Bob wrote:
Hello,

Have a forced hot air heating system, where the duct work is also used
for the house air conditioning.
Pretty typical setup: Condenser is outside the house, of course, and has
two pipes running to the furnace where the Evaporator section of the A/C
is.
Furnace blower then bolws air thru the evap. section into the ductwork.

"Plumbing" from the outside Condenser to the Evaporator is run thru the
ceiling and walls.

Might be a leak somewhere.

It's not a very long run, but I really don't want to rip away part of
the ceiling and wall to try and find.

Thinking of having the A/C guy, or a Plumber just run new tubing on the
bottom of the existing ceiling. Tubing would be exposed, but would paint.

Question: good idea or approach ?

Would this new tubing have to be insulated ? How ?

BTW: are leaks in the connecting tubing fairly common after 20 years or
so, or is nearly "always" a leak in the compressor or elsewhere in the
actual A/C unit ?

Thanks,
Bob
Hmmm,
Why play with unqualified guess work. Call for service.
They have leak sniffer. Don't assume anything.