Keeping your home cool during the summer isn’t always easy—and it can get expensive fast if your AC system isn’t properly sized. Having an AC that is too large or too small presents numerous challenges, and the only way you can effectively overcome them in most cases is by upgrading to a new system that’s the correct size for your house. In this article, we’ll look at the ways you can tell if your AC system is sized incorrectly and why hiring an experienced HVAC company to replace your system is so important.
Short-Cycling
Short-cycling refers to a situation where an AC system usually only stays on for around 10 minutes and cycles on and off in quick succession. While an AC can short-cycle for various reasons, it most commonly happens because the system is oversized. You may think that a bigger AC is always better, but this really isn’t the case. If the system is oversized, it often won’t run long enough to sufficiently cool every room. Short-cycling also leads to much more wear and tear, which is the main reason why oversized systems typically have a much shorter lifespan.
Long, Continuous Cycling
Unless it’s extremely hot and humid or you’re making a large temperature adjustment, your AC typically shouldn’t run for more than 15–20 minutes at a time. Much longer cycles or your AC running continuously can be a sign that the system needs to be serviced or repaired. However, it can also indicate that the system is undersized and can’t cool quickly and effectively enough to meet your home’s needs.
High Indoor Humidity
As an AC system runs, at least some moisture continually condenses into liquid when the warmer incoming air flows across the cold evaporator coil. This allows the system to reduce the indoor humidity level in addition to cooling the house. An oversized AC that continually short-cycles typically never stays on long enough to provide effective humidity control. With an undersized system, you can also encounter frequent issues with high indoor humidity because it doesn’t circulate air throughout the house effectively.
High Energy Bills
Another clear indication that your AC system is improperly sized is if your monthly electricity bills are much higher than the average for your area. An oversized AC always leads to higher energy bills partly because it has a higher energy demand and also because of how often it cycles on and off. An undersized system consumes much more electricity simply because it doesn’t cool efficiently and has to run longer.
Uneven, Inconsistent Cooling
A properly sized AC system should cool every room evenly so that the temperature stays fairly consistent throughout the house. You may still experience some issues with hot spots in rooms that have large south- or west-facing windows/skylights or in areas that aren’t sufficiently insulated. If some rooms feel too cold while others never cool down, your AC may be the wrong size. An undersized system doesn’t put out enough cool air to supply every part of the house, while an oversized system typically only stays on long enough to fully cool the more central areas near the thermostat.
How to Properly Size an AC System
Proper AC sizing requires a Manual J load calculation, which should always be performed by an experienced, certified technician. Many people make the mistake of thinking that the square footage of the house and how hot/humid the local climate is are the only things that matter. While both are important, there are also numerous other factors that need to be considered when calculating a home’s cooling requirements and determining what size system will work most efficiently.
Older homes tend to need a higher-BTU system because they usually have issues like air leaks and insufficient insulation that contribute to increased heat gain throughout the day. Houses with higher ceilings or more windows and doors also need a larger AC system.
There are some steps you can take to improve AC performance if your system is only slightly oversized or undersized. This includes things like replacing air filters more frequently, making sure to keep all of your vents open and using ceiling fans to help keep cool. However, the best solution is simply to invest in a properly sized, quality replacement so you can enjoy more efficient cooling, more consistent room-to-room temperatures and lower energy bills.
If you’re tired of dealing with the summer heat and your home never being cool enough, G. R. Freeman Heating & Air Conditioning, Inc. is ready to help. We’ve been providing top-notch AC installation services in Evansville and Southern Indiana since 1977 and offer customized solutions to meet your comfort needs. We work with both central and ductless mini-split AC systems and will help you find the best option for your home.
Don’t settle for uneven cooling or rising energy bills. To schedule an inspection and in-home evaluation, contact us today.
