Insulating Return Lines

Bruce M

Is there any downside to insulating return lines on hot water systems? I know that steam returns are not to be insulated.

Brad White

All returns

steam or hot water, should be insulated. The objective is to put heat where you want it, when you want it. Uninsulated piping is uncontrolled heat loss.

Most energy codes prescribe that with some exceptions. The exceptions might be any piping after a control valve and within the space to be heated and/or within an enclosure where protected from direct contact.

Steam returns (condensate) should be insulated to minimize CO2 reabsorption which forms carbonic acid and can groove the pipe invert over time. This is not to mention the energy savings of uncontrolled heat.