HVAC Ducts & Conditioned Attics

[@keithdavidson6995]

Great PSA

[@pigsplayingpoker]

In that climate zone, you have to use closed cell foam on the roof decking, right? But you can also use other insulation below it, like you did with the open cell foam? Do you have to put a supply and return duct in the attic? How many do you put in? Do you need a moisture vent at the ridge line (I have read that is required in southern climates, but I am curious about RI)?

[@Scatch85_YT]

Our house in SC everything is in the attic. Our AC tech didn't seal up the air handler after working on it and now it's full of dirt and bugs etc. not only that because of the humidity here the air handler sweats like crazy. I'm so torn what to do I hate having it in the attic but no real way to change that. I have been thinking about spray foaming the attic vs our soffit and ridge vent system.

[@elmaddog1978]

The definition of a conditioned space is an area within the envelope with a heating or cooling system by direct or indirectly with 3 air exchanges per hour by a mechanical or wood burning device above 5BTU's, what are your thoughts?

[@JustinOsborne1]

When you have a conditioned attic, do you need to have any air registers or returns specifically located in the attic?

[@umeng2002]

Yes. To handle moisture that will eventually work it's way to highest part of the structure. Not as much as a livable space though. And I'm not sure about a return though... the spray foam makes fire concerns an if you also put a return in there... but maybe the codes have been updated.

[@Sotexmafia]

I came here looking for that answer. I wish they would go over that more. The build show has a million videos on airtightness that just explain the same thing over and over. They need to explain how to do it properly and what materials to use specifically. They are all over the place and it’s hard to nail down exactly what to do.

[@JustinOsborne1]

@@Sotexmafia I didn't have either a return or register in my house. It gets humid (~60-65 at peak summer in Alabama), so at the end of the year, I put a dehumidifier up there and that's solved any fears I had with moisture there.

[@JaykayRva]

You find the answer yet bro? I got the same question lol

[@ericspence]

If the attic is vented what good does moving the insulation from the floor to the roof joists do. They still have soffit/gable vents. Wouldn't they need to seal those before moving the insulation?

[@dondumitru7093]

Conditioned attics do not have soffit/gable vents, conditioned attics are fully-sealed and are WITHIN the envelope of the main house. Soffit/gable vents are used in an unconditioned attic to provide venting to the outside for moisture removal. A conditioned attic connects to the air conditioning or heating for the main house, and gets moisture removal thru that system.

[@Mikey__R]

In the UK at least, I believe we're required by building regs to keep a 50mm gap between the top of the insulation and the slate / tile above. This keeps the ridge and soffit vents and allows the rafters to dry out if they do get wet. There are plenty of 30 / 40 year old loft conversions with rotting rafters.

[@WKPConstruction]

No need for soffit/gable vents in this scenario

[@TitusChristopher-b7z]

Thomas Elizabeth Lopez Kimberly Robinson Lisa

[@MacDonaldEdmund-t6o]

Jones Brenda Thompson Shirley Johnson Margaret