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Insulating Ducts Answered

I was thinking about opening one side or the top of the "metal box" that "insulates" the out/intake ducts of HVAC unit, and filling that space with styrofoam popcorn used for shipping fragile stuff.

We recently had a couple of trees cut down in the backyard and now our HVAC unit is completely exposed to the sun for most of the day! We bought a shade to set up but I was thinking the styrofoam would just be a little bit more of a help!

What do you think?

All ideas and advice would be greatly appreciated!


i would imagine that most waterfowl that have survived over history long enough to breed and continue their species are sufficiently insulated, what with the waterproof feathers and what not...wait, you said ducts, with a T

do you have a maintenance agreement on your HVAC system? if so i'd contact the people that you have the agreement with and ask them for ideas,

but, assuming your HVAC is similar to mine (packaged heat pump) there are two shiny ducts coming out of the back (output and return) that are in a sort of, squared cone of sheet metal (yeah, squared cone, 3 dimensional trapezoid?) that's screwed into the back of the HVAC, then the other end of the "cone" is attached to your house. assuming that there are no openings around the two round ports that come out of the HVAC itself you could just fill the "cone" with expanding foam insulation (the spray foam stuff).

or take said cone off, and use duct wrap (fiberglass insulation sheets with a Mylar backing) to wrap the ducts.

kind of surprising to me that they're not already insulated.

*chuckle* I saw the T in ducts, but came here wondering why anyone wanted to insult ducts LOL I am tired and need to go to bed....

We've built a shade for the HVAC unit itself, what I wanted to insulate are the ducts running from the unit to the house. Right now, they are just "covered" with metal sheeting. The duct that sends cold air into the house is my main concern. It does seem to have a good bit of condensation at the base of the duct (against the HVAC unit. What can we do about that? It's not blocked, that we can tell. Any suggestions? Would photos help?

The HVAC unit that is outside should be designed to get rid of the heat to the outside air so I don't think you would want to insulate it in any way. It might help to shade the compressor part and insulate the cold return hose back into the house but you shouldn't need to add any insulation to the unit.

.  I think the OP is talking about the type of unit that has the compressor and evaporator in a single outside unit with air ducting between the house and the outside unit (very common on house trailers around these parts), in which case extra insulation would be helpful.
.  I'm not at all sure that packing peanuts would be the way to go. There is usually a lot of vibration in the area and the peanuts would probably compact in short time. How much heat will they take? I think I'd look at styrofoam (or other insulating material) sheets first.
.  Also need to make sure that the cold side can "breathe" or condensation will collect and cause corrosion/rust. Too much insulation may block needed air flow.