Air Filter Sizes
Find a wide range of sizes to fit your system. Here are some of our most popular air filter sizes.
Find a wide range of sizes to fit your system. Here are some of our most popular air filter sizes.
Most filters should be replaced every 1 to 3 months, depending on the filter type, your HVAC system, and indoor air quality.
The size is usually printed on the side of your current filter. Common sizes include 16x20x1, 20x25x1, and 16x25x4. You can also check your HVAC unit manual.
Turn off your HVAC system. Locate the filter slot, slide out the old filter, and insert the new one with the airflow arrow pointing toward the system. Turn the system back on.
MERV stands for Minimum Efficiency Reporting Value. It rates the filter’s ability to capture particles. The higher the MERV rating (1–16), the better the filtration.
For most homes, a MERV rating of 8–13 offers excellent filtration without restricting airflow. Higher ratings are better for allergy sufferers or homes with pets.
Only if your HVAC system can handle it. High-MERV filters can restrict airflow in older or less powerful systems.
Fiberglass filters are cheaper and capture larger particles, while pleated filters offer better filtration and last longer.
Turn off your HVAC system, locate the filter compartment, remove the old filter, insert the new filter with the airflow arrow pointing in the correct direction, and close the panel.
Absolutely. High-MERV filters can trap allergens like pollen, pet dander, and dust mites, improving indoor air quality.
Yes, using a filter with too high of a MERV rating can reduce airflow and strain your system if it’s not designed for it. Always consult your system manual or a technician.
Electrostatic filters use static electricity to attract and trap particles. They can be washable or disposable and offer good filtration.
Washable filters can be reused and are eco-friendly, but they typically have lower MERV ratings and require regular maintenance to remain effective.
Most air filters are not recyclable due to the materials used. Place used filters in a sealed bag and dispose of them in your regular trash.
Factors like pets, smoking, construction, and poor ventilation can lead to faster filter buildup. A dirty filter is a sign it's doing its job!
Thicker filters (like 4" or 5") generally last longer and provide better filtration, but only use them if your HVAC system is compatible.
Keep them flat in a cool, dry place away from direct sunlight or moisture to maintain their shape and performance.
Filters with activated carbon can absorb odors from cooking, pets, or smoke, improving overall air freshness.
Yes, a clean filter allows your HVAC system to run more efficiently, reducing energy use and potentially lowering your utility bills.
An HVAC air filter traps dust, pollen, pet dander, and other airborne particles to improve indoor air quality and protect your HVAC system from debris buildup.
Pleated air filters have folds that increase surface area for better filtration. They typically offer higher MERV ratings and last longer than fiberglass filters.
Filters with activated carbon or charcoal can absorb and reduce odors from pets, smoke, cooking, and chemicals.
The nominal size is the rounded number used for labeling (e.g., 16x25x1), while the actual size is the exact measurement (e.g., 15.5x24.5x0.75 inches). Use nominal size when ordering.
When it comes to home maintenance, certain tasks are easy to forget—changing the air filter in your HVAC system is one of them. However, this seemingly small chore can have a big impact on your comfort, your health, your energy bill, and even your HVAC system’s lifespan. In this article, we’ll break down why replacing your air filter regularly is one of the most important things you can do for your home.
Your HVAC (Heating, Ventilation, and Air Conditioning) system’s air filter is a barrier that captures dust, pollen, pet dander, mold spores, and other airborne contaminants before the air is circulated through your home. This filter is usually made of fiberglass, pleated paper, or cloth, and is housed in the return air duct or blower compartment of your system.
Its primary purpose is twofold: to clean the air entering your living spaces and to protect the internal components of your HVAC system from dirt and debris buildup. A clean filter ensures clean air and system efficiency, while a clogged filter can do quite the opposite.
One of the biggest benefits of regularly changing your air filter is improved indoor air quality (IAQ). The EPA estimates that indoor air can be up to five times more polluted than outdoor air. A dirty or clogged filter can't trap as many pollutants, meaning more allergens and irritants are circulating through your home.
This can be especially troublesome for people with asthma, allergies, or other respiratory conditions. Even those without these issues may experience dry throats, sneezing, coughing, or headaches due to poor air quality. Clean filters make a real difference in the air you and your family breathe every day.
A dirty air filter restricts airflow, forcing your HVAC system to work harder to pull air through. This strain reduces efficiency and can increase the energy needed to heat or cool your home. The Department of Energy notes that replacing a dirty filter with a clean one can lower your air conditioner's energy consumption by 5% to 15%.
In other words, not changing your filter makes your system less efficient and more expensive to operate. Over time, the increased strain can cause more wear and tear on the system's components, shortening its lifespan and resulting in costly repairs or even full system replacements.
HVAC systems are a major investment, typically costing between $5,000 and $10,000 or more to replace. Regular maintenance, including changing the air filter, helps protect that investment. A clean filter allows air to flow freely, reducing the risk of overheating or frozen coils, two common causes of system failure.
Dirty filters can lead to clogged ductwork, blower motor failure, and reduced system lifespan. By simply changing the filter, you can add years to your HVAC system’s life, saving you money in the long run and avoiding the hassle of premature replacement.
Energy costs are one of the biggest ongoing expenses for homeowners, and your HVAC system is usually the single largest contributor. When airflow is blocked by a dirty filter, your system uses more energy to maintain your desired temperature. That extra energy translates into higher utility bills.
According to the Department of Energy, heating and cooling accounts for about 48% of the energy use in a typical U.S. home. Replacing your air filter regularly is one of the easiest and most cost-effective ways to reduce your monthly bills and improve efficiency—without compromising comfort.
When your HVAC system is overworked due to poor airflow, it’s more prone to breakdowns. Components like the blower fan motor, evaporator coils, and compressor are forced to work harder and may overheat or fail altogether. These parts are expensive to repair or replace.
Most HVAC technicians agree that many service calls could be avoided by simply changing the air filter on a regular schedule. This small step can help you avoid sudden breakdowns in the middle of summer or winter—when you'll need your system the most and when emergency repair costs tend to skyrocket.
A clean air filter ensures that your HVAC system distributes air evenly and efficiently. When filters are clogged, you may notice uneven heating or cooling, with certain rooms staying too hot or too cold. It can also lead to excess humidity in the summer and overly dry air in the winter.
Changing your filter helps maintain consistent temperatures and proper humidity levels, keeping your home more comfortable throughout the year. It also reduces how often your system cycles on and off, leading to quieter operation and less wear on your system’s parts.
Have you noticed dust accumulating quickly on your furniture, vents, and electronics? Or are your allergies flaring up more than usual? A clogged filter could be to blame. If your filter is too dirty to trap particles effectively, those contaminants will continue circulating through your home.
Changing your air filter regularly helps trap more dust, pollen, pet hair, and other allergens. It’s an essential part of reducing indoor allergens and creating a cleaner living environment for everyone—especially in homes with pets or smokers.
If you've upgraded your HVAC system with a smart thermostat or zoning system, maintaining proper airflow is more important than ever. Smart thermostats rely on accurate temperature readings and steady airflow to work properly. Dirty filters can cause inaccurate readings and inefficient performance, undercutting your investment.
Regularly replacing your air filter helps ensure that your smart thermostat, sensors, and other tech tools can operate as intended and provide the energy savings and comfort you’re counting on.
Changing your HVAC filter is one of the simplest DIY home maintenance tasks. Most filters cost between $10 and $40, depending on the size and type. No special tools or technical knowledge are required—just locate your filter, slide it out, and replace it with a new one. It takes less than 5 minutes.
Compare that to the cost of repairs or increased utility bills and it’s a no-brainer. Spending a few bucks and a couple of minutes every month or two can save you hundreds—or even thousands—over time.
The answer depends on several factors, including:
As a general rule, check your filter every month. If it looks dirty or clogged, replace it—even if it hasn’t reached the manufacturer’s suggested timeline yet. Your HVAC system and lungs will thank you.
Neglecting your HVAC filter can lead to a range of issues, including:
In extreme cases, completely clogged filters can even become a fire hazard or cause the system to shut down entirely. That’s why most HVAC warranties recommend or even require regular filter changes to remain valid.
There are several types of filters available, each with different efficiency levels, measured by their MERV (Minimum Efficiency Reporting Value) rating:
For most homes, a pleated filter with a MERV rating between 8 and 13 offers a good balance of air quality and airflow. Just make sure your HVAC system can handle the filter’s resistance level—some high-MERV filters may restrict airflow too much for older systems.
Changing your HVAC air filter may seem like a minor chore, but its benefits are anything but minor. From improving indoor air quality and system performance to lowering your energy bills and extending the life of your HVAC equipment, it’s one of the best things you can do for your home.
Think of it as cheap insurance—regular filter changes keep your system healthy, your air clean, and your wallet a little heavier. Set a reminder, stock up on filters that fit your system, and make it part of your monthly or seasonal home maintenance routine. Your comfort, your health, and your HVAC system will all thank you.