Sam wrote:

i wanted to add air conditioning to my new home. i have copper
tubing(4m) ready laid out but i noticed both tubes are taped together
inside the same insualting jacket. most a/c installations i see the
refridgeant lines are insulated seperatelty.

will it have much of a performance penalty on the A/C or is it ok?
anyone have tubing insulated like this?

It will have a slight performance cost, but unless they're touching, not
enough to worry about.

--
Grunff