Frig Compressor Problems

[wessmith]

I know some of you have single and 2 door drink cooler cabinets being used for fermentation so thought the following advice might be of assistance. Over the Christmas period I needed to brew some ales (pilots for a new brewery) and consequently had my 2 door cabinet running at a nominal 16C. All was fine - the 7year old compressor maintaining an exact temp. Then in February, the cabinet stopped cooling and we found a very small gas leak. No probs, recharged the system (R143A) and put down another ale. Five days into the ferment and the motor suddenly stopped - seized solid.

The problem with these cooling cabinets is they are designed to run at 3 to 5C and when the temp is set at 16C or so the back pressure on the compressor is massive. Continuously running at this temp had literally stuffed the compressor. OK, so I got 7 years which is OK I guess, but in the course of finding a replacement compressor, we discovered that nothing is rated to start continuiously at 16C and in the end we settled for a 10C unit. Even at that temp there was only 1 make that would do the job, most compressors being rated at 5 or 6C max. starting temp.

Just a small point to note - if you intend to run the cabinet at 16 or so then the life of the compressor will be shortened. Needless to say, I wont be running higher than 11 or 12C with the new unit!

Wes

 

[PhilS]

Excellent info on these types of compressor/fridges Wess.

I'd love to have one, but after hearing your advice, I'll probably stick to an all-fridge for fermenting. They sound great for CC'ing :beer:

 

[Jazzafish]

Did you have any tolerance with the settings of the thermostat?

For example, I have a chest freezer set to 4*C (+/-2*C). It will cool down to 2*C and remain off until it reaches 6*C. I run it this way instead of it cutting in and out every degree it fluctuates.

Yeah I know it is alot cooler at this temperature, but it would be less stress on the compressor if it had some play.

I also have the same set up on my fermentation fridge. The +/- 2*C of the ambient air has no change to the wort temp. I haven't had any issues with compressors over a year.

Maybe next time attach an old wall mounted air conditioner? I guess they are custom made for what we want?

 

[wessmith]

Jazzafish, I always set the controller to give a dead band of 3C. On top of that there is a lockout timer than wont let the compressor start until several minutes have passed. The aircon unit would work fine for 18C but would be no good down at 5 to 10C.

Anyway, there is a cylindroconical with glycol jacket on the way... Have the Glycol chiller unit ready to plumb and plug in.

Wes