[hswerdfe]

I live in a bungalow. I have a series of 5" round metal ducts running in the floor joists.

I am currently finishing the basement and everything is exposed now. I wasn't going to touch any existing ductwork but I did notice that they are quite hot to the touch some times. My local big box sells 5" round by 10' long insulating sleeves for ~$15. they claim R value for 4.5 to 6.

So, what do you think? is this a worthwhile investment of time and money?


Thanks

 

[beenthere]

6 one way, half a dozen the other.

The heat they put off also helps to keep the floor above them warm. may not feel as comfortable if the floors are cooler.

 

[concretemasonry]

You are not really losing any heat since it is still inside the house. It is just being distributed a little differently (if you do not have any leaks).

dick

 

[bobinphx]

Insulation is good, but duct mastic might be better bang for the buck. Seal all the joints and seams with mastic. I might also be a good time to clean the ducts one time before you seal them up!! (diy is fairly easy)

now others may disagree, but if it was me, I would lay in some standard unfaced fiberglass all along the sides and bottom (you may need to thin the fiberglass on the bottom). The r13 rolls are cheap and by insulating the sides and bottom, you will still let a little heat out to possibly keep the floor above warm...

 

[hswerdfe]

Thanks all.

For the record I have decided not to insulate them for now.

bobinphx: the reason I was considering it in the first place is that I was already doing exactly what your propose "Sealing the ducts".