Here are two main variables to take into account – your facility and climate conditions.
If you have a water source ready in your facility and the temperate and humidity tend to be inconsistent, a water-cooled CT scan machine is an option.
On the other hand, if your space is limited, you might want to go with the more popular air-cooled CT scanner.
Furthermore, most manufacturers today focus only on producing air-cooled CTs since this technology is more advanced.