Background
Most cooling systems today do not take into consideration that compartments within the system may represent drastically different thermal loads. Consider an academic building with a room running computer calculations twenty four hours a day. If the building is controlled by a central cooling system, during the day the cooling unit would be required to supply enough cold air to sufficiently cool the computers and maintain a comfortable temperature in both class rooms and offices. But during the night, while the computer room still needs to be cooled it would be inappropriate to provide equal cooling to both classrooms and the computer system.
The Concept
The Efficient Cooling and Ventilation System (ECVS) attempts to solve this problem by controlling the intensity of airflow so that each compartment will receive an amount of cooling air proportional to its thermal demand. Instead of cooling each room evenly, more airflow goes to where it's hot, and less to where it's cold. This avoids overcooling compartments that are near ideal temperature while not compromising the cooling demand of the warmer compartments. If ECVS were implemented in the computer room example, it would restrict the cool air supply to all other rooms besides the computer room, allowing the central cooling unit to focus its cooling power on the computer system instead of the entire building. The cooling unit therefore runs at a much lower rate and uses only the amount of energy it needs.
The Project
The bench model we built to demonstrate this concept features three compartments whose temperatures we vary with thermoelectric heaters. Two computer fans provide the air flow into the system, which leaves through vents in the back of each compartment. The air flowing into each compartment is regulated by louver doors (think of the vent registers inside a car) that open and close to increase and decrease air flow into each compartment. These doors are actuated by servos, which receive instructions from the microcontroller based on readings from temperature sensors in each compartment. Once the computer program calculates which settings need to be corrected, it modifies the speed each fan should run at, and position of each servo.
