rangerssuck wrote:

On Saturday, May 6, 2017 at 2:32:40 PM UTC-4, dpb wrote:
On 05/06/2017 1:16 PM, rangerssuck wrote:
...

I surely am hoping that we are on the low side of this range - this
stuff is expensive.


Well, how much _did_ you recover, you know? If _that_ number is big...


My only experience w/ rink refrigeration systems were all
ammonia-based...I suppose that is telling on their age!

--

We didn't get nearly enough - not enough to re-start the system. As I
said, there have been non-insignificant leaks.

This rink was built in 1980. I am familiar with much newer facilities than
this that run ammonia systems, though not under the ice. They have heat
exchangers and run chilled glycol or brine under the ice.
Hmmm, how about converting the system to chilled glycol? You'd have to
replace the whole chiller, of course, but that could actually come out
cheaper than the refrigerant you would need. If the piping is of sufficient
diameter to support the required flow rate, it ought to work. You mentioned
leaky shaft seals, so maybe you are replacing at least the compressor.
Geez, shouldn't you be using a semi-hermetic, anyway?

Otherwise, a do-it-yourself conversion would require an evaporator/heat
exchanger and a circulator pump. This would obviously save thousands of $,
even with a relatively affordable refrigerant.

Jon