Most of us do not spend too much time analyzing or thinking about the process of breathing, what our air is made up of, and the role that air filters play in the air quality of our indoor spaces. Using pleated air filters in our heating and cooling systems can be highly beneficial in scrubbing pollutants and allergens from the air in our homes. There is actually a great deal of interesting data about this seemingly insignificant subject.
Did you know?
- The average adult inhales and exhales almost 400 cubic feet of air each day
- We take an average of 17,000 – 23,000 breaths per day
- While oxygen makes up about 20% of our air, our body only requires 5% of that
- If Earth were compared to an apple, the layer of atmosphere containing the air we breathe can be compared to the skin of the apple
The Anatomy of Air
The air we breathe is a combination of gases: 78% nitrogen, 21% oxygen, and 1% argon, carbon dioxide, and trace amount of other gases. Within the air are particles and gases that originate from many sources, nature and man-made. Although much of what we breathe is filtered and exhaled, there is a host of contaminants that can impact our health and surroundings. Whether the source may be indoor or outdoor, naturally-occurring or from a man-made process, all particles are categorized as either an aerosol or a gas. Many types of particles can be captured with the air filters we use in our heating and air conditioning systems.
Aerosols – defined as a suspension of a solid or liquid particle in the air. This encompasses a multitude of particulates that can be a solid, liquid, or compound:
- Dust – a solid aerosol created from the reduction of a larger solid particle or material. This can be created by drilling into a surface such as wood or concrete or from a natural occurrence such as a volcano or sandstorm
- Mold – a bioaerosol that has indoor and outdoor sources derived from soil, plants, and moist surfaces such as walls, insulation, clothing, or carpet.
- Bacteria and viruses- also classified as bioaerosols that are transported by air currents and are estimated to include millions of varieties of each
- Fumes – created from vapor condensation from such processes as combustion or welding
- Fog – a liquid created during water vapor condensation
- Mist – a suspension of liquid droplets that can include oils, paint, acids, and chemicals
- Smoke – from the burning or combustion of organic matter such as wood, coal, or tobacco
- Smog – air pollution caused by industrial or chemical processes
Gases – defined as a material that can expand indefinitely to fully occupy the space it is in. Gases exist in the form of molecules and include vapors along with the gases that make up the composition of our air. Gases can be odorous, toxic, and corrosive in nature. The presence of most gases will be recognized, but some such as Carbon monoxide are undetectable by the sense of smell. Gases may originate from chemical, manufacturing and biological processes.
Particles are measured in micrometers (also referred to as a micron), using the abbreviation “μm”. A micron is 1 millionth of a meter or an inch divided by 25,400. For perspective, the average human hair is about 150 μm while the smallest visible particle is around the 25 μm range. Particles measuring less than 1μm make up over 98% of the particles found in the outdoor atmosphere while only 0.005% consist of those measuring 20 μm.
The Role of Air Filters
Air filtration provides us with a means to attain the desired level of indoor air quality. Air filters were originally intended to simply shield the components of your expensive HVAC system, thus protecting it from harmful dust build-up and extending its life. As the manufacturing process of air filters evolved over the decades, filtration media became more refined and specialized which allowed us to go beyond system protection into cleaning contaminants, allergens, and other bothersome particles from our air using high-efficiency pleated air filters. This has allowed a significant improvement in indoor comfort and cleaner air in our homes and businesses.
If indoor air quality is important to you, begin by selecting the level of filtration based on the types of particles that you aim to capture with your air conditioning filters and furnace filters. You can choose a MERV rating that targets specific types of particles such as pet dander, mold spores, or pollen. The higher the rating, the smaller the particle that can be captured. A general guideline for MERV ratings is:
- MERV 8 – for mild allergies and average dust particles
- MERV 11 – for moderate allergies and smaller dust particles
- MERV 13 – for severe allergies and the finest dust particles
Determining the size that your system requires and choosing the MERV rating that is best for you can be a little overwhelming, especially if you have never purchased air filters for your home or if you have a new unit or home to buy filters for. You can take a look at our air filter measurement guide to help you pick the right size or call us and we can easily assist you with ordering the exact air filter size you need and recommend the best rating for you depending on the level of filtration you want. Whether you need AC or furnace filters, a specialty Whole House filter, a Grille filter, or even a custom air filter size, we have a professional and helpful staff ready to take care of you!