Factors to consider when selecting the right AC size

Are you wondering about the size of AC you need for your home? Can not decide on the tonnage or BTU of AC suitable for your home? We are here to help you get answers to your questions. Getting the right size of AC for your home is necessary as it will affect the performance of the AC and the temperature of your home. If you get over-sized AC, your home will be too cold and if you get under-sized AC, your home will be warmer than you want it to be. There are some factors to consider when selecting the right AC size for your home, that you should keep in mind. Let dig in deeper to understand the meaning and measurement of AC capacity and the factors affecting it. 

How the capacity of an AC is measured?

The three most common measures of  AC capacity are a ton (tonnage), Watts, and BTU per hour. Since all the three measure the same thing, they can be connected to better understand them for our needs. 

1 Ton AC= 12,000 BTU per hour= Approx. 3,500 Watts of cooling

Now, let’s have a look at it in a little more detail.

In relation to AC, Ton or tonnage does not refer to the weight of the AC, but it refers to Ton in refrigeration also known as RT or Refrigeration Tonne. However, BTU is a modern term to define an AC’s capacity. BTU or British Thermal Unit refers to the amount of heat required to increase the temperature of 1 pound of water by 1 degree Fahrenheit. It represents the amount of heat that should be added to a room to produce heating or taken away from the room to produce cooling. 

The specification sheet of your AC has either Ton or BTU or Watts of your AC mentioned on it. Choose carefully what capacity you need, as it will affect its performance, efficiency, and temperature inside your house. 

The amount of heat or cold a room needs depends on various factors such as room size, windows, heat-generating appliances present in the room, number of occupants, etc. The more heat you need, the higher the BTU of your AC should be and vice versa.

Top recommended air conditioners for your home:

  1. MIDEA MAW05M1BWT Window air conditioner 5000 BTU with Mechanical Controls, 7 temperature, 2 cooling and fan settings, White
  2. LG LW8016ER 8,000 BTU 115V Window-Mounted Remote Control Air Conditioner, White
  3. Midea U Inverter Window Air Conditioner 8,000BTU, U-Shaped AC with Open Window Flexibility, Robust Installation, Extreme Quiet, 35% Energy Saving, Smart Control, Alexa, Remote, Bracket Included
  4. Frigidaire 5,000 BTU 115V Window-Mounted Mini-Compact Air Conditioner with Mechanical Controls, White
  5. BLACK+DECKER BPACT10WT Portable Air Conditioner, 5,500 BTU DOE (10,000 BTU Ashrae), White
  6. MIDEA MAP08R1CWT 3-in-1 Portable Air Conditioner, Dehumidifier, Fan, for Rooms up to 150 sq ft, 8,000 BTU (5,300 BTU SACC) control with Remote
  7. Rollibot ROLLICOOL Portable Air Conditioner w/App & Alexa Voice Control | Wi-Fi Enabled Portable AC & Dehumidifier | Quiet Operation, Easy Installation (10,000 BTU, White)
  8. SereneLife SLPAC Portable Air Conditioner, 10,000 BTU, Fan, Exhaust Hose, Window Seal, Wheels, Remote

Factors to consider when selecting the right AC size

Following are the factors that affect the heating or cooling of your room or house and therefore also help in determining the AC capacity that you need.

  1. Ceiling height:

    Some standard measurements are followed whenever a home is built. But, sometimes the ceilings of the home are higher than the standards as the higher ceilings give a spacious feel to the place. In case the height of the ceiling is 4 feet or higher than the standard height, it will affect the heating and cooling aspects in a room or home. A room with a higher ceiling has a greater volume of air that needs to be kept cool. Now the rooms with standard ceiling height have sufficient cool air circulating inside the room, but the rooms with the higher ceiling can face a deficit of cool air. Rooms with high ceilings will need high-capacity AC to cool the entire room or home. If an AC has insufficient BTU capacity it will not be able to produce sufficient cooling power for a room with a larger air volume. A smaller AC or an AC with insufficient BTU will cause the AC to work harder leading to higher cooling costs.

  2. The number of occupants:

    Every human body releases a certain amount of heat and the amount of heat released might increase based on the activity level. A human body releases 100 W of heat while at rest. If more than 2 individuals are going to occupy the room, 600 BTUs per hour per person should be added to the cooling power of the AC. Also, if you are installing AC in your gym, it will need higher cooling power compared to the AC in the bedroom, because of the higher activity levels in the gym during exercise. Keep in mind every factor to avoid buying an oversized or undersized AC for yourself.

  3. Room insulation:

    Insulation helps in stopping the passage of heat or cold from the room or any given space. But, how much heat or cold you can keep in or out of the room will affect the size of AC you will need. A well-insulated room will need a smaller AC to keep it cool. However, various factors influence the insulation of your room such as the construction material used, window covers, installation of insulation materials, the gap between the doors and the floor, choice of flooring, etc. The better the room is insulated, the easier it will be to keep the heat or cold inside.
    Image credit: Flickr

  4. Location of the room:

    Though windows give a spacious and open look to your room, it also affects the temperature of your room and house. They allow the heat and cold to pass from outside to inside your home, and it will make your room colder in the winters and warmer in the summers. The number and size of windows highly affect the performance of your AC. If you have bigger and more than one window in your room, it will make the room warmer in summer and your AC will need to work harder to cool it down. If you get direct sunlight in your room during the day, get an AC with 10 percent higher BTU.

  5. Amount of heat emitted in the room/ Type of room:

    The purpose for which you are using the room also affects the decision about the size of AC you need. For example, if you are installing the AC in your kitchen, you will need to increase the BTU level of your AC by 4000. Areas or rooms that have appliances generating heat will need your AC to work harder to keep them cool. Also, the rooms that are east or west facing can be very hot during summers as the direct sunlight falls on them for most of the day. Keep all these factors in mind while deciding the size of AC that you need for your room as they are vital in deciding how much heating or cooling you will need. 
    Image credit: pixabay.com

  6. Window covering:

    We use curtains, blinds, or shutters on our windows as decorations or as a system to avoid excess light when you want to through the day on your weekends. But, these window coverings also help in keeping the heat out of your room during summers or trapping the heat inside during the winters. Keep your windows well covered and insulated to prevent your AC from having to work harder to keep your room cool or warm based on the season. If you keep your windows covered for most of the day, you can decrease the BTUs of your AC by 10 percent.
    Image credit: Piqsels

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