Motion-Activated A/C: How it Works

Smart air conditioners are getting smarter all the time. While Wi-Fi thermostats that enable remote monitoring and control of an HVAC system already make home comfort more convenient and energy-efficient, new smart air conditioners now on the horizon will also incorporate motion-detection functions.

Motion Controlled Comfort

Motion detectors for lighting have always made sense: Why waste electricity to illuminate rooms with no occupants? The same theory is now applied to air conditioning. Ductless mini-split heat pumps that cool individual rooms are among the fastest growing segments of the market. Highly efficient and compact, these units are a perfect match for technology that integrates an occupancy sensor with the mini-split’s wireless thermostat. Here’s how a typical configuration would work:

A motion sensor mounted on the ceiling detects persons entering a room cooled by the mini-split unit. The sensor could be a common passive infrared unit, or an ultrasonic or acoustic model.

The A/C quickly brings room temperature down to the preset “occupied” temperature setting programmed into the thermostat and maintains that temperature as long as occupants are present.

When all persons leave and the motion sensor no longer detects occupants, it signals the thermostat to default back to a preset “unoccupied temperature” already programmed into the unit.

The thermostat signals the outdoor heat pump component serving that room to reduce compressor output, significantly reducing system energy consumption. It may also reduce blower speed of the indoor air handler. The system maintains this unoccupied room temperature and enhanced efficiency until someone enters the room again.

Sleeping Comfortably

Smart air conditioners will also automatically override motion-sensor control during time spans when persons in the room aren’t usually moving around—such as the overnight period when occupants are sleeping. During that specified time period, the unit defaults to the normal desired thermostat setting for sleeping. A “one touch” button on the thermostat remote control typically utilized with mini-split systems may also override motion control operation at any time the user desires.

For more about the advances smart air conditioners are bringing to home comfort and efficiency, contact CCAC.

Our goal is to help educate our customers in Corpus Christi, Texas about energy and home comfort issues (specific to HVAC systems). For more information about your HVAC system, download our free Home Comfort Guide or call us at 361-678-2495.