10 Air Conditioning Myths Busted

10 Air Conditioning Myths Busted


As HVAC professionals, we field all sorts of questions about heating and air conditioning. Summer is definitely a busy season for us, and we routinely engage in conversations about what you should and shouldn’t do to keep your air conditioner running at peak performance. We noticed recently that we have been hearing some of the same myths over and over again from our clients, and we’re here to clear up some major misconceptions!

Without further ado (and in no particular order), here are the 10 most common air conditioning myths we have come across recently. Are you guilty of buying into these commonly held beliefs?


Myth #1: Having your air conditioner serviced does nothing to reduce costs.

We recently wrote a post on why our service plans can truly benefit our clients. It wasn’t just a marketing ploy – regular servicing can do a lot to help keep your air conditioner running in the most efficient way possible. When technicians come out to service your A/C unit, they’re doing a full checkup of the system – making sure coils and filters are clean, looking for leaks, and double checking that parts aren’t on the verge of wearing out. Servicing is especially great for clients who don’t do a fantastic job with preventative maintenance, and prevention is generally the best way to avoid major HVAC problems.


Myth #2: Closing vents will help to reduce your energy costs.

This only works in houses with zoned systems. If your home isn’t “zoned”, then shutting vents actually makes your air conditioner less efficient by not allowing the air to flow through your home the way it was designed to do. If you have parts of your home that you’re interested in keeping shut off from the rest of your HVAC system, then it might be time to speak with a professional about how zoning could work for you.


Myth #3: A giant air conditioner will keep your home cooler.

Unless you have a giant home, all a huge air conditioner will do for you is raise your energy bills. Air conditioners are designed for specific space sizes, and you should always purchase a system designed for the square footage of your home. Anything larger will have trouble maintaining the proper temperature in your space, leaving you uncomfortable and paying a larger bill.


Myth #4: “Energy efficient” automatically means reduced costs.

Not so fast. Energy-efficient systems have the ability to save you money – if you use them as directed. For example, if you have an energy efficient programmable thermostat, and you set the temperature more than a few degrees different during certain times of the day, you’ll end up with an HVAC system trying to control large temperature differences. That’s not energy efficient, and will be reflected on your electric bill. So if you buy energy efficient, make sure you know how to use the system to save yourself the most money.


Myth #5: Ceiling fans help to cool the air in your home.

False – ceiling fans only help to move air around your home. They will not lower the temperature at all; however, they can aid in the comfort of homes during periods of hot weather. Ceiling fans help to circulate air, keeping the cool air lower in the room. Make sure that during the summer months your ceiling fan is set to spin counter clockwise, and change the rotation in winter to pull warmer air down into your home.


Myth #6: Setting your air conditioner to a super low temperature will cool the room faster.

We hear this one all the time, and it absolutely isn’t true. If you want your room to be 74° F, and you set the thermostat to 70° F, the room will still cool at the same rate, so your air conditioner will hit 74°F at the same time regardless of the programmed temperature. What will happen is that your A/C will continue to cool until it reaches 70°F, in the event that you forget to shut it off, which means longer run times that make the room colder while costing more money.


Myth #7: Where you install your air conditioner and thermostat isn’t important.

Thinking about installing your thermostat across from a window that gets a lot of direct sunlight? What about right next to a heat-producing TV or lamp? Be prepared for uneven heating and cooling, as the thermostat uses the nearby temperature to determine the temperature of the entire house.

Your air conditioner unit can also suffer due to improper placement. If it is constantly in direct sunlight, being hit by debris from large trees, coated by vines or crowded by fences or vegetation, it may end up with maintenance issues. When considering placement, it’s always a good idea to talk to a professional who can offer pointers for your specific home and system.


Myth #8: Air filters need to be changed every 90 days.

This may be what the box says, but the box is overly generous. Filters should be checked at least every 30 days, especially if you have pets, are using a HEPA filter, or live in an area that is particularly prone to dust and allergens. If the filter is dirty, it’s time for a replacement.


Myth #9: Running your A/C all day will lower your energy costs.

This one was recently covered in our Constant vs. Changing Temperature post. It turns out, neither approach is 100% efficient – it comes down to the temperature changes that occur. Usually, turning your air conditioner off during the day won’t increase the temperature in the space dramatically (especially if you’re taking extra precautions like closing blinds to save energy), so when you turn the A/C back on it won’t take a lot of extra effort to lower the temperature. If you run your air conditioner all day, you are likely not saving yourself any money over the long run.


Myth #10: Not running your A/C will keep it in better shape for the long run.

Know the saying, “If you don’t use it, you lose it”? It applies to your HVAC system as well. Kind of like cars, it’s not a great idea to just let an HVAC system sit around unused for a long time. Sure, air conditioners do experience wear and tear from normal use, but not using them can cause a whole different set of problems that could also end up requiring repair work. So why not make your home comfortable instead of saving the system for special occasions?