[Alumifab]

You know the more I'm up in my attic inspecting my unit, the more frustrated I become noticing all of the shoddy work.
It's proof that who installs the unit is what really matters.......

Stupid question, can these flex duct lines be placed on top of the insulation?
Why do they have to hang?

 

[Bud9051]

Don't feel alone, what you are looking at is very common. They can lay flat, but should turn as gently as possible when turns are required. What should be hanging up there is the guy who installed those.

From a technical point of view, moving air wants to go straight. When it turns it requires energy which subtracts from the desired flow. To simplify the explanation they have set values of length they add to a run when it makes a 90° turn, something like 10'. So a flex duct that looks like a snake is performing like a duct twice as long as it could be. Then, those straps reduce the diameter.

IMO, flex ducts should always be resting on a straight surface, be that your attic floor or a provided 2x along the path.

Bud

 

[WhatRnsdownhill]

they were probably hung off the floor so the insulation could be blown in..ive seen worse...

 

[Alumifab]

I'm sure the ends aren't sealed either......
I contacted the energy company for last years numbers and they are through the roof!
So I am trying to fix things as best as possible before the summer comes and heats up Dallas.
I appreciate your feedback.
I'm going to lay these flat, after I look for leaks......
Should I lay some plywood down so they can rest on a hard surface?

 

[supers05]

Should I lay some plywood down so they can rest on a hard surface?

Would be a great idea. Both for the ductwork, and you....

Cheers!

 

[Alumifab]

Well, it's going to be a big project, but well worth it, I think.
I'm going to have to rake that blown insulation away so I can see where the wood is so I can put down some .5" plywood and to make sure everything is sealed properly at the ends.
I think I'm going to need more mostic and aluminum tape and rent a mask so I don't kill myself breathing this stuff in.....

Please tell me I'm not the only one dealing with stuff like this, lol.
:biggrin2:

 

[supers05]

You'd be the the vast majority. A good portion of southern houses are made that way. Some are done well, others not so much.

Cheers!

 

[beenthere]

Or, you can get saddles and put the saddles under the duct where the straps are.

Here is some info you may like to read.

http://www.flexibleduct.org/images/ADC~IR5E.pdf

 

[Alumifab]

Good article.
I like the idea of saddles.
I would need to add more straps with the saddles to make sure the dips and turns are appropriate.
I'll have to look into that.

 

[Alumifab]

You know thinking about it, I could buy a few flexible plastic sheets and create some long saddles to go the length or most of it to support it. I could puncture holes in the sheet sections to hang. Might come out cheaper this way. Not sure, have to price it out.......

 

[joecaption]

Why would you rent a mask?
Any cheap disposable dusk mask would work.

 

[Alumifab]

I have a few of those, just really never confident that they worked, but if you say they do, I'll use them....