freezer insulation

[jayjay]

Need help with a 3500 sf freezer. We are burning up compressors and we think the answer is to reduce the load by adding insulation. I get conflicting information. I would like to spray 2" a closed cell foam on the outside of box. Will this work? Is it worth it?
The box is old, walls and ceiling are 4" thick. floor is concrete with no insulation. We are running 3 - 8 hp compressors to maintain 0 degrees F. When temp outside hits 90 F we need to run water on confessors outside.
Help

[Magoo]

Have you comfirmed that the refrig systems are operating within their design envelop, high discharge pressures can be a sign of non condensibles which will in turn screw up performance, water over condensers will relieve issues, but can mask the real issues, and corrode aluminum fins long term. Insulation 4 inch poly or eurothane
What are your operating pressure conditions, suction and discharge pressure, refrigerant applied, liquid line temps at TXV, suction gas temps at compressor.

[THE DUDE]

It sounds like you have mechanical problems causing Compressor failure. If Capacity is a additional problem, You may want to check into installing a Mechanical Subcooler or Additional Equipment. Not much info to go on.

[r.bartlett]

If it's R22 it will be high discharge SH which needs to be addressed..but we're guessing

[EnricoA]

I dont know in your case. But i myself did insulate my 19 years old fridge with styrofoam which indeed reduced power consumption down to 50%. For details have a look here: http://coolfridge.blogspot.de/

Greetings! Enrico

[number4]

Insulation is an excellent non technical fix and underpins refrigeration efficiency.
What I would love to know, is how much difference does it make?