When summer temperatures spike, or server rooms need constant cooling, air conditioning becomes an essential investment. But, as anyone who has used a fan in the heart of a heatwave knows, you can’t just move air around and hope that it will cool things down. So how does air conditioning work where other solutions don’t? Understanding the basics isn’t just a matter for engineers – it can help homeowners and businesses use their systems more efficiently, solve simple issues, and make more informed choices when upgrading or installing new units.
Whether you’re a facilities manager looking after multiple units, or a homeowner considering an upgrade, read on to learn how your AC system works; it could make a real difference.
The Science Behind Air Conditioning: The Cooling Cycle Explained
At its core, air conditioning is all about moving heat, not generating cold. That may sound counterintuitive, but it’s true: your air conditioning unit works by removing heat from indoor air and releasing it outside. This process relies on a refrigeration cycle, which includes four main steps:
- Evaporation: Inside the home or office, warm air is drawn across the evaporator coil, which contains a cold, liquid refrigerant. This refrigerant absorbs the heat and evaporates into gas.
- Compression: That gas is then pushed into a compressor, usually located in the outdoor part of the system. This increases the pressure and temperature of the refrigerant.
- Condensation: The now-hot, pressurised gas flows through a condenser coll, where it releases the heat into the outside air. As it cools, the refrigerant returns to a liquid state.
- Expansion: The liquid refrigerant passes through an expansion valve, reducing its temperature before it returns to the evaporator coil to start the cycle anew.
While your air conditioner is running, this cycle repeats continuously, maintaining a consistent indoor temperature.
Key Components of an Air Conditioning System
Most air conditioning systems, whether a home split unit or a larger commercial installation, use the same core elements. Here’s a breakdown of how an AC system works and what each of these parts does.
- Compressor: Think of this as the engine of the whole assembly. It pressurises the refrigerant and propels it through the system.
- Condenser Coil: Located in the outdoor section of the system, this releases the absorbed heat into the air.
- Expansion Valve: This controls how much refrigerant enters the evaporator coil, dropping its pressure and temperature.
- Evaporator Coil: Found in the outdoor unit, this draws in warm air from your space, and cools it by absorbing the heat into the refrigerant.
- Fans and Blowers: These circulate air – drawing warm air in, and pushing cooled air back out into the space that needs cooling.
- Thermostat/Control: This tells your air conditioner when to turn on and off, and lets you set the temperature you want or need.
Understanding these components helps explain how an AC unit works as a whole. It also helps identify what the problem might be if things don’t seem to be running right.
Step-by-Step: How Does Air Conditioning Work?
Here is a simplified version of the process by which the air is cooled from the moment you switch your system on:
- The thermostat detects that the room is warmer than your desired level.
- It signals the AC unit to start the cooling cycle.
- Warm air is pulled in and passed over the evaporator coil.
- The refrigerant absorbs the heat, and cooled air is blown back into the room.
- Heat is transferred to the outdoor condenser, and the refrigerant cycle continues.
- Once your target temperature is reached, the thermostat tells the system to pause.
- The cycle is then reactivated if the thermostat detects a rise in ambient temperature.
This seamless cycle is what keeps your space comfortable throughout the day, whether you’re relaxing at home or running a business.
Types of Air Conditioning Systems Explained
There is no one overall solution that works for everyone when it comes to air conditioning. Here are the main types:
- Split Systems: These are the most common in homes and smaller businesses. They consist of an indoor unit and a separate outdoor unit. They’re efficient, and relatively easy to install.
- Ducted (Central) Systems: These systems cool the entire building via ducts in the ceiling or walls. They’re often used in larger homes, offices, and retail spaces.
- Portable/Window Units: These are standalone systems that can be moved around, or fitted to windows as appropriate. They’re a useful temporary setup, and also useful for cooling smaller rooms.
- Commercial Systems: More powerful and customisable, these are designed to suit the space, handling large-scale cooling. They can be controlled zonally to provide cooling where it is most needed, and usually have much greater capacity than other systems.
The main difference between residential and commercial AC lies primarily in scale and flexibility. Commercial setups may include rooftop units or variable refrigerant flow (VRF) systems to cater to different zones with varied needs.
Common Questions and Myths About Air Conditioning
Is air conditioning expensive to run?
Modern systems are very much designed for energy efficiency. Running costs depend on the unit’s size, how well the building is insulated, and how it is used. Typically, the system will idle while the room is at an appropriate temperature, so it’s only using energy when it needs to.
Do I need to top up the gas?
Strictly speaking, refrigerant isn’t supposed to get used up. If levels are low, this indicates a leak in the system which will need professional repair. Air conditioning in a car may occasionally need to be “re-gassed”, but home and commercial systems are different.
Can air conditioners heat as well as cool?
Yes, usually. Many modern systems are reverse-cycle, which means they can heat your space in winter and cool it in summer, for a great energy-efficient system year-round.
How does AC work in the UK’s milder climate?
Perfectly well. Indeed, AC with a heating functionality is growing in popularity due to rising temperatures – some recent summers have seen highs of over 40 degrees – as well as for their benefits in indoor air quality.
Local Expertise: Why Choose Absolute Climate Solutions?
If you’re in Oxfordshire or the surrounding areas and need advice, installation, or maintenance for your air conditioning system, Absolute Climate Solutions is the local partner you need. This is because we bring:
- Innate local knowledge and experience with residential and commercial systems
- Transparent pricing and honest recommendations
- A commitment to quality service and ongoing support.
If you want to know more, or need help with air conditioning in your home or business, please contact Absolute Climate Solutions for expert guidance and a free quote.