If you really want to cool then think like a grower. Mini ductless AC unit and inline ducting for intake and exhaust. Use an environmental control and when temps go higher than ducting can handle they shut off and mini split system kicks in. The inline venting alone can do the job minus those really hot days. I highly recommend the Panasonic whisperline duct fans. Do the math, get the right size, x 2 since you want intake and exhaust unless you have passive intake like an open door to suck air in from.

You can find lots of growers on craigslist selling equipment all the time.