"G. Matthew Bulley" wrote:
>
> I've heard from two AC techs that the key to keeping your LONG-TERM AC
> bill to a minimum, is do some SHORT TERM maintenance. That means
> bi-annual evacuation, and replacement of the receiver/filter/dryer, and
> a topping-up of the oil. Evacuation boils off ALL moisture in the
> system, keeping the parts from rusting internally
>

I don't understand about "topping-up of the oil".  How can you tell how
much oil is in the system.  Seems to me you would have to drain the oil
from every component and start from scratch.

Larry A.
Chicago (Beautiful, walkable, Hyde Park)