The HVAC system in your Wausau, Wisconsin home performs a number of important functions. This equipment regulates indoor temperatures and moderates indoor humidity. To a lesser extent, it also provides a limited measure of indoor air quality (IAQ) control. By upgrading your HVAC air filter to one that has a higher minimum efficiency reporting value (MERV) rating, you can breathe a bit easier and rest assured that there are fewer airborne contaminants floating around.

However, for households with major IAQ concerns, such as those with residents who live with chronic respiratory ailments, HEPA filters are considered the gold standard in air filtration. Following is everything that you need to know about having a HEPA air filter put in.

What Is a HEPA Air Filter?

A high-efficiency particulate air (HEPA) filter can collect airborne particulates that are small enough to evade all other air filter types. The smallest particulate that a HEPA filter can capture and retain measures just 0.3 microns in size. One way to understand the effectiveness of this type of filtration is to consider its origins. Although they’ve been upgraded and refined throughout the years, HEPA filters were first invented during World War II as part of the Manhattan Project. Then, scientists working on the development of the atomic bomb used it as a way to capture radioactive particles.

Residential HEPA filter use brings this same outstanding level of efficiency into the home to create cleaner, fresher-smelling, and healthier air overall. Unlike standard pleated filters, HEPA filters are made with interwoven glass fibers that form a dense, fibrous maze. They extract micro-fine particulates from the indoor air in four distinct ways:

  • Diffusion
  • Interception
  • Sieving
  • Direct impaction

With direct impaction, pollen, mold, dust, dander, and other larger particulates collide with a HEPA filter’s fibers and stick to them. With sieving, ultra-fine particulates are ensnared by a HEPA filter’s fibers due to the air molecules that are carried between them. Interception ensures that particulates that pass through a HEPA filter’s fibers while being carried along by normal airflow are captured and retained by the sides of these same fibers. Finally, with diffusion, micro-fine particulates are collected by a HEPA filter as the course of their own erratic movements.

Understanding the True Purpose and Multiple Limitations of Standard Air Filters

Many homeowners aren’t aware of the actual purpose of standard HVAC air filters. Although it’s easy to assume that these components are designed to protect and improve the IAQ in HVAC service areas, they’re actually not. Instead, standard air filters are designed with the sole intention of protecting HVAC equipment. Product manufacturers use these filters to protect the sensitive, internal components of heaters and air conditioners from fairly large-sized particulates like:

  • Pollen
  • Pet hair
  • Dander
  • Dirt
  • Lint

Without a standard air filter, your heating and cooling equipment wouldn’t last throughout its projected lifespan. The same thick accumulations of grime that coat HVAC air filters every month would build up in the HVAC system instead. Just as dirty, blocked filters impede airflow and cause HVAC equipment to overheat, running an HVAC system without this component would do the same.

Understanding this, your HVAC system’s standard air filter isn’t contributing to a healthier and safer living environment. Instead, it’s just doing the bare minimum to ensure that your HVAC equipment manufacturer isn’t having to pay money to replace products that are still under warranty.

The Benefits of Having a HEPA Air Filter

To understand the benefits of HEPA air filters, it’s important to know what MERV ratings are and how they relate to the different types of airborne particulates that air filters can collect. MERV ratings for HVAC air filters range from one to 20, with 20 being the highest level of air filtration possible.

Filters with MERV ratings of just one are typically found in small and very basic window air conditioners. These filters only capture lint, dust, and other elements that might cause a window AC to overheat. For household use, most HVAC equipment comes with filters that have MERV ratings ranging between 6 and 8. At this level, HVAC air filters can collect larger particulates such as pollen and dust mites, but they can also collect various chemical agents such as airborne hair spray, certain household cleaners, fabric protectors, cement dust, and mold spores. As MERV ratings and filtration abilities increase, HVAC air filters move away from only protecting HVAC equipment and closer toward protecting human health. Thus, if your HVAC system came with a filter that has a MERV rating of just 6, upgrading to a filter with a rating of 8 will make a marked difference.

All HEPA air filters have MERV ratings of 17 or higher. These components aren’t about protecting HVAC systems. Instead, they’re designed to provide fresher, cleaner indoor air and a higher standard of living for all building residents. HEPA air filters can pick up micro-fine particulates that easily pass through other filter types including:

  • Carbon dust
  • All combustion smoke
  • Cigarette smoke
  • Dangerous viruses, bacteria, and other pathogens
  • Lead dust
  • Chemical contaminants that pass through other filters

In fact, HEPA filters are so effective that they’re used in hospitals and other clinical settings, clean rooms, and industrial environments in which carcinogenic materials are present. Having one installed in your home will allow you to enjoy the same quality of indoor air that’s present in all of these and many other highly regulated facilities. This can be especially helpful for anyone who suffers from:

  • Asthma
  • Allergies
  • Chronic pulmonary obstructive disease (COPD)
  • Immuno-suppressive disorders

With a HEPA filter in place, you’ll have fewer asthma and allergy triggers being circulated throughout your home. They’ll be fewer airborne contaminants to exacerbate existing respiratory ailments and a far lower likelihood of having IAQ-related illnesses develop.

However, HEPA filters can also be beneficial, if not critical, in households that lack residents with respiratory or other chronic health issues due to other factors. For instance, you might want to have a HEPA air filter put in if your home is:

  • On a busy street
  • Close to a major freeway
  • Near an airport
  • On unlandscaped grounds
  • Near active construction
  • Regularly affected by smoke from nearby forest fires

HEPA air filters are strategically designed and rigorously tested to ensure that they’re capable of reliably capturing 99.97% of all airborne particulates measuring 0.3 microns in diameter or larger.

The Challenges of Upgrading to a HEPA Air Filter

Unlike upgrading your HVAC system’s standard air filter to one with a higher MERV rating, upgrading to a HEPA air filter is by no means a do-it-yourself project. As filter ratings and filtration capabilities rise, airflow challenges manifest. Given their extraordinary level of effectiveness, HEPA filters cannot be accommodated by central HVAC systems until special modifications have been made. Thus, if you think a HEPA filter is the right integrated HVAC accessory for your home, you should start this process by contacting a licensed HVAC professional.

At Southport Home Services, we provide advanced indoor air quality solutions to residents of Wausau, Wisconsin and the surrounding areas. We also provide water heater service, sump pumps, drain and sewer cleaning services, HVAC services, and commercial services. To find out more about HEPA air filters or to have one installed, call us today.

Meet the Author
Thomas Suchla
Thomas Suchla


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