How does air conditioning work?

Posted May 16, 2023 by Jon Matthews
Woman at home sitting on chair reading book

Air conditioning units are commonplace at work – but what about the home? Estimates suggest that less than 5% of homes in England have air con installed. But with UK temperatures predicted to make 2023 one of the Earth’s hottest years on record, you might be thinking about investing in air con for the first time.

From single and multiple split systems to portable units and ducted systems: we guide you through how air conditioning works, the different types of air conditioning systems, and the benefits of installing air con at home.

The different types of air conditioning systems

Did you know that not all air conditioning units are the same? The various air conditioning unit types fall into four broad categories. Let’s look at each one in turn:

Portable air conditioners
As its name suggests, a portable air conditioning unit is a form of AC that is easy to move around. They are fully self contained, usually with wheels, to allow you to ‘spot cool’ areas that need it. Due to their compact size, portable air conditioners are ideal for use in smaller rooms – all you need is a socket. They work in the same way as other types of AC unit, but condense all the mechanics into a smaller space. The newest models extract water using an exhaust vent, or less commonly, via a hose. If your AC unit has a bucket to collect the water, then consider yours a vintage model!

Single split unit air conditioners
A split unit air conditioner can be used in home and commercial properties, such as offices, factories and shops. They consist of an outdoor unit (the condenser) and an indoor unit (the evaporator). The two units are ‘split’ between the indoor and outdoor parts of a building and joined by a drain line, refrigerant and electrics, which are fitted into the wall. One of the main advantages of a split unit is that the compressor – often the noisiest part – is located away from the area to be cooled, keeping the home or commercial property as quiet as possible.

Multi-split air conditioners
A multi-split installation is the type most suited for large industrial installations. The main difference between a single split and a multiple split unit is that you can power more than one indoor evaporator from a single outdoor unit. Typical installations feature as many as 11 separate wall mounted units which make this solution ideal if you have lots of different rooms with different AC needs. The ability to cool rooms independently of each other is also more energy efficient than using lots of separate installations.

Central air conditioning
Also known as ‘ducted’ air conditioning, a central air conditioning system involves one central unit (often situated in the basement or loft) and a fan system, which blows air into different rooms around the house. They’re most commonly used across the pond, although some UK houses and commercial buildings also opt for this type of system. A central air conditioning system can provide hot air, as well as cold air, making them a versatile form of temperature control.

The different components of an air conditioning system

Regardless of the time of air conditioning system, they all have some elements in common:

Found in a gas or liquid form, refrigerant works alongside every other part of the AC system to remove heat from the room around it. It sits inside the system’s coils, travelling smoothly to all the parts of the system, going from a gas to a liquid to soak up heat.

The filter comprises a mesh grid that keeps out anything that could stop the flow of air. It removes contaminants such as dust, grease, pollen, pet hair and even smoke particles. Filters play an important role in ensuring that the unit operates as efficiently as possible.

Ducts in an air conditioner distribute the cooled air around your home. There are different types of air ducts, from large metal ducts to more flexible steel wire spirals that allow you to get cooled (or warm) air where you want it to go.

The compressor turns the refrigerant from a liquid to a gas, pumping it through to the condenser coil where it is then cooled. It’s at the heart of your AC system and is one of the most expensive components.

Condenser coil
This works to cool down the gas that leaves the compressor. Its purpose is to remove heat from the refrigerant and transport it to the evaporator coil.

Evaporator coil
The aim of the evaporator coil is to soak up as much heat from the air as possible. The coil is made from materials such as steel, aluminium or copper, all of which are good heat conductors.

Expansion valve
The expansion valve in an air conditioning system works alongside the compressor and condenser to keep a constant and even cycle of gas and liquid flowing through.

Situated at the back of the outdoor unit, the fan is easy to spot. Its job is to remove heat from the condenser coil.

What are the advantages of air conditioning?

Improved air quality
We all know that cooler air makes us feel more awake, but did you know that it keeps the air clean, too? An air conditioning system filters out nasty dust and dirt particles, as well as bringing in air from outside. Basically, air is constantly being ‘laundered’ to keep it clean and fresh. This can help reduce pollution, bad smells and the likelihood of allergens getting in, which can all cause attacks in asthma sufferers and those with respiratory problems.

More comfortable home
An air conditioning unit can create a comfortable environment not only for days when it’s hot, but when it’s cooler, too. An air-to-air cooling & heat pump is capable of both heating and cooling; plus a split system can help you manage different temperatures in different parts of the house or office.

A better night’s sleep
Last year’s temperatures weren’t just unbearable in the daytime. In July 2022, many of us were forced to get used to sleeping in temperatures of over 20°C, while those in Oxfordshire suffered a record 26.8C (80F) during the early hours of the morning of July 19th 2022. Bad sleep creates tired families, reduces focus and concentration at work and increases stress. For all these reasons, an air conditioning system to create a cooler and more comfortable nighttime temperature is a very smart move.

Controls humidity (important in the heatwaves)
As well as cooling things down, air conditioning systems can reduce humidity – that horrid ‘wet air’ feeling that causes us all to feel hot and sweaty when we’re trying to work or sleep. As such, the right air conditioning system acts like a dehumidifier, without you needing to purchase a separate unit.

How energy efficient is air conditioning?

When it comes to choosing the right air conditioning system, there are two things to consider:

  • SEER (Seasonal Energy Efficiency Ratio): the SEER rating measures the efficiency of the AV unit on a seasonal basis. The higher the number, the more efficient (and cost effective) the air conditioning system.
  • EER (Energy Efficiency Ratio) ratings: this is a measure of how well the unit cools things down compared to the power it uses. It’s most often used to review the efficiency of split system air conditioning systems and portable air conditioning units.

How can I improve the efficiency of my air conditioning system?

Regardless of the type of system you use, there are key factors that will increase the efficiency overall. These include:

Proper maintenance: there are some easy things that home and commercial owners can do to keep things running efficiently, such as cleaning filters and keeping the fan free of dust or anything else that restricts the airflow. For everything else, it’s best to book a professional service by a professional, who will check for electrical connections, and review any leaks from the refrigerant.

Selecting the right size system for your home: when the mercury rises, it’s tempting to choose the biggest air conditioning unit that money can buy. However, it’s more important to calculate the size of your room and purchase a system accordingly. To do this, you’ll need to get to grips with BTUs – these are a rating system that indicate the power output. As a rule of thumb, small rooms require at least 7,000BTUs, medium rooms 10,000 BTUs and larger rooms and offices around 15,000BTUs or more.

Don’t sweat it in Summer 2023

Are you looking for a new air-to-air heating and cooling system? Want to upgrade to a more energy-efficient setup? We can help. With flexible costing and finance options available, there’s never been a better time to get cool air in your home. Get in touch for your free quote today.