Comments on: The Invisible Problem With Duct Insulation https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/ Building science knowledge, HVAC design, & fun Mon, 22 Mar 2021 16:10:02 +0000 hourly 1 https://wordpress.org/?v=6.6.2 By: Namita https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-13562 Fri, 13 Nov 2020 23:04:00 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-13562 In reply to Curt Kinder.

Hi, This is very helpful
Hi, This is very helpful article. In my house the ducts are being installed withouth insulation in the ducts that goes in the walls inside the house (not the outside wall or attic). Do you typically recommend the ducts to be uninsulated if it runs between the drywall within the house if the ducts are not in the exterior wall or attic.

Thanks!

]]> By: jiu https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-13540 Fri, 23 Oct 2020 13:45:01 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-13540 thanks
thanks

]]> By: ben https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-13400 Wed, 02 Sep 2020 16:56:54 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-13400 we just renovate a house in
we just renovate a house in the deep south and the HVAC system is in the unconditioned attic. RH can get into the 90% + and temp to 100F in the attic. My hard metal duct is wrapped in R-6 and it sweats as well as the plenty on a humid day. A lot of builders are now seeing a big problem with spray foam in the area due to humidity and we just didn’t think it has stood the test of time in the south as of yet… so we went with Batts on the attic floor.
Is there a high R value wraps for my metal duct system?
According to research I would need R-10-12 to prevent condensation on the worst days.
Any recommendations.

]]> By: Luke Vigg https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-13298 Wed, 22 Jul 2020 01:24:15 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-13298 How about all the air that is
How about all the air that is lost from not properly sealing the seams on the duct work. With both tape and liquid mastic. In the Carolinas duct work sweats even with the R8 under the home. The best solution I have found being a hella great duct installer whos blast test came back 100,% efficiency in a Habitat For Humanity home. The tested it 3 times and took apart to see what I did. If you use tape then liquid mastic on the metal then seal the insulation. In the same manner you will have great results. Why is there not a better solution for strapping. There are many things that can be done. I have cut open old insulation taped and masticed the seams then wrapped the silver Unfaced bubble wrap around the old insulation and cut to go around the take offs. The taped and seals that in a really great looking finished product. I will be going back tomorrow to see what it looks like 1.5 years later.

]]> By: Kingsley https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-12890 Tue, 07 Apr 2020 11:49:02 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-12890 Do residential evaporative
Do residential evaporative Air condition lose much cooling in short say about 14 feet un-insulated ducting.

]]> By: Steve https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-12765 Tue, 28 Jan 2020 02:20:21 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-12765 I have been in the commercial
I have been in the commercial residential hvac trade for over 20 years and have been a journeyman mechanic for over 15 years.i have worked all across the u.s.a.
I would not consider a plenum with 8 supply runs of 30 ft of flexible duct (example in Florida) anything even close to a hvac system
I would call it a joke and for sll the hacks that do that you should run only 5 ft maximum of flex ductas per smacna standards. How the heck are you going to balance that system?
Insulation or not no need for the insulation when the whole system is junk

]]> By: Planning State https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-12607 Mon, 11 Nov 2019 03:22:31 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-12607 In reply to Curt Kinder.

I could be missing something,
I could be missing something, but I think Florida only *requires* insulation, even in unconditioned space, to meet this condition: “Ducts that operate at temperatures exceeding 120°F (49°C) shall have sufficient thermal insulation to limit the exposed surface temperature to 120°F (49°C).” Source:
https://up.codes/viewer/florida/fl-mechanical-code-2014/chapter/6/duct-systems#604 (604.2)

There are multiple requirements for insulation when it is used, but only that one for when insulation is actually required.

]]> By: CYA247 https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-12466 Wed, 25 Sep 2019 19:44:57 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-12466 I live in the panhandle of
I live in the panhandle of Florida. I have been told that I may need new ducts. However, my house was built in ’65 and contains metal duct. Granted the insulation on that duct has surpassed it life expectancy and my duct resides in the unconditioned attic. The ducting currently rests on the attic-joist which causes any residual R-value, from disintegrating insulation, to be non-existent. In my mind if feel metal duct is better than duct board ducting, as it is not as porous and less likely to absorb moisture and start growing funk in my air ducts. My question is, If I removed all the current insulation, wrapped the metal duct in R-8 Eco-foil bubble wrap, then applied suspension straps (effort to reduce heat transfer/condensation from Hot strap touching cold duct), suspend the duct to get it off joists, and then added a minimum of R-8 fiberglass Duct insulation; would I have a better product than just replacing it all with new duct board & flex duct work (that is what ever company has given me quotes for as metal is apparently cost prohibitive)?

]]> By: blaze2051 https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-12412 Sun, 28 Jul 2019 04:01:43 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-12412 i live in las vegas and i
i live in las vegas and i have 1995 home and i think my duct system is not the best design and i have r-11 or r-19 of cellulose. i recently added attic foil and attic fan after i sealed all the top plates and wire and pluming that was in reach. and the results are great. but can i improve it by adding more insulation and some how increase duct R value? My ducts are flex and has ductboard. zero metal ducts

]]> By: Jeff Classen https://www.energyvanguard.com/blog/the-invisible-problem-with-duct-insulation/#comment-12349 Thu, 27 Jun 2019 20:40:21 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-invisible-problem-with-duct-insulation#comment-12349 I am currently working on a
I am currently working on a project where increasing the duct insulation is essential, but I am running into problems finding flex duct or duct wrap with anything higher than R-8. We are planning to use closed cell foam on the trunk-line (which happens to be suspended 4.5 ft above the attic floor) to R-21. But the branches off of that are more difficult. We are redirecting those to the attic floor rather than being strapped to the rafters. Getting an R-20 over the flexible lines would be a great step. Any Thoughts?

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