Different types of air conditioners – A guide to choosing the best AC

Air conditioning units (ACs) are so common that we simply take them for granted. That said, it’s still important to think about the air conditioners we use, and why we use them.

ACs are ubiquitous, but they can also be fairly large, power-hungry appliances that are a major contributor to your electricity bill. They also come in a variety of designs, not to mention shapes and sizes, which offer different advantages depending on use-case.

The various AC units you can buy today can broadly be classified into six categories:

Central air conditioning system

This is the kind of AC system you’ll be familiar with if you’ve been to any large venue like a mall, hotel, airport, train station, or even a large house. As the name suggests, a central AC system involves a large, centrally located compressor system (usually on the roof, in the case of large buildings) that cools the air and transmits it around the property via a system of ducts and fans.

This is great for large buildings as the larger compressor is more efficient for the cooling capacity required. Maintenance and filtration are also centralised, simplifying management as engineers won’t need to run around the building inspecting multiple individual units.

The downsides include high upfront cost, a central point of failure – if the compressor dies, the entire building is without cooling – and high inefficiency when the building isn’t fully occupied. Central ACs are available for large homes, but they’re better suited to commercial and public spaces.

Split air conditioner

This type of AC is very common, and one that we’re all likely to be familiar with. A split AC is called as such because the compressor and air distribution system are separated. The compressor – which is hot, large, noisy, and essential for cooling the air – can be placed outside the target area, say, in a balcony. 

The air that the compressor cools is ducted into the home or office via a system of ducts and vents, and then distributed by a sort of fan and control unit. In this way, the interior of your home or office stays cool and quiet while all the heat and noise is dissipated elsewhere.

A split AC is relatively expensive and complicated to set up. While maintenance is usually not a problem, the copper pipes used to move coolant between the compressor and fan are fragile and difficult to repair in case of any damage.

Window air conditioner

By far the simplest air conditioner is the window AC. It’s a single unit that includes all the working AC parts in a simple, box-like structure that needs to be mounted in a window or similar opening. This type of AC is relatively cheap, and simpler to install. However, window ACs tend to be very noisy as the compressor is right behind the fan. They’re great for small rooms, but we’d recommend a split AC for larger spaces, and when silence is important.

Portable air conditioner

Think of a portable AC as a window AC on wheels. It’s similarly self-contained, but it’s on wheels and can be moved around more easily. While portable ACs can be moved around and placed anywhere, it’s important to remember that an AC, even a portable one, generates a lot of hot air and noise. 

These ACs generally come with a flexible duct that can be placed over an exhaust or by a door or window to dissipate heat, but the noise you will have to live with. Portable ACs are great for events and outdoor venues, but not recommended for home use.

Smart air conditioner

Any air conditioner can be smart if it includes some smart functions and integrates into your smart home setup. Most window and split ACs have some level of smart functionality today, and they’re a great option for modern homes. These ACs learn your usage habits, for example, base their cooling on motion sensors and a temperature feedback loop, weather, etc. They’re more convenient than regular ACs as they require less input and management from you.

When it comes to downsides, smart ACs only inherit the issues of the AC type they’re based on.

Duct air conditioner

A ducted air conditioner is a hybrid between a split AC and central AC. Where all the cooling requirements of a building are handled by a central cooling unit in a split AC, a ducted AC works like a split AC in that the compressor is placed very far away and the air is let in via ducts. 

The compressor used is generally not as large as the one needed for a central AC, but one can use multiple such compressors to cover a large area. These are a great option for venues that could benefit from a central AC, but either need redundancy or don’t benefit greatly from a centralised cooling unit. The downside is, of course, cost, making these more suited to commercial and public spaces.

Other types of ACs:

Floor-mounted ACs

Floor-mounted ACs are placed or mounted on the floors. They tend to be used in large spaces without nearby windows, or where window ACs or split ACs are infeasible. They’re generally found in large, commercial space. Floor-mounted ACs tend to be difficult to maintain and are not very common.

Hybrid/Dual-fuel AC

This type of AC is found in cooler areas that need heating. Hot ACs use electric furnaces and heat pumps to heat the air, but these are inefficient at very low temperatures. In very low temperatures, dual-fuel ACs can switch to a more powerful fuel source like coal or natural gas.

Geothermal AC

This design is generally used in areas where a massive amount of cooling is required, such as data centres. Hot air is pumped 20-30ft below the ground where it’s much cooler. The ground acts as a heat sink and absorbs the heat. The cooled air is then recirculated. This is an environmentally-friendly option but is expensive to set up.

Factors to consider while choosing the best air conditioner

When choosing an AC, there are many factors you should consider.

Budget: Two things must be considered when deciding on a budget for an AC. These are upfront costs and running costs. Upfront costs are the cost of purchase and installation, while running costs are based on projected power consumption and maintenance. 

Cooling Capacity: You may have seen terms like 1-ton AC, 2-ton AC, etc. when describing ACs. This is a measure of the ACs cooling capacity, i.e. its ability to cool down a certain volume of air and transfer the heat elsewhere. The 1-ton or 2-ton rating refers to the fact that one tonne or two tonnes of ice can be melted to liquid in a 24-hr period. As a rule of thumb, the higher the ton value, the more capable the AC. 0.5-1-ton ACs are fine for small rooms, but you’ll need 1.5 ton or higher for larger rooms.

BEE Star Rating: The BEE Star Rating is a system for rating the energy efficiency of an appliance. The rating ranges from one star to five, with one star just confirming that the device’s energy consumption has been verified, and a five usually equating to a 50 percent improvement in efficiency. Two-star and three-star ratings generally indicate a 15-30% improvement in efficiency. This rating is important as it can significantly impact the running cost of an AC or other appliance.

Ease of Maintenance: ACs can last 15-20 years but can only do so if they’re maintained properly. Different types of ACs have different maintenance requirements, and unless properly maintained, will wear down over time. Wear and tear not only decreases efficiency, but also causes permanent damage that will shorten the life of the AC.

Air conditioners are a vital part of life in most cities, and the only way to maximise their use while reducing their environmental impact and cost is by choosing the right type of AC. As we’ve learned, ACs come in a variety of shapes and sizes designed for a variety of use-cases, and a better understanding of your cooling requirements will help you choose the right one more easily.