There is no such thing as perfect. All refrigeration systems
leak to some extent. When I got my EPA card, the law said we
can top off any system with less than 50 pounds of
refrigerant.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"TimR"
wrote in message
...

As far as I know, there is no consumption of refrigerant in
any
residential system.

If you're low, you have a leak. You fix the leak and
refill. There
is no periodic topping off of refrigerant that got used up,
can't
happen.