[Amps] Water cooled amp question

[Joe Subich, K4IK]

> In a message dated 05/03/2005 16:31:26 GMT Standard Time, 
> r at somis.org  writes:
> 
> Peter --  Which is the better coolant, pure ethylene glycol or pure  
> water?

Water (pure, distilled) has the higher specific heat (e.g., absorbs 
more heat per unit) than ethylene glycol.  When I was running UHF 
TV transmitters, in some cases where the heat exchanger was marginal 
we had to dump the 50/50 glycol water mix in the spring and replace 
it with pure water to get that last 10 to 20% cooling efficiency. 

Unfortunately, since the transmitters were not operated 24 hours a 
day we could not use distilled water all year (I had an owner try 
it one year ... we lost the entire cooling system on both amplifier 
chains when an untrained master control operator shut everything 
down at sign off and the temperature dropped to 0 degrees F!).  

73, 

   ... Joe, K4IK