Bigger is not always better, especially when it comes to cooling your home. An oversized AC unit not only costs more to run, but it may also actually perform badly compared to a properly sized unit. Replacement with the right sized AC for your home can save you money and increase your comfort during hot weather.
1. Humidity Problems
An AC unit works to remove heat from the air and replace it with cool air instead. In the process of doing this, it also removes moisture from the air which is then processed through the AC and drains out of the condensate line outside of the home. If the AC is too large, it cools quickly and shuts down before this process completes. This leads to more condensation remaining in the home, which can lead to issues with high humidity.
2. Constant Cycling
Overly large AC units will cycle constantly. This is because they will cool the parts of the home closest to the AC quickly, thus triggering a shutdown. Unfortunately, the rest of the home may not be cooled yet, so within a few minutes the temperature equalizes and rises and the AC comes back on. Frequent cycling uses a lot of energy and shortens the life of the AC unit.
3. Frequent Freeze Ups
A large AC unit doesn't mean that the ducts that service it are the right size. If there are too few ducts to take away cold air, the unit may freeze up and shut down without properly cooling your home. The issue can also occur if there are insufficient return vents so that insufficient amounts of air are recirculating into the unit. The AC won't be able to run again until it has thawed out, which can take several hours.
4. Loud Noises
Bigger ACs can be louder, which can be more noticeable in a smaller home designed to house a much smaller unit. Although some of the noise can come from the AC blower motor, most of the excess noise often comes from the ductwork. The more powerful and greater volume of air blowing through the smaller ducts can lead to rattling, shaking, and creaking noises that can be very annoying.
5. Uneven Cooling
Uneven cooling is a major issue when the AC unit is too large. As mentioned previously, the unit will cool the rooms closest to the AC quickly, which triggers it to shut down before cool air gets to the outermost rooms. The result is uncomfortably cold rooms near the AC, and hot rooms further away.
Contact an air conditioning service if you suspect that your unit is the wrong size for your home.