An air conditioner is indeed a blessing when you want to escape the summer heat and humidity in the Bay Area. It not only removes indoor heat and provides you with cool air, but also filters the air entering your home to ensure a clean environment.
It is interesting to note how an air conditioner actually works. Air conditioning is based on some really simple physics. The laws of science that matter in air conditioning are gravity and displacement of heat from warmer to cooler places. What an air conditioner basically does is to pump heat out of your house and replace it with cool air. This air is not cool by itself but is cooled using a refrigerant.
The process that works the air conditioner and gives you cool air is a thermodynamic cycle called the refrigeration cycle.
Let’s see some details about how an air conditioner functions.
What does the refrigeration cycle consist of?
Step 1- Trapping indoor heat
The blower inside the air conditioner pulls the air inside the house and passes it over a very cold coil. This cold coil has refrigerant running through it, making the air passing over it cold too. The air that passes over the coil and comes off the other side has dropped its temperature drastically.
As heat flows from warm to cool areas, heat from indoor air flows into the cold coil. The heat inside the coil causes the refrigerant to become hot as well and to eventually start boiling. The boiling refrigerant thus goes from a liquid to vapor state inside the coil.
Step 2- Pumping of the refrigerant
The now vaporized, cold refrigerant then flows to the outdoor unit to enter the compressor. Next, the refrigerant is pumped to high pressure by the compressor, increasing its temperature again.
From step 1 to step 2, the refrigerant travels through copper tubes that go from the indoor AC unit to the outdoor unit. If you touch a part of these copper tubes, they will feel cold on your skin.
Heat flows from warm areas to cooler ones and not the other way round. So, the refrigerant temperature is increased well above ambient temperature by the compressor.
Step 3- Expelling hot air from the house
The hot, vaporized refrigerant once again passes through another coil surrounding the compressor in the outdoor unit. A fan sends outdoor air through the coil and expels it over the top. When hot outdoor air passes over a hotter coil, heat from the refrigerant is transferred to outdoor air.
Step 4- Cooling of the refrigerant
As all the heat from the refrigerant is taken out and expelled, the refrigerant cools back down to condensation point and goes back into liquid state. As this refrigerant travels back from the outdoor unit to the indoor unit, it passes through a device that expands it into a large volume. This causes a huge drop in temperature. The refrigerant must remain colder than indoor air so that it can pull heat from the house.
All these steps keep on repeating in a cycle, keeping your house cool.