Hey bud,
So the 3500 btu per light is for uncooled lights?
Right?
Yes it is. That taking in consideration that your ballasts are
outside of your grow room
What would you suggest if the lights were air cooled?
Wouldn't be worth while ( electricity saving ) air cooling your lights instead of having a bigger air conditioner.
To be honest, I've never worked with the air cooled reflectors. Most people say they help a lot. Others not so much. As for electricity saving you would just have to try it out and calculate calculate and then calculate some more.
IMO, don't bother. Considering the size of your grow and the fact that most recommendation are that you put a 6" fan for every 2 1000W it adds up to a lot of fans.
If the AC cost is your problem, you might want to research water cooled air handlers. Something like this:
They are harder to find but are cheaper than ACs and are used in the professional cold storages/commercial fridges/freezers and so on. Technically it is a water cooled ac but
cheaper and more reliable. If you pay for your water $ (for some of us it's free) put an old horizontal fridge under your air handler.
Drill 2 holes on the top (one in, one out), fill it with water, connect your hoses and let it act as a recirculating water cooling system
If you don't pay for water, just put your water in/out and roll..
To summarize:
I think you shouldn't bother with the air cooled reflectors because of the size of your grow. Just keep it plain simple and stick to things you
know work.
There's a short but informative post on the matter:
https://www.rollitup.org/t/do-air-cooled-reflectors-work.418504/
hope this helps, good luck