Most people almost never think about their HVAC filters, let alone microns. But when it comes to air quality, especially for allergy sufferers, the very young or elderly, and those with respiratory sensitivities or illnesses, microns do matter.
If you want clean air and easy breathing then you’ll want to understand microns and how they affect the choices that you’ll need to make about filters.
What’s A Micron?
Indoor air pollution comes in many sizes. And those sizes are measured in microns. Technically it’s one millionth of a meter but don’t get out your ruler just yet – comparing particles is a lot more complex than checking the diameter. Since particles come in all kinds of shapes and dimensions, the final measurement is abstracted from a pretty serious mathematical formula.
For us, the important thing is how different particles compare to each other in size – and what that means when it comes to choosing HVAC filters.
If you’re still trying to wrap your head around a millionth of anything, consider this: the width of a single hair is around 75 microns. A grain of sand is about 1200 microns. Particles under 40 microns are invisible to the human eye.
Why Size Matters
All this talk of measurement may get you a high five during a round of trivia, but what does it have to do with your health? Well, the size of particles is a huge factor in how harmful those particles are when inhaled. Airborne particles, along with the air you breathe, travel through your respiratory system all the way to your lungs.
Along the way, they can get trapped in your nasal passages, embedded in your sinuses, stuck in your throat, all the way into the deepest recesses of your lungs, and from there into your blood and circulatory system. When you consider what those particles might be – dust, viruses, mold spores, bacteria, pollen, lead dust, tobacco smoke, pesticides – you can see why you might not want them in your body.
But if you choose the right type of air filtration, you can remove the vast majority of those harmful particles from the air before they end up in your body. Knowing which types of filters remove which sizes of particles can help you choose the ones that are best suited to your environment and your needs.
Sizes Of Common Pollutants
If you’re wondering where on the “it’s gonna kill you” scale a particular particle falls, here are the comparable sizes of some common household pollutants. But don’t worry – if there’s a particle then there’s probably a filter! So don’t panic yet. We’ll let you know in just a minute how to tackle some of the toughest ones.
Some of the smallest particles come in the form of gases, from cigarette smoke, oil smoke (watch that frying pan!), and coal flue gas, which come in as small as .01 microns.
Pollen, the bane of many a seasonal allergy sufferer’s existence, is much larger, up to 1000 microns.
Along the scale are other irritants like mold (between 3 and 40 microns), pet dander (2 to 10 microns), dust (.5 to 100 microns), bacteria (between .3 and 60 microns) and viruses (clocking in well below .3 microns).
The Role Of Filters
Now that you know how particles are measured and how big (or minutely small) some are, let’s talk about why filters are so important.
All HVAC systems need some type of filter to prevent particles from accumulating and damaging components. The role of air filters from a strictly functional standpoint is to keep your furnace and air conditioner working effectively and efficiently. When you follow the minimum filter requirements for your system, you’re essentially protecting it from excess wear and tear, which is important – but isn’t necessarily the ideal solution for your health.
That’s where high efficiency filters can come in. Unlike standard filters, these can rid the air in your home of the most common pollutants and irritants, including dust, pollen, mold spores and pet dander, which otherwise might not be trapped by the basic filters.
That’s good news for allergy sufferers, but you may be wondering about smaller particles, from sources like smoke, or even viruses and some bacteria. For those particles, you need another plan of attack.
Activated Carbon As An Added Protection
Even the best media filter doesn’t stand a chance against particles from cigarette smoke and odors like wet dog or burnt popcorn. But your options don’t stop there! For these particles, consider including an activated carbon filter along with your regular media filter.
Also referred to as activated charcoal, these filters are made of carbon that has been treated to be highly porous. A much larger surface area allows activated carbon to absorb exponentially more pollutants than regular carbon.
With a media filter to trap dust, dander and pollen, your carbon filter is free to trap odors and gases.
Tackling Some Of The Smallest Contaminants Of All: Viruses
Between a media filter and an activated carbon filter, you’re well on your way to breathing healthier, cleaner air. But viruses, which can be as small as .005 microns, will sail through both of those filters with ease.
To tackle these buggers in particular, you need to think past strictly filtration to air purification. Air purifiers that use UV light right within ducts can destroy airborne viruses before they get recirculated throughout your home. Other air purifiers can even handle bacteria and viruses on surfaces by emitting a harmless burst of hydrogen peroxide that will go wholly unnoticed by you, but will kill viruses where they lay.
A combination of filtration and purification will get the air in your home as healthy, clean and safe as it can be. For those with kids (who are notorious for bringing germs home along with books and supplies), the elderly, or someone with a compromised immune system, this extra protection can be a good choice.
If you’d like to learn more about improving the air quality in your home, get in touch with us for a free consultation and estimate. We’ll visit your home, look at your existing HVAC system and give you recommendations for breathing better, healthier air.