Emergency A C Repair, Tune Ups & New Installs

5 Reasons AC Systems may be underperforming

On a hot summer evening, you expect your air conditioning system to be working at peak performance, keeping your family cool and comfortable. Afterall, it’s a good quality system and it is fairly new. But overall you are disappointed in the performance of your system, and this may be why. A federal study published in 2015 by the National Institute of Standards stated that a typical central air conditioning system installed in the United States works to 65% or less of its rated capacity from the very first day it is installed.

You may think that buying a central air conditioner is like buying a refrigerator or a dishwasher.

In fact, nothing could be further from the truth. With those types of appliances, the equipment is a self-contained unit, built in a factory that has a consistent environment, with highly control standards. They make it, you buy it, bring it home, plug it in and it works as expected.

Central air conditioning systems are not “plug and play”

AC systems are designed and built in your home by a contractor. Your system is made up of many components, not just one, and they all have to work together for you to most out of your expensive equipment. Typically, there is a condenser, an air handler or furnace, an evaporator coil, an airflow system (ducts), your filter, and so much more. All of these must be properly selected for your specific home and climate, then installed correctly in order for your new super duper high-efficiency AC equipment to properly work to cool your home and achieve the performance and efficiency that you paid for and expect. Because your system is custom built in your home, there are actually five major reasons why you may not get the expected HVAC performance from your system.

Assuming your system components are in good working order, these would be the next culprits for a poorly performing system:

  1. The system is not properly sized for your home – This doesn’t always mean the system is too small. A system that is too big can be a big problem, too.
  2. The refrigerant is not properly charged – An equipment charge that is off by 10%  could have an impact of 20% of even more on the performance and efficiency. Charging the refrigerant is a tricky matter and AC installers often prefer to guess and save time, which can cost you a lot.
  3. Fan speed wasn’t set correctly – Most systems come from the factory with the fan set on high. If it isn’t adjusted to match the needs of the other equipment installed, the system may be trying to move far too much air for your needs, making a lot of extra noise and using more electricity than needed. Further, if the air moves through your system too fast, the moisture, or humidity, may not be removed as effectively as it could be with slower moving air.
  4. Airflow systems (ducts, returns, registers) don’t meet the needs of the home  – The duct system needs to be designed and laid out with the airflow needs of the home and the AC equipment in mind. If the ducts (returns and registers) are not properly designed and installed, your AC equipment can be damaged and your AC equipment won’t be able to perform properly, leaving you paying more for utilities than you should and enduring an uncomfortable home.
  5. Air Duct Leakage – Several years back, Austin Energy determined that most duct systems are not sealed properly and lose more than 25% of their air to leakage. With duct leakage, you are either sucking in a hot or cold attic air into the system (instead of conditioned air from your home) or you’re sending the air you just paid to cool or heat into the attic or outside your home.
As you can see, there are many things that can lead to reduced HVAC performance. Typically, it’s not one thing that causes the system to not perform, it is a combination of things. Working with the experts at McCullough Heating and Air is the best way to diagnose performance issues, give us a call (512) 280-0011.