How Does Air Conditioning Work? Understanding the Science Behind Cool Comfort

How Does Air Conditioning Work

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Absolute Climate Solutions

Understanding How Air Conditioning Works

Air conditioning is a convenient (and sometimes essential) part of modern life. Some homeowners rely on it to keep them comfortable and safe.

At the same time, it remains a technology shrouded in mystery. How does adding electricity to a box with a fan make cold air? 

That’s what we discuss in this post. We delve into the details of how the various A/C components work together to offer indoor climate control (without violating the laws of physics). Read on to learn the basics of air-con systems, how the cooling process works, and how to maintain your unit properly armed with this knowledge. 

How Does Air Conditioning Work

The Basics of Air Conditioning Systems: What is an AC? 

Air conditioning units’ job is the opposite of boilers. Their role is to cool down your home. 

Many homes in hot parts of the world rely on air conditioning units, using the technology to control temperature, humidity, and airflow (depending on how premium they are). Like boilers, thermostats control air conditioning systems’ operation by determining how cool the room has to be before they switch off. 

Some units connect directly to the outdoors through a hole in the wall while others use ducting and vents to transfer hot air. However, all air conditioning units have components inside and outside the home for energy dissipation. Systems can’t work without this feature. 

The Cooling Process: How an Air Conditioner Works

Air conditioning systems rely on compressors, condensers, evaporators, and refrigerants to cool incoming warm air. These components work together to eject the excess energy outside where it dissipates into the environment. 

The process begins when the onboard thermostat senses the air temperature is higher than the user’s settings. When this happens, it signals the A/C unit to start cooling, telling a fan to pull warm air into the unit and pass it over the evaporator coil. Coming into contact with the coil raises the temperature of the refrigerant inside this component – a special cooling liquid – causing it to turn to gas. As the liquid absorbs the heat, it takes it out of the air, causing it to cool down. Another fan then sends the cooled air back into the room. 

Once the refrigerant becomes a gas, it travels through a copper tube to the compressor. This large electric pump squeezes the gas into a smaller volume, causing the molecules it contains to press against each other more violently, raising the temperature. It then moves to the condenser – a radiator-like coil where the refrigerant can release its newfound energy to outdoor air. This process causes the coolant to liquefy again under high pressure. 

Finally, the refrigerant travels to the expansion valve to release its pent-up pressure, returning to a low-pressure fluid where the cycle starts again. 

The Role of Refrigerants in Air Conditioning

Refrigerants are chemicals with low boiling points. This property allows them to leverage state-change physics (moving from liquid to gas and vice versa) to absorb and dissipate energy. 

During the first phase of the air conditioning process, refrigerants are in liquid form. Then, when warm indoor air passes over them, they evaporate and become gas. This process removes heat from the air similar to how evaporating sweat removes heat from the body. The compressor then pressurises the hot gas, increasing its temperature more. It then travels to the condenser coil outside to release the collected energy into the environment where it returns to a liquid state. When the pressure is removed after going through the expansion valve, it lowers the temperature relative to the room, allowing it to absorb more energy. 

Different Types of Air Conditioning Systems

There are several different types of air conditioning systems: 

  • Window Units. These are popular because of their affordability. The blower part of the unit sits inside the window with the condenser coil and cooling fan outside. These work on the same principles described above, but can be noisy and block incoming light. 
  • Split systems. These are two-piece systems with an indoor air-handling unit and an external condenser. They are useful for cooling multiple rooms and are quieter than window units but cost more to install
  • Central Air Conditioning. Finally, these systems cool entire homes and use ductwork to distribute heat. However, they require professional installation and servicing to maintain

The unit you choose will depend on the size of the space you want to cool. A window unit is okay for reducing the temperature in the bedroom at night. However, central air conditioning is the only feasible solution for multiple rooms or cooling the entire home. 

Maintaining Your Air Conditioner for Optimal Performance

Maintaining your air conditioner regularly is also essential. Checkups keep it in good working order and ensure it continues to function as intended in coming years. 

Critical maintenance tasks include: 

  • Cleaning filters – removing dust and other particles from meshes that might gum up A/C units’ internal mechanisms
  • Checking refrigerant levels – ensuring there are no leaks and that there is sufficient coolant to cool the desired volume of air
  • Scheduling professional maintenance – getting the pros to come over to check nothing is getting in the way of the A/C unit working efficiently

Maintaining your air conditioning unit regularly will allow it to continue providing optimal performance. Running it without maintenance can increase bills and cause wear and tear to internal components, shortening the unit’s life. 

Energy Efficiency and Cost Savings in Air Conditioning

Maintaining air conditioning units is straightforward once you understand how they work. Moreover, this knowledge can help you achieve better energy efficiency and more fuel savings

The first (and most important) step is to relate air conditioning capacity to room size. Getting this balance right reduces the risk of short cycles or A/C units that run constantly. Right-sized units have high-efficiency compressors that don’t have to work as hard to maintain a constant temperature. Compressors that are too small can’t remove energy fast enough, while those that are too large go underutilised. 

The second step is to ensure clean (dust-free) filters. Fans don’t have to work as hard when fresh air can pass through unimpeded.

Finally, thermostat settings can increase energy efficiency further. Leaving settings a few degrees higher can cut energy use massively. 

Conclusion: Appreciating the Mechanics of Air Conditioning

In summary, air conditioning units work by taking advantage of the special physics of refrigerants.  Units suck in cold air and pass it over coils containing these substances, causing them to evaporate and become gas. This phase-change activity transfers heat to the coolant that various pumps and radiators can dissipate to the outdoor air. 

Once you understand how A/C units work, you can maintain them better. You know what to look out for, and what can go wrong. Priorities include checking coolant levels, cleaning filters, and choosing an air conditioning unit capable of cooling your spaces.