Insulating a cold water valve against condensation
DC_Contrarian_
| Posted in General Questions on
I thought someone here might have a good answer for this quandary. I have a house where the water supply runs through an unconditioned garage. In the summer it is very humid, and the water is very cold — it’s well water. Any exposed part of the plumbing sweats considerably. On the pipe I have a shutoff and drain valve. The pipe itself is well-insulated, but I haven’t been able to figure out a way to insulate the valve. It needs to be operable as I drain this pipe in the winter so I can’t just wrap it in insulation.
Right now I put a dish under the valve, but I have to empty it every few days in summer. Is there a better way?
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Replies
DC C,
My first thought was to create something like the molded insulation on recirc pump housings. So 3D print a 2part clamshell mold, cover the valve in wax or
petroleum jelly, mount the mold over the valve and fill the space with spray foam, after it's set, you cut the spray foam in half, and you've created a clamshell molded insulation part. Sounds easy to me anyways...
But the easier way might be this:
https://youtu.be/HQM1Zqpl7Lg
PS, don't forget to wrap the insulation with electrical tape, especially around the open ends, to air seal it and prevent moisture ingress.
Jamie
The commerical mechanical supply houses have rigid foam pipe insulation that is made to fit over valves. This amterial is rigid and split in two halves so that you can put it onto pipe in the field. This stuff is commonly used commercially on hydronic heating and chilled water systems. It's not very expensive. You'll want to get some of the matching white tape to install it properly.
For smaller lines, you can usually just cut up some of the usual box store pipe insulation (fiberglass with a white outer backer) to wrap around the valve body.
You don't need much insulation -- just a little goes a long way for condensation control. There used to be a sort of gummy tape for condensation control too, it wasn't really insulation, more of a tacky 1/8" or so tape with a rough texture, but I haven't seen that stuff available for purchase in a very long time.
Bill