Changing your HVAC filter is one of the simplest things you can do to protect your heating and cooling system and improve your home’s indoor air quality. But let’s be honest—life gets busy, and it’s easy to forget.
Your HVAC system works hard to keep your home comfortable, but a dirty air filter can bring it all to a halt. In this blog, Thiele Heating & Air Conditioning explains what happens when filters are neglected, what your options are, and how our indoor air quality service can help.
5 Things That Happen If You Don’t Change Your Air Filter
Your HVAC system needs proper airflow to function efficiently. A clogged air filter restricts that airflow, which leads to some not-so-great consequences. Here’s what could be happening behind the scenes if your filter hasn’t been changed in a while.
1. Poor Indoor Air Quality
A dirty HVAC air filter can quickly turn your system into a delivery route for dust, dander, allergens, and other airborne pollutants. Instead of trapping contaminants, a clogged filter allows them to circulate through your ductwork and settle in every room. That affects the air inside your home—and your health. According to the Environmental Protection Agency, the air inside your home can be 2 to 5 times more polluted than outdoor air, and sometimes even more.
That means when your filter isn’t clean, your home’s air is filled with particles that can trigger allergies, aggravate asthma, and lead to general discomfort. Regular filter changes are one of the simplest and most effective ways to improve your indoor air quality (IAQ) and keep your HVAC system running smoothly.
2. More Dust Around the House
Do you feel like you’re dusting more than usual? Your filter might be to blame. When filters are clogged and ineffective, dust and debris settle on furniture, surfaces, and vents. You’ll spend more time cleaning—and still feel like things never stay clean for long.
3. Strain on Your HVAC System
Your HVAC system was designed to move air efficiently. When airflow is blocked by a clogged filter, the system has to work harder, causing stress on components like the blower motor or compressor. Over time, this extra effort can lead to overheating, mechanical failure, or a complete system breakdown.
4. Higher Energy Bills
If your heating and air conditioning system is working overtime to push air through a dirty filter, it’s using more electricity than it should. According to the Department of Energy, homeowners can save up to 15% on energy bills just by keeping up with their AC filter replacement. That’s an easy win for your budget.
5. Reduced System Lifespan
When an HVAC system is constantly overworking, parts wear out faster. The added stress can shorten the lifespan of your equipment and lead to costly repairs or early replacement. Changing your air filter on a regular schedule is one of the easiest ways to protect your investment.
How Often Should I Change My Air Filter?
So, when are new air filters needed? It’s one of the most common questions we get—and a good one. The answer depends on your home, your HVAC system, and your lifestyle. Filters don’t last forever, and as we just discussed, waiting too long to change yours can lead to all sorts of issues, from reduced airflow to poor IAQ. Here’s a quick guide to how often you should replace your air filter:
- Every 1–2 months if you have pets, allergies, or someone in your home has a respiratory condition.
- Every 90 days for the average home without pets or allergies.
- Every 30–45 days during high-use seasons like peak summer or winter.
- Every month if you use lower-end fiberglass filters or have multiple people in the home.
- Every 6–12 months for some high-efficiency, manufacturer-specific filters (always follow the label).
No matter what type of HVAC system you have, staying on top of filter changes is an easy way to protect it and improve the air you breathe. When in doubt, just check the filter—if it looks gray or clogged, it’s time for a fresh one.
Your HVAC Air Filter Options (And How to Choose the Right One)
Air filters come in different sizes and styles, and not all filters are created equal. So how do you know what’s right for your home?
First, know your MERV rating. MERV stands for Minimum Efficiency Reporting Value—it tells you how well a filter captures particles like dust, mold, and pet dander. The higher the MERV rating, the better the filter is at trapping smaller contaminants. But keep in mind: higher MERV filters may restrict airflow in older systems not designed for them.
Here are a few common filter options and what they do best:
Fiberglass Filters
- Budget-friendly and disposable
- MERV rating: around 4
- Good for homes without allergy concerns
- Must be replaced every 30–60 days
Pleated Filters
- Better filtration with more surface area
- MERV rating: 5–8
- Captures mold spores, dust mites, and pollen
- Lasts 60–90 days depending on usage
Electrostatic Filters
- Reusable and washable
- MERV rating: around 8
- Great for homes with pets or allergy sufferers
- Needs regular cleaning every 1–2 months
HEPA Filters
- High-efficiency filtration
- MERV rating: 17+ (not all systems can support them)
- Captures up to 99.97% of pollutants including bacteria and viruses
- Ideal for severe allergy or asthma concerns
Not sure which filter is compatible with your HVAC system? Just contact Thiele. We’ll help you select the best filter for your needs and show you how to keep it maintained.
Contact Thiele for Your Home’s Heating, Cooling, and Indoor Air Quality Needs
Since 1883, Thiele Heating & Air Conditioning has been serving homes across Central Indiana with expert HVAC services. From air conditioning installation to seasonal maintenance and air quality testing, we’re here to keep your system running strong and your air clean.
We offer a variety of indoor air quality solutions including air purifiers, humidifiers, and air cleaners to help you breathe easier and stay healthier year-round. Our NATE-certified technicians install, repair, and maintain HVAC systems of all types and brands—and we’re happy to answer your questions along the way.
Want to take air filter maintenance off your to-do list for good? Join our Annual “Rewards” Service Agreement Maintenance Program and enjoy:
- Seasonal HVAC tune-ups (spring and fall)
- 15% discount on parts and repairs
- Priority service when you need it most
We check your filter, inspect your system, and keep everything running as it should—so you can focus on everything else. Clean air, better airflow, fewer breakdowns: that’s the Thiele difference.
Interested in an indoor air quality service or an HVAC maintenance appointment in the Indianapolis area? Call Thiele Heating & Air Conditioning today or request service online. Let’s take great care of your home together.
