Pipe Insulation

[jimdeq]

I a going to start insulating all my boiler piping and I am wondering if the fiberglass or the foam type is better for insulating hot water pipes. What R value or how thick of insulation for 1-1/4" pipe? Anyone know of any good spots to purchase it ?

 

[woodsmaster]

I just did mine the other day. A friend who works at johns mansville was supposed to hook me up but I got tired of waiting so I made my own to get me by till he comes threw. I took some 16"
wide fiberglass unfaced and peeled pieces 1" thick off. I then wrapped the 1" thick insulation around the pipes and wrapped with gray tape loosely ever foot or so. It works great. The only downfall I see is there is no coating on the outside to repel dirt. didn't cost much at all and made a huge difference in the temp of the boiler room and my storage even holds heat better. Almost no heat loss in storage now,wish I would have done it right after install. Pex supply has some pipe wrap for around .60 cents / foot.

 

[NYEDGE]

I used commercial grade fiberglass insulation. (with the white paper on the outside)
I got mine from the plumbing supply house that I always use.
It is much better than the one Home Cheapo stocks, and the heat loss from the pipes is tremendously reduced.
Seeing that the water is circulating through the pipes for hours at a time from boiler to storage tanks, or when heating zones,
the savings in heat loss is well worth a couple more dollars for better insulation.

 

[nate379]

If the fiberglass type gets wet from the pipe condensation (like a cold water pipe) it will reduce the insulation value to pretty much zero.

I did a bunch of reading on it to figure out what was better when I did all my piping and for same thickness foam is better.

Here is some good reading:
http://www.diychatroom.com/f7/pipe-insulation-foam-rubber-other-12534/

Made a big difference in my place. My boiler and all the piping is in the garage. When the house heat was running full bore (cold days) the garage would get over 70* just from the heat coming off the piping. I keep the T Stat in the garage at 55-57* and at 70* I had to open the door or windows when working in there or I was sweating.

With the pipes all insulated the garage heat will often come on... The heat wasted to the garage is going to heat the house like it should.

 

[afblue]

I havent researched it yet myself but from what I have seen same thickness foam to fiberglass, faom has a higher R value. But the thing to check is heat operating temp. Fiberglass was/is used for steam applications, because foam will melt. I am guessing the cheap foam from HD or Lowes is for DHW thats only 120-140, not boiler temps of 180+

 

[nate379]

The foam pipe that the Lowe's by me sells was rated to 220* I believe. I know when I had looked it up it was a fair bit higher than my 170* boiler temp.

 

[DaveBP]

If you're talking about "foam" pipe insulation, especially at the low-price big-box stores, you need to keep in mind there are two broad categories of foam. The really cheap stuff is polyethylene and the more expensive, usually black, stuff is rubber of some sort. Big difference in heat tolerance I believe.

I've noticed they are not real forthcoming with service temperature ratings on the packaging of either when I've looked them over.

My assumption is that the rubber, more expensive stuff is better at heat tolerance.

 

[Willman]

My assumption is that the rubber, more expensive stuff is better at heat tolerance

Your assumption is correct. The cheap foam sleeves do degrade and melt at bolier water temps even many feet away from boiler. The black foam (armacell) handles the heat ok, though I have noticed it does degrade somewhat over time. Mostly right next to tubeing, nothing major just slightly brittle and get crumbly. If I didn't change a loop I wouldn't have noticed this. I also use the fiberglass sleeves with the tyvek covering on the 1 1/4" the armacell on the 1/2" pex.

Will

 

[henfruit]

I used amourflex, comes in 8 foot lengths. Whole or split. I bought whole and cut it with scissors. It works great.

 

[4acrefarm]

I did foam on all except the hottest pipes there I used fiberglass. Over either of these I put a layer of bubble foil. It looks good and certainly helps are value. I tend to go crazy on insulating.

 

[jimdeq]

Thanks everyone, I did some research on all of your opinions. The biggest difference I have noticed is the thickness. Is a 1/2" thick enough for hot water pipes( R 2.5)?

 

[woodsmaster]

That's one advantage to the way I did mine. I'm sure I have more R value than a store bought wrap. Now I need to find a coating to put over the fiberglass. I did my spirovent Y strainer and every thing but the boiler, gauges, and circulater.

 

[4acrefarm]

Woodmaster, try foil or bubble foil. It works for me.

 

[in hot water]

You can purchase just the jacketing. White PVC is common, it also comes in colors and there are fitting boots available. For outdoor solar or where you want a rough service product consider the embossed aluminum cover. Insulation suppliers will often cut and roll it to the diameter you need.

There are different grades of insulation even in the black rubber products. it has to do with the % of EPDM. Armaflex offers a HT (high temperature) and now an extended temperature for solar with 300F and above potential.

I doubt any of the foam products will hold up around boilers operating at 180F or above. Extended temperature will turn it into a brittle, hard, underperforming product.

Stick with fiberglass, high temperature EPDM based, or the melamine products.

hr

 

[velvetfoot]

The cheap foam stuff worked fine on my oil boiler except near the boiler, where it melted. I put some fiberglass there.

 

[nate379]

If you have the room thicker is better. With my setup I had a hard time fitting 1/2" thick wrap in some places cause the pipes where close together.

Thanks everyone, I did some research on all of your opinions. The biggest difference I have noticed is the thickness. Is a 1/2" thick enough for hot water pipes( R 2.5)?