i kept a fan dedicated to the pots(roots) and i use aero pots myelf. easy to bring down temp just spraying cold water on them and letting the fan do the rest of the work. you can try the fan method if your using the usual pots and wrap some old shirts around it and keep it wet. simple, cheap, yet it gets the job done.
as far as roots go the "perfect range" is usually 75-85 thats of course talking about the rockwool temp.just do the same method to the propagator or cup you have the clones in and you should be fine.