Aprilaire 4200 Owner's Manual page 3

PERFORMANCE
A whole-house air cleaner, like the Aprilaire model 4200
or 4400, is installed by your heating and air conditioning
contractor as one of the components in your heating and
cooling system. It cleans the air that circulates through your
home (see Figure 1).
When the heating or cooling equipment turns on, the air in
your home travels through the registers and return duct(s) to
the heating and cooling equipment where it is conditioned
and sent back into the rooms of your house through the supply
ducts. Small particles from numerous sources are suspended
in your home's air, just as they are suspended in the air
outdoors. The largest of these particles will eventually come
to rest and appear as dust. Smaller particles may come to rest,
but with even the slightest disturbance will re-suspend into
the air. These particles are very small, and come from natural
sources such as dust and pollen and from manmade sources
such as tobacco smoke or exhaust. The air cleaner is installed
on or near the furnace/air handler and removes the particles
that travel with the air that circulates through your heating
and cooling system. Removing these particles keeps the
equipment components clean and more importantly removes
particles from the air you breathe. Particles are measured in
microns, which is a unit of measure used for very small things
(1 micron = 1/25,400 inch). For reference, the diameter of a
human hair is approximately 100 microns. Figure 2 shows the
size of various particles that can be found in the air.
Your model 4200 or 4400 with genuine Aprilaire SelfSeal
filters is a highly efficient air cleaner. The removal efficiency
defines the percent of particles entering the air cleaner that
are trapped (see Table 1).
Until now, the air cleaner has been a passive component of
your heating and cooling system; when the equipment turned
on to heat or cool your home, the air cleaner was doing its job
whether you were aware of it or not. Your thermostat turns on
your heating and cooling equipment and so, essentially, the
thermostat determined when you clean your air. Your model
4200 or 4400 air cleaner comes with an exclusive Air Cleaner
Control that allows you to clean your air when you want! Not
only does the Air Cleaner Control allow you to actively clean
the air, it will show you when the air cleaner is filtering the air
and when it is time to change the filter.
FIGURE 1
FIGURE 2
™
Common Pollutants
Particle sizes in microns
0.01 0.1
SMUDGING
SMOKE
*American Society of Heating, Refrigeration and Air Conditioning Engineering Guide
TABLE 1 – Particle Removal Efficiency
Particle Size (microns)
1
3
5
7
10
*
(1 micron = 1/25,400 inch)
1 5 10
POLLENS & SPORES
DUST
AIRBORNE BACTERIA
Removal Efficiency
76%
93%
91%
93%
97%
50 100
90-1148
3