Fiberglass or Steel Ductwork?

[enigma]

I've been told that a fiberglass ductwork falls apart with time and even blows fiberglass into a house. Some HVAC installers use fiberglass ductwork while I was suggested to only accept a metal (stainless steel?) ductwork. Any suggestions?

[airconman]

YES use steel duct

[square2round]

Metal, metal, metal. Galvanized steel is used...you don't need stainless. Stainless steel is at least 5 to 6 times more expensive, on top of an already higher sheet metal cost than what it was two years ago.

[edrock]

You couldnt give me a truck load of fiberglass duct,,,,ok I'll take it...thats less duct my competitor will have to install JUST MY TWO CCENTS

[bluetooth751]

Originally posted by enigma
I've been told that a fiberglass ductwork falls apart with time and even blows fiberglass into a house. Some HVAC installers use fiberglass ductwork while I was suggested to only accept a metal (stainless steel?) ductwork. Any suggestions?

Metal duct is one thing, but it can be insulated on the interior or exterior.

Ask for wrapped on the exterior.

We used Duct Board early when starting out. We now manufacture our on metal duct.

We like to call Duct Board "Crack Board"

[rsp4834]

I was told a few years ago that the duct board was being banned because of Indoor Air Quailty issues. Not many contractors in my area use it anymore.

[dec]

I used it for years and really didnt have a problem with it. Finally ended up with a new house that the women that owned it could hardly breath half the time in it. Now we were using the spray glue on the rough cuts and trying to keep do everything right so it would last. After a while I started hearing how hospital were banning it and some areas were stopping it so I decided to stop using it after that one ladies house. We ended up tearing all of hers out and replacing it with metal. I didnt want to end up replacing a lot of ducting if we started seeing that showing up a lot more often down the road. I just started thinking its just another asbestos waiting to happen down the road and as much as people like to sue, I think I will just pass on using it. I insulate the outside with ductwrap in cold or hot spaces but as far as insulating the inside for sound I avoid it . Only when its exposed on roof or ouside were I cant use wrap.

[Irishmist]

I think you can probably draw a conclusion from what you have been told, but I will chime in: USE GALVANIZED DUCT. I agree that it should be externally insulated in NON CONDITIONED SPACES. Internal insulation can be an IAQ issue at some point, and it also inhibits the ability to clean the ductwork in the future. IF internal insulation is used, be sure to adjust the duct size to still provide the clear air space required. More and more duct is required to be sealed at joints anyway, so you might as well externally insulate. I have never seen an OLD FIBERGLASS DUCT SYSTEM. What does that tell you?

[zoom38]

How about Spacepak GR8 Red plenum duct? Supposedly doen't expose fiberglass into the air stream and the interior is also supposedly washable. Any thoughts??

[jeffkillen]

I've said it before on this site,ductboard is in my opinion is only good for insulating your dog house,that is assuming you don't care much about your dog.

[billva]

ductboard=cheap

metal=quality

[dash]

I doubt there is 1 home in 100,000 with metal duct in Florida.Lots on homes built in the past 30 years.No problems with correctly installed ductboard ,that we know of.

[trane]

I agree with Dash. I don't use duct board but if its done right there is no problem using it. The biggest problem I have seen with its use is installing it in places that people use for storage or have to crawl over it.