Thermo Pride MODEL OPA - Manual (Page 24)

All installations and services must be performed by qualified service personnel.
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8. As a final step in the installation, the appliance must be adjusted to deliver a
temperature rise within the range of 50° to 80°F. Adjust the blower motor
speed to obtain a temperature rise within the acceptable range. The required
blower speed will depend on the airflow resistance of a supply and return air
duct systems.
I. Air
Filters
1. Filter Installation
This OPA unit has been factory supplied with a high quality, re-usable filter
rated for air velocities up to 600 ft/min.
2. Use of non-Thermo Pride Filters or Retention Means
: Failure to comply with minimum filter installation
requirements may affect the performance and/or void the warranty on
this unit.
If a method other than Thermo Pride filter racks is selected for retention of the
filter and/or use of a different filter type is desired, refer to Table 4 for
minimum sizing guidelines for selecting filter for the unit.
Table 4: Minimum Required Filter Area (in square inches)
Model Number Filter Type
Maximum
Air Velocity
(ft/min) OPA24 OPA30 OPA36 OPA42
*Thermo Products
Supplied
Permanent
600 192 240 288 336
Standard
Permanent 500 230 288 346 403
Disposable 300 384 480 576 672
∗ The Thermo Products supplied filter can be cut to size to fit other filter
retention systems as long as the minimum size requirement is met.
NOTICE: Any internal stiffeners used in the filter must not be removed,
although they can be cut to size as needed.