Condensation on cold water lines
Trevor_Lambert
| Posted in Mechanicals on
I’m getting massive condensation on the main water line from the pressure tank, to the point that a pool of water is forming on the floor below and the steel bits on the two valves on the pipe are rusting. Is it simply a matter of insulating the pipe? What about the valves? I can’t think of a way I could insulate those.
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Replies
Insulating the pipe should fix the problem.
The valves are small surface areas in comparison, I probably wouldn't bother.
If you really want to insulate the valves, and they aren't used/moved much, you could possibly try putting something like vaseline on the moving parts of the valve, and then cover the valve with expanding spray foam...but this is a wild idea off the top of my head. I'd leave the valves alone and just insulate the pipes.
If I knew how to edit my previous post, I'd say just insulate the pipe and spray the valves with some rust inhibitor.
What part of the world are you located?
What part of your house are the pipes located?
What is the dew point and temp of the air around the pipes?
What is the temp of the well water?
In general I like Andrew’s suggestions.
Walt
Trevor,
If you live in a climate with cold winters, the entering water temperature will be cold, even in summer, because the water lines are buried, and the soil at 3 or 4 feet below grade stays cold in summer. So when warm, humid weather arrives, you get condensation.
This is normal, as Andrew explained, and the usual solution is insulation. You can buy pipe insulation at any building supply store. To insulate a pressure tank, use duct insulation, which comes with a polyethylene jacket, and tape all seams. (The jacket prevents moist interior air from reaching the cold surfaces). You can also use the type of insulation sold to wrap around water heaters.
If you want to further address this issue -- and I don't think you need to -- it's possible to lower the indoor relative humidity with a dehumidifier. But that increases your energy bills.
Of course, if you have open vents in your basement or crawlspace, you are inviting warm, humid air into your basement or crawlspace, thereby worsening the condensation problem. So make sure all vents are closed.
Thanks everyone. I'm not getting any condensation on the tank, so I think I'll leave that alone. Maybe I'll wrap it in the winter. I'll wrap the pipes and seal the ends, and put some lanolin on the valve parts.
Trevor, if you want to protect your valves from condensation, I would use a removable cover made for the purpose, instead of messy goop. Something like this: http://www.valvewraps.com/standard_wraps.php.
Chances are that your indoor humidity is higher than ideal - you should measure it. You might want to use dehumidification even though insulation would fix this problem.