I have a rig that should fit the purpose.
1- 5 gal bucket w\lid
1-holmes\honeywell 9" round fan(walmart/home depot)
1-large humidifier wick(It may take 2)
1-fountain pump 130gpm
1- full circle mister head w\spike & riser tube(micro mister 3-7' radius 1/4" tubing head)
Take the 5 gal bucket drill 3/8" holes around the sides starting 4" up from bottom to just under the lip(THE MORE HOLES/THE MORE AIR)
Secure humidifier wick to inside of bucket walls using zip ties through the holes.
Setup fountain pump into bottom center of bucket adapt output of pump to 1/4" mister riser & head.(set hight 1" below top of wick) cut out a couple holes in the bucket to run the cord out(above first row)
Disassemble fan from base(make sure your fans switch isn't in the base section)use fan to mark circle onto bucket lid,cut out hole. Mount fan into lid and seal with duct tape.
Fill bottom of bucket with 3" water,snap lid/fan on top,set fan high, plug in
and presto you have a cooler(you may need a few of these and place them inbetween plants)
THEORY: the water being misted will evaporate into the air being moved by the fan and create cooling 10-20 degrees
AND GUESS WHAT? IT ALSO INCREASES HUMIDITY
Parts available from Harbor frieght/Home depot/Walmart cost about $55.00 usd