Just finished an 8 hour experiment at customer's request to see if we could get free cooling from their existing arrangement. I had read up on the subject but never had the opportunity to try it and I was surprised by the outcome.
Customer has large chiller room with 5 - 2000 ton YK's and 1-1000 ton YK. Upon arrival 1000 ton chiller running at no production winter load of 60%. Forced flow over multiple towers to drive condenser water temperature to low 40's and turned off chiller. Opened valves (chilled and condenser) on 2 idle 2000 ton machines, vanes and hotgas valves were manually driven 100% open and monitored operation. Condenser water continued to fall to 37 (28 ambient today) and chilled loop temp maintained 40f all day long, no tower fans and the same amount of pumps running.
Anybody else ever encounter this type of cooling just utilizing natural convection from refrigerant flow to condenser from evaporator and how much capacity were you able to attain? Quick calculations come to about 400 tons of free cooling and a power reduction of about 430 KW/hr.
Once the test was complete the owner wanted the chiller put back online, YK's never cease to amaze me. Started and ran with 38 entering tower water and didn't make any fuss.
The link shows in theory what we manged to accomplish with standard factory equipment.