The Ultimate Guide to Finding the Right Air Filter Size for Your HVAC Unit

Have you ever wondered if the size of your air filter really matters? Well, the answer is a resounding yes! Using the right size air filter for your HVAC unit is crucial for keeping your system running smoothly and ensuring that all the air in your home gets filtered.

Finding the right air filter size can be a bit confusing, especially since the air filtration industry standard is to make filters slightly smaller than their slot or frame. This allows them to easily slide into place without getting bent or smashed. But don’t worry, we’ve got you covered with a simple yet comprehensive sizing guide.

Nominal vs. Actual Sizes

When shopping for air filters, it’s important to understand the difference between nominal and actual sizes. The nominal size is the big, advertised size that you usually see on the packaging. It’s a rounded-up whole number version of the actual, measured size. On the other hand, the actual size is the exact dimensions of the filter, which are usually 0.25″ to 0.5″ smaller than the nominal size. This slight difference ensures a proper fit in most standard residential units.

3 Ways to Find Your Air Filter Size

There are three easy ways to determine the size of your air filter.

1. Refer to the label on the filter’s frame

The simplest method is to remove the existing filter from its slot and look for the size printed on the frame. However, keep in mind that the size listed in bold on the frame is the filter’s nominal size, which may differ from its actual size. If the actual dimensions are not listed, it’s a good idea to measure the filter to double-check.

2. Measure your air filter

If you can’t find the size on the filter or you’re unsure of the dimensions, you can measure it yourself using a ruler or any other measuring device. Measure the length, width, and depth of the inside edge of the air filter’s slot or frame. Round down to the nearest whole number to determine the nominal size, keeping in mind that the actual size should be slightly smaller.

3. Measure your air intake

This method is a bit more challenging but can provide accurate measurements. First, turn off your AC system to ensure safety. Then, use a measuring tape to measure the length, width, and depth of the inside edge of the air filter’s slot or frame. Again, round down to the nearest whole number for the nominal size.

It’s generally recommended to use the sizes on your old filter or measure your old filter first, as measuring the air intake can be more difficult and may not yield the most accurate results.

How Tightly Should Your Air Filter Fit?

Finding the right fit is crucial for proper air filtration. If you have to force or bend your air filter into place, it’s too big. Conversely, if your filter doesn’t come within 1-2 fingers’ width of all four corners of your HVAC unit’s slot or frame, it’s too small. There should be a little wiggle room to easily slide the filter in and out without it getting bent or smashed. If your filter doesn’t fit well, consider trying a different brand or ordering a custom size air filter with a slightly smaller actual size.

Best Places to Buy Air Filters

When it comes to purchasing air filters, you have several options: online sellers, HVAC service companies, and in-store retailers. Let’s explore the pros and cons of each.

Online Sellers

In today’s world, online shopping has become the norm, offering convenience and safety. You can find a wide range of air filters online, including the advanced technology and quality customer service of Airisy. Online sellers like Airisy offer free 2-day shipping, making it easy to get the filters you need right to your door.

HVAC Service Companies

HVAC service companies not only provide filter replacement services but also offer system repair and unit installation. However, they may add an additional surcharge to the filter cost. Additionally, these companies may have vendor-supplier relationships that could influence their recommendations.

In-Store Retailers

Big-box retailers like Walmart, Home Depot, and ACE Hardware carry air filters, but their selection may be limited. It’s worth noting that online sellers often have a wider variety of brands and sizes available. If you can’t find your size in-store or need a custom-made air filter, online sellers are usually the best option for you.

Standard Size Not Fitting Well? Try a Custom Size

If you’re having trouble finding a filter that fits your HVAC unit perfectly, you may want to consider a custom size air filter. While it may be challenging to find a retailer that sells custom sizes, there are many online options that can deliver custom air filters right to your door. When ordering a custom size, make sure to specify the exact dimensions to get the perfect fit. Airisy’s customer service team is always ready to help you find the right filter for your needs.

Can You Stack Air Filters?

It’s important to note that stacking multiple smaller air filters on top of each other to fit a larger air handler is not recommended. This can cause damage to your AC unit, as residential furnaces are not designed to handle this level of airflow restriction. It’s best to use the correct size filter to ensure optimal filtration and system performance.

Remember, Airisy filters are specially designed to eliminate chemicals and odors at the molecular level, providing superior air filtration. To learn more about the next generation of air filtration technology, visit Airisy.

FAQs

• Q: Where can I find the size of my air filter?

• A: You can find the size on the label of the filter’s frame or measure the filter itself.

• Q: How tightly should my air filter fit?

• A: If you have to force or bend the filter, it’s too big. If it doesn’t come within 1-2 fingers’ width of the slot or frame, it’s too small.

• Q: Can I stack air filters to make them fit?

• A: No, stacking air filters is not recommended as it can cause damage to your AC unit.

• Q: Where can I buy air filters?

• A: You can purchase air filters online from sellers like Airisy, or visit in-store retailers like Home Depot or Walmart.

Conclusion

Finding the right air filter size for your HVAC unit is essential for proper air filtration and system performance. By understanding nominal vs. actual sizes, measuring your filter or air intake, and ensuring a proper fit, you can ensure that your home’s air is clean and healthy.

Remember, Airisy offers a wide range of high-quality air filters and is committed to providing the best air filtration technology. So, why wait? Visit Airisy now and experience the next generation of air filtration.