Alen A350 User Manual

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AIR CLEANING SYSTEMS and INdOOR AIR QUALITY 
Why should I be concerned with the air  
I am breathing?
Sometimes it may be better to not know what is in the air, but since you are reading 
this we’ll share what the leading health agencies are reporting. 
First a little background on particulate matter. The particles that float through the 
air are a combination of solid particles and liquid droplets.  Particles are measured 
in microns, where a micron is one millionth of a meter (10-6 meters) and is also 
called a micrometer. The particles that we can see with the naked eye are those 
larger than 50 microns. A human hair is approximately 100 microns in diameter. The 
airborne particles that result in allergies or impact our health are much smaller and 
not visible with the naked eye.  Mold spores and pollen particles are from  to 10 
microns.  At times they can be visible but this is when there is a large concentration 
massed together.  
Before we get to the types of particles in the air, let’s review the particulates in the 
air that are 10 microns and smaller and why we need to care about them.  Particles 
10 microns and smaller can pass through and deposit in our respiratory system 
and are referred to as respiratory particulates.  The concern here is that the smaller 
particles can be breathed deep into the lungs.  These smallest of particles tend to 
stay suspended in the air longer than very large particles such as dust so there is a 
greater chance for inhalation.  They can also serve as a vehicle to transport contam-
inants deep into the lung area.
Particles 5 microns and larger are trapped in the throat and nasal regions, particles 
between 1 and 5 microns are trapped in the trachea (leads to the lungs) and larger 
lung branches and particles less than 1 micron in size go to the alveolar area which 
are the tiny air sacs in the lungs.  This is where the exchange of oxygen and carbon 
dioxide takes place.
The primary composition of our air is made up of Nitrogen, Oxygen, Argon and 
Carbon Dioxide.  All of this is obviously invisible to us.  Unfortunately, the respiratory 
particulates are also not visible to the naked eye.  Here is a summary of the com-
mon “pollutants”:
Bacteria: 0. - 5 microns
Mold spores:  – 10 microns
Pollen: 10-0 microns
Dust mites: 300 microns (feces 0 microns) – most common allergen in US
Viruses: 1 micron and smaller