Pipe insulation question

Sleepless in NJ

The piping of my one pipe steam system has fiberglass clamshell type insulation, but the return lines are not insulated.
Is there any benefit to insulating the return? It’s approximately 45 feet of 1.25” pipe total. Also if yes, what kind of insulation should I use?

Thanks!

AI

Brad White_203

I would insulate the returns

The principal benefit is energy savings, even if you rely on that bare pipe for heating the basement, it is not controlled by you for that purpose.

There is a tendency for cooling condensate to absorb CO2 from the air (that which has been driven out in the heating process) and which in so doing, forms a mild form of carbonic acid, which erodes piping over time.

That said, absent high amounts of make-up water, the piping even if left bare will last for years.

I would use fiberglass. I am not a fan of the 1/2" stuff sold in box stores, but if the issue is insulated partially or insulated not at all, the half-inch stuff will be OK. To do it right (by most energy codes), I would use a full one inch thickness.