As an expert in the field of air conditioning, I am often asked questions like “What size air conditioner do I need for 2000 square feet?” or “How many BTUs of air conditioner are needed for a 1500 square foot house?” These are important questions to consider when looking for the right AC unit for your home. Fortunately, there is a simple calculation that can help you determine the appropriate size based on your house size, climate, and other key factors. A good rule of thumb to start finding the right size air conditioner unit is to have 20 BTU for every square foot of the house. This means that a 1,000-square-foot home would need a 20,000 BTU air conditioner. Keep in mind that this number can then be converted into tons. In general, for every 600 square feet, 1 ton of air conditioning is needed.
However, it's important to take into account other factors such as climate and humidity levels. For example, if you live in a humid area like Florida, you may need a larger unit to combat mold problems caused by high humidity levels. I recently encountered a situation where a homeowner was advised to install a 3-ton unit due to a major mold problem. However, upon further inspection, it was determined that this unit was not sufficient and a larger unit was needed. The difference between a 3.5-ton unit and a 4-ton unit may seem small, but it actually represents a capacity difference of 12.5%.
In this case, it would be more appropriate to install a 4 or even 5-ton unit. When temperatures exceed 80 degrees and humidity levels reach 50%, an undersized unit will struggle to keep the space cool and will constantly be running. This not only leads to discomfort, but it also puts unnecessary strain on the unit and can result in higher energy bills. The general rule for air conditioning is “20 BTU per square foot”; however, it's important to take into account other factors such as ceiling height. If you have a ceiling height of 8 feet, then the 20 BTU per square foot rule still applies. But if your ceiling is higher, you may need a larger unit to properly cool the space. It's also important to consider practical experience when determining the appropriate size for your AC unit.
While theoretical estimates can give you a general idea, testing a unit in practice will provide a much more accurate result. For example, I once had a client who purchased a 2293-square-foot prefab house with a 3-ton central unit installed by the manufacturer. However, upon inspection, it was determined that this unit was not sufficient and a larger unit was needed. When it comes to choosing the right size AC unit, it's better to err on the side of caution and go with a larger unit rather than risk having an undersized unit that struggles to keep up with cooling demands. An oversized unit may seem like a waste of money, but it actually provides better humidity control and more even cooling.
Plus, it puts less strain on the unit and can result in lower energy bills in the long run. Another important factor to consider is SEER (Seasonal Energy Efficiency Ratio) ratings. A higher SEER rating means that the unit is more energy-efficient and can save you money on your energy bills. If you have an older unit with a low SEER rating, it may be worth investing in a newer, more efficient unit. In fact, switching from a 10 SEER unit to an 18 SEER unit can result in significant savings over time. Ultimately, the best way to determine the appropriate size AC unit for your 3500 square foot house is to consult with a professional.
They can take into account all of the necessary factors and provide you with a more accurate recommendation. Don't rely solely on theoretical estimates or manufacturer recommendations; trust the expertise of a trained professional to ensure that your home stays cool and comfortable all year round.