First of all, I don't believe 5 tons of cooling is enough for 13200 unvented watts, unless you are in a cooler climate. But in socal, it probably won't bring the room below 80. (this is a separate conversation)
The reason you should find the best solution is because saving 40 amps on a 2nd 5 ton will result in hundreds of thousands of dollars at the end of the year. We are in the business of maximizing amperage and square footage.
I believe that 3 units is the true solution here, here is what I think you should do if saving amperage matters to you.
1. Purchase 1 5 ton with 2 zones. This 5 ton can only work for 2 flowering rooms obviously.
2. Purchase 2, 2 ton mini split AC's and put 1 in each room. These will be about 9 amps each and should be programmed to come on only during the lights off cycle. This mini split will be responsible for cooling the hot air from the dehumidifier during the off cycle and will even aid in dehumidification. You can use 1 or 1.5 tons if you're rooms are smaller. And if you have enough power, you can even run the minisplits to augment your primary AC in the lights on cycle...which i think you're going to need.
2 minisplits will cost you less than 6k installed, which is the same price as another 5 ton installed. But with this solution, you're saving about 30 amps. If you used that amperage to turn on more lights, you end up making more money.
No disrespect to TrichromeFan, but I don't believe people should plan on equipment malfunctioning because it doesn't happen often if installed correctly. Instead, you can install a High Temp Shutoff with a line voltage thermostat in between your lighting controller and electrical panel. So if your AC malfunctions, it shuts off the lights.
Another solution which is even cheaper is to use Window AC units for the lights off cycle. You can buy a 2 ton unit for $600. So 2 of them would be $1200 plus installation, maybe 2 grand total. But then you'll run into the issue of venting the hot air from the back of the Window AC. This can be accomplished by positioning the Window AC's, so the back end of the AC's are in a room that can be vented outdoors...Then you'll have the added expense of 2 max fans and a carbon filter. You'll need a lot of cfm's to remove the exchange the air. So $1200 plus installation is about 2k, plus the exhaust fans is another $1200, so using the window AC's is actually only saving you about $3000 after everything is said and done.
I think if money isn't an issue, you use the minisplits, but don't go with 2 5 tons. No disrespect to TrichromeFan, but 2 units isn't the true solution, 3 is.
