How Air Filters Work: MERV vs. HEPA | Canada HVACGood air filtration and air conditioning are crucial in homes and commercial spaces, whether during a global pandemic or just the annual cold and flu season.

But not just any air filter will do. There are many different types of air filtration systems to consider, so it’s important to know what to look for. If you are unsure what kind of air filter you need for your space and want to understand which filters are most efficient, keep reading to learn more.

What Are Air Filters?

An air filter is a device that fits into your heating, ventilation and air conditioning system. It is used in homes and commercial spaces to remove airborne particles and pollutants that can be harmful to your health and the environment.

Without air filters, you can end up exposed to airborne contaminants, including:

  • Dust and dust mites
  • Smoke
  • Viruses and bacteria
  • Mould
  • Pollen
  • Pet dander
  • Odours

Over time, these airborne contaminants can cause health issues like respiratory illnesses, skin conditions, allergies and other illnesses.

How Air Filters Work

There are many different air filters on the market, and most work similarly. First, air passes through the filter screen, where contaminants like pollen, dust and dirt get trapped inside. Over time, contaminants and debris build up until, eventually, the filter becomes clogged and needs to be replaced.

What to Look for in an Air Filter

There are two main factors to consider when it comes to air filtration: Minimum Efficiency Reporting Value and High-Efficiency Particulate Air. Below, we will explain what these are and how they work.

Minimum Efficiency Reporting Value (MERV)

MERV stands for Minimum Efficiency Reporting Value, which is essentially a way to rank the efficiency of different types of air filters. MERV uses a scale ranging from 1 to 16. Air filters with a 1 rating are considered the least efficient, and those with a 16 are considered the most efficient.

When shopping for a new air filter, look for ones with a MERV rating of at least 13 to 16, as they are considered the most effective and can remove up to 75 percent of airborne particles.

High-Efficiency Particulate Air (HEPA)

A HEPA filter is a specific type of pleated mechanical air filter designed to trap dangerous contaminants like viruses and bacteria instantly. HEPA filters are extremely effective and can trap up to 99.7 percent of all contaminants 0.3 microns or higher.

Because of their ability to trap airborne contaminants in the first pass-through, HEPA filters are often used in hospitals and other settings where airborne contaminants thrive.
A downside to HEPA filters is that they are more resistant to airflow, which means it takes more work and energy for your HVAC blower to push air through the filter.

Which Air Filter Is Best?

You may be wondering if it’s better to choose a HEPA air filter or one with a high MERV rating. It all depends on your individual needs. If you want an air filter that is more energy efficient, you may not want to go with a HEPA filter. However, if you are looking for one for a high-risk setting, such as a hospital or a home where elderly or immunocompromised people live, a HEPA filter may be the best choice.

Heating, Ventilation and Air Conditioning in Canada

Contact the air filter and air conditioning experts at Canada HVAC for help choosing the best possible air filter for your home or commercial space. Our team has over 30 years of industry experience and will help you find an air filter that meets your needs.

Call us at 833-672-8975 or complete our contact form to speak with a specialist.