Geolocation relies on the reported location of your location through the mobile network or the phone's GPS, whichever is available first. Sometimes, you are heading into the arrival zone and one of the two sources has reported that you are in entered the zone, hence triggering on your air conditioner or heat pump. However, it is possible that while you're travelling closer to your device location your GPS or the mobile network may report you to be outside the zone, in which case would make it appear as if you've subsequently exited the zone without re-entering. 

If you're experiencing this problem, please note down the date and time that it's happening and talk to our support staff through our in-app support.
Otherwise, you could also try setting two different zones for arrival and departure with differing zone radius to prevent these problems that happen because the zones are too close together.