If you get the inkbird I have you can use it to control your exhaust fan. Model ITC-608T $70.00 on Amazon. You can use them to control A/C, Heat, Fans, Humidity by temp and rh. But you can only use any two functions at a time. So in your situation you can plug your exhaust fan into the unit. Set your temp set point and differential. Set your fan speed controller at what ever you want the fan to run at and it will cycle your exhaust fan by tent temp. All you need is a very simple and cheap turn it on humidifier of at least 1 gal capacity. Plug it into the Inkbird. Set the Inkbird up and it will cycle your humidifier. Once you have control of your temps and humidity that leaves lights, watering and feeding. The problem with the
AC Infinity system is it requires the humidifier to be on all the time then cycles the exhaust fan to control the rh level in your enclosure. So you use a whole bunch more water and at times it will fire up on temp and rh and pull your rh down really low so your rh spread works out to be more like a possible 30% swing or more. Where if you use the Inkbird you will stay closer to a 10% swing and use much less water. Also get the Inkbird like mine in the pic. They have another popular unit that is cheap for just humidity control. Or cooling/fan control. But there sensors are hardwired in the unit so if you have to replace a rh sensor or a temp sensor it's a pain in the ass for the average stoner. And the rh sensors seem to fail more than the temp sensors. The units I use just plug in and are like $14 to $20 each on the jungle store. Good Luck