Angel Rosendo

Air filters are an essential part of any HVAC system. They help to remove pollutants, allergens, and other particles from the air, making it cleaner and healthier to breathe. But it's important to make sure that air filters are properly fitted to their slots.

Why proper fit is important

A poorly fitted air filter can have a number of negative consequences. First, it can reduce the efficiency of your HVAC system. This can lead to higher energy bills and a decrease in the lifespan of your system. Second, a poorly fitted air filter can allow pollutants to pass through, which can contribute to respiratory problems and other health issues.

How to achieve a good fit

The first step to achieving a good fit is to make sure that you have the right size filter for your system. The nominal size of an air filter is the size listed on the packaging. The actual size of an air filter may vary slightly from the nominal size, due to manufacturing tolerances. This is why it's important to measure the slot in your HVAC system before you buy a filter.

Once you have the right size filter, you need to make sure that it's properly installed. The filter should fit snugly into the slot, with no gaps or openings. If there are any gaps, you can use masking tape to seal them up.

Here are some tips for achieving a good fit:

  • Make sure that the filter is the right size for your system.
  • Install the filter snugly into the slot.
  • Use masking tape to seal any gaps.
  • Use self-adhesive gasket tape to ensure a tight seal.

Nominal vs. actual sizes

The nominal size of an air filter is the size listed on the packaging. The actual size of an air filter may vary slightly from the nominal size, due to manufacturing tolerances. This is why it's important to measure the slot in your HVAC system before you buy a filter.

In general, the actual size of an air filter will be slightly smaller than the nominal size. This is because the filter needs to be able to fit snugly into the slot, without any gaps or openings.

If you're not sure how to measure the slot in your HVAC system, you can consult your owner's manual or contact a qualified HVAC technician.


A poorly fitted air filter can reduce your HVAC system's efficiency and lead to higher energy bills


A robust IAQ strategy involves more than just advanced filtration and CO2 control. It also encompasses maintaining proper ventilation, controlling humidity, and reducing indoor pollution sources. The integration of high-MERV and HEPA filters into this broader IAQ management plan is key to achieving a balance between air purity, energy efficiency, and overall indoor environmental quality.

These elements, while individually significant, achieve their fullest potential when integrated into a comprehensive approach to IAQ. This strategy not only ensures cleaner air and better health outcomes but also supports sustainable and energy-efficient practices. In an era where the quality of our indoor environments is more important than ever, this combination of tactics is indeed a winning one.

✅ Registration is free, and you can perform unlimited optimizations without needing a credit card.

Get started today at https://app.filtrationadvice.com/register