I want to replace the insulation on my 3/4" copper air-conditioning
pipes. The length is about 12 feet. There are two types of insulation
available, polyethylene and rubber. Which would be best?
The polyethylene has 3/8" thick walls and an R value of 2. The rubber
has either 3/8" or 1/2" thick walls, and I have no idea about the R
I'm primarily concerned about which one will insulate the pipe from the
outdoor heat better, and withstand the sun, rain, insects, etc. Cost is
not an issue.
On Mon, 1 Aug 2005 12:42:30 -0400, "Carolina Breeze HVAC"
Yeah, that's why I was confused! I wasn't sure what "that cheap ass
The pipes have a rubber-type insulation on them, but it's 20 years old
and not in great shape. I've got the garden cleared-out, so now's the
time to replace the insulation, before the new plants and mulch go in.
The rubber stuff will outlast the other stuff unless painted with a UV
inhibitating paint. However the rubber sometimes usees amonia af a
blowing agent to make the rubber foam up. This amonia will react with
the copper and make it brittle over time.
If rou the pipe is somewhere where it will be constantly wet, use the
There have been studies done on this. The effect is called "Stress
Crack Corrosion" and can cause refrigerant leaks, especially in under
ground lines. (Don't run lines underground for many reasons, this is
just one of them).
The reason you insulate the lines, besides reducing the chance oc
condensation damaging something, is to keep the refrigerant as cold as
possible. The refrigerant cools the compressor motor better if it is
cold, prolonging motor life. It also keeps the refrigerant hot gas
discharge temperature lower, which is better for the refrigerant oil,
as hagh temperatures can break the oil down. The compressor is a gas
pump. It pumps just so many CFM at any given pressure difference. If
the gas is colder, more mass is pumped, increasing efficiency.
So insulate those lines and keep that gas cold.
And if the lines are outside, the insulation will last longer if you
wse a UV retarding paint to coat the insulation.
All that said, I usually use the rubber as the best insulation for most
of my applications.
Now you're making me nervous. The pipes are 20 years old, and are just
laying on top of the dirt. Maybe I should leave well enough alone
instead of moving the pipes around trying to replace the insulation.
20 years ago they probably used rubber. Put rubber insulation on the
pipe(just the big one) If you want, you can dig under the pipe with a
claw hammer, gently. Or you can lift the pipe, gently and put the
insulation around the pipe. It isn't rocket science, Just don't be
abusive to the pipe. Reasonable care should sufice nicely. Don't
sweat it :-)
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.