ReplyDoesn't meet the specs of class 1 ,duct,Flame and smoke developed rating.
If there's a fire,not a good thing.Some codes allow it under a concrete slab,little fire danger.
Regular Guest
Is there any reason as to why there is not a use of PVC for ductwork applications for HVAC?
Gordy
Banned
Doesn't meet the specs of class 1 ,duct,Flame and smoke developed rating.
If there's a fire,not a good thing.Some codes allow it under a concrete slab,little fire danger.
Regular Guest
That makes sense to me. So how does flexible duct get around this? Is it the insulation?
Gordy
Regular Guest
i believe there is a type of duct system that is of pvc type construction you may want to contact your local dealer for info
Banned
Just a different material,than PVC,there is a type of PVC that meets this rating,very expensive though.Originally posted by gordy
That makes sense to me. So how does flexible duct get around this? Is it the insulation?
Gordy
Professional Member*
there is pvc coated spiral duct. i don't quite get your question. what do you want to do?Originally posted by gordy
Is there any reason as to why there is not a use of PVC for ductwork applications for HVAC?
Gordy
FILL OUT YOUR PROFILE!!
Professional Member*
Originally posted by tinner73
there is pvc coated spiral duct and rectangular. i don't quite get your question. what do you want to do?Originally posted by gordy
Is there any reason as to why there is not a use of PVC for ductwork applications for HVAC?
Gordy
FILL OUT YOUR PROFILE!!
Professional Member
Thats only for the first 5 feet.I think the price would be to much.Originally posted by dash
Doesn't meet the specs of class 1 ,duct,Flame and smoke developed rating.
If there's a fire,not a good thing.Some codes allow it under a concrete slab,little fire danger.
[Edited by framehvac on 03-05-2005 at 02:19 PM]
Regular Guest
Well, I want to install AC in my attic for a 2300 square foot ranch. Looked into Hi Velocity turned off by the reduction in seer rating. So thinking conventional. Not an avid fan of flexible ductwork. Just wondering about the pvc duct work, an avenue that went through my head knew there must be a reason why not widly used.
I have read alot about ductwork in unconditioned spaces. I know its not my best option. But its doable. If done right. I have ceiling radiant heat (hydronic). My concerns with the ductwork would be A. Condensation in the winter or summer, leading to mold issues. B. Lack of performance, ductwork being warm/ hot between cooling cycles leading to longer than needed cycles.
This system would only be for AC. So I'm tryin to get my ducks in row here. Thinking of using two air handlers so I can keep my attic center unobstucted for storage. The ranch is a U shape. HeatGain 40,000 Btu high side. I presently use 30,000 Btu's worth of window shakers and it cools they handle the load.
Thanks for your replies Gordy
Banned
The heat gain for the ducts in the attic,should have been accounted for in the Manual J,load calculation.Use an R-8 insulation,to reduce the loss.
Professional Member*
any kind of ductwork can be done. it depends how thick your wallet is. i would use standard galvanized metal that would get wrapped on the outside. i too dislike flex systems, Dash would disagree with me.
FILL OUT YOUR PROFILE!!
Professional Member
Its a southern thing tinner73.Originally posted by tinner73
any kind of ductwork can be done. it depends how thick your wallet is. i would use standard galvanized metal that would get wrapped on the outside. i too dislike flex systems, Dash would disagree with me.
[Edited by framehvac on 03-05-2005 at 03:09 PM]
Professional Member*
i understand.
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Regular Guest
It is all about the gass released when the stuff melts or burns.
PVC is will release toxic gasses that will cause you to die before you can get away from the fire..
AB
Professional Member
Most everything in your house andrew boyce released gass when it burn.Plummers use it to in house.Originally posted by andrew boyce
It is all about the gass released when the stuff melts or burns.
PVC is will release toxic gasses that will cause you to die before you can get away from the fire..
AB
This is pvc duct
Professional Member
First time I've ever seen this type of PVC duct. Can it come in any rectangular size? I assume this is designed for underground slabs? Besides being used underground, what other applications would it be used in? That would have to be expensive. It's not like you can fab this in the shop.Originally posted by framehvac
Most everything in your house andrew boyce released gass when it burn.Plummers use it to in house.Originally posted by andrew boyce
It is all about the gass released when the stuff melts or burns.
PVC is will release toxic gasses that will cause you to die before you can get away from the fire..
AB
This is pvc duct
I've only dealt with the PVC coated spiral duct for underground.
Get back to work.™
Professional Member
Any,its just all about saving the money that is why no one uses it.It's not like you can fab this in the shop you could do it,you would just have to learn how & get some new tools for the shop.
Professional Member
Professional Member
gordy
Member
Registered: Feb 2003
Posts: 11
Is there any reason as to why there is not a use of PVC for ductwork applications for HVAC?
Gordy
So they do,do it.
Regular Guest
True.. but in the infinite wisdom of the US government they have decided to rate some types of materials more of a risk when burning or melting than others... this is the reason that the PVC ducts you have in those pictures are most likely designed with low levels of this gas...
I feel that if one attempts to breath anything that is burning you will likely die. so what’s the point. Best thing to do is get out of a burning house or structure as this in it self is likely to result in death.. LOL
:-)
AB
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