Breath of Fresh Air: What You Need To Know About Air Filtration

You want a lot out of your home — a sense of security, a promise of safety, an opportunity for relaxation — and proper air filtration is a key component of ensuring your expectations of total home comfort are met. 

It’s impossible for any one individual to control the air quality of their surrounding outdoor environment, but every homeowner expects them to be able to control the what they’re breathing in inside the house. According to the Environmental Protection Agency (EPA), indoor air levels of many pollutants may be up to five times as high as those outdoors. Proper air filtration is one of the most effective and most urgent means of combatting poor indoor air quality, and thankfully its much easier than may be expected. 

Ensuring you and your family are breathing in clean air, with as minimal pollutants as possible, for as affordable and conveniently as possible, begins with the basic comprehension of your home’s needs for air filtration. 

Air Filtration Overview

For something seemingly as simple as ensuring clean indoor air, the science of air filtration has advanced significantly over the years to better protect families and facilities everywhere. As the National Air Filtration Association (NAFA) explains, air filtration supplies the means to obtain the level of cleanliness required by any definition of “air conditioning,” including everything from preventing lint from clogging heating coils to removing particles as minuscule as 0.1 micrometers that could otherwise short circuit a computer’s microchip. 

Proper air filtration is a must-have for ensuring the health and wellness of a home’s occupancy, but its benefits extend well beyond simple comfortability. Air filtration helps protect the décor by removing staining qualities of airborne dust, eliminates fire hazards by removing lint that may amass in ductwork, extends the shelf life of foods by removing airborne mold, and much more. 

However clean you try to keep your home, there’s much more going on within its walls than meets the eye. 

Airborne Pollutants



Among the innumerable worries a homeowner juggles, most will admit that air filtration is seldom their top concern. Nonetheless, the EPA states that indoor air pollution is among the top five environmental health risks Americans encounter every day. As pollutants congest indoors, the best way to foster clean air in your home is to ventilate the house with as much clean outdoor as possible, as well as, of course, eliminating the source of the pollutants. That is seldom enough to protect your home, so robust air filtration is paramount to keep your family safe and your home clean of the various pollutants that can affect indoor air quality. 

These include particulate matter and gaseous pollutants. Particulate matter includes dust, smoke, pollen, animal dander, tobacco smoke, particles generated from combustion appliances like cooking stoves, as well as organisms such as dust mites, molds, bacteria, and viruses, the EPA explains. Gaseous pollutants arise from combustion processes like gas cooking stoves and vehicle exhaust, as well as from building materials, furnishings, paints, cleaning products, and pesticides. 

As particulate matter and gaseous pollutants are composed of completely different bases, different air filtration services are used to remove them from your home. 

Air Filtration Services

There are two types of air filtration devices that can address particulate matter: mechanical air filters and electronic air filters. The former removes particles by capturing them on filter materials, including high-efficiency air (HEPA) filters. Conversely, electronic air cleans like electrostatic precipitators leverage a means of electrostatic attraction to trap charged particles and accumulate them on an oppositely charged collector. 

Gaseous pollutants, on the other hand, are removed by gas-phase air filters that use a material called “sorbent” and are generally limited to a few types of pollutants, which therefore inhibits them from addresses the types for which they were not designed. 

Because of the range of gaseous pollutants and particulate matter that may affect the home, it is important to select the air filtration device that best addresses your family’s needs and lifestyle. 

Filter Types & Their Efficiency

The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) developed a system by which to measure an air filter’s efficiency in removing airborne particles, called the minimum efficiency reporting value or MERV. These ratings range from a low of 1 to a high of 20, allowing homeowners to compare different air filters based on their various needs. 

Air filtration systems with a MERV rating ranging from 4 to 1 can typically address pollutants like carpet fibers, pollen and dust mites, applied often in window A/C units, which may be enough for some residential homes. 

Air filtration systems with a MERV rating ranging from 8 to 5 can control contaminants like mold spores and dusting aids, passing for most residential and commercial buildings. Air filtration systems like pleated filters and cartridge filters are often included in this range. 

Air filtration systems with a MERV rating ranging from 12 to 9 can handle pollutants like lead dust, auto emissions, and welding fumes, as well as the pneumonia-causing pathogen Legionella, making these a requirement for settings like hospital laboratories. 

Air filtration systems with a MERV rating ranging from 16 to 13 can protect against virtually all bacteria, and therefore imperative for surgery settings as well as hospital inpatient care. These can also capture most tobacco smoke, so smoking lounges leverage them, too. 

Air filtration systems with a MERV rating ranging from 20 to 17 address contaminants like viruses, carbon dust, and combustion smoke, as well as particulates with a diameter as small as .3 micrometers. 

Selecting Your Air Filtration Device

For the most part, air filtration systems with a MERV rating between 1 and 4 are used to protect heating and cooling equipment from the buildup of pollutants, but cannot completely manage the complete air quality of your home. Their low efficiency allows for smaller airborne particles like viruses, bacteria, animal allergens, and some mold spores to remain in the home. 

As the EPA purports, medium efficiency air filtration systems between 7 and 13 are nearly as effective as HEPA filters at removing the majority of airborne indoor particles. These medium efficiency air filtration systems are, for the most part, more affordable than true HEPA filters, permit quieter heating and air operation, and allow higher airflow rates than HEPA filters. 

HEPA filters have a MERV rating range of 17 to 20 and are rarely installed in residential homes due to the limited motor capacity of most heating and air systems. Instead, higher efficiency air filtration devices with a MERV rating of 14 to 16 can often get the job done just as effectively with the home’s existing HVAC system. 

Once you determine the best MERV rating region your home requires based on the pollutants created based on your family’s lifestyle and location, consider other factors such as costs, odors, and noise that you can reasonably tolerate in your house. 

Every family is different, and the pollutants that are created in the home change in every household. Talk with an expert in indoor air quality to determine the best air filtration system for your family needs to ensure total home comfort. 

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