Dwelling or Hanging Out Around the Filter Longer Provides Cleaner Air
Dwell time has a number of meanings for various industries. Right now, you are taking part in a dwell time metric. How long will you stay (or dwell) on this page? In theory, the longer you stay, the more time you are investing into reading and engaging with this piece of content.
Ironically dwell time can be deemed a negative term just the same, since it can also represent the length of time customers spend waiting in a queue.
In air purification, dwell time is a as important as it is desirable. You want longer dwell times when you turn on your air purifier. The longer harmful indoor air contaminants dwell inside the air purifier, the more filtration is taking place.
To clarify: dwell time in air purification means the amount of time indoor air pollutants spend going through an air filter. Longer dwell times mean more pollutants can be removed by the air filter. This is especially important when it comes to gases, volatile organic compounds and odors, because of the way these contaminants are filtered -with activated carbon.
Dwell time: A secret weapon for activated carbon filters
Many air purifiers use activated carbon to address odors, chemicals, and gases. It’s the most effective, and there are not many other filters that promise to remove VOCs. HEPA filters, for example, can rid the air of airborne particles, dust and pollen, but they do not trap gaseous pollutants. HEPA and carbon filters used together are the optimal way to clean your air.
Activated carbon has become the go-to filter material for odors and VOCs not only because it is the most effective gas filter out there and does not produce harmful by-products. AllerAir offers fresh, non-recycled, virgin carbon, made strictly from natural ingredients.Activated carbon is a very porous material because it was treated with oxygen and has become riddled with fissures and tiny holes. That means there is a lot of surface area available for airborne chemicals and gases to chemically bind themselves to it. This process is called adsorption. So the more surface area you have and the longer dwell times for contaminants, the cleaner your air will get with each bypass.
Tips increase the dwell time of your air purifier
As a consumer, there is not much you can do to change the dwell times AFTER you have bought a unit. Let’s hope you have a granular activated carbon filter. One suggestion is to operate the air purifier at slow speed, which also helps to reduce white noise. And it never hurts to call the manufacturer. Some companies will help you change filters in order to get the right combo of air filters.
Nevertheless, it’s best to decide on an air purifier with the right filters and long dwell times before the purchase to make sure you get the best filtration in your space.
Insist on granular activated carbon
Thin mesh filters sprayed with activated carbon simply are not as effective as multiple pounds of activated carbon. Pellets are better than powder, so look for the most activated carbon you can find in granular form.
Deep-bed filters (and more carbon)
Imagine a wall of activated carbon that stands between contaminated air and your nose. The thicker the wall, the more surface area separates the two and the longer the dwell time will be. This often means more carbon. But don’t worry, unless you live in a highly polluted area, activated carbon can last a few years.
The right airflow design
Keeping the last image in your head, imagine the air going through the carbon wall in a straight line. Now imagine the same wall, but with the air coming in from the bottom left and going to an outlet on the top right side. There is no way the air will be filtered straight through. It is more logical that it will look for the fastest way through the filter in a steep diagonal line, thereby increasing the dwell time in the carbon filter as well.