Is there a temp controller that can control 2 fridges

[Henning1966]

Well there is another defunct one out there that could do it but it is on hold because of the economy and other issues. The brew droid could do it.

[CRBrewHound]

I am building one right now, 2 channel 2 stage controller. You are mote than likely going to need to build your own controler (at what level, not sure).

Also you don't want to use a PID for a fridge, PID control theory relies on the ability to throttle power, fridge compresses are on or off, and cycling them with PWM will burn out the motor.

I am not sure that is true, PIDS are either on or off (at least when working in a relay mode controlling a solid state relay), you can adjust dutie cycle to adjust or by temperature. Now you may be refering to the 1 second on 1 second off which would burn out the compressor. However, almost all PIDS offer you setting that allowing you to adjust the temp change required before on and before off of example on at 36 degrees off at 34 or a differential, as well as how the logic works for the on/off states.