Things to think about

Cold air drops, so with this in mind mount the cold plates as high in your box as you can. This will give you the most useable cold area possible in your cooler or freezer. If you want a cool place but not a real cold place, mount the plates a little lower, this will leave you room above the plates for a crisper shelf.

The plates can mount in any direction. Keep in mind the plate and tubes should be mounted in such a way when you turn off your unit to defrost, the plates are not sitting in a standing puddle of water.

Mounting the thermostat sensing tube.

A thermostat is an on off switch which is activated by temperature. When you turn the knob clockwise it will make the thermostat require a colder plate (box) temperature before it opens and shuts the unit off. Conversely when you turn the knob counter clockwise it will shut the unit off with a warmer box or evaporator.

Do not get confused by thinking if you turn your thermostat to 7 it will get colder quicker. It will not, it will only make the unit try to achieve a colder temperature over time.

Unlike the gas pedal in a car, which will give more fuel to the engine when you step on it, which will make the car go faster quicker, the thermostat is only one speed on and off.

7 sets the thermostat in the coldest position and 1 is the warmest position.