The Rainsystem did run well with three nozzles - once a day and 3-4 times per week
When I bought many new orchids, the nozzles didn't water all of them. So I had to still do it manually. If you plant your orchids mainly at the back wall, you can easily water them with the automatic rainsystem. But if the orchids are round the orchidarium, it is more complicated.
In my case - without setting up the hole orchidarium - I try to raise humidity with fogger and water 'chids manually. Now I've got one basic fogger in action. Still I must remove a water container a little bit, so it is under the lower fans.
You have to consider how often do you want to maintain your orchidarium - daily, weekly, monthly?