Some air conditioners and heaters have a control system called a thermostat. A thermometer inside the thermostat continually
measures the temperature in the room. If the air temperature
in the room rises above a preset temperature, the thermostat
signals the air conditioner to turn on. If the air temperature in
the room falls below the preset temperature, the thermostat
signals the air conditioner to turn off.
ANALYZE Number these steps in order to illustrate the
feedback loop that occurs when the air temperature becomes
warmer than the thermostat setting (78 °F)
a. The thermostat senses the decrease in air temperature.
b. The air temperature reaches 78 °F.
c. The air conditioner turns off.
d. The thermostat senses the increase in air temperature.
e. The air temperature reaches 79 °F.
f. The air conditioner turns on.