main trunk line off the furnace in which I can start to run the insulated runs which will go to the floor registers.
I have a 2 year old 98% force air furnace and want to make the trunk line system as efficent/insulated as I can.
I have ordered UL-181 mastic for the joints which I wont change to insulated runs.
I have one hard line which branches off at the end of it and runs to two different registers on the main floor.

So in short is there any area of the trunk line that should not be insulated (due to higher heat temp) or is it all safe to insulate? Also is there a prefered insulating product anyone has used on hard trunk lines once the air leaks have been sealed up?

Thanks
Joel

TarheelTerp 01-09-2012 02:14 PM

Quote:

Originally Posted by hummer4x4guy (Post 817491)
So in short is there any area of the trunk (or other) line that should not be insulated (due to higher heat temp) or is it all safe to insulate?

In conditioned areas (like finished basements) there is little point to insulating ducts.

Quote:

Also is there a preferred insulating product...
Check with your county for their minimum requirement.
Most mins are R6 (which at 1.5") is often hard to fit *above* installed duct.
Better insulation... is even thicker.

Quote:

...want to make the trunk line system as efficient/insulated as I can.
UL-181 mastic for (ALL) the joints (everywhere)
And a few zip screws here and there never hurts either

I wanted to know if there is a specific distance from the main trunk line off the furnace Nah... but if it isn't square it's harder to do.
Quote:

My latest project I am working on is to remove the hard duct lines 6" round and replace them with insulated 6" round runs. OK


hth

hummer4x4guy 01-09-2012 02:33 PM

Tht,
Thanks for the reply. The basement isnt finished and mainly a storage room, and not a type of a basement for hanging out. Otherwise the leaks and insulating of the trunk lines wouldn't be something I would be working on.

Good point also on the screws as they will be needed in a few places I saw also.
Thanks for the input.
Joel

fitter1 01-09-2012 03:11 PM

If you are replacing metal duct with insulated flex you will likely encounter air flow issues. Flex should only be used in 3ft lenths and pulled hard and tight and straight due to its high friction loss. A lot of jobs will not allow this to be installed for this very reason. I would use insulated duct wrap and keep what you have.

harleyrider 01-09-2012 03:52 PM

Quote:

Originally Posted by fitter1 (Post 817582)
If you are replacing metal duct with insulated flex you will likely encounter air flow issues. Flex should only be used in 3ft lenths and pulled hard and tight and straight due to its high friction loss. A lot of jobs will not allow this to be installed for this very reason. I would use insulated duct wrap and keep what you have.

Fitter is correct, if you want to insulate round ducts they make a "pull over" insulation just for that purpose.


All times are GMT -5. The time now is 09:51 AM.