How often should I replace my HVAC filter if I have pets or allergies?
Changing your HVAC filter is a quick, 10-minute task that can improve your home’s air quality, lower energy costs, and extend your system’s life. Here’s what you need to know:
Regularly replacing filters (every 1–3 months for standard filters) keeps your system efficient and your air cleaner. Look for filters with a MERV rating of 8–13 for most homes. Set reminders to check your filters monthly, especially if you have pets or allergies.
Getting all you need before you start will make changing an HVAC filter easy. The good news? No special tools needed – just some simple things from around the house.
Begin with a small flathead screwdriver – some panels may need one to open. Use a flashlight or your phone’s light to see well, if the filter is in a dark place. Also, wear work gloves to keep your hands clean and safe from any sharp parts.
If the filter is up high, step up safely with a step stool – don’t use a chair or stretch too much. For cleaning, a microfiber cloth is best, and a vacuum with a brush attachment helps with washable filters. To clean tight spaces, wrap the cloth around your screwdriver.
When your tools are set, you’re ready for the next thing: finding the right new filter.
Getting the right filter size is key. Check the size on your old filter (length x width x depth) and the model number. Not sure? Snap a picture of its label for help. If there’s no label, look in your HVAC manual or measure the filter space.
Know that filter sizes are often shown as “nominal sizes,” which are a bit bigger than real sizes. To find the nominal size, round your measurements to the nearest inch. For instance, a filter marked 16x20x1 might be close to 15.5×19.6×0.75.
The filter should fit in its spot with no need to push it hard. If you use more than one HVAC unit, mark each filter spot to keep them straight. Note the size in this order: length x width x depth, and check the way the arrows point on your old filter.
Most filters are a set thickness: 1″ (real 0.75″), 2″ (real 1.75″), and 4″ (real 3.75″). If these sizes don’t work for your system, you can get them made to fit.
Now that you have your tools and replacement filter ready, it’s time to locate your current filter. Most filters can be found on or near the return air grille.
Start by locating the return air grille. These are typically found on walls, floors, ceilings, or inside utility closets. They’re larger than standard air vents and pull air back into your HVAC system.
For wall-mounted grilles, the filter is often positioned behind the cover. Simply remove the grille cover to access the filter compartment.
If the filter isn’t there, check your air handler unit or furnace. Many filters are housed in the blower compartment, often sitting in a tray or behind a small door. Look for a removable panel near the unit to find the filter area.
In older systems, filters might be located inside a duct opening, upstream of the air handler. While this is less common, it’s worth checking if other areas don’t have the filter.
Don’t forget to inspect less obvious spots like basements, attics, or the back of closets. Look for a narrow slot, about an inch wide, with a hinged or removable cover. These hidden compartments can sometimes be overlooked.
If your HVAC system has a return in each room, there could be a filter behind every return grille. Take time to carefully inspect your home for multiple filters.
Another tip is to follow the path of the return air ducts. This can help you locate any access points along the system.
Once you’ve pinpointed the filter’s location, it’s time to safely power down your HVAC system.
Before removing the filter, make sure to turn off your HVAC system. Shutting it down not only ensures your safety but also prevents debris from being drawn into the system while you work.
Locate the power switch on or near your furnace and switch it to the “off” position. Most units have a clearly labeled switch or dial for this purpose. Alternatively, you can turn off the system using the thermostat, a wall switch, or the circuit breaker – whatever is most convenient for your setup.
Wait until the system fully powers down. You’ll know it’s off when the blower stops running and no air is coming from the vents. Taking this step will help protect your equipment and make the process cleaner.
With the system off and the filter located, you’re ready to remove the old filter and install the replacement.
Taking out an old filter is a simple process, but doing it carefully helps prevent damage and keeps dust from spreading.
Before you begin, take a moment to inspect your setup. Access panels are usually held in place by screws, clips, J-hooks, or twist locks. If screws are involved, grab a screwdriver, remove them, and keep them in a safe spot. For panels with knobs, turn them counterclockwise to unlock. Some panels may need to slide up or sideways about ½ inch before they release. If there’s a handle, gently wiggle and slide it free. If the panel feels stuck, apply steady, even pressure.
If tape seals the panel, carefully cut through it with a utility knife, ensuring you don’t damage the panel or nearby parts. Once the panel is open, you’ll notice a gasket along the edges. This gasket ensures an airtight seal, so handle it gently to avoid tearing or damaging it.
Pay attention to the arrows on the filter that indicate the airflow direction before removing it. These arrows are key for installing the new filter correctly.
For most setups, the arrows should point toward the furnace or ductwork. If your filter is in a ceiling or wall return, the arrow should face the ductwork, meaning it points toward the ceiling or wall.
Once you’ve removed the filter, dispose of it carefully. Then, clean the filter slot using a damp cloth or a vacuum brush to remove dust and debris. Pay special attention to the gasket and slot edges, wiping away any buildup. Avoid using too much moisture – this could harm nearby electrical components or create conditions that encourage mold growth.
With the area clean and the airflow direction noted, you’re ready to install the new filter.
With the old filter out and the area cleaned up, it’s time to put in your new filter. Double-check that your replacement is the right fit and properly oriented to keep your HVAC system running smoothly.
Before installing the new filter, make sure its size matches the old one and that it meets your HVAC system’s specifications. Using the wrong size can mess with airflow and reduce efficiency. A filter that’s too small might let particles slip through, while one that’s too large could get crammed in, risking damage.
You’ll usually find the size printed on the side of the old filter or in the owner’s manual. If not, measure the length, width, and thickness of the old filter to ensure a perfect match.
The right filter should slide in easily. If you’re forcing it or bending it to make it fit, it’s probably too big. On the other hand, if there’s more than a finger-width gap between the filter and the compartment edges, it’s too small.
Don’t forget to check the filter’s MERV rating. Most residential systems work best with filters rated between MERV 8 and MERV 13. A filter that’s too dense can make it harder for your system to circulate air effectively.
Once you’ve confirmed the size and rating, you’re ready to install.
Proper orientation is crucial for your filter to work as it should. Look for the arrow printed on the filter that shows the airflow direction. For most systems, the arrow should point toward the furnace. If your filter is for a ceiling or wall return, the arrow should point toward the ductwork. Installing the filter backward can restrict airflow and strain your system.
Slide the filter in snugly to prevent air from leaking around it. Once it’s securely in place, reattach the access panel. Tighten screws, snap clips, or secure twist locks as needed. If you removed tape earlier, apply new tape to maintain a tight seal. Finally, check that the gasket around the panel edges is seated properly to keep unfiltered air from sneaking into your system.
Now that your new filter is securely in place, it’s time to get your HVAC system running again. Start by checking that your thermostat is set to your desired temperature.
Begin by turning off the AC at both the thermostat and the circuit breaker. If your unit has a reset button, press and hold it for 3–5 seconds. Wait about 30 seconds before switching everything back on.
Once the power is restored, set your thermostat to “cool.” Listen for the system to cycle on and check that it’s blowing air properly. If everything seems to be working as it should, you can move on to setting up a regular filter replacement schedule.
To keep your HVAC system running efficiently, regular filter changes are a must. For standard filters, replacements are typically needed every 30–60 days. High-efficiency filters can last anywhere from 90 days to six months, but it’s a good idea to inspect them monthly.
“To keep your unit running efficiently, air filter replacement is crucial. Whether you need to replace it every 30 days or every 90 days, it’s important to stay proactive about your HVAC system’s needs.” – Summit Air Conditioning & Heating
Signs that it’s time to change your filter include visible dirt, discoloration, or reduced airflow. Keep in mind that factors like larger homes or poor outdoor air quality can cause filters to clog more quickly, while lower occupancy might allow them to last longer.
Replacing a clogged filter can improve your system’s efficiency by 5–15%. To stay on top of this, consider setting a monthly reminder to check your filter.
Choosing the right filter for your home is easier when you understand the differences between disposable and reusable options. Each type has its own benefits.
| Feature | Disposable Filters | Reusable Filters |
|---|---|---|
| Initial Cost | ~$15 each | $25–75 each |
| Replacement Schedule | Every 30–90 days | Clean every 1–3 months |
| Lifespan | Single use | 5–10 years |
| MERV Rating | 4–12 (up to 95% particle capture) | 1–4 (up to 75% particle capture) |
| Maintenance | Simple replacement | Wash, dry, reinstall |
| Environmental Impact | Creates waste | Reduces landfill waste |
Disposable filters are highly effective at capturing particles and are simple to replace. On the other hand, reusable filters, while more expensive upfront, can save you money over time if maintained properly.
Taking just 10 minutes to change your HVAC filter can significantly improve your home’s air quality and keep your system running efficiently. Here’s the process in a nutshell: turn off your HVAC system, locate the filter compartment, remove the old filter (noting the airflow direction), and replace it with a new filter of the correct size and MERV rating. This simple task not only enhances air quality but also helps you save on energy costs and extends the life of your HVAC system.
Regular maintenance of your HVAC filters can improve system efficiency by 5–15%, which translates to lower energy bills and less wear and tear on your equipment.
Did you know that indoor air can be two to five times more polluted than outdoor air? By changing your filters regularly, you can trap dust, pollen, and other harmful particles, helping to protect your family’s health.
It’s a good idea to inspect your filter every month, and most standard filters should be replaced every 1–3 months. However, homes with pets, smokers, or allergy sufferers may need more frequent changes. When buying replacement filters, aim for those with a MERV rating of 13 or higher for better particle removal.
Experts also suggest looking for filters that meet specific allergen reduction standards:
“When selecting air filters, we recommend looking for filters with a Minimum Efficiency Reporting Value (MERV) rating of 13 or above, to effectively remove small particles. Additionally, we advise seeking filters that carry the CERTIFIED asthma & allergy friendly® mark, as they meet specific standards for allergen reduction.”
If you have pets or deal with allergies, you should aim to replace your HVAC filter every 15 to 30 days. Pet hair, dander, and allergens can quickly build up, clogging the filter and impacting both air quality and the efficiency of your system.
Swapping out filters on a regular basis does more than just improve the air you breathe - it also keeps your HVAC system running at its best. Make it a habit to check your filter often and adjust how frequently you replace it based on the specific needs of your home.
If you can’t find the exact filter size, start by measuring your current filter or the dimensions of the filter slot in inches (length × width × depth). Then, look for a slightly smaller filter that fits snugly without leaving any gaps. Never use a larger filter, as it might not fit correctly and could impact your system’s performance.
If standard sizes don’t work, you may need a custom-sized filter. Many manufacturers or HVAC professionals can create one tailored to your system’s requirements. Just make sure the replacement filter is compatible with your system to keep it running efficiently and maintain good air quality.
A clogged HVAC filter can lead to a range of noticeable problems. You might find that the airflow from your vents feels weaker, or that certain areas of your home have inconsistent temperatures. Another clue could be higher energy bills, as your system has to work overtime to keep your home comfortable. In some cases, you might even notice your system overheating or experiencing frequent breakdowns, which can result in expensive repairs if ignored.
To keep your HVAC system running smoothly and maintain better indoor air quality, it’s smart to check and replace your filter regularly - usually every 1–3 months, depending on how often you use the system and the type of filter you have.
