I would suggest 4000 btu's per 1000 watts and then a bit more to cover the normal cooling for that space. I have a sealed room and I have 2 600 watt lights and a 9000 BTU ductless mini split and it will keep the room cool if I turn the lights up to 1000 but the humidity drops like a rock. I would suggest an 18000 BTU unit if you can afford it. Portable would be best to control odor but they are really inefficient. Ductless mini split is the best but they are pricey. I am hanging vertical lights by the way. If you have hoods then you can take air from outside to cool the lamps and direct the hot air back outside. You could also get something like the Fresca Sol water cooled lighting solution. There would be no need to vent anything at that point (except for fresh CO2).