It is not uncommon for many people to make incorrect assumptions about how their air conditioners work. We get it, and we certainly don’t expect everyone to be an HVAC expert. However, there are some pervasive myths out there that lead to some bad habits that we see time and time again. Although held by some well-intentioned folks who just want to save some money on their energy bills, these bad air conditioning habits actually just end up causing more harm than good.

As we head into the scorching summer months here in Southern California, keep the following information in mind!


Can’t remember the last time you had your AC serviced? It’s time to schedule with All Pro!

Click here to request service online


Bad Habit #1: Closing Vents in Unused Rooms

Do you have one or more rooms in your home that are seldom used, such as a spare bedroom or a study? You might be tempted to shut the HVAC registers in these rooms in order to avoid having to cool or heat them along with the rest of your home. For many people, this logically seems like it would help you save energy by redirecting treated air elsewhere.

Pro AC tip: Keep your HVAC vents open, even in unused rooms!

The truth is that this practice could actually be hurting your HVAC equipment. The reason why has to do with air pressure. Think of it sort of like trying to breathe through a regular drink straw—no matter how hard you blow through a straw, the straw can only handle so much air at a time. In the same way, your duct system is specifically designed to handle a certain amount of air output. Closing off one of the registers increases air pressure in your duct network, and in turn this is harder on your AC’s blower fan, evaporator coils, and more. It can also cause problems with uneven temperature control, creating hot and cold spots throughout your home. Believe it or not, you’ll spend more money on energy and wear out your AC even faster than you would have if you had just left all of your air vents open.

Bad Habit #2: Blocking Floor Vents with Furniture

Do you have registers located in the floor of your home or low on the wall? This is common in traditional homes, manufactured homes, and mobile homes where there is a crawlspace built beneath the floor that air ducts run through. Sometimes these vents are located right where you want to place a piece of furniture, such as a sofa or bookcase.

Pro AC tip: Blocking air return vents is a bad idea!

It may not seem like a big deal to block a vent, particularly if a piece of furniture has legs that elevate it so that airflow isn’t completely cut off. However, just because a vent isn’t fully blocked doesn’t mean there’s no threat of harm to your HVAC system. Blocking vents prevents treated air from reaching your home as efficiently as possible, and that means longer cycle times (which also means more wear and tear and higher energy bills). Likewise, a blockage could actually still cause an air pressure increase in your air ducts, resulting in the same type of damage we just discussed in closing off vents in unused rooms.

Bad Habit #3: Turning Your Thermostat Down Super Low to Speed Up Cooling

When you live here in the Inland Empire, you pretty much have a summer routine for getting in the car: open the doors, turn on the air conditioner, crank the temperature all the way down, and open the vents all the way up. This helps get the air conditioner working as quickly as possible and brings the nasty heat inside your car back down to a more tolerable level. Many people think this same routine should logically work the same with their homes, but the truth is that it doesn’t.

There’s a key difference to your home’s air conditioner and your car’s climate control system: fan speed. A car’s cooling system has a fan that can have several speeds, often four, five, six, or even more. This allows you to change the rate at which cooled air is pushed into the vehicle, and thus allows you to select your comfort level. A typical home HVAC system’s fan, on the other hand, has only one speed, and thus the cooled air is pushed through at only one rate. A home air conditioning system doesn’t cool to a specific temperature, but rather cools air as much as it can.

Pro AC tip: A lower AC setting does not cool your home down faster!

When cooled air mixes with the warm air in your home to the point where your desired temperature is reached, the system ends the cycle and shuts off. Therefore, reducing the temperature down several degrees below your actual target does not actually cool your home any faster or more effectively than it would by setting your thermostat to your ideal temperature in the first place. In fact, setting your AC too low, to the point where it runs and runs without actually being able to achieve that temperature, will only increase wear and tear on your system and waste money.

Is Your AC Ready for Summer Heat?

Knowing what to do and what not to do with your air conditioning system is only half the battle. The other half is maintenance. Having your air conditioner professionally serviced at least once per year is key to getting the best performance and the most longevity from your system. If your AC is overdue for a maintenance appointment, now is the time to schedule with All Pro. We can ensure your AC is clean and in good repair as we head into another scorching Inland Empire summer.

Have your air conditioner serviced by the experts at All Pro Plumbing, Heating, Air & Electrical! Call (909) 500-8193 today!