In general, a 12 x 12 room is considered a small room with a total area of 14 sqft. According to air conditioning experts, such a room would request an air conditioner with a cooling capacity of 5000 BTU if there are two people in the room. If there is proper shading, you would need a 4500 CTU capacity AC.
The ideal AC required for 12x12 room is typically around 1 ton for effective cooling.
Larger unit may be more efficient (larger condensers generally are), but make sure you don't oversize it. If the unit is oversized it'll cycle more frequently, which is hard on it. Oversized can also cause some issues with humidity if you have any outside air connections.
Room Size: The cooling capacity of an air conditioner is measured in BTUs (British Thermal Units). For a bedroom: - Up to 300 sq. ft.: 7000 - 8000 BTU is typically sufficient. - 300 to 400 sq. ft.: 8000 - 10000 BTU is recommended.
A 6,000 BTU mini split system will be able to handle a 12 x 12 room. Once you go over a 260 square foot room, you're going to need to go up to a 9,000 BTU mini split system. A 6,000 BTU mini split can usually handle up to 6,500 BTUs.
You also don't want to buy a model that's too powerful for a room. Sure, a 12,000-BTU air conditioner will cool a small space (150 square feet or less) quickly. But it might cool it too quickly, preventing it from removing some of the ambient humidity from the room and leaving the room damp.
An air conditioner with BTUs that exceed the recommended square footage in your home may also take on more wear and tear over time because it will initiate its on/off cycle more frequently. It could also create a subpar cooling experience because your AC's compressor may turn off much sooner than it should.
As a general rule, the recommendation for an average double bedroom is a 9,000BTU air conditioning unit. 'BTU' stands for British Thermal Unit and is a unit most commonly used to measure energy when they're discussing machines that heat or cool air – such as air conditioning units and heaters.
Since an oversized AC is too powerful for your home, it will quickly cool your home then shut off, which can raise your energy bills and wear out your AC (from all the starts and stops).
Difficulty cooling large or open spaces
Small stand-alone AC units often aren't powerful enough to cool bigger rooms or homes with open floor plans. They may start “short cycling” or turn on at full blast, cooling the air directly around the thermostat and then shutting off before the entire room is cooled.
Energy Consumption and Savings: While two AC units might initially seem like they would consume more energy, they can actually offer savings by allowing you to cool only the spaces you're using. For example, you can shut off the upstairs unit when it's not in use, reducing overall energy expenditure.
The average cost of installing a new central air conditioner in 2024, including equipment and labor costs, is $5,750 for a 3-ton unit in a 2,000-square-foot home. On average, a new AC unit cost will fall between $3,300 and $7,800.
The Temperature Outside
Most central air conditioners can cool a moderate-sized (3 to 4 bedroom) home by about 5 degrees every 3 hours. This means while it can take no more than a couple hours to lower the temperature to a comfortable range in the fall or autumn, it can take much longer in the summer.
Higher Utility Bills
A bigger unit simply gobbles more power than a smaller one. To make matters worse, your oversized air conditioner will likely never reach its promised level of energy efficiency. Just as it is cycling up to its most efficient level, the thermostat will tell it to shut off again.
What Is BTU in AC? BTUs measure the energy output of your AC system. It takes about 20 to 35 BTUs to cool each square foot of space. Higher BTUs cool a room faster, but boost humidity and wear your unit down.
You'll need to know your room size too. In general, a 5,000 to 6,000 BTU air conditioner can cool between 100 and 300 square feet. Seven thousand to 8,200 BTU units are adequate for cooling 250 to 550 square feet, while 9,800 to 12,500 BTU models cool up to 950 square feet.
If you're wondering whether a central air conditioner is a lot more energy savvy than window types then the answer, quite simply, is yes. Central air conditioning systems are more energy-efficient than window air conditioners, meaning you'll save money on your monthly energy bill.
Don't run your AC 24 hours a day
In a published analysis that was not peer-reviewed, Pigott and other researchers found that less energy was used across the three types of air conditioners studied when cooling was shut off for an eight-hour period, compared to running the systems all day at 76 degrees Fahrenheit.
On average, an air conditioner costs between $0.06 and $0.88 per hour to use. Let's see how much air-conditioning costs every month (assuming it runs for 8 hours per day). The cheapest option is $14.40 per month and $211.20 per month on the high end.
In general, a 12 x 12 room is considered a small room with a total area of 14 sqft. According to air conditioning experts, such a room would request an air conditioner with a cooling capacity of 5000 BTU if there are two people in the room. If there is proper shading, you would need a 4500 CTU capacity AC.
The general rule of thumb is that you should have 20 BTU for every square foot of space that requires heating or cooling. As such, multiply the square footage of your room or home by 20. For example, a 300-square-foot room would need approximately 6,000 BTUs for heating (300 sq ft x 20 BTUs = 6,000 BTUs).