Insulating the hot waters pipes in your house is something of a no-brainer. Pipe insulation is inexpensive, and the project is one that any homeowner could finish on a Saturday afternoon.
Whether to insulate the cold water pipes is less clear-cut. The project is still pretty inexpensive and easy — but does it have a point? Insulation retains heat, and these are cold water pipes. So why do it?
There are a few good reasons. If the basement or crawl space has un-insulated walls, insulated cold water pipes would be less prone to freezing in cold climates.
If the basement is conditioned space, an insulated cold water pipe won’t absorb heat. A fully taped and insulated cold water pipe won’t condense moisture on its surface.
Should cold water pipes be insulated in cold climates?
From USGS groundwater temperature data, we know that groundwater temperatures in Maine are generally below 50°F.
If the basement space is insulated, cold water pipes may absorb heat. The basement air temperature would be in the high 50s while the cold water pipes would be 10-12 degrees colder.
If the pipes are left un-insulated, this would be a continual, low-level draw of heat from the building. Normally this might be too small to bother, but the cost of insulating pipes is so minimal it becomes worth discussing.