Insulation, Radiant and Vapor Barriers - extra-insulating water heater

I want to put more insulation around my 40 gal water heater than the standard R-6 fiberglass blanket from Home Depot. There is a thicker blanket available (R10 or so) but it is for large (100 gal) water heaters.

I'm wondering if I can buy a roll of R-19 fiberglass insulation and make my own blanket for the water heater. Can someone comment on this idea, especially mentioning pitfalls and safeguards that would be necessary. One advantage that comes mind would be that I could wrap the fiberglass pieces with a less noxious piece of plastic, then I wouldn't have PVC off-gassing into my basement for a month.

jc

Water heaters are often wrapped with fiberglass batts for a less expensive alternative to the store bought blankets.

See this link: http://muextension.missouri.edu/explore/hesguide/houseeq/gh4862.htm

Since air quality in the home has become an issue, more and more people have become aware of volatile organic compounds (VOCs) offgassing and causing odors in the home. Much has been written about the offgassing of fiberglass insulation. There is low VOC fiberglass batt insulation available. Tell the sales person this is what you want. Many people are sensitive to the odors of offgassing of home building products and furnishings. Low VOC home products are especially important for those with allergies and respiratory problems.

Don't think you will see any real cost savings by insulating it.

TwelvePole, thanks for the good reply. Just what I needed, and I especially appreciate the info about low-volatility fiberglass batts as I wasn't aware of them.

Airman...I've used heater blankets before and they do make a noticiable difference in how long the water heater retains heat, at least here in S. Calif. I keep my current un-blanketed water heater turned off most of the time, and as the weather cools down I can see how quickly the water cools off. Most of the time I only need luke warm water, so if good insulation extends the warm water a few hours it is worth it because it can keep me from turning the water heater on.

Turning a water heater off an on is the worst thing you can do to it. Most water heaters or lined with glass or plastic. The expanding and contracting will cause this liner to fell.

Airman, water heaters by nature are always turning off and on 24 hours a day. The way I'm using it, I turn it on once a day and 30 minutes later turn it off. Seems like my way would cause a lot less expanding and contracting.

Perhaps during the winter I might turn it on twice a day, but since I take my showers somewhere else 4-5 days a week, I just don't need that much hot water.

jc

Its not the off and on, it's the cooling down and heating back up!