Cooling your home is essential during a hot Virginia summer, but there are many misconceptions about air conditioner efficiency that may be making your electric bill higher than they should be.
The Most Common Air Conditioning Myths
These five cooling habits below can not only cost you unnecessary money but can cause premature damage and replacements with overuse.
1. Fans Cool a Room
Ceiling fans don’t cool the air they only circulate the air, but they do cool off your skin, which can make a room feel cooler. The windchill effect created by circulating air can make a room feel up to 4 degrees cooler! However, the windchill effect only makes you feel cooler when you are in the same room as the fan. Leaving a fan on in empty rooms will just drive up your electric bill.
2. The Location of Thermostats Doesn’t Affect Your AC Efficiency.
Your thermostat’s location is important to efficient heating and cooling. A thermostat reads the temperature around it and gives commands to your HVAC unit based on that information. If the temperature near the thermostat is not consistent with the rest of your home, it won’t be able to do its job effectively. That is why it’s important to place your thermostat in a central location like a hallway and away from drafty windows or lamps. Anything that could heat or cool the temperature around the thermostat could affect efficiency.
3. Closing Vents Will Save Money
Closing a vent seems like a good way to focus your cooling energy only on the rooms you use. However, it actually reduces the energy efficiency of your system and causes other issues that end up hurting your system (and wallet) in the long run.
A central HVAC system is designed to heat or cool your entire home, not just a portion of it. When you block off a vent, it disrupts the airflow and causes issues with air circulation or can even lead to leaking ductwork! If you want to heat or cool only a portion of your home, a separate system may be a better solution for you.
4. Plants Improve AC Efficiency
A common misconception about air conditioners is that they’re less efficient when the condenser is sitting in the sun. The logic checks out: in theory, the heat from the sun makes the system hotter overall and reduces its ability to release the heat.
However, the reality is that the sun doesn’t have much of an impact on a central air conditioning system’s efficiency. The Department of Energy reports that shading your exterior HVAC unit only improves efficiency by around 3% — which isn’t much of a difference. Some add plants or overhangs to hide their outdoor unit from view or try to protect it from the sun. This can actually impact the flow of air or dirty your outdoor coils more than necessary which inhibits your system from working as efficiently as it can or even failing!
Note that while this isn’t true for central air conditioners, window air conditioners ARE negatively impacted by exposure to the sun.
5. The Bigger, the Better
Oversized HVAC units are inefficient as this causes “short cycling” or prematurely turns off and on. A properly sized air conditioner should run for about 20-25 minutes depending on the outdoor temperature. This cycle is most efficient. As the unit turns on, it uses a lot of energy, but after a few minutes, it requires less energy to keep going.
If the unit is too powerful, it will cool your home too quickly to take advantage of the efficiency that comes after a few minutes of running. Also, keep in mind that a powerful AC can cause issues with humidity regulation. Your AC is meant to draw moisture from the air, but if it doesn’t have time to do so, your home can become overly humid.