Dust Bunnies and Fur: When to Change an Air Filter

Air filters play a crucial role in keeping your home's air clean and your HVAC system running smoothly. By trapping dirt, dust, pollen, and even pet fur, air filters prevent these particles from circulating back into your living spaces and protect your system from unnecessary strain. Changing an air filter regularly is one of the simplest yet most effective steps homeowners can take to improve indoor air quality and reduce energy costs. In this guide, we'll walk you through the ins and outs of air filters and how often you should really be changing them.

When changing an air filter, it helps to know what kind of filter you're working with. Your HVAC system manufacturer may have a recommended type of filter, or after changing a few yourself, you might find one you like best. Here are the most common options homeowners will come across:

• Fiberglass: These are the most basic and budget-friendly options. Fiberglass filters are made with layered fiberglass fibers that trap large particles like dust and lint. However, they still allow smaller particles through compared to other filter types. They're a good choice if you want inexpensive filters and don't have allergies or pets in the home.
• Pleated: A step up from fiberglass, pleated filters are made with folded material that increases the surface area for capturing particles. While typically more expensive, this design makes them more efficient at trapping smaller debris such as pollen, pet dander, and mold spores.
• HEPA: High-Efficiency Particulate Air (HEPA) filters are the gold standard in filtration. They can capture up to 99.97% of particles as small as 0.3 microns, making them ideal for households with severe allergies, asthma, or respiratory concerns. However, not every HVAC system is designed to handle HEPA filters, so check your unit's specifications before installing one.
• Flat: Flat panel filters are similar to fiberglass filters but can vary. Some capture only large particles, while others use denser materials for finer filtration. Their simple design makes them easy to replace, but like fiberglass options, they often need to be changed more frequently to maintain airflow and efficiency.

The most obvious sign is a filter that looks dirty or clogged with debris. If you notice your HVAC system isn't heating or cooling as effectively as before, a blocked filter could be restricting airflow and forcing the unit to work harder. Another red flag is a sudden increase in your utility bill, which can happen when your system runs longer to push air through a clogged filter.

You might also wonder, "Can't I just wash it and put it back?" While a few specialty filters are reusable, most standard filters are designed to be replaced, not cleaned. Ignoring this step could lead to poor air quality and potential damage to your HVAC system.

Even though most HVAC professionals recommend changing an air filter every one to three months, the right schedule for your home depends on several factors. Understanding what can shorten or extend the life of your filter will help you keep your system running smoothly without over- or under-replacing it.

Pets

If you have cats or dogs, expect to change your air filter more often. Pet hair and dander quickly clog filters, reducing airflow and spreading allergens through your home. Homes with multiple pets often need a fresh filter monthly to stay on top of fur and odor.

Allergies

For households with allergy or asthma sufferers, clean air is a top priority. A dirty filter can let pollen, mold spores, and dust recirculate indoors, worsening symptoms. In these cases, switching filters every 30 days—or even sooner during peak allergy seasons—can make a big difference.

Local Air Quality and Seasons

Your environment plays a big role, too. If you live in a city with high pollution, a rural area with lots of dust, or a region affected by wildfire smoke, your filters will clog faster. Seasonal changes also matter—spring pollen and summer dust storms can all shorten the lifespan of a filter.

Dust Tips: Clean the Return Vent

Sometimes, the problem isn't just the filter itself—it's the vent. If your return air vent (the large grille where your filter sits) collects layers of dust, that debris ends up on your filter sooner. Wiping the vent down regularly with a duster, a damp cloth, or a vacuum brush can help your filter last longer and improve airflow.

Changing an air filter is simple, but doing it correctly makes all the difference in how well your HVAC system performs. Here's a step-by-step guide you can follow:

1. Turn off the system
   Always start by switching your HVAC system off at the thermostat. This prevents unfiltered air from being pulled through the system while you're changing the filter.
2. Locate your filter
   Air filters are usually found in one of two places: behind the return air vent (a large grille on a wall or ceiling) or inside the furnace or air handler. Depending on the setup, you'll either pull back small tabs or unscrew the cover to access the filter.
3. Remove the old filter
   Slide the filter out carefully and throw it away if it's disposable. Most household filters are not reusable—unless you've purchased a washable specialty filter, assume it's meant to be replaced.
4. Install the new filter
   Look for the airflow arrows printed on the side of the filter. These arrows should point toward your HVAC unit (away from you when you're standing at the return vent), ensuring that air flows through the filter in the right direction.
5. Make sure it fits snugly
   The filter should slide in smoothly and sit securely in place. Double-check the dimensions before turning the system back on if it's loose.
6. Turn on the system
   Once the filter is installed, switch your thermostat back on to resume normal heating or cooling.

Take a marker and jot the installation date on the filter's edge or in the space provided. This simple step helps you remember when it's time to check or replace it again.

Take a marker and jot the installation date on the filter's edge or in the space provided. This simple step helps you remember when it's time to check or replace it again.

Changing an air filter is a simple task that makes a big difference in your home's air quality and HVAC efficiency. With the right filter and a regular replacement schedule, you can lower utility costs and protect your system from unnecessary wear. McCoy's has the air filters and expert advice you need to keep your home comfortable year-round.