For most of us air conditioning systems either work, or they don’t work. How they work remains a mystery we don’t concern ourselves with. It’s a little like flipping on a light switch. We can get light without understanding how a light bulb or electricity itself works. The difference is, when a light bulb goes out, we can usually diagnose and fix the problem ourselves. Air conditioning systems are a different matter, and we have other files here explaining what to do and what not to do if you have an air conditioning problem.
Still, it never hurts to know the basics of how air conditioning works.
The principles of air conditioning have been known for well over a century. They were originally applied by Willis Carrier when he invented the first air conditioning system in 1902. We’re a long way from the basic system he developed, and like everything in today’s world, air conditioning has been refined to make it more efficient and more effective. Electronics have been enhanced sufficiently to allow many air conditioning system tasks to be handled by computer modules. Just as the days of shade-tree mechanics have passed, installing and working on air conditioning systems requires training and education. Despite all that, the basic principles have remained the same.
No matter what brand of air conditioning you have, all systems use the same basic concepts and procedures to cool your home. That’s because the basic goal of air conditioning is to cool your home, and it does that by removing heat. Let’s go into more detail on that idea.
In warm and hot months, your home has no difficulty producing, accumulating, and retaining hot air. It comes in through your windows and doors. It radiates down from your attic. It spreads from your kitchen when you cook. Your electronic devices (televisions, computers, and so forth) create heat when they’re turned on. Your own body temperature gets in on the act. Your furniture absorbs heat and holds onto it.
In the past, homes were designed with this in mind. They had higher ceilings because hot air rises. Their interior design allowed outside air to enter at one end of the house and be drawn inside so it could exit on the other side. Windows were larger, and they could be opened widely. Large, expansive porches and nearby trees provided shade to cool the air before it got in the house. In fact, even with the windows closed, it was possible to tell if it was a windy day because homes weren’t as tightly sealed as they are today. Homes were typically painted white to reflect sunlight, and those expansive porches allowed the household to gather outside as the evening progressed and the air within the house cooled.
In drier climates, evaporative coolers pulled outside air through water-soaked filters that cooled it as it was blown into the home. Those type of units are still used effectively in desert areas. Unfortunately, North Texas does not allow them to be very effective.
So what makes modern air conditioning work?
We’ve established that your home is naturally hot in the summer. Air conditioning draws the heat from that air and then blows it across cold pipes called evaporator coils. These coils contain a very cold liquid refrigerant that absorbs the heat from the air.
This refrigerant changes to a very hot gas after absorbing all that heat, and it is subsequently sent outside the home to the compressor which allows the hot gas to release its heat and revert to a cold liquid. That cold liquid is sent back into your home to collect more heat. This cycle continues for as long as your thermostat determines necessary for your home temperature to cool to your desired comfort level. The efficiency of your air conditioning system, allows it to do all this without costing a lot of money. In fact, the cost of running your system is one of the ways you can tell if it’s doing a good job. If your bill goes up unexpectedly, there may be a problem requiring attention from a professional.
Most air conditioners also have an air filter. The filter is usually found where the ductwork starts. As the filter removes particles from the air, it gets dirty and clogged. This reduces the efficiency of the system, and the filter either needs to be cleaned or completely replaced. The filter ensures the air conditioner and the air traveling through it is as clean as possible. To keep your system efficient and working properly, filters should be changed regularly.
Obviously, there is a lot more to this process, but this is the basic idea. Your conditioning utilizes a very complex system to accomplish this basic task, and that system needs to be maintained regularly to ensure it remains effective and efficient. Always have this maintenance done by a qualified professional at least once a year.