Bosch FHP RT-20 Installation, Operation And Maintenance Manual page 50

Internal Filter Maintenance
The RT units will typically be provided with 2-inch,
pleated filters in the supply airstream. These filters
should be checked per a routine maintenance
schedule and replaced as necessary to ensure proper
airflow through the unit. See table below for pleated
filter size and quantity for each unit. Replacement
filters shall be of same performance and quality as
factory installed filters. Filter type must be pleated
design with integral metal grid. Two acceptable filter
replacements are Aerostat Series 400 or Farr 30/30 ® .
RT offers an optional final filters. Either MERV 8, 11
or 13 filters are available in 2 or 4-inch depth. An
acceptable replacement filter is an AmAir ® 1100 or
similar model.
Outdoor Air Filters: Access to the outdoor air filters
is through the door labeled as "Filter Access" on the
access side of the unit.
Refer to Subassemblies/Filters section for additional
information on filter locations.
WARNING
REFER TO GENERAL SAFETY INFORMATION
Do not operate make-up air ventilator without the
filters and birdscreens installed. They prevent the
entry of foreign objects such as leaves, birds, etc.
Do not remove access panels or other unit
components while standing on a ladder or other
unsteady base. Access panels and unit components
are heavy and serious injury may occur.
External Filter Maintenance
Aluminum mesh, 2-inch deep filters are located in the
supply weatherhood (if the weatherhood option was
purchased). Filters should be checked and cleaned
on a regular basis for best efficiency. The frequency
of cleaning depends upon the cleanliness of the
incoming air. These filters should be cleaned by
rinsing with a mild detergent in warm water prior to
start-up.
Filters upstream of the coil should be checked
regularly. If the filters are dirty, they should be cleaned
or replaced. It is important that the coils stay clean
to maintain desired airflow. See Filter Maintenance
section for additional information. See also Access
Door Description.
50 Model RT Energy Recovery Unit
Coil Maintenance
Coils must be cleaned to obtain maximum
performance. Check once a year under normal
operating conditions and if dirty, brush or vacuum
clean. Soiled fins reduce the capacity of the coil,
demand more energy from the fan, and create an
environment for odor and bacteria to grow and
spread through the conditioned zone. High pressure
water (700 psi or less) may be used to clean coils
with fin thickness over 0.0095 inches thick. TEST THE
SPRAY PRESSURE over a small corner of the coil to
determine if the fins will withstand the spray pressure.
For coils with fragile fins or high fin density, foaming
chemical sprays and washes are available. Many coil
cleaners contain harsh chemicals, so they must be
used with caution by qualified personnel only. Care
must be taken not to damage the coils, including the
fins, while cleaning. Caution: Fin edges are sharp
WARNING
Biological hazard. May cause disease. Cleaning
should be performed by qualified personnel.
Drain pans in any air conditioning unit will have
some moisture in them, therefore, algae and other
organisms will grow due to airborne spores and
bacteria. Periodic cleaning is necessary to prevent
this buildup from plugging the drain and causing the
drain pan to overflow. Inspect twice a year to avoid
the possibility of overflow. Also, drain pans should be
kept clean to prevent the spread of disease. Cleaning
should be performed by qualified personnel.