Expert's Desk: Occupancy Sensors vs. Vacancy Sensors

Occupancy and vacancy sensors both save energy by controlling lights, but they work in different ways. How? Let’s take a look.

Imagine a room equipped with an occupancy sensor. When someone enters the room, the lights automatically turn on. When they leave again, the lights stay on for a set amount of time, often as long as 20 minutes. If another person comes in and leaves again during that timespan, just for a few seconds, the sensor resets for another 20 minutes. That’s wasted energy.

A vacancy sensor requires someone to turn on the lights when they enter a room. The lights still automatically turn off after the set time period, but the lights will stay off unless someone enters the room and manually turns on the switch. This will save energy by eliminating those extra minutes of unnecessary lighting. You can save even more by reducing the set time period down to just a few minutes.

So although they may look the same, vacancy sensors leave less room for energy waste on your electric bills.