It is also important to define the processes that will take place inside the cleanroom, and what can be done outside. The more work is done inside, the bigger your cleanroom will have to be, the more heat and particles it will generate, the stronger the HVAC will have to be, hence the more expensive your cleanroom project will be. If any of the steps of the process do not have to be completed in a cleanroom, perhaps you should consider doing them outside the clean environment.