Pipe insulation.

randallkc

I have two boilers in two different buildings.

I have decided I need to insulate the pipes. I will be doing this myself and don't want to go broke. Those little short fiberglass pieces are lie $10 ea! I will easily need 100 pieces.

Any ideas on some DIY alternatives?

vr608

Many on this site prefer using buyinsulationproducts.com and expressinsulation.com. I've only tried the former, not sure of the pricing differences. I think the only notable cost is the shipping charges.

TXBDan

I just bought fiberglass pipe insulation from buyinsulationproducts.com just this week and it worked out great. Arrived in two days and was half the price of Lowes/HD/Amazon.

Installation was also very easy and came out looking great. Great satisfaction/effort ratio on this one. (for once)

Jeff_H

One thing to be aware of is the thickness of the insulation. Home Depot's (and probably's the others') pipe insulation is only 0.5" think, which most commenters on this board say is not thick enough (there is much discussion of whether to go with 1" or 1.5" - I have not seen many recommend going higher). The more challenging issue is how to handle the elbows and tees, which the typically pipe wrap insualtion does not cover. Some people say not to bother, but most feel that it clearly makes a difference from heating efficiency. Both companies mentioned by VR608 sell PVC fittings (which come with loose insulation to go inside the fittings). The only issue is whether you will use to use special tape or tacks to put them in place (the tape seems easier but some sites say that for steam pipies, you shold use the tacks). There is also some discussion about mitering (ie. cutting existing pipe insulation to line up). The latter is much cheaper than buying fittings, but seems to involve ALOT more time.

vaporvac

You could also try looking into local places that serve the commercial trade. They'll often sell to regular folk. I got very good pricing this way.
There's a chart floating around somewhere on this site that gives the proper minimum size for each diameter pipe. It also depends on whether you're dealing with a conditioned space. I'm using 2" in my large well-insulated, but unheated garage. It's the last bit before returning to the boiler feeding 4 rads, so it needs all the help keeping the steam that I can give it. The additional cost is marginal.
Some say just use batting and tape, but that takes forever and is more difficult to do. This is one case where you need to just suck it up; the gains in comfort and efficiency are immediately apparent.

Steamowner

vaporvac said:

I'm using 2" in my large well-insulated, but unheated garage. It's the last bit before returning to the boiler feeding 4 rads, so it needs all the help keeping the steam that I can give it. The additional cost is marginal.
.

Interesting. I have two pipes going through an uninsulated, very drafty garage. Basically it's like 40 degrees in the winter if not less. I currently have 1" since that's what my local supplier had in stock but I may buy the bulkier stuff from the website that people have mentioned. I can move the 1" stuff to some pipes inside the basement where it's warmer.

vr608

Jeff_H said:

The more challenging issue is how to handle the elbows and tees, which the typically pipe wrap insualtion does not cover. Some people say not to bother, but most feel that it clearly makes a difference from heating efficiency. Both companies mentioned by VR608 sell PVC fittings (which come with loose insulation to go inside the fittings). The only issue is whether you will use to use special tape or tacks to put them in place (the tape seems easier but some sites say that for steam pipies, you shold use the tacks). There is also some discussion about mitering (ie. cutting existing pipe insulation to line up). The latter is much cheaper than buying fittings, but seems to involve ALOT more time.

For my mains I simply used white duct tape over the PVC fittings at the seams, and it seems to have held up pretty well so far (one season). Its not the best thing to look at but it does the job.

KC_Jones

I did the mitered joints on my pipes and honestly didn't think it was that difficult at all. I made up a basic miter jig out of some plywood I had laying around which made it easy. Also for doing saddles (for a tee connection) I double mitered to make a point then just follow the contour left by the white covering and it fits perfectly to the contour of the other piece of insulation. I agree with vaporvac sometimes you need to spend some money....and I am cheap....really cheap.

Jeff_H

KC - I think that I will give the mitering a try. Any advice on how to go about measuring and cutting (I tried looking videos and other guides, but could not find anything)?

KC_Jones

I haven't seen a how to video on mitering the pipe insulation. I actually leaned a bit on my woodworking skills to figure out lengths needed and how to cut. As much as I could I tried to make the joints with straight cuts. Basically if I had 2 elbows I would miter for one and leave a straight cut, miter the other one and then mock it up on the pipe and mark for the straight cut to join the first piece. Kind of tough to explain with words. I messed up a couple pieces, but luckily could cut them down and use elsewhere. If you take your time it's not that bad. Some of us go slow and save money, others spend the money on the PVC to save time. It depends upon your personality. I will spend hours to save a buck...did I mention I was cheap? That said I think it took me about 3, 5 hour days to insulate which I didn't think was too bad since I had never done it before. Once you get the near boiler piping complete the rest is pretty straight forward. Here is a video with some good general information.
https://www.youtube.com/watch?v=oThP70IHMvM

hvacfreak2

A 2 piece 90 is 45 degrees , a 3 piece is ( I want to say 30 but I don't want to give the wrong info ). The box that it comes in has alot of information on it for this. A good hack saw works as well as anything for making cuts through the pieces ( higher teeth per inch ) . Fosters white mastic applied with care is also a nice touch. For valves and unions and such try and get insulation of the inside diameter that will match the outer diameter of the adjoining insulation and over shoot the length on to it ( so it looks like a larger cylinder in the line ). Take care on the straight pieces when peeling the self stick flaps so as not to wrinkle them , it takes a certain feel when doing this ( apply pressure with one hand while smoothing with the other ). If using pvc fittings tacks are the best by far. It is crucial to fill with the proper amount of loose insulation before attempting to form the fitting. Be sure to get it tight and where you want it before inserting the tack , and constant pressure until both sides are fastened. Go slow , good pipe insulators are fairly slow . A good pair of scissors work good for some things as do serrated kitchen knives.

vaporvac

@KC_Jones and @hvacfreak2 , did you have to size up for the insulation when mitering?

KC_Jones

I sized the insulation to the pipe size then trimmed some of the insulation out of the inside for the fitting. On my near boiler piping (mix of 2"&3" pipe) I used 1 1/2" insulation on the 3" and 2" on the 2" so the OD would all match up.

randallkc

One of my boiler systems had no insulation on it. The fiber glass pipe insulation was crazy expensive for the amount I had to do. So I just purchased R19 fiberglass backed wall insulation and taped it around the pipes. Worked well and cost 1/10th what fiberglass pipe insulation costs. It's in a basement. I don't care what it looks like and it came out pretty good.