Air conditioning isn’t just a convenience for home and office dwellers—it’s an essential part of our comfort. While many people take it for granted, a well-functioning cooling system requires complex machinery that’s designed to provide comfortable, controlled humidity and temperature.

Home air conditioning is slowly becoming more popular in the UK after not being very common here for a while, but many people still aren’t sure exactly how it works or what the best home cooling systems are. Having a little more knowledge about the technology behind your air conditioning can help you understand what’s going on inside your house when it comes to cool air, and may even allow you to make smarter choices when it comes to picking a new cooling unit.

Most modern home air conditioners use a method called vapor compression refrigeration to keep you and your family cool. The indoor unit of the system contains a blower fan that pulls warm air from your room over a set of cold pipes—the same way cool water evaporates off your skin to cool you down. The cold pipes are lined with a material called an evaporator coil that is filled with a special liquid called refrigerant. As the refrigerant evaporates, it absorbs heat from the air and changes into a gas. The refrigerant is then pumped outside the home, through copper tubing, to the outdoor compressor and condenser coil. Here, the heat is released into the atmosphere, and the cooled refrigerant returns to the evaporator coil inside your house.

The process of cooling is repeated as the cycle continues, and the cool, conditioned air is then distributed throughout your building. This precise control of temperature and humidity has helped drive many industries that we now rely on, including indoor shopping malls, transatlantic flight, and computers and server farms that power the internet.

While air conditioning uses high levels of electricity to function, there are things you can do to reduce energy consumption and lower your carbon footprint. Adding insulation, lowering your thermostat settings when you’re not at home, or installing ceiling fans can all make a significant difference to your home’s energy efficiency and cooling capabilities.

Choosing an ENERGY STAR certified home air conditioner can also make a big difference. These air conditioners are built to reduce energy consumption and offer more cooling for less money, thanks to higher seasonal energy efficiency ratings (SEER).

Understanding How Air Conditioning Works