steam pipe insulation

Garret

I'm a homeowner... I was in the same boat, and decided to make do with fiberglass duct wrap and tape. The pro stuff looks much better, but what I did has held up fine for 5 years+ and looks good enough to me (it's an unfinished basement). And it cost <$100 to do my whole basement.

At a good home center or hardware store, look for rolls of foil-faced fiberglass "duct wrap." Don't get the stuff with a paper backing, you want foil (which can take steam temps no prob). The stuff I got is about 1" thick by a yard wide, maybe 10 yards to a roll. Also get aluminum foil tape.. not plastic duct tape, the real (and more expensive) stuff.

Cut the insulation to fit each straight run of pipe, and wrap around (with the foil on the outside), and close up the seam with the foil tape. Get as fancy as you want with the elbows and bends.

Because the insulation wraps around a couple of times (it's a yard wide!), you end up with about 2-3" of insulation. Just don't pull too tight, or you'll compress it and it won't work as well...

-Garret

Mike AK

steam pipe insulation

I'm trying to add insulation to the steam pipes in my basement. I finally found someone local who carried molded fiberglass pipe insulation, but it's pretty expensive ($2.50-$4.00 a foot). This would mean I'd be spending just under $600 just to insulate the two main loops (about 150 ft.) (not including elbow fittings), and then another $250 or so for the accessible pipes that head to the radiators. This seems expensive to me, and I have trouble believing I'd recoup those costs in a reasonable amount of time. Is this worth it? Should I just insulate the mains? Is there a less expensive option? Can I just wrap the pipes in fiberglass insulation? Thanks for any help!

Mike

Brad White_146

Expensive Insulation?

Those prices seem reasonable. Have you priced gas and oil lately, recent fluctuations aside?

If your mains are say 2-inch, each foot is equal to 0.622 SF of radiation. As bare pipe each foot will emit 149.22 call it 150 BTU's per hour. If your basement is colder than 70F, this will increase. 150 feet of pipe like that will cost 22,400 BTUH or more, any time the boiler fires, whether it is cold out or warm-ish. That 22.4 MBH would heat a small home in a temperate climate. And that is just your mains. Your branches will likely add a fair percentage to that, maybe 25 or 30% is just a guess. Call it 28,000 BTUH for discussion.

If you insulate the pipe, you would knock that down by about 80%-84%, to a fifth or sixth of the bare pipe number, to for our purposes 5,000 BTUH. Granted what goes into your basement is still inside your house but it is not controlled is it? I for one would not accept it.

Figure your cost of fuel and compare what it would cost to recover that. While your boiler is firing, each time, it has to lose heat at that rate before it gets to your radiators. Also think about how long you will live in your house. If you are selling it in a couple of years that is one thing. Personally, I am committed to leaving places better than I found them, within reason. This is one such task of responsible stewardship, not to lecture. Just my own opinion.

Can you wrap the pipes with fiberglass insulation? Sure you can. Will it look like you gave up? I think it would. Duct wrap has about 2/3 the insulative value per inch of the moulded material and because it is molded, it fits without excess air gaps. Because of this, the integrity is there. Wrap it and even if it looks ok, you cannot predict performance without a good before and after profile. If you did, you might regret not doing it the right way. Once you wrap the pipe you would be hard-pressed to go back, take it off and start anew.

Start with the larger pipe if cost is an issue and notice the difference. Continue with other straight pipe until that is done. Do fittings last as they are fussy and time consuming. Straight pipe alone is the best bang for the buck in my estimation.

My $0.02

Brad

thfurnitureguy_5

Mike I just bought a bunch of 2"
wall thickness from Smock and Schonthaler out of Erie PA. nice people and were good to deal with. 814-465-4222
If it will shorten you run time, you will save money. heat radiates toward cold and not just up. So how hot you want your basement?

Mike AK

insulation

To all three who responded: I am amazed at your kindness and fullness of explanation. I very much appreciate it.

I'll have to think about this. I agree, at least in theory, with Brad on trying to improve the house as a matter of principle--but I guess my principles are being tested here : ) I will be in the house for a while--perhaps 20 years or more, certainly no fewer than 5--so that argues for biting the bullet and doing this right. The primary argument for the less expensive approach for me (beyond my checkbook) is that much of our heat in the spring and fall comes from two gas stoves--the big boiler doesn't run much except the three months of true winter. Looks, too, is a secondary concern (but the molded would protect my head a bit in the basement!)

Anyway, I've copied your messages and put them in a file so I can mull about them for a bit. Thanks very much for your help. Anybody else have a take on this debate?

Boston

pipe insualtion

why not use the standard fiberglass pipe insualation designed for insulating pipes? They have slits in them and you seal them with duct tape. I have not had steam in a house for a while, but our first house had steam, I put the insulation on the boiler piping and mains - then I had to remove some because the basement became too cold. So the insulation worked pretty well.

I have seen the stuff in Home Depot , at least in MA.

Patrick Mullaney

85 Degrees

My mains are uninsulated currently (not for long) and my basement is about 85 degrees, if not warmer. I coulld probably put a cot in there and a toilet/sink combo and call it a livable space. Getting insulation this weekend and doing all my mains - prefer the house and its inhabitants are warm and happy, not the critters living underground.

Do your research on insulation - every penny you spend saves you twice that in energy costs.

bob young

if you decide against the insulation you can paint it.

Brad White_146

But.....

The stuff they sell in Home Depot is 1/2" thickness that I have seen.

It is better than nothing and will prevent you from getting burned at best.

This is far short of the 1.5" and 2" thicknesses mandated by code (MA 780 CMR Ch.13 and model codes just about everywhere).

Save the thin stuff for a base layer over which thicker layers will be nested. Best bet is, do it right the first time in one pass. Same labor, better results.

Boston

Brad -

It probably meets code from the time when the boiler was origially installed(existing)

And I just remember the 1/2 inch stuff I put on chilled the basement to a point I took some off. Plus, I did not go crazy and do all the real short areas. If you are going to depend on any of the heat loss to heat the basement, the thinner stuff might be the ticket.

I suspect it depends on the application.

Brad White_147

I tend to agree, Brian

on a couple of points.

When the boiler was originally installed, it was likely BC (before code) as far as energy is concerned. And the big pipes, the "low hanging fruit" is an easy choice, you are right.

We also have a saying that, "the first inch does all the work", which begins the law of diminishing returns. The first inch will knock the bare pipe heat loss of 150 BTUH per foot down to about 25. The half inch we are talking about will take that down to about 35, pretty significant. That next half-inch, bringing it to a full inch, is worth only about 10 BTUH per foot.

Hard to argue with your experience- I have had it also but could not bring myself to remove any
Being an insulation of any thickness it will block the radiant effect from the piping which probably contributed a lot of the chill that you were feeling.

But as long as we have energy codes (even if not "enforced" as in this case it is self-policing), it is good to know what the standard is, the ideal.

Still- your points are well made and bear out by the numbers. I can endorse the half-inch absent the funds to do it the "right" way. I would rather see that done than nothing.

The regret in this is that there is little incentive to go back and add nested insulation on top of it. That half-inch sets the bar to a point where additional inches would not seem worth it.

Good call, Brian!

Brad

Mike AK

Thanks

Thanks Brian and Brad. I'm interested to see how much the insulation cools the basement, since it is not particularly warm now. I'm not sure what I'm going to do, but I have a much better idea of my choices. I appreciate it.

Bernie Riddle_2

bargain basement approach

A neighbor has 2" mains insulated with pipe wrap surrounded by 20' + lengths of 6" dryer duct. It seems to work ok but must have been a lot of labor. They slit the dryer duct and wires length-wise and stretched it over the pipe wrap. Then they taped it up with aluminum tape. It makes sense as there would be no air movement, good radiant barrier. It is not hot to the touch.

Interestingly enough her returns are insulated with DuPont molded fiberglass.