Plumbing Question: Best Pipe Insulation?

I have hot water pipes in the basement I would like to insulate because they sweat and additionally I would like to conserve energy. These are hot water pipes both from the water heater and from the boiler (baseboard heating).

I stopped at home depot and learned that I have 3 choices: polyethylene foam, rubber and fiberglass insulation. As far as the R value is concerned, the plumbing expert said fiberglass is the best and polyethylene is the lowest. I plan to wrap all hot water pipes and seal them with tape. Anything I should watch out for or avoid? My other concern is that if the pipe still sweats while wrapped in insulation, would this lead to mold or something similar? What would you guys suggest?

I use the poly foam (I believe its closed cell foam).. Its cheap and does the job. Run duct tape along the seam, hit it with a hair dryer to warm it up a bit so the adhesive gets a good grip on the foam Seems like the fiberglass insulation could absorb water or "sweat" and loose its insulating value.

The black rubbery closed cell 1/2" wall is the best in my opinion. The good stuff comes with peel off self adhesive. Duct tape only needed at the corners. Cut each at 45 degrees, make fit & tape.

If you can only insulate one, insulate the cold water pipes. They sweat much more than the hot.

This site has the best information about pipe insulation I have come across. That spun fiberglass wrap? It has the lowest R value and the greatest amount of labor with it. The best you can get is closed cell rubber insulation with 5/8" walls. Check out this site as it has tons of information about insulation for pipes.

http://www.leaningpinesoftware.com/hot_water_pipes.shtml

Rev. Larry

The insulation you want is closed cell elastomeric tube insulation. The closed-cell structure creates exceptional thermal properties (k-value of 0.245 at 75F and wvt of .03 perm-in). It's widely used in the HVAC/R industry. It's available in a wide range of diameters and wall thickness. It will not be available at the big box building stores. A HVAC supply house will have in the common sizes for A/C piping sizes. Depending on the supply house they may have to order the sizes you need. One manufacturer is K-Flex. See: http://www.kflexusa.com/

Do an engineering heat loss calculation to determine what wall thickness you need. OR, buy the thickest wall you can afford. Make sure whatever you choose is closed cell. Get the manufacturer's data sheet, don't trust the salesman B.S.

coaledsweat wrote:The best is asbestos. Probably a felony at this point.

LOL.. but so true....