Occupancy Sensor for HVAC: Any recommendations or experience?

[Michael Weeks]

Background: just purchased a 15-unit (SRO type units with all utilities included in rent) apartment building in Central Florida.

Current HVAC is comprised of window air conditioners and wall gas heaters.  

Plan: move to mini-split systems for each unit to provide heating & cooling.  

Question: To save money; I would like to incorporate a system (occupancy sensor, perhaps) that would reset heating and cooling to minimal levels when the tenant has left their unit/no motion is detected for XX minutes.  

Any experience with this?

Any (alternative )suggestions or feedback?  

Thanks in advance!