Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
I have sheet metal heating ducts in the attic, and just one of the runs has rusted on the inside on its entire length. The rusting happened because there was a palm sized opening (must have happened due to the effects of earthquakes) at one of the joints, and I have fixed it. But I am now contemplating if I should replace the duct itself. Is there any danger of dirty and rusty air being circulated? I read somewhere that, on a heating duct, dusts and rusts stick to the inside wall of the duct, so there is no worry. But what do you guys think? Should I replace it?
You and a Friend could probably do the whole house.
Quote:
Originally Posted by sakash
I have sheet metal heating ducts in the attic, and just one of the runs has rusted on the inside on its entire length. The rusting happened because there was a palm sized opening (must have happened due to the effects of earthquakes) at one of the joints, and I have fixed it. But I am now contemplating if I should replace the duct itself. Is there any danger of dirty and rusty air being circulated? I read somewhere that, on a heating duct, dusts and rusts stick to the inside wall of the duct, so there is no worry. But what do you guys think? Should I replace it?
Many new installation and retrofits use the round flexible ducting that comes compressed in a box. I helped my brother replace all the attic ducts in a 1350 square ft house one Saturday. Pick up a couple of boxes of the size you need and the sheet metal transition pieces from the duct to the vent.
It can get very hot in the attic. I would not want to do the job in the summer. Cover up, or wear one of those white tyvek suits and a good industrial quality particle mask and you are good to go.
I think I would if you are planning on staying more than a few years. New ducts will pay for themselves in efficiency gains, especially if you have and use central AC.
The rust will continue circulating through the house if you leave the old ducts in place.
On the downside... new flex ducts are susceptible to rodent damage vs. sheet metal ducts.
You will be disappointed in flex duct versus sheet metal duct. There is a significant loss in flex vs hard sheet metal duct. If you decide to do it...Make sure the runs are straight as possible and you choose R-6 insulated or higher. If I were you I would get the sheet metal replaced and have it sealed as well as all the rest of the seems that can be sealed. The if it is not insulated duct work I would get it insulated with the best insulation possible. Because of the nature of flex duct with the ridges that allow it to flex it has a poor airflow resistance as opposed to sheet metal. If you decide to go with flex make sure you account for the loss you may end up needing to redo the entire runs. You could have a pro come in a provide you with a manual D which would tell you exactly what you need. But cheapest best route IMO is just get that section replaced and make sure the rest of the runs are well sealed.
Had my AC checked out yesterday. The unit was replaced in 2007. Now the ac guy tells me one duct needs to be replaced, because it is crushed. Don't know how that happened, and another duct needs to be re-wrapped.
So what am I really looking at here? What is the ball park cost? My husband is not well enough to go up in the attic. I guess I could do it if I knew what to do.
Location: Visitation between Wal-Mart & Home Depot
8,309 posts, read 38,782,175 times
Reputation: 7185
Quote:
Originally Posted by BigJon3475
You will be disappointed in flex duct versus sheet metal duct. There is a significant loss in flex vs hard sheet metal duct. If you decide to do it...Make sure the runs are straight as possible and you choose R-6 insulated or higher. If I were you I would get the sheet metal replaced and have it sealed as well as all the rest of the seems that can be sealed. The if it is not insulated duct work I would get it insulated with the best insulation possible. Because of the nature of flex duct with the ridges that allow it to flex it has a poor airflow resistance as opposed to sheet metal. If you decide to go with flex make sure you account for the loss you may end up needing to redo the entire runs. You could have a pro come in a provide you with a manual D which would tell you exactly what you need. But cheapest best route IMO is just get that section replaced and make sure the rest of the runs are well sealed.
BigJon,
I've been battling with condensation problems soaking the insulation on my rigid duct since I purchased my house. I've stripped all the insulation, overkilled the hell out of sealing the joints, re-insulated and done a much more thorough and ongoing job of sealing the insulation than any HVAC tech would have done and I'm still not able to make things truly airtight and I get wet insulation at all the low points. I'm starting to think that the flex duct may be a better match for hot, humid coastal areas.
I've been battling with condensation problems soaking the insulation on my rigid duct since I purchased my house. I've stripped all the insulation, overkilled the hell out of sealing the joints, re-insulated and done a much more thorough and ongoing job of sealing the insulation than any HVAC tech would have done and I'm still not able to make things truly airtight and I get wet insulation at all the low points. I'm starting to think that the flex duct may be a better match for hot, humid coastal areas.
What do you think?
Do you have any sort of vapor barrier around your insulation? Without that, you are likely going to get condensation no matter how much insulation you have. With that, I would not think the moisture should be able to get to the insulation to condense???
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
You and a Friend could probably do the whole house.
