if my tank hits 27°C I put a fan on low on the sump, and click it up a notch for each degree higher.
I also have rather large (1800 CFM) fan in the porch area too if i feel it getting to warm I circulate the air around.and open doors.
Only problem is I'm doing everything via readable probes (electric thermometer, glass thermometer) so I have to physically turn things on, which there was a relatively cheap temperature controller so I can turn fans on/off depending upon the ambient air temp.