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Air flow required for PTAC units must not be restricted by
exterior plants or walls.
Plants or shrubs must not be planted in close proximity
to the outside grille of the PTAC unit.
Vegetation planted too close to grilles will cause discharge
air to be recirculated, thereby increasing electrical
consumption.
Warranty will be voided if it is determined that the
compressor life is shortened from overheating due to close
proximity of outside obstructions.
Note: Discharge air restrictions include, but are not
limited to:
• Vegetation
• Concrete walls or barriers
• Overhangs that do not allow discharge air to rise
Example:
X
Free Area % =
x 100
Y
Where X = .7
Y = 1.0
.7
Free Area % =
x 100 = 70%
1.0
Figure 14. Louver Designs
Two styles of exterior louvers are available. The standard
louver is a one-piece stamped aluminum type that is finished
natural and clear anodized, (Figure 12). Attractive, rugged ar-
chitectural louvers (Figure 13) are extruded aluminum and are
finished natural and clear anodized (optional colors are also
available).
Louvers by others are acceptable as long as they meet
factory specifications. They must have a minimum free area
of 70% or a pressure drop not exceeding .05 in. w.g. at 300
fpm face velocity, and a blade design that will not cause recir-
culation of condenser air.
Free area is defined by ASHRAE as the minimum area of
the openings in an air inlet or outlet through which air can
pass. Have your local McQuay/Remington representative
evaluate the application of special louvers or building facade
treatments that may affect normal operation of the unit or re-
strict free air discharge of condenser airflow. A louver design
that restricts the passage of condenser air or causes con-
denser air to be recirculated can dramatically alter the perfor-
mance of the unit. Unit capacity and efficiency may be de-
creased and fan motor and compressor life can be
shortened.
If the louver does not meet the requirements set out above
or it is only marginally acceptable, then a drawing will be re-
quired for factory evaluation. If acceptance cannot be deter-
mined by the drawing, then a sample of the proposed louver
must be sent to the factory for testing and certification. The
sample sent for testing must be at least 16" high by 42" wide.
Typical Louver Design
Figure 14 illustrates some typical louver designs.
The “X ” dimension represents the narrowest dimension
through which air must pass. The “Y ” dimension represents
the increment of rise between the blades. To calculate the per-
centage of free area, divide dimension “X ” by dimension “Y ”
(see Example).
Figure 12. Standard Stamped Louver
Figure 13. Architectural Louver
Outdoor Louvers
IMPORTANT!
