I have a salt-water aquarium built into a dividing wall. it houses a 180-gallon display tank over another 180-gallon tank that houses the filtration. Each tank is 6'l x 2't x 2'w. and there is cabinetry on either side of the tanks. I have an exhaust fan at top of the cabinet that draws in air from the bottom, across the bottom tank, up and then back across the upper tank and out the top of the cabinet, through the wall into the next room. Currently this is helping me keep my room and the fishtank about 3 degrees cooler than when I was relying on just passive heat dissipation. My challenge is that I would like to try and improve upon this and am currently considering two possibilities but am uncertain which would be more effective.
Option 1 would be to introduce an evaporative cooling unit in the line of the airflow to reduce the temperature of the air as it circulates through the cabinet.
Option 2 would be to add additional fans to blow air at the surface of the water increasing the rate of evaporation in the tanks.
I keep the house at about 77degrees f and roughly 50% humidity. The exhaust fan currently draws about 100-110 cfm per minute through the cabinet and there is roughly 100Cf of airspace within the cabinetry. Currently, the system loses about 3 gallons of water a day to evaporation.
I know there are a lot of other variables that may need to be accounted for, but any ideas which option would provide better, more efficient cooling? or if you have any better suggestions? My preference would be to feed cold dry air but there is insufficient space for a proper air conditioner and don't want that noise or expense.
Thanks in advance.