On Wed, 31 Oct 2007 20:10:48 GMT, "Tom Gardner"
wrote:

My air supply is in stages. One 7.5 hp 3-phase 230v Quincy can usually
carry the load. It come on at 90 and runs to 120, or there about. If the
demand is bigger, another Quincy gets put on line. I also have a 10 hp.
Hydrovane as a back-up. I have yet another Quincy in reserve. I hate not
having air! We're looking at #1 that seems to be about 50% duty cycle with
just less than 1 minute off time. We're wondering if we would be better off
financially running the motor continuously and unloading the valves at high
pressure.

One of my ideas was for the lowest mechanic to catalog every air leak and
repair them...they add up quick. It seems we can go about a year before
they become an issue.

I once worked on a project with Ingersoll Rand. They'd found that a
significant consumer of energy in many or most factories is ... leaks!
Some of those facilities had energy cost of over $1 million per year
just for compressing air. There's one consultant, don't recall his
name, who makes a very good living finding ways to save a few percent
of that.