For anyone that works in a large office building, odds are you know the pains of dealing with a poorly regulated HVAC system. [Robovergne] and his co-workers recently moved to a new location, and found that the air conditioning control was less than effective, leaving the office as hot as a sauna or as cold as a meat locker.
While they manually triggered the A/C on and off every half hour for a while, that grew tiring, so [Robovergne] decided to take things into his own hands. He had never used an Arduino before, and figured that regulating the air would be a great first project. He mounted a small hobby servo onto the front of the A/C remote, and wired a DS18B21 temperature probe to the Arduino. A small pot is used to adjust the temperature setpoints, which are displayed on the attached LCD screen. Now, when the temperature starts to rise, the Arduino triggers the servo to turn the air conditioning on without human interaction.
[Robovergne] says that while his solution is ugly, it works quite well. It definitely gets the job done, we can’t argue with that!
Continue reading to see a video of his automatic A/C controller in action.