What I would do is set it up how it will be in "The room" and turn it on and get it up to the highest level you will want it, and time it to see how long it takes to drop to the lowest level you want it, and then time again how long it takes to get back up, that should get you an idea of cycles

Say it takes 20 minutes to get it to the highest you will want it, then takes an hour to drop down to the lower limit, then only 10 minutes to get it back up to the higher limit, from the lower limit. Then you will need it to turn on every hour for 10 minutes, to keep it in that range