Why Do My Air Filters Get Dirty So Quickly?

Air filters are the unsung heroes of any HVAC system. Not only do they help protect your HVAC system, but they help keep the air in your home clean. So, why do my air filters get dirty so quickly?

Air filters get dirty fast when you live in a home with pets and a large family due to excessive contaminants. Remodeling your home also releases lots of contaminants in the air that can clog your filters. Filters quickly get dirty when an HVAC system runs more frequently during extreme seasonal temperature fluctuations. 

Replace your air filter no later than once every 90 days to avoid straining your HVAC system. However, it’s worth checking the filter monthly, as you may need to replace it sooner. Follow along as we explore why your air filters get dirty so quickly, and highlight how to avoid this problem.

What Causes Air Filters To Get Dirty?

1. Pet Hair

Do you have a pet or two that shed a lot? If so, that could explain why your air filters get dirty so quickly. Pet hair is one of many contaminants that blows around in a home and eventually winds up in an air filter.

Excessive pet hair is often more cumbersome than standard dirt and dust. It can even clump together with dirt and dust, further clogging the air filter. You may need to replace your air filters sooner than every 3 months if you have many pets.

Otherwise, it’s worth regularly brushing your pet’s hair, collecting it, and throwing it away. Invest in lint rollers to keep your clothes and surfaces clean. That way, less dog and cat hair is likely to get into your HVAC system and clog the air filters.  

2. Recent Construction

Construction and renovations are quite messy, and the process can affect your HVAC system. Plenty of debris gets in the air between all the cutting, sawing, sanding, and hammering. Not only does this make the surfaces in your home dirty, but it can also clog your air filter.

Eventually, this debris can wind up in your HVAC system when the AC or furnace runs. Luckily, the air filter will catch much of this debris, stopping it from spreading throughout your home. However, this can quickly clog your air filter, rendering it useless.

It’s worth routinely checking your air filters during renovations and construction. You may even need to replace your filter a few times during long-term construction. While it may be inconvenient, it can protect your HVAC system from unnecessary strain. 

3. Excessive Use

Constantly running the fan on your HVAC system is bad for many reasons, including the toll it takes on an air filter. The more frequently the fan runs, the sooner the air filter can become clogged. It’s all too easy to set your fan to “on” and forget about it.

This can increase your energy bill, strain your HVAC system, and clog your air filter. Ideally, you should set your fan to “auto”, so it doesn’t run all day. Otherwise, dust, debris, dirt, and pet hair will constantly cycle through the air filter.

Setting your fan to “auto” ensures it only runs as needed to keep up with the set temperature. This typically entails running for 10 to 20 minutes, but it can run longer in some cases. Even that can be excessive at times, but it’s better than running constantly. 

4. Dirty Air Ducts

Many homeowners understandably forget about the air ducts in their homes. After all, they are out of sight and don’t require as frequent maintenance as other parts of an HVAC system. However, dirty, neglected air ducts can explain why your air filters get dirty so fast. 

Like filters, air ducts get dirty because of everything from dirt and dust to dead skin cells, pet hair, and even mold. Ductwork carries air throughout your home where it comes out of several vents. Dirt, dust, and other contaminants can enter your ductwork just as easily as air comes out of it.

Dirty air ducts can quickly clog your filters, and clogged filters can make air ducts even dirtier. You can combat this problem if you change your filter every 30-90 days and regularly have your air ducts cleaned. The average homeowner has their air ducts cleaned every 4 years, but any time between 3 and 5 years is ideal. 

5. You Live In A Full House

The number of people living in your home affects many aspects of your HVAC system, including the air filter. Naturally, the more people there are, the more dirt, dust, debris, and dead skin cells there is to accumulate. This can understandably lead to a messier home, and much of this mess winds up in the HVAC system. 

In many cases, it’s necessary to replace air filters sooner than the recommended 90-day mark. For example, you may need to replace your filter in 60 days or less if you live in a 4-5-person household. This takes some trial and error, and you must pay attention to how quickly your filter gets dirty. 

Ideally, you should at least check your air filter monthly. This makes it easy to keep track of how quickly it gets dirty, so you can replace it before it’s too late. Today, they make reusable air filters that you can wash. These come in handy in large homes, but you must keep up with cleaning them. 

6. The Type Of Filter You Use

Using the best air filter for your home is essential to HVAC maintenance. Many homeowners use 1” pleated air filters because of how effective they are. While they are effective, they also quickly become dirty and must be replaced.

That’s because of the unique surface of these filters that won’t let anything get past them. They catch small and large debris, which helps keep your home and ductwork clean. However, it’s a double-edged sword, as they work so well that it doesn’t take long for them to get clogged. 

This is a great option for homeowners who are sensitive to contaminants and prone to allergies. That said, you may want to switch to a thicker filter if you struggle to keep up with replacements. 

7. Temperature Fluctuations

Many homeowners notice that their air filters quickly get dirty at the start of a new season. That’s because HVAC systems kick into high gear when temperatures quickly increase and decrease. For example, your AC will likely run more when it gets quite hot.

This means that more air will move through your ductwork, whether it’s your AC running in summer or the furnace in winter. That’s why you may notice your HVAC system struggles during extreme temperature fluctuations. HVAC systems get strained when filters get clogged, and that’s more likely during temperature spikes. 

Routinely check your air filter during extreme temperature changes and replace it as needed to protect your HVAC system. 

Summing It Up

Air filters quickly get dirty during construction and renovations in a home because of airborne contaminants. Hire an HVAC contractor to clean your ductwork if they haven’t been cleaned in over 5 years. Set your thermostat’s fan setting to “auto” instead of “on” to minimize how much dirty air passes through the filter.

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