8,000 BTU Air Conditioner – What Room Size?

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With the heat rising, many people are heading indoors for some relief. However, if your room isn't getting cold enough, you may not have the right size air conditioner in your window. If you currently have an 8,000 BTU window unit, we've done some research to find out if it's big enough for your room. See our findings below.

An 8,000 BTU air conditioner will cool a 350 square foot room. To help you figure out what size is best for each room, you will need approximately 20 BTUs for each square foot of room space. 

After reading the above answer, have you discovered that your air conditioner is too small for your room? We are ready to help you find the right window unit for your needs. We have also answered a few other questions you may have, including whether your air conditioner can be too big. Keep reading for more information.

The technician under repairing the air conditioner by use screwdriver, 8,000 BTU Air Conditioner - What Room Size?

What Size Room Will an 8,000 BTU Air Conditioner Cool?

According to HVAC specialists at AirConco, for best results, an 8,000 BTU air conditioner is suitable for cooling a 350 square foot room. If you are trying to cool a larger room with this size air conditioner, the unit will have to work extra hard to do its job, causing the system to overheat. It will also increase your electric bill.

Below, you will find a range of air conditioner BTUs along with the proper room sizes they should cool:

150 - 350 Sq Ft 5,000 - 8,000 BTUs
350 - 550 Sq Ft 8,000 - 12,000 BTUs
550 - 1,050 Sq Ft 12,000 - 18,500 BTUs
1,050 - 1,600 Sq Ft 18,500 - 25,000 BTUs

How Do You Determine What Size AC You Need?

Shot of a middle aged handy man measuring a window

When determining the size of air conditioner each room needs, there is a simple formula. For every square foot of room space, you need 20 BTUs. For example, if your living room is 500 square feet, you will need a 10,000 BTU air conditioner.

Is it Bad to Oversize an Air Conditioner?

We have already established that it's not good for an air conditioner to be too small for a room, but what about too big? Is it okay for a window AC to be larger than recommended? The answer is no. While an undersized air conditioner will struggle to keep a room cool, an oversized unit will pump moisture back into the air and won't remove enough humidity.

Too much moisture and humidity make excellent breeding grounds for mold and dust mites. It can also be problematic for individuals with asthma and other breathing conditions. Not only is mold unsafe for people with prior conditions, but it can also cause health issues of its own.

What Should You Check Before Buying an Air Conditioner?

woman buys a air conditioner

Shopping for a new window air conditioner may seem like a simple process. However, ACs have more features now than they did in the past. There are several things to consider, in addition to square footage and BTUs, before making your choice.


You have already decided which size air conditioner you need. You have also decided to go with a window unit instead of a central cooling system. However, do you know how to properly install an air conditioner? Window units are moderately heavy; therefore, you will need someone to help with installation.

Before purchasing your new AC, ask someone with prior experience to help you unload your window unit and install it properly. During installation, the back must be slightly tilted to ensure proper drippage. Check out other articles on our blog to find out more about properly installing and tilting your window AC.

The technician under repairing the air conditioner by use screwdriver, 8,000 BTU Air Conditioner - What Room Size?

Noise Control

Anyone who has ever had a window air conditioner knows they can be noisy. Have you ever sat in the living room with someone who has a loud AC? Your air conditioner is something that you will run throughout the hot summer months; therefore, you will want to ensure you purchase a unit that is not going to interfere with your everyday life.

You should be able to hold conversations or hear the television above the air conditioner. There is actually a way to tell how loud a unit will be before purchasing. Each manufacturer is required to disclose the noise level of their machines.

According to AirConco, the quietest air conditioner emits approximately 37 decibels, while the loudest emits about 82. You should make sure you don't purchase a unit with greater than 50 decibels.

Energy Efficiency

Energy efficiency is important to the environment as well as your pocketbook. An air conditioner that is not energy efficient will cause you to have high electric bills. It can also cause more pollution than a more energy-efficient AC. Manufacturers assign star ratings to their products that will help customers choose the best air conditioner for their families.

More stars tell you it is more energy-efficient, meaning it doesn't have to work as hard or use as much energy to cool your home. Air conditioners containing inverter technology will be the most energy-efficient. They will be more expensive than other units; however, the lower energy bills may make it worth the extra money. Inverter technology will also cool your rooms more consistently and effectively.

Air Quality

Choosing an air conditioner with a quality filter can help you have better air quality. Basic filters can remove dirt and other particles, but more advanced filters can remove allergens, smoke, and more. Even if you buy an air conditioner with the most basic filter, you can purchase a more advanced filter separately.

Condenser Coils and Warranty

Some air conditioners are made with copper condenser coils, while others are made with aluminum. If possible, choose a unit with copper coils. They last longer and cool faster. Don't forget to check the manufacturer's warranty. Some units come with lifetime warranties while others only come with a year or two of coverage. The longer the warranty, the better.

Air Swing

Some air conditioners only blow air straight out. Some move from side to side slightly or up and down. Try to purchase a unit with the widest air swing possible. This will help cool the room more quickly and evenly.

This energy-efficient air conditioner works with your smart devices. It is 8,100 BTUs with an ultra-quiet design.

See this air conditioner on Amazon.

Is a Window Unit Cheaper Than Central Air?

Home thermostat

We know that it's important to choose the right size window air conditioner. We also know that it's important to choose the most energy-efficient window unit on the market. However, many people with central air find themselves wondering if it would be cheaper to use window ACs instead.

Window units, compared to HVAC systems, are cheaper to purchase and easy to install. However, are they more energy-efficient, and can they lower your electricity bills? The short answer is yes; window units are cheaper than central air conditioning.

If you have multiple rooms that need to be cooled, you can place a window unit in each room. If you need those rooms to stay climate-controlled at all times, running window units can be expensive. However, if you only run the window AC when you need it, turning the unit off when the room is not in use, you can save significantly on your energy bills.

Central cooling systems run continuously, maintaining a level temperature in each room at all times. This continuous use makes central air less energy efficient than window units, causing more damage to both your electric bills and the environment.


It's easy to figure out what size air conditioner you need for your room. It is also important to make sure your air conditioner is not too big or too small for the room you're trying to cool. Make sure you look at all the speculations before purchasing a new window unit. You'll be using it every day for several months, so make sure it's right for you and your family.

For more information and to discover all your cooling options, read this post about the types of air conditioners on our blog. If your family, like many others, cannot come to an agreement on how cold your living room should be, take a look at this article. It will help you better understand what temperature is most reasonable for living rooms and why.

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