Subcooler Theory

[Blackmira]

I know it doesn't work but the "why doesn't it work" is puzzling. On rack systems with subcoolers: If we feed liquid from rack A( med. temp.) to subcool Rack B (Low temp.) how come we cannot subcool rack B liquid with rack B liquid? Come off the liquid header, hit the expansion valve and subcool the liquid. Why do we have to use Rack A liquid??

[icemeister]

There was a thread on this recently:
http://hvac-talk.com/vbb/showthread.php?t=289932

Basically, you're subcooling the low temp rack liquid with the medium temp system because of energy savings. The MT rack runs at a much higher efficiency (Btu/Watt) than the LT, the load on the LT subcooler gets shifted to the more efficient rack.

If you were to subcool the LT liquid from the LT rack there's no efficiency gain and no energy savings. That's what we used to call "Bootstrap" subcooling, since it's like trying to lift yourself up by your boot straps.;)

[Blackmira]

Excellent thanks for the clarification

[Dowadudda]

bootstrap subcooling. Interesting. :eek::D