What Size AC Unit Do You Really Need?

If you are considering installing an AC unit in your home in Bloomington-Normal size is everything. A unit that is too small means it will run constantly. This will spike your energy bill without actually cooling your house. If the unit is too big for your house, it will constantly short-cycle. When an AC unit turns on and off too fast, it cannot remove humidity, leaving your house feeling like a damp cave.

Summers PHC can advise you on the appropriate AC unit size for your home. We also have a current special: only $69 for a spring AC tune-up of your existing units. Don’t suffer from the heat in summer. We can help you choose and install the right AC unit and ensure it is in perfect condition for the hot months ahead.  This is a limited-time offer only. (Terms and conditions apply.)

The Basics of AC Size and Capacity

When choosing an AC unit, the size refers to its cooling capacity. Capacity is typically measured in BTUs (British thermal units) or tonnage. For example, 1 ton equals 12,000 BTUs. 12,000 BTUs refer to the cooling power of the AC unit. The higher the tonnage figure, the more capacity the AC has to cool your home.

Factors That Influence Your AC Size Choice

Buying an AC unit does not simply mean choosing one with high BTUs. There are several factors you need to consider.

• Climate. Bloomington-Normal typically experiences hot, humid summers, so temperatures can reach or exceed 86°F. You will likely need a unit with higher BTUs to cope with the intense heat. At the same time, you need to consider the room orientation. If it faces direct sunlight, you need a larger unit. If the room is shaded, you can opt for a small AC size.
• Room or Area Size. If you have a big house, you need a unit with a high cooling capacity. Small AC units do not have the capacity to effectively cool large homes.
• Number of People in the House. You will notice that more heat is generated when many people live in the same house. With each occupant, you need increased cooling, so invest in a larger AC unit.
• Existing Insulation. If your home is well-insulated, it can retain cool air better. This means you might be able to get by with a smaller unit. If you have an older home that is drafty or poorly insulated, a larger unit can compensate for energy loss.
• SEER2 Ratings. AC unit energy efficiency is indicated by SEER2 (Seasonal Energy Efficiency Ratio 2) ratings. SEER2 ratings refer to the total amount of cooling provided over the entire cooling season. This figure is divided by the total amount of energy used during the cooling season. As such, the higher the SEER2 rating, the more energy efficient the AC system is.

Calculating the Correct AC Unit Size

It is best to start with the basics when calculating the right AC size for your home. The gold standard is “around 20 BTUs for each square foot of living space.”

The following chart can help you establish the right size before buying a unit:

If you prefer to measure in tons, this chart can help.

The Manual J Load Calculation

In most cases, it is best to have an HVAC professional advise you on the best size AC unit for your home. Professional HVAC sizing relies on a Manual J Load Calculation. The calculation accounts for:

• Local climate (depending on the neighborhood or city)
• Orientation of the house
• The R-value of the attic and wall insulation
• Lighting and appliances that can affect the internal load
• The number of occupants in the home.

Advantages of Buying a Correctly Sized AC Unit

When you buy the right size AC unit for your home, you will enjoy the following:

• Fewer hot or cold spots, which means even and consistent cooling
• Lower utility bills as the AC unit will operate more efficiently
• A lesser chance of an unexpected breakdown or repeated repairs
• Great humidity control to prevent dryness and dampness

When to Consider Upgrading Your AC

If you already have a functioning AC, there are signs to look out for that could mean you need to upgrade. Even if you do not need to upgrade, you may need to have a professional check that the sizing of your existing AC is correct.

Some of the tell-tale signs or reasons for a checkup include:

• Rising energy bills with no apparent reason
• The AC unit almost never shuts off when it gets very hot outside
• The system continues to cycle on and off instead of running consistently
• You notice that some rooms are a lot warmer or cooler than others
• You have recently renovated or added extra rooms to your house

Summers PHC Can Help Ensure Your Home Stays Cool During Summer

You do not have to struggle with figuring out the right size AC unit for your home. Summers Plumbing Heating & Cooling can provide you with the advice you need and install the unit you choose. We can also ensure that your home stays cool when it is hot and humid by tuning up your AC system once every year. Our team is experienced and qualified to assist with all AC-related requirements.

Let us help you get the perfect AC unit for your Bloomington-Normal home. Find out more about our expert AC services by calling 309-319-9009 or booking a consultation online. Remember to check out our local service specials for May.