Residential Home Air Filtration

Have you ever noticed that no matter how much you clean, you can still see particles floating in a beam of sunlight coming in through a window?

This isn't just dust! It's made up of pollen, plant and mold spores, pet dander, lint, bacteria and other contaminants. Regular daily activities within the home, such as dusting, vacuuming, cooking and smoking, can increase particulate concentrations. And major home remodeling and renovation projects can introduce even higher levels of particles in the home!

These particles, measured in microns, range in size from fairly large to microscopic. To better understand the size of a micron, note that a human hair is about 70 microns in diameter. The tiniest particles - those smaller than 1 micron (1) - make up 99 percent of the particles in the air circulating within your home. Because the respiratory system's defense mechanisms (i.e. nose, sinuses and windpipe) are designed to filter out particles 3-5 microns in size, these tinier particles can be breathed deep into the lungs.

Breathing in these particles can have a negative impact on your health, ranging from irritation of the eyes and/or respiratory tissues to the potential of more serious long-term effects, such as decreased lung function and cancer. They can also trigger allergic reactions, asthma attacks and infectious diseases.

One of the simplest, but most often overlooked ways to create a healthier home is to use good quality air filters. How many of you are still using the fiberglass panel filters in your home? If you do you are not only. An estimated 85% of households use these. These may provide some protection for your air handling system, but they provide little protection for you. Such fiberglass filters remove only about 2-5% of all the particles in the air.

In 1999 a new standard was adopted by which filters are to be rated for their efficiency in remover particulate matter from air. The new standard is known as the MERV standard or minimum efficiency reporting value. A MERV rating is a numerical value that can go as high as 20. To put things into perspective, the fiberglass filters mentioned above have a MERV rating that ranges from 1-4. In contrast:

>>>A MERV 10 rating corresponds to 50-65% removal efficiencies for particles 1-3 microns in diameter and greater than 85% for 3-10 micron particles.

>>>A MERV 13 rating corresponds to 75% removal efficiencies for particles 1-3 microns in diameter and greater than 90% for 3-10 micron particles.

>>>A MERV 15 rating corresponds to 85-95% removal efficiencies for particles 1-3 microns in diameter and greater than 90 % for 3-10 micron particles.

>>>A MERV rating of 16 is a HEPA (high efficiency particulate air) filters, and a MERV rating of 20 is an ULPA (ultra low air penetration) filter.

For more information on this topic please go to the Healthy House Website found at www.healthhouse.org