Improving your indoor air quality is essential for creating a healthier home environment, and whole-home air filtration or purification systems can play a significant role. While many assume outdoor air pollution is the bigger concern, the Environmental Protection Agency (EPA) reports that air inside buildings is often three to five times more polluted than outdoor air. This is due to indoor allergens, volatile organic compounds (VOCs), and other contaminants.
Although people often use the terms “air filtration” and “air purification” interchangeably, they refer to different processes. Air filtration is sometimes a component of air purification, but purification can also involve other methods like integrating UV lights. In this article, we’ll explore the differences between whole-home air filtration and purification systems to help you determine which option best suits your household’s needs.
HVAC Air Filters
Any central HVAC system always provides some level of whole-home air filtration. That’s because the system continuously circulates the air in the building and draws it through the filter in the return duct. However, standard HVAC air filters don’t provide a very high level of filtration and are primarily designed to capture dust and other larger particles. Their primary purpose is to prevent dust and debris from getting sucked into your HVAC system, which could damage its internal components.
MERV Ratings
MERV ratings, which stand for Minimum Efficiency Reporting Value, are used by manufacturers to measure how effectively an air filter captures particles. Standard residential air filters typically have MERV ratings between 6 and 12. While higher ratings mean better filtration, they also increase resistance to airflow, which can impact your HVAC system’s performance.
MERV 12 is the upper limit for standard 1-inch filters in most residential systems. Going beyond this can significantly restrict airflow, potentially overworking the system. Smaller residential HVAC units may struggle with filters rated higher than MERV 8 or 10 because of the added resistance. Restricted airflow can cause the system to operate less efficiently, leading to higher energy consumption, reduced comfort, and more frequent breakdowns. Over time, this strain can even shorten the lifespan of your HVAC system.
Upgrading to a Media Filter
To achieve a higher level of whole-home air filtration, you can have an HVAC professional adapt your return duct to accommodate a thicker, more efficient filter, commonly called a media filter. This type of filter is usually between 4 and 6 inches thick, whereas standard filters are only 1 inch thick. The main benefit of media filters is that they trap much smaller particles that pass through a standard filter and continue recirculating through a home’s living spaces. This modification is a relatively inexpensive and common practice for homeowners seeking better air quality.
Media filters usually range from MERV 10 to MERV 16. Even a MERV 10 media filter will provide a higher level of filtration than a 1-inch MERV 10 filter. That’s because the increased thickness means the air gets drawn through much more filter material, which traps more airborne particles. Media filters in the MERV 14–16 range can remove over 90% of airborne contaminants while maintaining proper airflow in most residential systems. Regardless of the filter, you need to get your HVAC ducts cleaned regularly to prevent contaminants from building up. At a certain point, they will recirculate these particles from ducts and vents that have captured high concentrations of pollutants.
HEPA Air Filter Systems
If you want the highest level of filtration available, you need the help of a professional to install an air filtration system that uses a HEPA filter. They can integrate most models with your current heating and cooling system.
HEPA filters are so effective that they trap over 99% of airborne particles, including bacteria and viruses. Unlike standard or media filters, a HEPA filtration system uses an internal fan to pull air out of the ductwork and force it through the HEPA filter. This design prevents the filter from causing airflow restriction in your HVAC system.
HEPA systems are ideal for homeowners with severe allergies, respiratory conditions, or anyone looking for medical-grade air quality in their home. However, they are typically more expensive than media filters and may require additional maintenance to ensure the system continues performing optimally. If air quality is your top priority, a HEPA filtration system is an excellent investment.
Why Whole-Home Air Filtration Isn’t Always Sufficient
While a quality whole-home air filter can address many indoor air quality concerns, it has limitations. Air filters are specifically designed to capture particulate matter, such as dust, pollen, and pet dander. However, they are ineffective against gaseous pollutants, including a group of chemicals known as volatile organic compounds (VOCs).
VOCs are emitted from many materials and products found in most homes. They are commonly used in the manufacturing of furniture, flooring, carpeting, paints, varnishes, adhesives, and stains. Everyday household items like cleaning products, dryer sheets, and fabric softeners also release VOCs, as do certain electronics, such as printers. Even cooking activities contribute to VOC emissions.
The problem with VOCs is their tendency to “off-gas,” meaning they continuously release gas into the air over time. This results in elevated indoor concentrations of common VOCs. They include benzene, formaldehyde, toluene, xylene, methylene chloride, and ethylene chloride. Many of these chemicals are classified as carcinogens. In addition, prolonged exposure can lead to health issues such as headaches, dizziness, nausea, and respiratory irritation.
Whole-home air filtration systems are an essential component of improving indoor air quality. However, additional solutions, such as air purifiers equipped with activated carbon filters or increased ventilation, may be necessary to address VOCs effectively.
Whole-Home Air Purification Systems
Whole-home air purification systems vary in their design and capabilities. Some models target specific concerns, while others provide comprehensive indoor air quality solutions.
For instance, UV light purifiers neutralize biological contaminants such as airborne mold spores, bacteria, and viruses. They are also effective at inhibiting mold and bacteria growth within an HVAC system, particularly on damp components like coils and drain pans. However, UV purifiers do not address particulate matter or chemical pollutants.
Comprehensive air purification systems aim to tackle a broader range of indoor air quality issues, including airborne particles, microorganisms, chemical pollutants, and odors. For instance, some systems integrate a high-efficiency media filter to trap fine particles alongside additional components designed to reduce the concentration of volatile organic compounds (VOCs) and other gases that standard filters cannot capture.
Other systems utilize electrostatic filtration, which charges airborne particles and pollutants as they pass through the purifier. The charged particles then adhere to oppositely charged plates within the unit, effectively removing them from circulation.
It is also common to find hybrid systems that combine a media filter or electrostatic filter with UV light technology. This combination allows the system to simultaneously address particulate matter, biological contaminants, and chemical pollutants. They offer a well-rounded solution for maintaining healthier indoor air.
Contact Your Local Professionals
At Markool Heating & Cooling, we have been serving the residents of Frederick, MD and the surrounding areas for years. We install, maintain, and repair heating and cooling systems. Additionally, we can help with all your indoor air quality needs, including installing air filtration and purification systems. We also offer HVAC maintenance plans to ensure that your heating and cooling system never contributes to less-than-ideal indoor air quality. Contact us today to schedule an appointment with one of our experienced technicians.
