Duct shortening

[D'Olier]

We have been told that our A/C ducts in our attic are way too long and after being show this, it's obvious. Some of them snake around for about 15 feet when they could really be half that. I would like to do the work of shortening them myself. I assume you have to cut them and then rejoin them. Is this relatively easy work to do (besides the 140 degree heat in the attic), and how would I go about rejoining two ends of a duct?

It's the silver accordion type stuff, if that makes any difference.

Thanks.

[CBHVAC]

Why would you have to rejoin the duct in the middle? You dont.

You remove it from the trunkline, and cut it to fit, add mastic, slip it back on the start collar, use the correct banding, and thats it.

None. Other than the method used to reconnect to the start collars... .

[Ray]

Im a little concerned with what you call silver accordion type stuff, is it foilback insulated flex pipe your looking at or single layer aluminum foil flex pipe? FYI: 10 feet of flex pipe is the equivilent of 40 Feet of Straight galvanized pipe. Uninsulated is an abominal waste of energy, I would take the time to install straight galvanized 30 ga snap lock wrapped with foil back insulation, would take more time and money but the air flow, and temp of air flow would astonish you. just my 2 cents

[SQLit]

If you need to cut it in the middle get a piece of sheetmetal duct the same size. Slip it in the joint, sort of a inside coupling. Use mastic or metal tape on the liner to the collar then Tape the insulation last. Plan to have some slack in the duct after the shortening, it will make the re-assembly much easier.

[Arthur]

From what I am hearing "CBHVAC" has your solution. It sounds like you have flex duct for the branches and somebody did not cut to fit. Besure you don't try to pull the duct runs where there is no slack at all.

Don't tell me what I can understand, tell me what I can't mis-understand (Gen. Douglas McArthur)! No matter what you do you are a problem solver....what do you do? Arthur, Website:

Email: [e-mail]