By: Paul S. Cilwa Viewed: 5/27/2018
Posted: 6/28/2010
Topics/Keywords: #EnvironmentalToxins #NaturalHealth #Toxins Page Views: 3814
Blog Entry posted June 28, 2010, in which we change our home's air filters. Who says I don't blog EVERYTHING?!

Where do you breathe the most toxic air all day long? On the highway? In your office? Getting your nails done? Actually it might indeed be the nail salon, but few people have daily manicures. So the most dangerous place for you to breathe is actually your own home. And, as with all environmental toxins, no individual breath will kill you; it's the cumulative effects of millions of such breaths (plus other toxins) that result in what we call "aging" but is actually just reaction to a toxic body burden in the form of obesity, high blood pressure, cancer, wrinkled skin, and a host of other illnesses.

So…where do you start?

For those of us with central heat and air conditioning systems, a good place is simply your home's intake vents. They are generally located on an upper ceiling, and you probably replace them a few times a year, anyway. But not all filters are created equal, and the cheaper ones are not likely clearing the air of enough inhalable crap to make a difference in your toxic load.

What most consumers call "central air" is more properly known as an HVAC system, for Heating, Ventilation and Air Conditioning. HVAC systems draw air from your house into themselves, warm or cool it, then blow it back into the rooms from which it came. Understand, that means the air is recirculated—unless you open your windows occasionally, the same old, toxin-laden air is going to be breathed and re-breathed till the sun goes nova. Eventually these toxins build up to the point that they are more concentrated than the air from the street, even if you live next door to a sheet metal plant or dairy farm. So do air out your house as often as possible.

The air sucked into the intake vents of your HVAC must be filtered, and those filters must be changed or cleaned periodically. There are four basic kinds of filters.

  • Electrostatic filters are expensive but permanent; you clean them off instead of replacing them. They carry an electronic charge that attracts particles much like a magnet. The primary job of cleaning the particles they capture is by simply taking them out and vacuuming them. However, the manufacturers recommend following that up with a cleaning detergent and then hosing it off. Since heavy-duty cleaning detergents themselves contain toxic chemicals, you'd want to do this outside and make absolutely certain no residue remains. The average price for a single, 20" x 20" x 1" permanent electrostatic filter seems to be about $61. There are also disposable electrostatic filters, such as the Filtrete, that are more like $12 each.
  • Pleated filters provide more media, or surface area, where particles can be captured. These can also come in electrostatic models. The additional surface area also provides easier passage of air, making these filters more efficient as far as your HVAC goes.
  • HEPA filters were originally designed in the 1940s and were used in the Manhattan Project to prevent the spread of airborne radioactive contaminants. Its purpose is to allow the efficient passage of air molecules, while blocking and trapping the larger toxic molecules that float on the air. These filters are commonly used in room air filters and vacuum cleaners. However, because of their density, they are not efficient for HVAC use.
  • Activated Carbon filters contain a component that enables them to absorb chemicals, fumes, and odors as air passes through your HVAC system, including formaldehyde, ozone, and VOCs (volatile organic compounds, such as are emitted by wall paint for years after application, as well as by common cleaning supplies). These filters are quite expensive, but consist of a permanent framework that holds a cleanable electrostatic pre-filter (for particulates) and a replaceable activated charcoal pack (for gases). Expect to pay about $75 for one 20" x 20" x 1" filter.

In an ideal world—the one in which I won the lottery—I would go for the activated carbon filters for all five intakes at our home. And I might still try getting those one at a time—even one would undoubtedly reduce the toxic gas burden in our home considerably.

But for now, I had to settle for disposable, pleated, electrostatic filters.

Even those are available in grades. There are two measurements I've found, either or both of which may be printed on the filter or its packaging.

  • The MERV rating: MERV stands for Minimum Efficiency Reporting Value. The value typically ranges from a minimum of 4, to a maximum of 20, used to create "clean rooms" for high-tech manufacturing of critical components. A surgical room requires a MERV rating of 16. Dr. Crinnion, my environmental toxin doctor, urges a rating of at least 8 for the home. The MERV rating primarily concerns itself with particles 1 micron or larger in size. That's actually larger than the particles that cause most allergies.
  • The MPR rating: MPR stands for Microparticle Performance Rating. It measures how efficient an air filter is at capturing particles between 0.3 and 1 micron in size, which make up 99% of the air's particulate matter. Smoke, bacteria, and smog particles fall within this size range, so if filtering these out of the air is important to you, MPR is a good standard to examine. The higher the MPR, the more efficient the filter is at capturing these small particles.

We moved into our home at the beginning of last October; and, of course, have no idea how often the previous owners may or may not have changed the air filters. So we intended to change them right away, and I bought a set from Wal-Mart. At that time I didn't understand a thing about environmental toxins, or HVAC filters either, for that matter. I bought a mid-range filter with, as it turns out, an MPR of 700.

I also never got around to actually replacing them, until today, because we didn't own a ladder tall enough to reach the upstairs ceiling where the intake vents are located. I finally borrowed one from our friends Barbara and Peter, and Jenny volunteered to do the actual dirty work while I documented. (I did offer to let her run the camera, but she chose to climb the ladder.)

Jenny prepares to change the HVAC filters.

No tools (other than the ladder) were needed, because our intake vents are equipped with s simple clasp for opening them or locking them closed.

Since by now I knew a little bit about HVAC filters (I know more now; I did this research after the filters were installed) I was disconcerted to discover that the old filters had an MPR of 1250—almost twice as good as the ones I had bought! On the other hand, they were at least 9 months old, so the new filters would still be an improvement.

The old filters weren't as dirty as I expected.

I was quite surprised to find the old filters were not as dirty as I had expected. Oh, they were black, as you can see in the above photo; but the accumulation wasn't as thick as I had thought it would be. The filters in our last house were loaded up thick every three months (which is the manufacturers' recommended time between changes). I think that's because the house was in a newer neighborhood and bordered the desert; plus, the back yard was not landscaped. This house is in the middle of an established, 10-year-old development; it borders a golf course; and even the pool in our backyard might be absorbing some particulates from the air.

As is fairly common, our intake vents are "double-wide; each one (one for the upstairs HVAC and one for the downstairs) takes two 20" x 20" x 1" filters. Each comes with a directional arrow printed on the side, that indicates direction of airflow. The orientation of the pleats, on the other hand, is irrelevant.

Jenny installs the replacement HVAC filters.

Jenny then took a damp cloth to wipe the accumulated grime from the vent cover, since she was up there anyway.

She had a little trouble closing the far clasp on the second intake vent, due to the size of the ladder and where we had to put it. She wound up borrowing one of Zach's weapons—a battle-ax—to extend her reach.

Jenny closes the final clasp with a medieval weapon.

(By the way, this is not a toy. With his own allowance, Zach is collecting an impressive array of real, medieval-style weapons. If we should ever be attacked by the Black Knight, he'll be ready.)

We had one more vent to handle. This one is in the office space Michael and I share. It didn't require as high a ladder but there was no point in changing just one filter before. This time I took the honors.

Yours truly changes an HVAC filter.

This intake vent only takes one filter, not two; the good news is that it uses the same size filter as the other vents.

Dr. Crinnion recommends changing filters once every two or 3 months, but every month if there are pets in the home. That means that I have 30 days to shop for more effective filters to support my quest to de-toxify our home. We also need to hire someone to clean the air ducts, which is supposed to be done yearly.

But at least, we now have clean filters.