Is My AC Not Cooling Properly Due to Improper Sizing?

ac not cooling properly

If your AC is not cooling properly, it may be incorrectly sized for your home. You may experience issues such as uneven cooling or rooms not getting cool enough. An undersized or oversized AC is less efficient and can wear out faster. Proper sizing avoids these issues but typically requires AC replacement. We’ll now look at signs your air conditioner is struggling to cool your home and cover the benefits and other aspects of proper AC sizing.

Signs of Your Air Conditioner Not Cooling Properly

If your air conditioner isn’t serving your needs, the signs go beyond feeling warm and uncomfortable. Here are some other reasons to be concerned and call your local HVAC contractor:

  • Uneven Cooling: If your AC is cooling your home unevenly, you’ll notice hot spots, while other areas will be colder. This is a sign your AC may be undersized or oversized.
  • High Energy Bills: An air conditioner that is too small will run too long, consuming more energy. An oversized AC will short cycle, which also increases energy consumption. Either way, your energy bill will take up more of your budget.
  • Continuous Running: An undersized AC can run constantly because it’s not powerful enough to reach and maintain the set temperature, no matter how low you set the thermostat. 
  • Inconsistent Temperature: Your AC may seem to work fine, but the room temperature may unexpectedly fluctuate several degrees.

Consequences of Improper Sizing

Improper AC sizing doesn’t only cause a lack of comfort. Without a solution to the problem, your AC not cooling properly is just the tip of the proverbial iceberg. Some of the effects of an oversized or undersized unit include:

  • Reduced Efficiency: Since the unit will work harder to provide the same amount of cooling as a correctly sized one, it’ll be strained and consistently use more energy than a properly sized system.
  • Increased Wear and Tear: If your air conditioner runs constantly or has short cycles, various parts and components can wear out faster, leading to frequent repairs and premature unit replacement.
  • Shortened Lifespan: Improperly sized ACs don’t last as long as those matched with their environments. Aside from frequent repairs and breakdowns, your AC may last only a few short years before you have to pay for a new one.

Benefits of Correct AC Sizing

Correctly sizing your air conditioner resolves all of these issues. It ensures optimal performance, so your AC delivers consistent and even cooling to every room in your home. You won’t have to deal with your AC not cooling properly. Furthermore, proper sizing improves energy efficiency. A correctly sized air conditioner uses less power, so your utility bills may be significantly lower (your HVAC system consumes almost half the energy used in your home). You also save money on frequent repairs, so there’ll be more in your budget.

How Is the Proper AC Size Determined?

An HVAC installation professional has the knowledge and tools to determine the proper AC size for your home. Air conditioner sizing requires more than knowing square footage. A technician performs a professional assessment that includes a Manual J load calculation. They often use software to input specific details about your home. Nonetheless, the calculation process factors in the following:

  • Home Size: The size of your home is one of the most important factors considered. It can be determined by multiplying the length and width of each room and adding up the measurements of every room in your home. Or, the exterior of your home can be measured and the square footage of unconditioned spaces like a garage or basement can be subtracted.
  • Ceiling Height: A load calculation also factors in a room’s height. If the ceilings are higher than average, you’ll need an air conditioner with more British Thermal Units (BTUs) of cooling power than a home with standard-height ceilings.
  • Insulation Quality: The technician will examine the type, efficiency, and quality of the insulation in your home. The number of windows, airtightness, and sun exposure also impact your home’s insulating value, as does the number of people living there.
  • Usage of Your Living Space: A load calculation also considers how each room is used. Are some rooms occupied more or less frequently? Does one room have a high concentration of heat-producing appliances? These factors affect the cooling performance of your AC system.

An HVAC professional can provide expert advice on AC sizing. Therefore, it’s best to consult with a technician before selecting a unit and proceeding with AC replacement.

Frequently Asked Questions About AC Sizing

Why Is Proper AC Sizing Crucial?

The size of your AC has a direct impact on cooling performance. Too large a unit may be too strong for your home and not run long enough; too small an AC will run constantly to keep up. Each model is designed to cool a certain square footage. Generally, you need 20 BTUs per square foot, but this can be more depending on various factors.

How Can I Tell If My AC Is Incorrectly Sized?

If your AC turns on and off frequently or runs continuously, you feel hot and cold spots around your home, or the indoor air is humid, your air conditioner is probably the wrong size. Consult with an HVAC professional to remedy the problem, which often requires replacing the unit.

Can I Replace Only the Outdoor or Indoor Unit for Sizing Issues?

Replacing only one unit or another risks dealing with a mismatched system. Potential issues include the condenser coils not matching the evaporator coil size, varying efficiency ratings, and increased wear and tear. A mismatched system will be less energy efficient and not cool your home as effectively. 

Equipment damage and breakdowns are also more likely. You’ll probably have to pay out-of-pocket for these too, as mismatching AC components can void the warranty. That’s unless the AC unit is relatively new and the manufacturer can find a compatible one.

What Should I Do If My AC Is Improperly Sized?

If your AC is not cooling properly or you believe it’s improperly sized, have it assessed by an HVAC professional. They can provide a professional opinion and weigh your options. The solution is usually to replace the air conditioner. Your local contractor can help explore replacement options such as high-efficiency units and potential alternatives to central AC like a ductless mini-split system.

Call Hoover Today

Proper AC sizing improves cooling performance, efficiency, and system longevity. At Hoover Electric, Plumbing, Heating & Cooling, we provide high-quality AC installation and replacement for residents of Troy and Clinton Township, MI. Professional AC replacement can save you energy and money over time while avoiding frequent repairs and breakdowns. We provide free estimates and financing options, plus specials to help you save. Call (586) 371-5733 to learn more or schedule service.

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