It may seem wise to go big or go home in a variety of circumstances, but should you consider an oversized air conditioner for your home? At first blush, you may think that it never hurts to have some extra cooling capacity, but there are several notable downsides to installing a system that's too big for your needs. Keep reading to learn why "just right" should be your mantra for any HVAC installation.
The Fundamentals of HVAC Sizing
Air conditioning manufacturers measure the capacity of their equipment in British Thermal Units, commonly abbreviated as BTUs. You do not need to understand the technical details behind this measurement unit, but it is crucial to know that a higher BTU air conditioner can cool larger or warmer spaces. The higher your home's cooling load, the larger your AC system should be.
HVAC installers typically look at your home's square footage and the outside environment when sizing an air conditioning system. Larger homes require higher capacity systems, but so do homes in warmer or more humid climates. Most installers will use a set of straightforward calculations to estimate how many BTUs will be required to cool your home efficiently.
The Importance of Proper Sizing
If you've ever lived in a home with an undersized air conditioning system, then you know that it can lead to a variety of problems. Systems that are too small will run for too long, using far too much energy, wearing out components more quickly, and ultimately doing a poor job of keeping you comfortable. Unfortunately, installing an air conditioner that's too large can create its own set of problems.
When your air conditioner has more capacity than you need, the compressor will often suffer from a condition known as short cycling. A short cycling unit turns on and off much too rapidly since the conditioned portions of your home will reach their target temperature too soon. Surprisingly, short cycles can have the same effects as long cycles: increased wear and increased energy bills.
In addition to these problems, a short cycling oversized unit may be less efficient at removing humidity from the air in your home. The relatively short run time of your compressor will prevent sufficient amounts of water from condensing around your evaporator coils, ultimately leading to higher moisture levels. This excess humidity not only makes your home less comfortable but can also promote mold.
Getting It Right
To avoid the problems with undersized and oversized systems, always consult with air conditioning services. Trained HVAC technicians understand the calculations required to estimate your cooling needs accurately. They can choose a size that will ensure your AC system has adequate capacity to keep your home comfortable through even the warmest days.