A thermostat turns on an AC unit by detecting that the ambient temperature has risen above the setpoint and then signaling the AC system to start cooling.
Understanding the Thermostat's Role
The thermostat is the control center for your home's cooling system. It constantly monitors the air temperature and compares it to your desired temperature setting.
- Temperature Sensing: The thermostat uses a sensor to measure the current room temperature.
- Setpoint Comparison: It compares the measured temperature to the temperature you've set (the "setpoint").
- Signaling the AC: If the room temperature is higher than the setpoint, the thermostat sends a signal to the air conditioner to turn on. According to the YouTube video "How a Thermostat Works For Beginners", if the thermostat is set to 72 degrees and it's summer, the AC will turn on when the ambient temperature is above 72 degrees.
- Maintaining Temperature: The AC continues to run until the room temperature reaches the setpoint. Once achieved, the thermostat signals the AC to turn off. This cycle repeats to maintain a consistent temperature.
Example Scenario
Let's say you set your thermostat to 72°F (22°C) during the summer.
- The thermostat constantly monitors the room temperature.
- If the room temperature rises to 75°F (24°C), the thermostat detects that it's warmer than your setpoint.
- The thermostat sends an electrical signal to your AC unit.
- The AC unit turns on and starts cooling the air.
- Once the room temperature cools down to 72°F (22°C), the thermostat signals the AC unit to turn off.
- This cycle repeats, maintaining a temperature of approximately 72°F (22°C).
Key Components and Functionality
- Sensor: Measures the ambient temperature.
- Control Circuit: Compares the measured temperature with the setpoint and sends signals.
- Relay or Switch: Acts as an electrical switch, turning the AC unit on or off.
