How does an air conditioner keep a room cold? Its name aptly gives a clue on how an air conditioner works. Contrary to what many people think, an air conditioner does not produce and blow out cold air. Instead, it acts as a ‘conditioner,’ extracting heat energy from a room, conditioning this through a refrigerant, and blowing back cool air into the room. It may sound not very easy, but the process of cooling rests on something so simple, as developed and applied by inventor Willis Carrier.
Process of How Air Conditioner Works
Before breaking down the process into more detail, let’s first get acquainted with the major parts of an air conditioner unit: the compressor, the condenser, and the evaporator. As you may notice, part of the air conditioner is found in your house, and the other half is outdoors. What you see inside your house is the part of the unit that has the evaporator. The other two parts are found in the part of the air conditioner that juts out of the house. Here’s what happens:
The heat from the warm air inside your home is absorbed by a refrigerant, a cooling agent in the AC unit’s coils. This occurs in the first station, the evaporator. Refrigerants are compounds that can change at low temperatures.
The refrigerant follows a loop that passes through the three major parts or stations, from the evaporator to the compressor and the condenser. In this route, heat is changed from liquid to gas.
The next stop for the refrigerant is the compressor, where its temperature and pressure are raised. The station is called bringing down the gas’ volume by squeezing or ‘compressing’ it between two solid objects. In this step, the refrigerant becomes a very hot vapor that’s ready for condensing.
The last station before the cycle repeats is the condenser found in the AC unit’s outdoor part. The air outdoors removes the heat from the now superheated refrigerant. The latter then changes from a gaseous to a liquid state. This also explains the liquid that drips from the external part of your AC unit.
The now liquid refrigerant returns to the evaporator, the AC unit’s indoor part, where the cycle repeats. This process occurs over and over again until the room turns cooler, to your liking. The air conditioner’s thermostat then prompts the unit to turn off after reaching the preferred temperature.
A refrigerator is similar to how an air conditioner works, only that a fridge does not rely on your room’s walls to contain cold air. A fridge, on the other hand, has housing for insulation. In the last few decades, there has been much talk about the harm that the air conditioning unit poses on the planet. In terms of global warming, the blame is always on this and refrigerators for the energy they expend. Specifically, it’s the chlorofluorocarbons (CFCs) – the coolant chemicals considered the culprit. These are compounds found to be ozone-depleting and are made of chlorine, fluorine, and carbon.
What’s good is that many countries already ban these CFCs and have released air conditioner units that are more ozone-friendly. These new models use safer alternatives to CFCs, like halogen chlorofluorocarbons (HCFCs). You can be assured that labels that say ‘Ozone friendly’ are free from CFCs.
How about air conditioner alternatives, are there any good ones out there, especially those that don’t jack up your electricity bill?
Another option you can consider is air coolers. These primarily work through evaporation, much like how profuse sweating makes the body eliminate heat to cool down. When water becomes water vapor, it absorbs heat from any source nearby. For example, in a room, air coolers suck in the heat, use water nearby to cool it down, and then let this cooled air circulate. So the key component here is water.
Compared to air conditioners, air coolers are less expensive and can easily be carried around. However, they cannot make a room as cold as how an air conditioner works. Air coolers can only make a room less humid. They also need to be refilled with water, which is key in their process of cooling.
It’s interesting to know how an air conditioner works and how it compares to the other technology that we use daily. It’s often not customary to look closely at how a thing works, as long as it works, and it serves us alright. But it’s only through studying how these gadgets work that the good and the bad are exposed. It’s not about eliminating harmful technology and enduring a hot and humid room. It’s all about better appreciation and mindful use so that the earth is not harmed. Here’s how to learn more about how appliances work.