HVAC Filter Replacement: How Often You Need to Change Your Air Filters

One of the most common questions homeowners ask about their heating and cooling systems is simple: how often should you change your HVAC filter? The answer depends on your filter type, your household, and your lifestyle, but one thing is certain: regular filter replacement is the single most important maintenance task you can do to protect your equipment and keep your indoor air healthy.

In this guide, we'll give you a clear replacement schedule, explain the factors that speed up filter clogging, and help you spot the signs it's time for a fresh one.

HVAC Filter Replacement Schedule by Type

The recommended replacement frequency depends on which type of filter you're using:



• Basic fiberglass filters— Replace every30 days. These thin, inexpensive filters capture only the largest particles and clog quickly.
• Standard pleated filters (MERV 8–11)—Replace every 60 to 90 days. Their folded design creates more surface area, offering better filtration and longer life.
• High-quality pleated filters (MERV 12–13)— replace every 90 days under normal conditions. These capture finer particles, including some allergens and mold spores.
• Deep-pleated media filters / HEPA-style— Replace every 6 to 12 months. These thicker filters require a compatible housing and may not fit all HVAC systems.

Pro tip: Regardless of filter type, check it monthly and replace it whenever it looks visibly dirty. That's always the safest approach.

Factors That Shorten Filter Life

The general schedule above is a starting point. Several household factors can dramatically shorten the time between changes:

• Pets— Homes with dogs or cats should change filters 20–30% more frequently. Pet hair and dander accumulate on filter media much faster than dust alone.
• Household size— More people mean more skin cells, clothing fibers, and cooking particles circulating through the system.
• Allergies or asthma—Sensitive household members may benefit from more frequent changes, even before the filter appears fully loaded.
• Nearby construction or busy roads— External dust sources put extra load on your filter.
• Smokers in the home— Tobacco particles quickly reduce filter effectiveness.

For households with allergies, combining frequent filter changes with other strategies to improve indoor air quality can make a meaningful difference in daily comfort.

What Happens When You Skip Filter Changes

Neglecting your HVAC filter creates a chain reaction of problems that goes far beyond dusty air:

• Reduced airflow— The blower motor has to work progressively harder to pull air through the clogged filter, consuming more electricity and putting serious stress on the motor
• Frozen evaporator coils— Restricted airflow in summer can cause ice to form on the coil, shutting down your cooling
• Overheated heat exchanger— In winter, restricted airflow can cause the exchanger to overheat, potentially triggering safety shutoffs or, in worst cases, cracking
• Contaminant bypass— When the filter is too clogged, air finds gaps around the edges, allowing the very particles you're trying to capture to coat your evaporator coil, blower wheel, and ductwork

That internal buildup reduces efficiency and can promote mold growth inside your air handler, one more reason why testing your indoor air quality periodically is a smart move.

How to Choose the Right HVAC Filter

Picking the right filter means balancing filtration performance with your system's airflow needs:

• MERV 8–13 is the sweet spot for most residential systems, providing effective filtration without choking airflow
• Don't automatically buy the highest MERV rating. Very dense filters create more resistance, which can actually harm your system if the blower motor isn't strong enough to push air through.
• Check the size printed on your current filterbefore buying a replacement. A filter that doesn't fit snugly allows unfiltered air to bypass it entirely.

Not sure which filter works best for your equipment? A technician can give you a personalized recommendation during your regular HVAC maintenance appointment.

Simple Tips to Remember Filter Changes

Even homeowners who know filter changes are important sometimes forget. These tricks help:

• Set a phone reminderon a recurring monthly schedule
• Buy filters in bulkand store them near your HVAC system so they're always handy
• Write the install dateon the edge of each new filter with a permanent marker
• Tie it to another habit, like paying a particular monthly bill or the start of each season

Keep Your HVAC Running Strong with Royal Class Service

Changing your HVAC filter is the easiest, most affordable maintenance task you can perform, and it has the biggest impact on your system's performance and longevity. Stay on schedule, and you'll protect your equipment, lower your energy bills, and breathe cleaner air every day.

At Royal Class Service, filter inspection is a standard part of every maintenance visit. Our technicians recommend the ideal filter type and replacement schedule based on your specific system and household. We serve homeowners throughout the Hudson Valley and greater New York area.



Contact Royal Class Service today to schedule your HVAC maintenance.