Another 2 cents on H2O chillers-

At INSTAAR, U of Colorado, we use a chilled water recirculator to cool our
diff pumps with great results.  It saves heaps of water.   However, the
chiller has been known to break down, causing several instruments to trip
from diff pump over heating.  As a safe guard, we installed a couple of
electrically driven 3 way ball valves, that allow either chiller or
building water to do the cooling.  We monitor the temperature at one of the
diff pumps, and when it goes above a user defined temperature,  a small
contoller causes the ball valves to switch from chiller to building water,
and alerts us with a red light.  It has saved us numerous times.

Good luck,

Bruce
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        Bruce H. Vaughn, Stable Isotope Lab
        Institute of Arctic and Alpine Research
        University of Colorado  CB 450
        Boulder, Colorado  80309

        Office: 303-492-7985                 [log in to unmask]
        Lab:  303-492-5495                    FAX: 303-492-6388
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