I've researched portable a/c's for a long time now. You will definitely want to read this.
First off a few of you have posted that you have your grow rooms within another room. This is very good for a portable a/c IF you get the right one.
Many portable a/c's suck in air from within the room to do DOUBLE duty inside the a/c. They will suck in air from the front and shoot it thru the compressor side to cool the air over its grill. This will blow out the top as cold air.
The a/c will also suck in the room air from the back and sides to cool off the condensor side and shoot that out thru the exhaust. This gets ducted outside the room.
The problem with this is that you really don't want to use the ALREADY cooled air inside the grow area to cool the condensor side of the a/c. This is a total waste of cooled grow room air because it cools the condensor and gets blown outside.
What you want to do is get a portable a/c with dual exhaust. This way the a/c never uses the cooled air in the room to cool the condensor. It uses 2 hoses in the back of the unit......one to suck air from outside the room and cool the condensor, the other blows out the hot air.
Two very important factors to make this work correctly.
1) The air outside your grow room can't be hot. It needs to be somewhat cool or near ambient temp of your house. Most likely 75 to 80 degrees would be a safe but I'm sure it can be higher. I know window units use outside air to keep the condensor cool so it should work with portables. Window units can use over 100 degree air but I think they are made much better than portables.
2) The exhaust air from the condensor should NOT be blown back into the outside area of your grow room. Vent that shit to the outside if you can!
Questions you may want to ask about your purchase of a portable a/c include:
Warranty, Dual exhaust, 24 hour timer with auto restart if you have a power failure and loudness. Also ask if it has a dehumidifier function and heat if needed.
Don't go cheap or too low on the BTU's. If you have 2000 watts you better get 10,000 btu or above.
I will be looking to buy one soon so I may have more info in a week or 2.
Hope this helped