If you have a furnace, it has a filter (or it should!). It’s probably not something you think about too often, but it’s among the most important components of your entire HVAC system.
The efficiency and power of your system, the cleanliness of the air in your home, your health, and even the continued operation of your HVAC system rely in part on the filter.
You can easily change a furnace filter yourself, but many homeowners and renters don’t know how to do this. Below, we’ll walk you through the steps to changing your filter, and also explain what makes some filters better than others and when you’ll want to change filters. Each can be vitally important to the comfort in your home.
How to Change Your Furnace Filter
Here’s a quick step-by-step method for changing your furnace filter:
- Turn off your HVAC system.
- Locate the filter in your furnace unit. Often there’s an obvious insert that identifies it. The filter will be at the end of the return air drop in the ductwork as it flows back into the system.
- Remove the outer casing and slide the old filter out of the unit.
- Insert your new, clean filter, ensuring that it is positioned the correct way. There should be an arrow or similar symbol on the filter that indicates the direction the air should flow through it.
- Ensure the filter is properly positioned and locked in place. Turn your HVAC system back on.
That’s really all there is to it. It shouldn’t take you more than a few minutes once you’re used to the process.
How Often to Change Your Furnace Filter
It would be a copout to say “it depends” because there are ways you can know when you should be changing your filter. Some filters will last longer than others, but here are some ways you can schedule filter changes at the correct times:
First, filters usually come with recommendations for a replacement schedule. Some will last as long as a year, while your cheapest filters are usually only designed to last for a month before they need to be replaced.
Most will fall in the 3-6 month range, but this alone isn’t enough to be sure.
Here are some factors that can affect the longevity of a filter:
- How often are you using the HVAC? Constant use will cause a filter to clog more quickly.
- Any pets in the home? The more there are, the quicker a filter will fill with hair and pet dander.
- Are there smokers in the home? This affects air quality and can overwork a filter more quickly.
- What’s the smog/pollution level? General air quality in the area isn’t separate from your home, particularly if you frequently have the windows open.
Lastly, here’s an easy way to get a better idea: look at your filter occasionally! It will be obvious when it starts to get really dirty or clogged.
Make sure your system is turned off before doing this, but it’s even quicker to check an existing filter than it is to replace it.
Dangers of a Dirty Filter
Dirt! Mold! Pet dander!
Ok, so maybe those aren’t the most scary things, but I bet you’ll notice if you have more of those particles in the air you breathe.
We’re going to talk more below about just how powerful filters can be, up to and including capturing bacteria and virus particles. But a clogged or dirty filter won’t be able to do that.
Here are some of the possible dangers associated with dirty or clogged filters:
- The air you breathe will have more allergens.
- Odors will linger for much longer in the home.
- Bacteria and virus particles will exist in your home for longer, risking illness.
- Airflow will be slowed, causing your system to perform more poorly.
- Air flow issues will eventually cause a system to work harder and more often, which increases wear & tear on the entire HVAC system.
- A clogged filter may back up airflow entirely, causing a system shutdown or breakages in certain parts.
- Your ductwork will begin to clog with debris, making it harder to keep your home clean even after you replace the filter.
That’s a lot, right? And all because you put off changing your filter for too long.
When you look at it like this, the case for changing filters regularly becomes much stronger.
Don’t give an HVAC company more money to repair or replace your system. Keep your current one working longer and better with regular filter replacements!
Choosing the Best Furnace Filter
Furnace filters are not created equal. In fact, there’s a wide range of types and quality.
This can be important for more reasons than you may realize.
Did you know that your filter can stop virus particles? And bacteria? This includes well-known virus strains like the flu and COVID-19.
This doesn’t mean you won’t get sick during flu season, for example, but a good filter can reduce your chances considerably.
Not all filters do this, though. What determines which ones do and don’t? To discuss that, we have to discuss efficiency ratings.
MERV Rating and Filter Efficiency
The strange-sounding MERV Rating stands for Minimum Efficiency Reporting Value. You don’t need to remember that, just that it is a numerical rating that tells you how good a filter is at capturing particles.
Higher MERV ratings are better. The scale ranges from 1-20, but usually you’ll see filters between MERV 8 and 16.
Studies have shown that to consistently trap virus particles, MERV 13 or higher is required. So if this is a concern for your home, now you know the efficiency threshold to buy.
Filter Density
The other variable filters have is their width. Typically this is either 1-inch or 3-inch.
You can have identical MERV ratings with different widths, but these are not always equivalent.
The thinner, 1-inch filter will have higher density in order to capture the same amount and type of particles that a wider filter will.
In terms of particle capture, it’s the same, but the increased density can inhibit airflow, and so your best furnace filters tend to be the wider ones.
The slot for the filter in your HVAC system may only allow one or the other of these widths, so you may not have a choice between the two. When in doubt, consult the operating manual for your equipment or contact your HVAC contractor.
Tune-ups and Filter Changes
If your system has been operating fine for years and you’ve never personally replaced the filter, it’s likely because your HVAC contractor is performing this task during routine maintenance.
Filter replacements are often included in tune-ups and maintenance packages from HVAC companies.
If you are good about scheduling your yearly tune-up for major equipment (usually once in the Fall for your heating system and once in the Spring for your air conditioner or other cooling equipment), you may never have to worry about it.
However, if you are subject to any of the risks we mentioned above, this may not be often enough for optimal operation of your system. Speak with your HVAC partner to determine if you should be replacing the filter more often than just at these regular checkups.
Furnace Filters in Rental Properties
Heating is a requirement for rental properties here in the state of California, and most other states have similar laws.
This doesn’t always mean you’ll have a furnace filter, though. You may have baseboard heating, for instance. However, many rental properties will have a furnace, and thus a furnace filter.
You’ll want to refer to your lease agreement for details, but in many situations, your landlord is responsible for replacing the furnace filter and will do so periodically.
Other times, you may have to request that it be replaced, or replace it yourself. The steps above for replacing a filter are no different, but it’s advised that you speak to your landlord before doing this yourself.
Buy Your Furnace Filter Here!
CABS Heating and Air Conditioning has a built-in filter shop right here on our website. If you live anywhere in the contiguous US, you can order and ship your filters to your doorstep and choose from a wide variety of high-quality filters!
VISIT: CABS Filter Shop
Furnace Upkeep and Home Comfort
A filter is small but mighty. It keeps your home clean and your air healthy, can trap virus particles, and contributes to the efficient operation of your entire HVAC system.
Replacing your furnace filter isn’t the only step you need to take to ensure these things remain true. Regular maintenance from a trusted HVAC professional is required as well, both for optimal performance and to monitor for any concerning repairs or maintain your system’s warranty.
This simple step of replacing a filter isn’t followed by many people, though. We’ve even seen homes without ANY filter!
The dangers of this are myriad, and they can all be avoided with a few simple steps. We hope you feel more empowered to change your filter now, and when you need tune-ups or repairs, we hope you’ll think of us here at CABS Heating and Air Conditioning first!
