Brochure

6
TYPES OF EFFICIENCY TESTING
Air filtration efficiency depends on the type of air cleaner
used, and the type, number and size of the particles in the
air stream. The lowest ratings are typically found on ordinary
throw-away fiberglass filters. Resideo’s electronic air cleaner
has one of the highest ratings.
• Fractional Efficiency Testing measures the efficiency
of media filters and electronic air cleaners by size of
particle captured. The higher the test figure, the higher
the efficiency.
• Minimum Efficiency Reporting Value (MERV) is based on
Fractional Efficiency Testing and measures the efficiency
of media air filters and cleaners that have been in service
for a period of time. The higher the media MERV rating, the
better the efficiency over the life of the filter. See page 10
for more detail.
• Weight Arrestance Testing measures the weight of
particles trapped by the air cleaner and is typically used
for filters that have a MERV below 4. A small fraction of
all particles (10%) account for 99% of the weight of all
particles in the air. These heavy particles tend to settle
from the air before reaching an air cleaner.
• Initial pressure drop measures the decrease in air pressure
across new media filters or recently cleaned electronic air
cleaners. The lower the pressure drop, the better the airflow
in the HVAC system.
• Resideo air cleaners are tested using the Fractional
Efficiency Testing, MERV Testing, and Initial Pressure
Drop measurements. Weight Arrestance Testing does not
differentiate high-efficiency filters.
Air Filtration and Performance
Use air filtration efficiency ratings and the importance of maintaining airflow as the filter gets dirty to help
homeowners compare air-cleaning options.
1 YR 2 YR 3 YR
Electronic Air Cleaner
90
80
70
60
50
40
30
20
10
0
MERV 10 Media Air Cleaner
Cell Cleaned
Cell Not Cleaned
Filter Not
Replaced
Filter
Replaced
Filter Loading (Time)
Removal Efficiency (at 0.3 to 1.0 microns)
Our electronic air cleaners stay highly efficient
between washings, and cause much less
pressure drop when dirty.
MEASURING AIR FILTRATION PERFORMANCE
Every time the furnace or air conditioner blower operates, it circulates air through the ductwork. The force it must
overcome to move this air is called “static pressure.” Because air cleaners are designed to capture particles, they
present a barrier to airflow. This is important because air cleaner efficiency ratings can be related to static pressure
and pressure drops. Achieving an apples-to-apples comparison between different air cleaners can be a difficult
task because manufacturers may measure efficiency at different airflows and pressures.