Question on Differences in Pipe insulation

Brad White_203

Do shop around.

I do want to correct one thing though. The ASHRAE code (ASHRAE 90.1-2004) stipulates 1 1/2" insulation on 1 1/2" pipe and 2" insulation on 2" pipe on up to over 8" by the table.

This is for piping in the 201 to 240F temperature category, easily low pressure steam and higher temperature hot water.

One could argue that the next lower category of temperature (141 to 200F) would cover condensate, in which case you can use 1" insulation for up to 4" pipe size, then 1 1/2" thick insulation above 4" pipe size.

The "take-off" rule is for piping less than 12 feet long running to a single emitter. It is really designed to save space for piping concealed in walls and pipe enclosures. I would go the full recommended size per temperature in that case.

As Dave said though, the first inch does much of the work (do stay away from the 1/2" stuff though) but you are only doing this once, so factor in your labor and pride.

I would add though that once insulated, your basement ambient will be noticeably cooler thus increasing the need for insulation.

Tumbler

Question on Differences in Pipe insulation

So I am about to put insulation back on all the mains and takeaways in my basement that the prior owner removed. The question I have is on differences in insulation. Looking through past posts on this board, various people have suggested rigid fiberglass insulation, and referenced two suppliers - MSC and McMaster-Carr. What I am trying to understand is why there is such a huge price difference on what I think are essentially the same products:

2 3/8" ID 2" Thick Rigid
MSC - $33.06 for 3' length
http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=4259&PMCTLG=00
McMaster-Carr $25.93 for 3' length
http://www.mcmaster.com/ (Go to page 3419)

Is there a difference between these two products that I need to understand?

Second question - was thinking about 1.5 or 2 inch insulation on my 2 3/8 inch mains and2 or 2.5 inches on my 2 7/8 inch mains

Last question - do I insulate the pipes around the new boiler or only the mains?

Really appreciate any advice as this steam thing is new to me - "We got Steam' has been a great help so far.

Thanks,
Chris

David Nadle

Keep looking

If you're looking to get insulation shipped I recommend you shop around more. Take a look at buyinsulationproducts.com. Also realize that shipping a whole system's worth of insulation will add at least $50 to the cost so it might be worth it to find a local insulation distributor.

Finally, you should insulate all the pipes above the waterline including the near boiler piping. Your 2 3/8 pipes are called 2" nominal pipe size and the 2 7/8 is actually called 2 1/2" pipe.

I beleive the ASHRAE code calls for 1 1/2" insulation on 2" mains, 1" for takeoffs, and 2" on 2 1/2" pipe.

My personal opinion after looking at insulation performance data is that 1" insulation all around is adequate for 2" pipe. It's one third the price of 1 1/2" insulation for slightly less performance. But you're only doing it once, so...

Tumbler

Thank you both

Brad and David,

Thank you both so much for your responses! I would have been quite disgusted with myself if I had ordered the wrong size insulation. I also think I will opt for the thicker insulation. I only plan on doing this once, and as they say, in for a penny, in for a pound.

I will try to find a supply house that is local to me. The few I have found so far only carried up to one inch, but I am sure there are better supply houses in the Providence area. I will keep looking as I have a strong preference for supporting local businesses when possible.

Last question: What are your thoughts on leaving the joints and valves bare? My basement is acutally a finished area and so my thinking was that leaving the joints and elbows exposed would function as 'the radiator' for the basement, not to mention look cleaner. That said, I would hate to lose substantial benefits because I did not 'finish the job'

Thanks again - I really am blown away by how active and supportive this board is. I do hope that those contractors contributing to this site get incremental business, as you all provide a great deal of value to the rest of us.

Chris

Brad White_203

Chris

Thanks for the acknowledgment, by the way!

I think Homans Associates covers Providence. Regardless supporting brick and mortar businesses is a good thing anyway. At least here in MA we only (only??) pay 5% sales tax versus your 7%.

As for joints, the insulation comes with what is called "all service jacket" (ASJ). They give strips of peel and stick tape of this material to cover the joints. For the ends of insulation, especially cut ends, there is a brush-on white cement used to make a neat, fiber-free termination.

Fittings are fussy but worth doing, both elbows and tees. Valves? I have seen them left bare mostly. I suppose because unless you have extended stems, the insulation suffers in any case.

Remember you want to insulate it all. I recall a mention of "Above the Waterline" but I prefer to insulate all of it and control what heat I put in there, not just letting it happen.

If you feel compelled to leave any piping bare, that would be the returns but do your best.

In our business (engineering) we insulate it all, not just thermally but for burn protection too.

an old wrench puller

By all means

buy local if you can. as others said, the shipping will kill you. go to a profesional plumbing supply house and ask or call a mechaincal contractor and ask who they use for an insulation sub. They might sell you some over the counter. Heres another supplier to compare prices. http://www.statesupply.com/

David Nadle

You might try Knauf or Owens Corning websites and search for an RI distributor. If you run out of luck the website I mentioned above does ship UPS.

I would do the fittings. They make little fiberglass blankets for them with PVC covers that you tape on. They come in sizes to fit any insulation O.D. It takes patience and practice to get it right...

If you want to leave some uncovered for the basement I would omit some of the takeoffs.

stevel

insulation vendor (not local)


http://expressinsulation.com/fiberglass_insulation.html

This outfit is not local, but their prices are better than McMaster-Carr or MSC. They carry Knauf brand insulation.

Also, go to this web site http://www.pipeinsulation.org/ and download 3EPlus software. It'll let you enter the parameters and look at the heat loss of varying insulation thickness. After using the program, I would agree with David that 1" is adequate.

scott k_3

FW Webb

If you are in NE try FW Webb. did a whole basement in 1" wall thickness insulation on pipes sized between 1 and 3 inches. Generally each 3' pieces was between 5-8 bucks if memory serves.

Tumbler

Thanks to everyone for your responses

I very much appreciate everyone's help. - Straight sections are up - Tees, elbows and boiler are next.

Thanks again to all of you.