Air Conditioning Myths Debunked - All Systems Mechanical HVAC

Air Conditioning Myths Debunked - All Systems Mechanical HVAC

Whether it is your favorite home and garden magazine or Fox News, there are hundreds of air conditioning myths that claim to address how you can save tons of money.  But are they true?  Air conditioning myths can be be persuasive, useful or downright scary, so knowing what’s true and what is not is important in today’s market.  The reality is, however, that there are only a few tips that truly affect your air conditioning costs.  Since the temperatures are still in the triple digits here in sunny Santa Clarita, California, here are three air conditioning myths that we hear pretty often here at All Systems Mechanical HVAC, the truth of which may help you get off to a good start with your energy saving goals.

For information on how to actually save money on air conditioning costs, try: How to lower your AC bill in the summer.

Air Conditioning Myth #1 – Turning up the thermostat when you leave the house saves money.

air conditioning mythFalse.  This air conditioning myth just won’t go away.  We see people doing this a lot, and even my dear old father, despite my constant barrage of information still believes that this will save money in the long run. Unfortunately, this is not completely true – but there is some truth to it.  Raising the air conditioner temperature in the house when you leave actually increases the work load on your HVAC system. For more information on what HVAC means, try: What does HVAC stand for?  How is this possible? It all comes down to your insulation.  Decades ago when air conditioning was a luxury and electricity was cheap, this old adage was true – but these days, insulation is standard in any house, and what people don’t realize is that insulation doesn’t keep a house cold…or hot…insulation does only one thing – it slows the rate at which the temperature on one side of the insulation changes to the temperature on the other side. That’s it. So when you have your air conditioner set to a comfortable 68 degrees, and it’s 98 outside, it is your insulation that helps your air conditioner do this. However, this also means that the inside part of your insulation is 68 degrees and the insulation on the outside is 98 degrees. The 30 degree difference is what your insulation buys you. Unfortunately, when you raise the temperature of your thermostat to 85 when you leave the house, you are not only changing the temperature of your air conditioner’s thermostat, but you are raising the temperature of your insulation as well – raising the temperature that your air conditioner has worked hard to bring down to 68 degrees.  Therefore, when you return home and change your thermostat to 68 again, your air conditioner now has to work overtime to not only lower the temperature of the air in your house, but of the insulation as well.  This is why it seems like your HVAC system runs forever when you turn your thermostat down after you walk in the door, and also why it turns on more frequently.  Recent studies have shown that it is only cost effective to change your thermostat by 4-5 degrees when leaving the house.  Otherwise, you actually will lose money as your air conditioning system is forced to cool the house, and your insulation.

Pro Tip: Install a programmable thermostat that can automatically increase and decrease your air conditioning temperature throughout the day.

Air Conditioning Myth #2 – Keeping ceiling fans running will decrease energy costs because your air conditioner won’t have to work as hard.

Kind of false.  This air conditioning myth is a bit tricky.  The use of ceiling fans (an old air conditioning myth) are a useful tool in making your house feel cool, but not at actually cooling your house.  What’s the difference?  Ceiling fans work by increasing air flow over your body, therefore increasing the rate at which your body can lose heat – making you feel cooler.  But this only works for the room that you are in!  In other words, ceiling fans are very useful for the bedroom you are asleep in, or the man-cave when you watch the game, but they are completely useless unless you are in them to reap the benefits.  If you keep the ceiling fans running when you are out of the room, it doesn’t help your air conditioner at all, and actually can hurt it by messing up the natural air circulation that your HVAC technician has worked so hard to perfect.

Pro Tip: Use ceiling fans only when you are in a room, and turn them off as you leave the room.

Air Conditioning Myth #3 – Buying a new energy efficient air conditioning unit will significantly reduce air conditioning costs.

Again, this air conditioning myth is kind of false.  Although it is true that an energy efficient air conditioner will decrease the energy used by the unit itself, it will only decrease your air conditioning costs if it is properly installed and other factors are accounted for.  For instance, proper ducting size and location will significantly affect the airflow in your house, and consequently how hard your air conditioner must work.  It is also important to ensure that your HVAC technician installs the proper sized air conditioner for your home or business.  It is common for these units to be undersized, causing the unit to run longer and harder, decreasing the life of your air conditioning unit.

Pro Tip: For more information on this air conditioning myth, take a look at: What size central air conditioner do I need for my house?

Give us a call and we’d be happy to answer any of the questions that you may have, as well as to debunk any air conditioning myth you might have a concern about.

For more information on air conditioners and tips from the pros, visit ASM’s air conditioning blog.

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Timothy Kautz
About the author
Tim K.

The University of Virginia - 2005 / The Wharton School of Finance - 2016 / U.S. Naval Aviator 2005-2015. At All Systems Mechanical air conditioning and heating, we believe that the experience our clients have is every bit as important as the products they receive. Simply put, our results speak for themselves, and we'd be happy to help. If you're in the market for a new AC or furnace, make sure that you get a fair price! Try our online calculator; click the tab on the top of this page for more information.

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