Insulation thickness/ where to buy?

sm69th

I recently had my asbestos insulation remove from my steam heating system (not by choice), so now I have to re-insulate. The stuff they sell at Home Depot is only 1/2" thick, and I have read elsewhere that I should have at minimum 1"...not sure if that is correct?

I am looking at covering the 2 1/2" rolled steel mains as well as the 3" pipes on the header, ~140ft. I don't want to really cheap out and just get the 1/2" stuff, but I dont' want to waste money either...does it make sense for larger wall thicknesses in a residential setting? I have seen thicknesses go up to 3"...but at what point for a residential setting am I just throwing money away and not getting back anything on my return? I have a 3,509 sq ft 101yr old colonial house, heating with 18 cast iron radiators...brand new boiler too.

Any advice or reliable place to get this stuff (or brands) would be greatly appreciated.

David Nadle

There's a lot of info in the archives on insulation thickness. On 2" NPS and smaller anything over 1 1/2" is not cost-effective. For larger than 2" NPS, 2" insulation is recommended.

sm69th

David Nadle said:

There's a lot of info in the archives on insulation thickness. On 2" NPS and smaller anything over 1 1/2" is not cost-effective. For larger than 2" NPS, 2" insulation is recommended.

Since I have limited experience, I looked up NPS and I believe that means Nominal Pipe Size? Since my mains are 2 1/2 to 3" your recommendation is 2" insulation?

Anyone else want to chime in? Thanks for the info so far, at least I am not shopping in the dark!

Fred

Most of us use 1" on the steam pipes if it's in a basement and 1.5" in a crawl space. I think you can get some of the best pricing from: http://www.buyinsulationproducts.com or http://www.statesupply.com/pipe/insulation/fiberglass
1.5" is probably a good investment for all the pipes given the incremental additional cost.

KC_Jones

http://www.expressinsulation.com/
Is another online source for the insulation. I think it was mentioned their prices are better than the others. If you can find a local supplier sometimes that is a better source because of shipping costs associated with online retailers.

sm69th

Thanks for all the advice. The vast majority of the piping is in a full (unheated) basement, except for one corner which is a crawlspace.

My biggest reason for considering going up over 1" thick was that my new megasteam boiler is borderline undersized to begin with so one of my thoughts was to ramp up on insulation to keep that pickup factor to 33% or hopefully a little less.

David Nadle

I wanted to make sure you were using NPS because a 2" NPS pipe actually has an O.D. of 2 3/8", etc. My personal position is that 1" insulation is adequate for 2" and smaller, but the ASHRAE standard calls for the sizes I mentioned above.

sm69th

David Nadle said:

I wanted to make sure you were using NPS because a 2" NPS pipe actually has an O.D. of 2 3/8", etc. My personal position is that 1" insulation is adequate for 2" and smaller, but the ASHRAE standard calls for the sizes I mentioned above.

Well, our boiler installer told us it was 2 1/2" black iron pipes for the mains, and I went to the website http://www.buyinsulationproducts.com/ and checked the circumference of the pipe (9") against their chart, and it said to order 2 1/2"...so I am assuming I am ordering the right stuff? :-)

TheRooster

KC_Jones said:

http://www.expressinsulation.com/
Is another online source for the insulation. I think it was mentioned their prices are better than the others.

I can recommend expressinsulation. I purchased all my insulation from them. Between the insulation and mastic, I saved around 25% over buyinsulationproducts. The shipping was also cheaper and it arrived via freight. The brand of insulation I received was Manson Alley-K ASJ and expressinsulation even sent the pre-cut ASJ Tape strips to use on the joints.
http://www.imanson.com/en/alley-k-all-service-jacket-jacket

Fred

You are ordering the right stuff. Those 3' lengths of insulation are sized according to the pipe standard. Insulation for a 2-1/2" pipe is sized a bit larger to fit around a pipe that has an outside demension of about 2- 7/8".

David Nadle

sm69th said:

...so I am assuming I am ordering the right stuff? :-)

Sounds like you've got the sizing right.

KC_Jones

Fred said:

You are ordering the right stuff. Those 3' lengths of insulation are sized according to the pipe standard. Insulation for a 2-1/2" pipe is sized a bit larger to fit around a pipe that has an outside demension of about 2- 7/8".

If they measured 9" circumference that is indeed 2 1/2" pipe not 2"