When to Replace Air Filters in a Home:

Best Practices + Tip

You already know how important it is to change your air filter. The trouble is, you’re not sure when to start.

For most US households, you should replace your air filter at least once every 30 days.

But depending on your living situation, it may be more complicated than that.

Here’s everything you should know about when to replace air filters in a home (according to your household size and location).

When To Replace Air Filters in a Home

As mentioned, you typically replace air filters in a home at least once every 30 days. You can set a reminder on your phone to stay current, or mark it on your calendar (if that works better for you). Some people like to change their filter on the day they pay their mortgage. If this schedule works for you, by all means, give it a try.

But let me call out the elephant in the room — I know you’ve seen filters advertising ’90 day lifespans.’ As an HVAC technician of 20+ years, I can confidently tell you this is (usually) a marketing ploy.

Ultra-cheap filters can sometimes last this long, but at that point, you’re not really filtering anything in the first place. Higher quality filters will trap lots of dust and particles, which means they need to be swapped out at least once per month.

I’d like to point out that the ‘once per month’ rule typically applies to couples and families. There are a few instances where you can go longer.

You may be able to change your air filters less frequently if:

• You live alone. You won’t be kicking up as much dust and detritus.
• You don’t own pets. Cats and dogs shed several pounds of fur each year (depending on their size).
• You don’t work at home. If you do, you’re more likely to stir up particles.

If any of the above apply to you, I’d recommend changing your air filter every 60 days. But again, this is largely a personal decision. You should check your filter month to month and see how the pleats look depending on your activity.

On the other hand, you may have to change your air filters more frequently if:

• You own more than one indoor pet. That’s a lot of fur and dander, and it’s likely to clog up your filter quickly.
• You live with children. No matter how much you clean, children still find ways to pick up dust.
• Your home is in dry or dusty conditions. The same logic applies if you often experience wildfires.

In these situations, I’d recommend changing your air filter at least once every two weeks. But again, your specific frequency may vary. Start checking your filter after two weeks or so — this allows you to make an informed decision.

How To Keep Your Air Filters Cleaner For Longer

Let’s get this out of the way: you can’t (or at least shouldn’t) skimp on filter lifespan. There’s no vacuuming old filters or airing them outside. Once they’re used up, they’re only good for the trash.

But if you’re looking to maximize the lifespan of each filter, I have a few strategies to recommend:

• Keep your house clean. It may not be the most exciting advice, but it really does work.
• Get your ducts cleaned. I only recommend this if your home is very dirty (or if you’re about to move into a new home).
• Change your filters regularly. It may sound counterintuitive, but the more filtration you provide for your HVAC system, the longer it will take for future filters to clog.

Now, let’s talk about the types of filters you should buy.

What Filters Should You Buy?

When the time comes to replace your filters, don’t make the mistake of settling for low-quality options.

Will they be cheaper? Probably, yes. But will they provide good quality? Absolutely not. You may even need to replace them more frequently, which defeats the purpose of buying lower-cost items in the first place.

Here are my rules of thumb to help you make better decisions:

Don’t Buy:

• Fiberglass: Avoid these like the plague. They trap so few particles that they’re barely worth the cost. In fact, they tend to become more efficient the longer they stay in your vents.
• Ultra-High MERV: I recommend a max of MERV of 13 for residential homes. Any higher than that (say 14, 15, or 16), and you may run into some trouble with airflow.
• ‘Cleanable’ Filters: These may sound like a great idea on paper, but believe me, they’re not worth the novelty. Even if you can ‘clean’ a small part of these filters, there will still be some buildup in places you can’t reach. This will make your filter dirty faster, restrict HVAC airflow, and otherwise put strain on your system.

Do Buy:

1. Proper MERV: Like I mentioned earlier, you should aim for a MERV of 13 or less. If you’re looking for a specific effect (like odor reduction, for example), you may want to look for a carbon filter.
2. Commercial Grade: Commercial-grade filters refer to the actual construction of each filter. This means they come with a two-piece frame, have diagonal supports, and are properly bonded so the pleats won’t bend or bow. Grab Filters offers these.
3. Sealed Edges: You need your filter to sit flush against the duct opening. Otherwise, you’ll be allowing your HVAC system to pull in unwanted particles. It’s almost as bad as running your AC without a filter.

If you’re looking for filters that meet all three criteria, you can start right here with Grab Filters. We offer custom filter sizes and some of the fastest shipping times in the industry — you’ll receive your filters in one to five days.

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