AAF International PRU - Manual (Page 19)

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7.0 Spare Parts List
It is recommended that the following spare parts be stored at the installation site for routine maintenance purposes. The quantities required will
depend on the size of the system. Consult with your AAF representative to determine actual quantities required. Minimum recommended
quantities are provided in the table below.
AAF Part Number Description Recommended Spares
Refer to the original customer purchase SAAF cassette gas-phase chemical filters One full replacement set of each type
order and the AAF submittal drawing included in the system
Refer to the original customer purchase Particulate filters One full replacement set of each type
order and the AAF submittal drawing included in the system
2500932 Extruded plastic strips which provide 20% of the number supplied
low friction cassette bearing surface with the equipment
2500924 Hollow core track gasket One full replacement set or a roll of 50 feet
2500981 Access door perimeter gasket One full replacement set or a roll of 50 feet
2500999 Access door side seal gasket One full replacement set
Refer to the original customer purchase Fan One replacement fan
order and the AAF submittal drawing
To order replacement parts call: 1-800-477-1214.
8.0 Equipment Characteristics, Dimensions, Operating
Weights, and Shipping Weights
See the AAF submittal drawing supplied on the specific order.
9.0 Technical Guidelines
9.1 Fan Selection and Sizing: The following guidelines are provided
to inform the user of the criteria used by AAF to select an integral fan
that is provided with the RU.
9.1.1 Determination of Fan Selection Pressure Drop: The
following concerns initial and final filter pressure drop and the use
of pressure drop for fan selection. AAF’s standard product literature
indicates the start-up, being the clean filter or initial, and the
recommended final, or dirty filter, pressure drops for all filters at a
particular airflow velocity. If the airflow velocity in the actual
installation differs from that referenced in the literature, then the
start-up (initial) pressure drop will also differ. For instance, an AAF
PerfectPleat or M-Pak filter is typically rated at 500 FPM velocity.
However, when used with a type HD cassette, the airflow velocity
will normally be 250 FPM so the initial pressure drop will be lower.
Similarly, the final pressure drop referenced in the literature is a
“recommended” value only, and the filter may be changed out at a
lower pressure drop, if required.
Table 3: Nominal Pressure Drop (ΔP) @ 250 FPM Nominal Airflow Velocity
Pressure Component Initial ΔP (in. w.g.) Final ΔP (in. w.g.),
Recommended or Actual
External pressure 0.10 0.10
loss from inlet and
outlet ducts
2” PerfectPleat 0.11 1.0
HD Cassette with 0.73 0.73
SAAFOxidant
HD Cassette with 0.73 0.73
SAAFOxidant
After-filter 0 0
M-Pak filter 0.23 1.5
TOTALS 1.90 4.06
A typical pressure drop profile for an RU might be as shown in
Table 3 below: