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10 Air Conditioning Mistakes You Can’t Afford to Make

Ignoring proper AC management will raise your energy bills, decrease the efficiency of your system and ultimately require repairs. So avoid these 10 common mistakes and reap the cool rewards!

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Dirty filter of air conditioner in female hands. Cleaning and washing maintenance

Ignoring your air filter

Your home’s air filter helps to remove dust, allergens and more from all the air that passes through the system. These filters are typically light cardboard-and-wire constructs that are designed to be regularly replaced. After around six months or so, that filter is so filled with dirt, air has a tough time getting through and the unit can’t really do its job anymore. That not only raises the volume of dust in your home, it also greatly decreases airflow and efficiency for your AC unit. You can improve energy use for your AC by 5 to 15 percent just by replacing a dirty filter, so make sure that you get a new filter a couple times a year and remember to check and change it after particularly dusty activities, like a big demolition and remodel.
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Never cleaning fins and coils

Air conditioning evaporator coils and fins allow heat to pass from the refrigerant in the system out into the air, just as condenser coils absorb heat from inside the house. This process of moving heat is very important, but it can become impeded by layers of dust and grime. If you never check on your coils, that grime is costing you money and decreasing efficiency. Clean your air conditioner at the beginning of the warm season and check it from time to time, especially after storms or high winds to make sure your coils and fins stay clear.
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Climate control on office wall, selective focus

Not updating (or setting) your thermostat

A programmable thermostat is a must-have in today’s state of AC technology. Programmable thermostats allow you to set temperatures for various times throughout the day and automatically lower the temperature when you most need it to help you save money and manage your cooling without constantly hovering over the dial. Many advanced thermostats like Google’s Nest thermostat actually have learning capabilities, so the thermostat can shift to accommodate repeated schedules—not to mention allow you to change the temperature from an app. If you don’t have one of these programmable or smart thermostats, the time to upgrade is now! Save money and enjoy more accurate cooling with a simple thermostat replacement, especially if your current thermostat is a couple decades behind the times. Find out some tricks to keep your air conditioning costs down.

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Air compressor at the blockhouse or wood house.

Using the AC when no one is home

When setting schedules, pay close attention to when people will actually be in the house. In the middle of the weekday, when family members are at work or school, you can turn the temperature up significantly to save on money. The same is true of the middle of the night, when people are asleep. Don’t set the AC to lower the temperature when no one will be around to enjoy it.
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The shower drain with tile floors
Dmitry Bodyaev/Shutterstock

Not checking your drain

Many air conditioning systems use drains that take care of condensation and related issues by channeling water outside of the house. These drains can be easy to miss, but they have an important job. If one of these drains gets clogged, it’s bad news for your AC system and even worse news for surrounding floors and walls, which can get permanently damaged by overflowing moisture. So keep your drain line clean, and don’t be afraid to snake it with a wire every year or two to make sure no junk is accumulating inside.
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Hand with remote control directed on air conditioner

Turning the temperature down too low

This is a common mistake that comes from the old days when many homeowners didn’t know much about how their AC systems worked. People would frequently turn their thermostats down very low in hopes that this would make the AC respond more quickly or work harder. It does not. The AC works just as hard to lower the temperature one degree as it does to lower it by 20 degrees—it’s just a matter of time and the settings you have chosen. So program your thermostat to exactly where you want it, not lower than you need.
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Air compressor installation on pedestal.outdoor

Ignoring sizing requirements

AC units are carefully sized to the number of cubic feet they need to cool. That’s particularly important when you are purchasing a new AC unit or renovating your house. If an AC unit is rated for a smaller space than you have, it will work too hard to cool the air, wear out more quickly and struggle to meet the demands of the thermostat. If the AC unit is rated for a larger space than you have, it will constantly turn on and off, wearing itself out and growing undependable over time. Pay attention to capacity and pick the right unit for the space you have.
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Repairman fixing air conditioner unit

Avoiding replacement

The initial cost of replacing your AC unit is high, but that doesn’t mean you should avoid a new purchase. Don’t make the mistake of keeping your old air conditioner long after you should. An old air conditioner will perform poorly, cost you more money in repairs and eventually become more trouble than it’s worth. If your AC unit is 10 to 12 yeas old or older, you could start saving money on monthly bills by investing in a newer, more efficient version.
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Technician is checking air conditioner ,measuring equipment for filling air conditioners.

Never arranging a check-up

As we mentioned, most air conditioning systems use a refrigerant that absorbs heat from the house and disperses it outdoors. This refrigerant compound is very important to AC operation, but small amounts can escape over time, resulting in falling efficiency. How do you know if you need to add refrigerant? Arrange for an experienced technician to come out and test your AC system and adjust refrigerant levels to the proper amounts. Here’s how to keep your house cool without an AC.
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Forgetting about your windows

A lot of heat enters the home through windows, especially open windows. If you really want to control heat in your house, pay attention to your windows, too. Keep them closed and covered with blinds or drapes during the hottest parts of the day—especially windows that are currently facing the sun. In the evening, open both upstairs and downstairs windows if possible to encourage a natural flow of cooler air. The less work an air conditioner has to do, the better! Next, find out the genius ways to save on every household bill.
The Family Handyman
Originally Published on The Family Handyman