"The Reverend Natural Light" wrote in message
ups.com...
I'm curious to know the specifications of my central air conditioner -
size, efficiency, etc. The labels on the condenser unit have all
faded beyond recognition except for the brand label - "RUUD High
Efficiency". The furnace is a 1969 Chrysler Airtemp 150k BTU forced
air oil burner and for all I know this could be the original air
conditioner.

It seems to work fine but knowing more about it would help in
determining when to replace it. Any thoughts how I might figure that
out?

If it is working to your satisfaction, wait until it fails. If you suspect
that it is very inefficient and beyond its life expectancy, then you might
replace it ... but do the arithmetic on a cash outlay now versus the yearly
savings for a high-efficiency unit. It often takes many years to get even
and sometimes one cannot get even. If you are worried about our planet,
then that puts a different spin on your question.