insulating forced air heat ducts in WA (king county)

[roger beniot]

I have a gas furnace in the center of my 1200 sq. ft. house (in a closet). The furnace is around 8 years old. The furnace has some duct work that runs into the attic (not sure what it is for) and the majority of the ducts are below the house (in the crawl space). The ducts under the house run to each room and connect to floor registers.

Currently there is no insulation on any of the duct work (attic or crawl space). I've had one guy out and he said he would do it for almost $1200... I figure I can do it myself for much less.

I had the following questions:

1) does anyone know a reliable and inexpensive company/person to do this duct work in the King County (WA state) area? 2) What type of insulation would I want to use for the ducts (figerglass, closed cell foam, etc)... Specifics would be very helpful. 3) where can I get the insulation (home depot, lowes, specialty places) 4) any good how-to out on the net

Thanks in advance, Roger

[Joseph Meehan]

My personal opinion is you may get a pay back if you do it yourself. Having it done is likely to have a very long pay back.

If you had A/C as well that might help, especially with the stuff in the attic. However with just heat in King County you will not save all that much on heating cost.

I would suggest finding out what is in the attic, just for fun. Then measure the shape size and length of your ducts, then visiting a heating supply company. You should not have a problem finding on in King County. (Louis County might be more of a problem ;-)) They can fix you up with good quality materials and likely give you some hints to make the job easier.

To find out what the local cost to install is, get another estimate.

[Tom Baker]

The attic duct might be for a return.

TB

[Joseph Meehan]

...

I have to disagree with you here.

Advice is not good if the reader will not read it. It came across with a rather poor attitude and likely was not accepted. If you want to teach, which is want this is really about, you need to get the information to the student. I doubt if the original writer read past the first line and I don't blame him.

Even the best advice is no good if it does not get where it needs.

I have not seen your advice given in this manor, even when you strongly disagree.

[Uriah Heep]

I do not know your climent and repay time but insulating ducts is easy though like most insulation jobs nasty. None of the materials are restricted. You will need a quanity of foil backed fiberglass that will have a foil lap in one side to over lay the next strip. A quanity of metalic foil tape and a staple gun that spreads the staples outward. The hard part is firmly wraping stapling and taping the insulation to the pipes. Do make sure all joints in your ducts are well sealed and taped with metalic tape as a first step.

The stuff at home depot etc. is overly expensive and shoddy so do go to a heating supply company for material.

Louis

[Rudy]

On ours, after coating the joints with mastic, they wrapped it in unfaced 2" fiberglass insulation (Dry location) Is your crawl skimcoated and dry ?

(home depot, lowes

Yes

[CBHvac]

We can agree to disagree...thats called life, and thankfully, we all still can...

Ok..point taken, but Paul prob didnt check to see if it was in AHR, or AHVAC, and it was crossposted...AHVAC isnt a learning grounds, never was...it was not its original intent,and he was a founder.

True, but on the other hand.....some wont listen to anyone, if its not what they want to hear.

Oh..I have..LOL...worse even. Tried to calm it all down as time has gone on...since about 84...get in the sometimes year long bitch session..LOL...

[Larry Caldwell]

Here in Oregon the code is 3" of foil faced fiberglass, and the joints sealed with foil tape. I assume it would be the same in Washington. Before you insulate, make sure all ductwork joints are sealed tightly, then it's just a case of cut, wrap and tape. Piece and tape carefully around duct supports. Don't forget to insulate your water pipes. The crawl space will get a lot colder when you insulate the ductwork.

I bought mine from a lumber yard. The good stuff is godawful expensive, and comes in big rolls about 4' wide. Your $1200 bid would have just covered the materials at my house, but then I had a 30" return air duct in the attic that was 60' long.

Not that I know of, but putting up insulation is not rocket science. Just be neat and thorough, and you will do fine.

[Joseph Meehan]

I can agree with that.

...

And neither did I. Something I should have considered.

...

[roger beniot]

Thanks Larry...

I'm not sure there is code for this in WA... When we bought the house I asked the inspector about the un-insulated ducts and he said you can have them insulated or not (just depends if you want to spend more on heating costs). If anyone knows any different I'd love to know about it.

No worries on the water pipes I already did that job (after having to replace two leaking joints).

Rudy brings up a good point... the crawl space does get a little damp (a small 5' x 5' area approximately 2" deep forms after a lot of rain. Fortunetly the low spot is not near any of the ducting.

-roger