Bigger Isn't Always Better When It Comes To Your Air Conditioner

You want your home to be as comfortable as possible, so it only makes sense to have the most powerful air conditioning system money can buy, right? As it turns out, purchasing the biggest A/C system you can get your hands on isn't always the best way to take care of your home's cooling needs. The following explains why buying an oversized air conditioner can leave you and your home in worse shape when it comes to overall cooling comfort.

Why Homeowners Choose Oversized A/C Systems

Some homeowners decide to go with an oversized air conditioner based on their contractor's recommendations. The contractor may be going on the traditional but somewhat flawed "rule of thumb" in terms of cooling capacity calculation. The traditional rule of thumb may be quick and relatively simple for contractors to calculate, but it often leaves homeowners with the wrong A/C system size for their home.

Others may decide not to consult with a contractor and choose an air conditioning system on their own. This often results in homeowners buying the largest capacity air conditioner they can afford, often without understanding the risks of having an oversized A/C system.

The Risks of Going Big

Speaking of risks, there are plenty to consider when choosing an oversized air conditioner:

  • An oversized air conditioner is more expensive to purchase than a unit that's properly sized for your home and it can also be just as expensive to replace.
  • Oversized air conditioners are prone to short cycling, a phenomenon where the unit continuously starts up and shuts down for very brief periods in an effort to maintain a desired room temperature.
  • Short cycling also leads to poor air filtration, since there isn't enough air being moved through the air conditioner to make filtration worthwhile.
  • Oversized air conditioners also consume more electricity and require more maintenance than their properly sized counterparts. They also tend to have shorter lifespans than units that are correctly sized.

Air conditioners also serve double duty as dehumidifiers, removing large amounts of moisture from the indoor air that's being cooled. Since oversized air conditioners tend to cool down their indoor environments quickly, they don't run long enough to adequately dehumidify the indoor air. The end result is a home that's cool, but feels damp and clammy due to the excess moisture that's still in the air. The clammy and damp environment can also play host to mold and mildew growth, in some cases.

How to Avoid Oversizing Your A/C System

With all of the drawbacks of having an oversized air conditioner, you don't want to end up with a unit that's too much for your home to handle. Instead, it's important to choose an A/C system that's sized just right for your home's unique cooling needs.

The best way to accomplish this is by having your HVAC contractor perform a Manual J load calculation. Developed by the Air Conditioning Contractors of America (ACCA), a Manual J load calculation precisely determines how much cooling capacity your home actually needs. This process takes several different variables into account, from your home's orientation and insulation levels to the type of windows you have in your home.

After determining your home's exact cooling capacity needs, your HVAC contractor will then choose an air conditioning system based on the Manual S equipment selection process. Manual S takes into account all of the information gathered during the Manual J load calculation process along with the HVAC manufacturer's own performance data. With all of this information on hand, your HVAC contractor will be able to select the right air conditioning system for your home. 

For more information, contact an HVAC contractor at a company like A-1 American Services.


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