How to Choose an Air Conditioner, According to Science – 10 Factors to Consider

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When summer is near, there’s no other way to beat the heat other than buying an air conditioner. It’s so easy when you have an intelligent air conditioner that fits the bill in most homes. The cooling technology, fresh-air ventilation, and energy efficiency make an air conditioner a must-buy in the 20th century.

So if you don’t have one yet, what are you waiting for? A brilliant alternative to cooling without investing a big amount is buying room or portable air conditioners. They’re energy efficient as well as affordable to last for a longer time. Central air conditioner not only requires storage and maintenance, it’s not suitable for many homes.

It’s important to pick the right air conditioner that you won’t struggle with. Anything too small or too big in size will leave you with a damp and clammy space. So if you quickly want to know what features to look forward to when choosing an air conditioner, here are a few significant factors to consider.

1. Does It Suit Your Room?

Before you consider any other feature such as the type or sound level, start by determining the right air conditioner size for your room. If you’re cooling more than one room, buying an air conditioner that’s located close to the doorways is essential.

But if you’re planning on cooling a single room, that’s yours, you need to determine the cooling capacity of the air conditioner.

Buying any universally sized air conditioner isn’t effective and might less to less cooling efficiency and limited ventilation. An air conditioner is responsible for not only cooling the room, but getting rid of humidity and heat from the indoor air. With an air conditioner that’s too big for your room, it will skip directly to cooling the air; which isn’t a good atmosphere to spend time in.

Based on a report, the first thing to do when determining the size of the unit for your room is calculate your room’s square footage. Once you have the proper square footage, you can match it with the right air conditioner capacity. (1)

Starting from 100 square feet, which is the total area to be cooled, an air conditioner requires 5,000 BTUs per hour to cool effectively. Here is how the numbers progress based on the total area to be cooled.

  • 100 to 150 square feet - 5,000 (BTUs per hour) cooling capacity
  • 150 to 250 square feet - 6,000 (BTUs per hour) cooling capacity
  • 250 to 350 square feet - 7,000 (BTUs per hour) cooling capacity
  • 350 to 450 square feet - 8,000 (BTUs per hour) cooling capacity

And so on.

Based on this report, making minor adjustments for when the room is heavily shaded, sunny, or ventilated is necessary. If you have more than two people occupying the room, adding 600 BTUs per hour for an additional person helps enhance cooling effectiveness.

Looking for a unit with an Energy Star label can dramatically increase cooling efficiency and energy consumption. Such models come with proper ventilation for all room sizes. If you’re installing an air conditioner in the kitchen, increasing the ideal air conditioner capacity by a total of 4,000 BTUs per hour is recommended.

2. Selecting The Right Type Of Air Conditioner

There’s nothing better than using a window air conditioner to make your room feel comfortable and airy. For most people, buying a window air conditioner offers versatile cooling control and energy efficiency.

Ideally, looking for something more versatile than a window air conditioner means buying a split air conditioner. However, there is a less expensive option available on the market, which is a portable air conditioner.

Now that you know the 3 different types of air conditioners available to you, let’s understand the basics behind each.

Window air conditioner: A window air conditioner or through the wall air conditioner is the most common type of air conditioner and is mounted through the windows. The compressor is located outside the window, leaving the air vents and control panel facing inside the room.

A window air conditioner is ideal for cooling a single room only. And buying a single unit for each room is still less expensive than opting for central air conditioning. According to a study, window air conditioners are more energy efficient than other models. They’re also less space consuming that both portable and split air conditioners.

Based on the size of your room, you can opt for a small, medium, or large window air conditioner for extra cooling space.

Portable air conditioner: A portable air conditioner is usually installed in rooms with a small window opening. It’s when the window units are unable to accommodate a window air conditioner. Portable air conditioners are also seen in big balconies or patios for extra cooling during hot seasons.

Portable air conditioners lack the kind of energy efficiency and cooling effectiveness as window air conditioners. For more power, get a dual hose portable air conditioner. But they’re the most suitable model for your space when you lack proper windows and ventilation. They’re portable which means you can move a portable air conditioner around from one corner to the next.

Split air conditioner: A split air conditioner or ductless air conditioner is divided into two parts: the indoor unit and the outdoor unit. The indoor unit comprises of the fan, air vents, cooling coils, and control panel. The outdoor unit comes with the compressor and other parts that require proper ventilation for cooling the room.

Both the parts are connected with a duct wire which carries the refrigerant and power. A split air conditioner costs much more and is typically found in a central air conditioner, but they offer long-term energy savings and flexibility. Because of its big size and spacious cooling vents, it can cool versatile zones and rooms easily. (2)

RV air conditioner: If you live in a RV, you will need a RV air conditioner. There are many options available including ducted and non-ducted options. Some will also come with a heat pump in case you want to use it as a heater in the winter. 

3. Is It Too Noisy?

Buying a noisy air conditioner might distract you from your daily activities and even sleep. When choosing an air conditioner, it’s important to take into account its noise level and comparing it with an ideal noise level as per standard regulations.

Most people have an air conditioner in their homes, according to a report. And this has resulted in an increase in complaints about air conditioner noise in most residential conditioning systems. There are a lot of factors that come into play when considering allowable air conditioner noise levels. Factors such as barrier factor, presence of any reflective surface, and the distance between an air conditioner and the wall. (3)

So the best way to determine an air conditioner’s noise level is by measuring the decibel scale or dB of a unit. The average decibel level of an air conditioner is 60 dB. Anything above this range is considered “extremely loud”, which might cause damage to the eardrums due to constant exposure.

An air conditioner may have a lower decibel rating on higher cooling settings, but it’s also important to check for low speeds. Sometimes, low settings emit the most noise which may disturb light sleepers. So it’s important to check for the noise absorption and power settings of the air conditioner. (4)

Manufacture noise rating also depends on the size of the room and the number of barriers (or walls) blocking the air conditioner. High-efficiency units produce crackling noises when it needs maintenance. (5,6)

A small air conditioner will emit between 35 to 45 dB, which is less than a standard window or split air conditioner. So if sound is very important to you, buying a portable air conditioner is a good way to go.

4. Does It Need Proper Ventilation?

To understand why an air conditioner needs proper ventilation, it’s important to know how an air conditioner works. Air conditioners remove heat and humidity from the air by blowing cool air inside your room. This creates a sort of cycle that emits heat and cools the air inside the room.

The cooling action is carried out by cool evaporator coils inside the air conditioner. The evaporator coils contain a cooling agent, known as refrigerant, that take away all the heat from the air circulating inside the room. When the hot air comes in contact with the evaporator coil, the refrigerant converts from liquid to gas. That’s when it absorbs the head converting it into cool air.

The gas refrigerant is then transferred to a condenser coil where it turns into liquid form again. And so the process repeats turning hot air into cool air. All this is done with the help of a compressor which runs by a motor.

To sum it up, air conditioners are complex machines that require proper air circulation. Without it, the refrigerant creates more heat inside the unit, resulting in less cooling. The air conditioner needs to heat, cool, and dehumidify based on the temperature inside and outside the room.

So without proper ventilation, your air conditioner will emit more contaminants than cool air which might lead to health problems. It’s important to check whether there are sufficient airflow vents on the air conditioner, especially where the compressor is located.

According to a report, an air conditioner needs to emit heat and other contaminants once every 4 hours for proper cooling performance. This applies to all residential homes. (8)

On the other hand, installing an air conditioner close to leaky walls or ducts can result in more energy consumption, regardless of the ventilation it offers. It also leads to improper filtration of air, water, and gases which may not be the ideal approach for using an air conditioner.

5. Considering Energy Efficiency

Buying an energy-efficient air conditioner can have its own advantages. That’s why looking for an air conditioner with Energy Efficiency Rating is what you should consider for any type of unit.

According to a recent research paper, most countries offer high energy-efficient air conditioners that help cut costs and prolong shelf life. This paper also pointed out a whopping increase in energy efficiency, based on manufacturer testing and electricity usage in most households. (9)

Building on this report, another study proves that a standard air conditioner needs to maintain a healthy balance between heating and cooling demand. With temperature control settings, there is a higher heating demand when the air temperature is low. And at higher temperatures, there is a higher cooling demand.

To carry this out, air conditioners that are energy efficient offer a high ventilation rate and level of insulation to reduce power usage. (10)

Based on the type of air conditioning an energy saving system is prescribed. (11)

For window air conditioners: Window air conditioners is the most energy efficient cooling system in place. Since it contains all cooling components such as the compressor, motor, and evaporator and condenser coils in one box, it exhausts less energy and resources to cool effectively.

For portable air conditioners: Portable air conditioners take up more energy to cool a room than other models. Since a portable air conditioner is placed on the floor, it lacks sufficient ventilation abilities. This factor also makes some units noisier than window air conditioners.

For split air conditioners: Split air conditioners are the second-best energy-efficient units after window air conditioners. But it’s more economical and energy-efficient to use than central air conditioning systems. Since it comes in two parts, it takes up a little more energy than window air conditioners.

According to Energy Star, buying an air conditioner with energy efficiency ratings improves both performance and durability. An energy-efficient air conditioner takes up 9% less energy than a traditional unit.

Some units have gotten smarter, automatically control the temperature requirements of the room to save energy. It comes with sensors to adjust temperature settings in your room. So you don’t have to switch the unit on and off based on your needs.

You can learn more ways to cut back energy costs when using an air conditioning here and here.

6. Where Are The Filters Located?

Ensuring the air conditioner filters are durable can increase the efficiency of your unit. Knowing how many times in a year the filters need to be changed or replaced also depends on the placement of the filters inside the air conditioner.

It’s common sense to know that dirty filters can potentially block airflow and reduce energy efficiency of the motor. It can also impair the evaporator coil’s heat-absorbing capacity. It’s easier to clean and replace a filter when it’s located at a convenient and easy-to-reach spot.

Air conditioner filters are generally located along the vent duct. If that there, in standard split air conditioners, it is along the air vents facing toward the room. So as the cool air passes from the filter, it is more likely to get dirty and clogged if not cleaned for a long time.

For window units, the filters are located right behind the compressor that’s sticking out of the window. Cleaning window filters once a month is best since it’s most exposed to the outside air, so debris and dust is most likely to stick on the filter.

Once you locate the filters, it’s important to know what they’re made of. Common air conditioner filters are made up of fiberglass, pleated, or media filter. (12)

Fiberglass filter: Fiberglass filters need to be cleaned or replaced at least once in every 30 days. Fiberglass filters are traditional air conditioner filters with a much larger frame.

Pleated filter: Pleated filters resemble a rectangular shape and they’re an inch wide. Cleaning or replacing them once every 3 months is ideal. But based on the power usage of the air conditioner, replacing then once every 30 to 45 days is essential.

Media filter:  Media filters are very similar to pleated filters, but they are wider, about 4 inches wide. Due to its thick build, they’re far more durable than fiberglass and pleated filters. So replacing it once in 6 to 8 months is essential.

According to a study, cleaning air filters on a regular basis can prevent indoor allergens and other contaminants from entering the room. This also regulates better sleeping temperatures and environmental control for complete air filtration. (13)

7. Using Temperature Sensors

Modern air conditioners with touchpads or a control panel come with efficient temperature sensors which are easy to use. Using a traditional air conditioner without temperature sensors isn’t as common as you think.

People feel more comfortable in ways that enhance their productivity. And temperature control is a major contributor to that. One of the main purposes of an air conditioner is to prove optimal temperature settings. And temperature sensors are just the way to do that.

Some conditioners come with digital temperature read-outs for an air-conditioned room. That way you can adjust temperature settings and get better at directing cool air toward a corner of the room. The ideal temperature of an air-conditioned room is between 22 to 25.5 degrees Celsius in hot weather.

That way you can feel comfortable and cool while saving extra usage costs.

Most consumers opt out on temperature control and sensors because of their electric bill. But you can balance temperature control and cooling with more energy-efficient models.

According to Energy Star, the coolest air-condition room’s temperature should be 78 degrees Fahrenheit. And with a temperature sensor you can make it easy to match your coolest and most comfortable temperature setting in seconds. It also helps when you manually adjust your setting based on when you’re working, sleeping, or exercising in a room. (14)

8. Does It Come With A Control Panel?

Does your air conditioner come with a controls and LED displays? It’s good to choose an air conditioner that features adjustable temperature settings, digital temperature readouts, and a handy power button. Other settings such as fan speed, timer, and keep-warm mode can be accessed with the help of a control panel.

The various features of an air conditioner are on display in the form of uncrowded buttons on an air condition. This also includes versatile operating modes of an air conditioner starting from automatic, cool, heat, dry, and fan-only modes.

Sleep modes are extremely popular among modern air conditioners that allow you to set a comfortable temperature for sleeping, so you don’t exhaust too much energy.

Using an air conditioner with soft-to-touch buttons and an LED display is a good way to keep the unit under control. You can make the most of built-in timers and temperature settings when you have a digital control panel to fall back on.

However, a control panel on a split conditioner seems unnecessary because it’s located closer to the ceiling than the floor. Hence, a control panel is only suitable for portable, window, and central air conditioners.

9. You Need A Remote Control

Regardless of the type of air conditioner you use, using a remote control is necessary. It’s a more convenient way of accessing an air conditioner for making quick adjustments. With a remote control, you make adjustments from wherever you’re sitting, so you don’t have to get up every time your room gets too cold.

A remote control, based on a research paper, offers some of these important features.

Power button: All remote controls have a simple on/off button. You can switch an air conditioner on and off by pressing on its power button.

Fan speed: You can adjust the fan speed from low to mid to high to automatic from the remote control.

Timer: Some remote controls come with timer settings that allow you to set a time duration from 30 minutes up to 24 hours.

Mode: This feature adjusts the air conditioner’s automatic cooling mode for you. You can select from automatic, cool, dry, heat, fan only, sleep, or automatic.

Some modern air conditioners offer an energy-efficient mode or a sleep mode to save energy while you sleep.

Once activated, with the help of a remote control, the air conditioner will automatically increase the set temperature in specific periods of time. So you can sleep soundly without the room getting too cold or warm. You can even set the period of time in 1.5 or 2 hours of active operation. (15)

What’s more? With the help of a remote control, you can access features like mode setting, auto-random restart, and air vents flow for your benefit. Some remote controls come with a small indicator that lets you know when your air conditioner needs servicing.

10. Looking For Extra Features

If possible, ask around for additional features; that will elevate your experience. It’s a good to have extra features and functions by your side. It means you control your air conditioner exactly the way you want without compromising on comfort.

Here are some features that air conditioners might offer.

Sensors: Apart from temperature sensors, some air conditioner units come with human sensors. They detect when someone is in the room and automatically starts to direct the airflow vents toward that person for optimal cooling. While this may seem like a fancy feature, it does help when you work from home.

Airflow vents: Unlike sensors, you can manually adjust where you want the airflow vents to point toward. The adjustments can be made both horizontally and vertically. Based on your room’s layout, directing the cool air toward someone is always a good way to avoid cooling unneeded corners.

Clean filter notification: This feature lets you know when the filters are clogged and dirty. The air conditioner senses a minor disruption in normal airflow and notifies you immediately. This helps save energy and maintenance costs for the long run.

Exhaust setting: Don’t have plenty of ventilation to offer? This feature can alleviate problems with proper airflow. It offers complete ventilation without having to cool the room. So you get fresh air when you need it.

Installing An Air Conditioner The Right Way

It’s important to know that air conditioners last for at least 10 years without faltering. But the first few steps of buying an air conditioner can impact its shelf life. Factors like installing and maintaining an air condition are important steps to take.

Before you think about throwing away your old air conditioner, carry out these few steps to tell if it’s the right time to buy a new one.

  1. Check the seal encompassing the air conditioner. This is to ensure there’s no warm outside air leaking from the back.
  2. If the weather stripping of the unit seems sloppy, replace it for a brand-new one.
  3. Clean the filter with warm water (preferably with soap) to remove all debris and dust.
  4. The evaporator coils sometimes attract dust, so cleaning them gently with an upholstery brush is necessary.
  5. If you’re still facing a problem, it may be that your unit’s compressor is faulty. If the air conditioner is still under warranty, it’s easy to get it replace quickly without spending money. But if it has surpassed the warranty, it’s time to buy a new air conditioner with more energy-efficient protocols.

Now that you’ve decided to buy a new air conditioner, it’s time to know how to install one. It’s always good to call for professional help, but even so, knowing the basics is always a good thing.

You can ensure the professional follows these steps carefully to avoid damaging the air conditioner or your wall.

  1. The first thing to do is locate an appropriate position for your unit. Ensure that there is proper air circulation, there are no pipes close to the unit, and that it is away from doorways. When installing the unit, make sure the compressor or vents are not blocked by any sort of furniture.
  2. If you’re installing a split air conditioner, locating an ideal outdoor unit is very important. That’s where the compressor and motor is, so any sort of blockage can lead to faulty performance. Most split air conditioners come with weatherproof outdoor units to withstand rain, heavy winds, and other elements.
  3. The next step is to ensure the copper pipe is bended and the water drain pipe is away from the main unit. When you’re using an air conditioner during the summer, it gives away more water due to an increased cooling demand.
  4. The last thing to do is ensure the copper pipe has proper foam insulation. You should turn the air conditioner on for a couple of minutes to check if the refrigerant isn’t leaking or the back of the unit isn’t releasing too much hot air. Upon inspection, you’ll know when an air conditioner isn’t installed properly.


Do you have what it takes to buy a new air conditioner? There are many questions you need to ask yourself when choosing an air conditioner: how much power do you really need? What sort of extra features do you want? And is the air conditioner energy efficient?

Every air conditioner comes with features that make it unique and durable. The trick is to find something that suits your specific needs including the size of your room for a room air conditioner. And it always helps to follow the manual instructions that come with the unit for proper installation and maintenance tips.

After installing a new air conditioner, testing it for at least 24 hours gives all the components a chance to settle and adapt to the process. If the air conditioner doesn’t work as it’s supposed to, it’s time to exchange the unit for a new one.

That said, you no longer have to resort to buying bulky and ineffective air conditioners. With this guide, you can decide whether a portable air conditioner suits you best or a split unit. You can always back up a step and consider various factors before choosing an air conditioner.

Understanding what goes behind the mechanics of an air conditioner might seem a bit frustrating, but the end result is totally worth it! You get the best of many options available to you. Plus, air conditioners are our much-needed companions for dealing with sweltering summers.

Whether you’re buying an air conditioner for your home or office, an air conditioner buying guide will always put you on the right track. Giving you all the necessary facts you need to choose the best of the best unit for your home.

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