so you trying to cool off the inferno eh???
good plan. . . your journal goes so fast bro, i only read back 2 pages.
both of butchers suggestions are great as usual, but still, the number one thing to supplement to deal with heat, without actually dealing with the heat, is of course CO2. many people shoot for 95* when they are supplementing CO2 to get the stomata to really open fully and take in all that extra CO2.
I like the inline fans, they are loud as a bitch though aren't they??? thats why i dont use them, but i played with one on a dimmer switch in my hydro shop, and when i turned it down it was nice and quiet. if I knew that I would have never got rid of my 8", would just got a dimmer for it.
did you get a carbon filter too? if so, and you are exhausting fresh smelling air, you'll want a little vacuum affect in the room to make sure none of the smell gets out without passing through the filter first. most people do this intentionally. . . if you are sucking from a hole you don't want to (like a hot attic) just plug it, duct tape fixes everything. lol. then make sure you port it to somewhere with good air, and let it pull from there passively. no need for an active intake in 99% of situations (IMO).
and insulating the water heater, would not only keep heat out of the room, but in the tank, so you'll be saving money there too, if you wanted to try that.
the last option, might be your best, and most expensive. a stand alone AC unit might cost about $300-$400, but you can put it anywhere and port out the heat and port in the cold, and it should have a thermostat on there so you even have control over the temp you want to set it at.
i hate spending money too, especially when you dont have it, but sometimes in business you have to spend it to make it. $400 on an AC sounds expensive, but if better temps wards off some heat stress and translates to at least a couple extra OZ. in the end, you made your money back in one grow, and then you have it for the future.
good luck bro, i'm sure you'll come up with a solution that works for your space. as always, here to help out and give suggestions whenever it is wanted (and sometimes when it's not) lol. if i am preoccupied, gimme a hollar, i'll be around.