The Jobo CPP-2 provides lab-quality processing of film and prints with a recirculating water bath to temper the chemicals. It has a cold-water solenoid that allows you to either cool the process down below room temperature, or to quickly lower the temperature of the water bath (i.e. changing from a C-41 process at 38°C to an RA-4 process at 35°C). With the ues of an integrated digital thermometer, the CPP-2  holds the temperature of the process to within + 0.1°C.
 
The CPP-2 displays the water bath temperature on a digital LED readout.
Using a water-bath ensures even tempering of the chemicals, and the tank or drum that contains the exposed paper or film.
 
You don't need to install the CPP-2 in a darkroom, it's a relatively compact machine (for machines that are capable of developing 20x24" prints). They have a footprint of 38x15" (LxW). Once the lids are closed on the tanks, they are completely light-tight.
 
The CPP-2 use a contained system whereby chemicals are only exposed to the air during very short delivery times which cuts down on odors and oxidation.