AAON RN Series Installation Operation & Maintenance page 91

CAUTION
Disconnect electrical power before
servicing energy recovery cassette.
Always keep hands
bearing support beam when installing
or removing segments. Failure to do
so could result in severe injury to
fingers or hand.
The need for periodic cleaning of the energy
recovery wheel will be a function of
operating schedule, climate and contaminants
in the indoor air being exhausted and the
outdoor air being supplied to the building.
The energy recovery wheel is "self-cleaning"
with respect to dry particles due to its laminar
flow characteristics. Smaller particles pass
through; larger particles land on the surface
and are blown clear as the flow direction is
reversed. Any material that builds up on the
face of the wheel can be removed with a
brush or vacuum. The primary need for
cleaning is to remove oil based aerosols that
have condensed on energy transfer surfaces.
A characteristic of all dry desiccants, such
films can close off micron sized pores at the
surface of the desiccant material, reducing
the efficiency by which the desiccant can
adsorb and desorb moisture and also build up
so as to reduce airflow.
In a reasonably clean indoor environment
such as a school or office building,
measurable reductions of airflow or loss of
sensible (temperature) effectiveness may not
occur for several years. Measurable changes
in latent energy (water vapor) transfer can
occur in shorter
applications such as moderate occupant
smoking or cooking facilities. In applications
experiencing unusually
occupant smoking or oil based aerosols such
as industrial applications
away from
periods of time in
high levels of
involving the
ventilation of machine shop areas for
example, annual washing of energy transfer
may be necessary to maintain latent transfer
efficiency. Proper cleaning of the energy
recovery wheel
effectiveness to near original performance.
Aluminum Wheel Cleaning
See general energy recovering cleaning
section for how often to clean.
To clean, gain access to the aluminum energy
recovery wheel then use the following
methods:

Use a brush or vacuum cleaner to
remove small foreign materials.

Use compressed air at a distance of at
least 2 ft from the wheel. Too much
pressure can
aluminum media.

First remove the energy recovery wheel
from the unit.
distance of at least 2 ft from the wheel.
Do not use
temperature below 77F. Tightly cover
all electric parts and bearings while
used pressurized water. Remove excess
water before reinstalling the wheel.
Polymer Wheel Cleaning
To clean, gain access to the energy recovery
wheel and remove segments. Brush foreign
material from the face of the wheel. Wash the
segments or small wheels in a 5% solution of
non-acid based coil cleaner or alkaline
detergent and warm water.
CAUTION
Do not use acid based cleaners,
aromatic solvents,
temperatures in excess of 170°F;
damage to the wheel may occur!
will restore latent
easily damage the
Then use water at a
detergents. Keep
steam or
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