Here is a quick overview of how the External & Internal Energy Misers work.
External EnergyMisers, like the one shown above, use a controller and a machine or wall-mounted sensor to monitor room occupancy and temperature. If 15 minutes pass without any pedestrian traffic, the EnergyMiser will power down the machine. The machine is powered back up when people return and at regular intervals to to keep the product cold. External controllers are best suited for low traffic areas.
Internal EnergyMisers, like the VM2iQ and CM2iQ, use sales-based intelligence to power down the cooling system while leaving lighting and controller electronics on. Internal EnergyMisers monitor the room’s temperature and automatically re-powers the cooling system at regular intervals to keep the product cold. Internal controllers are best suited for high traffic areas.