The most common and easiest way to measure the tonnage of an air conditioner is using the area method. To calculate using this method, first, multiply the length and width of the room in feet. Then calculate the square root of the result and divide by 10. The obtained value will indicate the necessary tonnage.
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.
The square footage covered by a 3 ton AC unit depends on multiple variable but accounting for a quick estimate, roughly 1500-1800 square feet.
Homes measuring 1,000-1,500 square feet: You'll need a 2-ton unit, which corresponds to a cooling capacity of 24,000 BTUs per hour. Homes measuring 1,500-2,000 square feet: You'll require a 3-ton unit, equivalent to 36,000 BTUs per hour. Homes measuring 2,000-2,500 square feet: A 4-ton unit is necessary.
However, the truth is an oversized system will not do a better job of cooling the house or provide any extra comfort over a properly sized unit. Air conditioner size is calculated in BTU (British Thermal Units) and tons, and measures how much heat the system can remove from the home in one hour.
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.
Measure the length and width of each room you want to cool, then simply multiply the length by the width to calculate the square footage. Add your calculations for each room together to get the total square footage. Use the formula Total Square Footage x 25 to determine the required BTUs.
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.
Air conditioners that are too big consume more energy, endure more wear and tear, and simply don't work as well or as long as an appropriately sized unit. This can cause higher utility bills, more repairs, and discomfort in your home.
Divide the square footage of your space by 500. Multiply that result by 12,000 to convert your result to Btu. Add 380 Btu for each person who will regularly work in that space. Add 1,200 Btu for every kitchen in the building.
For a 100-130 square feet room 0.8 to 1 ton AC is enough. for a room of 130 square feet to 200 square feet of 1.5 ton AC is better. more than 182 200 square feet rooms require a 2 ton AC and more than 500 square feet rooms require more than one AC in multiple places.
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.
The ideal AC required for 12x12 room is typically around 1 ton for effective cooling.
First, it's essential to understand that the cooling capacity needed for a room largely depends on its size. Generally, an 8000 BTU air conditioner is suitable for spaces ranging from 300 to 350 square feet.
First, the basics. SEER stands for Seasonal Energy Efficiency Ratio or “Rating.” This is the ratio of the cooling output of an air conditioner and heat pump over a typical cooling season, divided by the energy it uses in Watt-Hours.
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.
First, if the system is too small for the space it is intended to cool, there may be inadequate cooling and an inability to maintain a comfortable temperature. This could result in overworked components due to the excessive strain on the system, leading to higher energy costs and a shortened lifespan of the unit.
A Higher BTU Number Doesn't Always Indicate a Better Product
On the other hand, AC units with too few BTUs will need to run constantly to reach the target temperature, which may add strain to the system. Therefore, it is crucial to choose the appropriate BTU based on the size of the space.
Is It Better to Oversize or Undersize AC Unit? Neither oversizing nor undersizing your AC unit is ideal. Both scenarios can lead to issues with efficiency, comfort, and longevity of the system.
Adjust the thermostat up a few degrees and settle for 76 degrees or 78 degrees inside your home.
If your AC is running but not cooling, it could be due to a dirty air filter, incorrect thermostat settings, a malfunctioning thermostat, a refrigerant leak, dirty condenser coils, blocked vents or ducts, a faulty compressor, frozen evaporator coils, or electrical issues.