Air Filter Replacement

AC FiltersHello, Austin! Air conditioning doesn’t have to be complicated. In fact, with a few basic maintenance tips, there’s no reason you can’t have perfect air conditioning year round. If you ever have problems with your air conditioning, AC Express can give you expert AC repair in Austin and all the surrounding areas.

One routine maintenance task that is just as simple as it is important is air filter replacement. Air filters are devices that filter out dust and other particles from getting caught up in your air conditioning system. It’s comprised of fibrous materials and though they are effective at what they do, their effectiveness drops significantly with time. What follows is everything you need to know about air filters in your home, what they do, why it’s important to replace them, when to do that, and how.


The air filter in your air conditioning system has two primary purposes. First and foremost, air filters protect and lengthen the lifespan of your air conditioner. In normal, everyday usage, your air conditioner moves a lot of air. And no air is perfectly clean. The air your air conditioner moves around carries with it everything from pollen to dust to mold and other particles. The main function of your air filter is to keep containments such as dust out of the air conditioner’s components, especially the evaporator coil.

The fan, the motor, and the evaporator coil of your air conditioning unit all benefit from the work the air filter does keeping out contaminants. Particles like dust and pollen, when they collect in the moving parts of your air conditioner, can have several negative effects. A dirty air conditioner will work less efficiently. It will have to be on longer to cool the air the same amount. It will have a shorter lifespan, and it will need repair more frequently. It’s estimated that an ineffective air filter can end up raising your utility cost anywhere from 5% to 40%. A working air filter is a big deal.

In addition to keeping your air conditioner clean, healthy, and working at peak efficiency, the air filters in your home have another purpose. They keep the air in your home cleaner, improving your own health and the quality of the air around you. From more benign allergens like pollen to potentially dangerous allergens like mold, the contamination of the air in your home is nothing to take lightly. A clean and properly working air filter will keep unwanted particles from cycling through the ducts and spreading throughout your house. This creates better air quality in your home and is essential in maintaining a healthy respiratory system.

So for the health of both yourself and your air conditioner, your air filter is important. Making sure you replace them often enough is in your best interest. Read on to find out more about why.


Air filters pick up pollutants and contaminating particles from the air in your home every time the air cycles through your air conditioning ducts. They do this quite well, but they can’t do it forever. Those particles don’t disappear; they stay lodged in the air filter. Air filters can do their job effectively for a while, but eventually, there will be too much build up. Once there’s no more room for more particles, they lose their ability to effectively remove unwanted particles from the air.

According to the EPA, the Environmental Protection Agency, the average person spends about 90% of their time indoors. Living in Austin in the summer, that number might be even higher. And because air indoors does more cycling and isn’t quite as fresh as the air outdoors, the air quality of your home is of utmost importance for staying in good health. For these reasons, replacing your air filter at regular intervals is something everyone should do, for their air conditioner’s health, and your own.


So, air filters, they do more work than you’re probably aware. They keep your air clean and your air conditioner in good shape. They save you money and keep the air you breathe free from pollutants. But they can’t do this forever, and as time passes, they slowly become less effective. Your next question might be: Okay, I’m convinced that air filters are important and that they need to be replaced, but how do I know when to do that?

Well, that’s going to depend on a couple of factors. The first factor is just what type of air filter your AC has. Then it depends on the general air quality around you and your area. And finally, the number of occupants in your house, and the number of pets, if any, also factor in.

The vast majority of homes have air conditioners that require air filters between 1 inch and 3 inches in thickness. For these kinds of air filters, there are some guidelines you can use to determine when you should replace them. Most air filters have specifications on them that recommend they be replaced every two months. This will work fine for most people, but depending on the previously mentioned factors, you might want to replace them less or more often.

For example, if the house that these air filters reside in is not often occupied, such as a vacation home, you could get away with replacing the air filters once a year. Of course, replacing them more frequently wouldn’t hurt, but if you’re trying to optimize the money you spend on utilities, an infrequently occupied house doesn’t need air filter replacement more often than that.

If you suffer from allergies, whether they’re mild or severe, and you live in an area polluted with those allergens, you may want to replace your air filters more than once every other month. Another option for those who need greater air quality is to upgrade the type of air filters you use.

If your house has many occupants, and especially if one or more of those occupants is a pet, such as a dog or a cat, you may want to change your air filter more frequently. Pets have a tendency to shed, and carry in particles from outside on their fur. This means more pollutants cycling through your air conditioner, which means your air filters are going to get dirtier, quicker, and need more frequent replacing.

Of course, ultimately, the best way to determine just how often you need to change your air filters is to check them manually. Read on to find out how to do that, and how to change a dirty filter.


The first step in checking and replacing your air filters is to locate them. Depending on the size of your house or apartment, you might have one air filter or several. Your air conditioning system is kind of like a big tube that runs all through your house and has both exit and entry points. These duct openings are the square grates, metal covers, that you can spot on your ceilings and walls in the various rooms of your house. The air filters reside just behind the metal grates through which the air enters the ducts.

To locate the air return duct openings in your house quickly, take a small piece of paper and place it against one of the metal covers. If the paper is sucked in and sticks to the metal grate, that means air is entering the ducts there and there should be an air filter just behind it. Shine a flashlight through the grate to make sure there’s a filter there. Before going further, turn off the AC.

Use a screwdriver to remove each of the screws holding the grate in place. Be careful not to lose the screws. Grab the filter and carefully remove it. It’s important to do this with care, as you don’t want to jar the filter and cause a bunch of dust to fall into the duct. If it hasn’t been too long since the last time the air filter was replaced and you’re not sure if it needs it, inspect it now. Use your best judgment, but generally, if it looks dirty, it is, and should probably be replaced.

A vital step in replacing your air filter is finding its exact size. When you go to the store to get a replacement filter, you’ll need to get the exact same size filter, or it won’t fit, and you’ll waste your money. There should be a number on the air filter you’re replacing somewhere. It’ll say something like 20x20x1 or 8x12x1. Write that number down somewhere. If there isn’t a number, that’s okay, you can get the size manually. Find a tape measure and record the three dimensions of the air filter, thickness, length, and width.

Next, you’ll want to clean out the area where the old filter was. Get a damp cloth and wipe the area of the duct where the filter resided to get some of the dirt and dust out of there. Another important step when getting a new filter is making sure it’s of the same type as the old one. If the air filter doesn’t say on it what type it is, it’s pretty easy to determine yourself. A fiberglass filter looks like a window screen. A pleated filter will be about 1 inch thick and will have a pleated texture. A media filter looks like a pleated filter but will be thicker. Then go to your local home maintenance store and purchase a new filter with the same dimensions and type as the old one. Home Depot will have plenty of options, and whether you’re in Leander or Lakeway, it likely won’t be a far drive to the nearest one.

Putting your new filter in is a simple process. There should be an arrow on the filter that will indicate which side faces the inside of the duct and which side faces out. Follow that and place the filter in the duct opening. Then you just need to screw the metal grate back on and you’ve successfully replaced your air filter.

It’s worth mentioning that all air filters aren’t created the same. Fiberglass filters are the most common type, but also the oldest type and they don’t last as long as other filter types. Fiberglass filters need to be replaced more often, sometimes as often as once a month. Pleated air filters will last longer, and filter more contaminants. HEPA filters (High-Efficiency Particulate Arrestance) are the best that money can buy. If you have household members with significant allergies or asthma you might want to invest in HEPA filters, which must, by the specification of the Department of Energy, filter 99.7% of all particles 0.3 microns or larger.

Air Conditioning Austin: Filter Replacement and Repairs

Air filters are there for two very important reasons: to keep you and your air conditioner healthy. They filter harmful particles out of the air you breathe, that you spend most of your time in. And they collect those particles so that they don’t clog up and damage your air conditioner, saving you from potentially costly repairs and part replacement. So, for both your respiratory health and your wallet’s sake, replace your air filters frequently.

Replacing your air filters frequently can save you from needing to get your air conditioner repaired, but it’s no guarantee of perfect air conditioner function. Quality air conditioning requires quality air conditioning service, in Austin and the surrounding areas, whether that’s Hutto, Taylor, Round Rock, or central Austin itself. This is a hot city in the summer especially, and we know if your AC starts to fail, you’ll want a fix fast. If you do find yourself in need of AC repair in Austin, call AC Express. Our expert technicians can solve any AC related problem. Call today! (512) 866-5520