Steam Pipe Insulation Question from a Noob

Brad White

Insulation is important for a number of reasons:

1) Safety- prevents burns.

2) Energy conservation- keeps heat in the piping so you can get it where you want to release it.

3) Performance- Bare pipe causes steam to collapse back into water. This can cause banging, clicking, noise in general. It slows the delivery of steam.

4) On the returns, keeping the piping warm slows the reabsorption of carbon dioxide from the air which slows the formation of carbonic acid which grooves your condensate pipes.

As for material, the gold standard has been molded fiberglass. Most model energy codes say for steam temperatures to use 1.5" thickness up to 1.5-inch pipe size and 2" above that, to 4-inch pipe size.

As a practical matter and for cost-benefit though, and as discussed in some threads here on The Wall, it was generally accepted to use at least one-inch thickness, more if you can afford it. The difference in performance beyond that first inch, per cost, was rapidly diminishing. The first inch knocks the heat loss down to about 1/6th (84% reduction). The next inch takes that down another 8 percent. Measurable, sure, but the stuff gets expensive. One-inch is fine for most return systems.

Forget the half-inch stuff sold in the box stores though.

Daniel Cayea

Steam Pipe Insulation Question from a Noob

I had ordered Dan Holohan's book "We Got Steam Heat" and it just arrived. As I am reading through I realize that just about everything I knew about steam heat was false. One of the things I learned was I do need to get my pipes insulated. My question is what is acceptable to use, what are technical specifications for insulation that I can use on my steam pipes?

Thanks for your time and input.

-Dan

Daniel Cayea

I understand, but my question is still unanswered.

Yes, I know I should insulate my steam pipes, but what kind should I get?

Brad White

See edits (NM)

scrook_2

fiberglass

One inch thick fiberglass (white paper cover covered). It comes in 3' lengths, See McMaster-Carr catalog no. 5556K36 (for 2" trade size pipe) as an example. http://www.mcmaster.com

This should also be available from a local insulation or plumbing vendor. The nearby big box store probably only has 1/2" thick however.

David Nadle

All due respect to McMaster...

but their pricing on fiberglass insulation is outrageous. I love them anyway though. In the old days I'd pore over that fat yellow catalog all day long.

I had a good experience with buyinsulationproducts.com. They have all the thicknesses and they have the PVC fitting covers too, and their pricing was about the best I could find.

Shipping is a significant part of the cost, however, so you may want to search locally.

n9uebot9611768781

just a visual/example for him...

not as the best priced source. They do have a lot of stuff in stock though, would love to see one of their warehouses.