They will work i am not sure if they will get it down to 65 and you will need to have a couple ready at a time. But the hight temps are not from th eambient heat its from the heat in the grow room... what is the temps out side the room... Rember unless you pump air from the outside like i do you can not get the temps any lower then what they are out side the room. Were is teh intake fan pulling air from?
I personaly will not grow durning the summer months. i dont find it profitable... I am running a 5x5 with a 1000 HPS two 4ft 6 tube T5s for side growth 8 inch fan on my 1000 going out the chimy and i use a 6 inch with adjustablity pulling cold air from the outside of my place. My room is dead nuts at 77 all of the time. And when lights are off i have both fans on timmers to kick on every hr for 10 minutes to get fresh air in and exuast the old.