Stormin Mormon wrote:
HVAC tubing is typically smaller. For example, 3/4 water
copper is the same size as 7/8 HVAC tubing. But, it's
possible.


HVAC tubing is measured by OD, plumbing is measured by ID.
That's why I have calipers in my pocket.

http://www.generaltools.com/Products...er__132ME.aspx

TDD