On Mon, 17 Aug 2015 07:57:21 -0400, Stormin Mormon
wrote:

On 8/17/2015 1:08 AM, John Smith wrote:
I have A/C units that look like the one in the following page:

http://www.achrnews.com/articles/125...nitsheat-pumps


Now, one of the unit needs to be replaced. Is it necessary to replace
also the copper pipes (I assume they are for freon)? The pipes are
inside concrete wall. So, if they need to be replaced, that'll be a
problem.

Needs to be replaced, why? The why helps determine
if the copper tubing should be replaced.

The copper tubes are for refrigerant. Freon is a
brand name. The tubes may carry Freon, Isotron,
Genetron, Forane, or some other brand of
refrigerant.
So purge the lines. We purged my entire unit with compressed air
first, then nitrogen before evacuating and recharging.