Type PBH Hooded Power Roof Ventilator
APPLICATIONS: American CoolAir Type PBH ventilators are designed to be economical, low-profile roof exhausters. The pleasing appearance of its low profile is accomplished by recessing the fan unit into the curb opening. Consequently, a mounting sleeve or higher-than-standard curb may be required for clearance between fan motor and damper.
CONSTRUCTION:Type PB PRVs incorporate Style H fan components for models in the 24 inch to 54 inch sizes. The PBH ventilators are constructed for down-blast discharge. The air velocity opens the damper blades and escapes through the bird/insect screen of the hood. When the fan is off, counterbalanced damper blades shut by gravity to a weather-resistant closure. The motor and drive components are recessed into the roof curb right aboove the back-draft damper. The ventilators utilize a cross-frame to support stationary shaft-bearing-cast aluminum hub-pulley assembly. Drive belt power is applied to the fan/hub assembly in the same plane as the bearings, reducing bearing load and increasing bearing life. Bearings are permanently lubricated and sealed. The six die-formed steel propeller blades are securely attached at three points on the hub. All blade assemblies are dynamically balanced.
MATERIALS: The PBH assembly and curb cap are fabricated of heavy gauge steel. Dampers are constructed of aluminum. The roof curb is made of galvanized steel with fiberglass insulation. Painted parts are coated after the American Coolair five-stage pretreatment system prior to the application of the thermosetting epoxy powder paint with an average thickness of 3 mils, baked at 400°F for smooth and durable finish.
BELT DRIVE: Belt driven models use V-Belts with Variable Pitch Pulles which allows fan speed adjustment.
MOTORS:The American Coolair air-over-motor design provides extra capacity and economy because it serves to dissipate heat and thus increase horsepower capability. Totally enclosed motors are standard. Several alternatives, such as explosion proof motors, two speed, energy efficient motors and severe duty motors, are available. Only nationally recognized brand motors with nationwide service facilities are used.
WIRING: Type PBH PRVs feature a conduit through the curb cap for convenience in connecting power supply. If a safety disconnect switch accessory is specified, it is mounted above curb cap and attached to the conduit for a rain-resistant connection and switch enclosure.
CERTIFICATION:All Types P vntilators are listed under UL705 – E39944 by Underwriters Laboratory, Inc. to U.S. and Canadian safety standards. Certified ratings licensed by AMCA (Air Movement and Control Association International, Inc.), for both air and sound performance, as well as octave band sound power levels are available for use by the design and acoustical engineers.