Hosted by Sandra Tsing Loh, The Loh Down on Science is a fun way to get your daily dose of science plus a dash of humor in less than two minutes.
Hosted by Sandra Tsing Loh
Airs Weekdays 2:31, 3:31 and 5:49 a.m.

Air Conditioner

Hello, Big Brother: This air conditioner cools only the rooms with people inside.

Air Conditioner
Ever feel like you're being watched in your own home?

This is Sandra Tsing Loh with the Loh Down on Science

Saying, but if it saves energy!

The problem with central air conditioning is it cools empty rooms as well as filled ones.

If cooling systems knew where people WERE within a building, they could efficiently direct their efforts.

Wrong, says Schwetak Patel from the Georgia Institute of Technology. He found a simple modification to the A/C itself that does the trick.

In an empty house, air flow is constant and stable. If someone opens a door and enters a room, however, those actions trigger tiny variations in air pressure.

Patel used just five air-pressure sensors on a large house's air conditioning system's central filter. Computer software interpreted the changes. It was able to detect and locate these pressure changes and identify which doors were opened or passed through up to eighty percent of the time, allowing the A/C could be shut off in empty rooms.

The system could automatically lock doors or call the police when rooms that SHOULD be empty are NOT. It could even count the empty wine bottles in your recycling. It's HAL-o-rific!