Thanks for your help. Sorry it has taken me a while to respond, I was out of town on work. Basically, I need to do a cold temperature test with a mechanism in transformer oil (mineral oil) and it needs to be at
-20C for the test. I will only have to maintain the -20C for a few moments until...
I need to figure out how much dry ice is needed to cool roughly 80 gallons of transformer oil (mineral oil) to -20 C and hold it for an hour. Does anyone have an equation to calculate this?