FREQUENTLY ASKED QUESTIONS

ARE ALL COPPUS VENTILATORS UL LISTED? COMMON PORTABLE VENTILATION TERMS

All electrical components (motors, starters, switches, junction boxes, cord, plugs, etc.) are UL listed. CONFINED SPACE Large enough area to be occupied by an individual, but with limited or restricted means for entry or exit; not normally de- signed for continuous occupancy.

WHAT TYPE OF VENTILATOR DO YOU RECOMMEND FOR EXPLOSION-PROOF ENVIRONMENTS?

CFM Cubic feet per minute—measurement of flow handled by a fan. BLOCKED TIGHT STATIC PRESSURE If compressed air is available as your utility, we recommend our RF series ven-tilators or our Jectair (venturi style) air movers. Pneumatic-drive ventilators are often desirable for hazardous locations. If electric drive is preferred or required, we offer most of our fans and ventilators in explosion-proof models. Explosion-proof units require all electrical connections to be enclosed, and moving mechanical pieces to be constructed of material so as not to create sparks. This requires special motors and starters, as well as fan blades and other moving parts to be made of non-sparking materials such as aluminum, stainless steel, fiberglass or plastic. STATIC PRESSURE Operating condition in which the fan outlet is completedly closed, resulting in no air flow. Usually expressed in inches water gauge (Wg); pressure measured in a direction normal to the air flow; static pressure combined with velocity pressure equals total pressure. FREE AIR DELIVERY Maximum airflow where static pressure across the fan is zero. CAPTURE VELOCITY Air velocity at any point in front of the hood opening necessary to overcome opposing air currents and to capture the contaminated air at that point.

WHY ARE PLUGS NOT STANDARD ON EXPLOSION-PROOF UNITS?

Local electrical codes can vary for hazardous location equipment operation, cre-ating a variety of different plug-receptacle configurations. We recommend that either the plug be installed by a local electrician, or the type and part number of the correct plug be submitted to us in writing for factory installation to ensure local code compliance.

WHAT IS THE MAXIMUM HORSEPOWER I CAN USE WITH 115V POWER?

A 1.5 HP motor is the largest practical power unit to effectively run on single- phase power. A larger HP motor will generate very large current in-rushes, tripping the electrical protection breaker.

IS THERE A DIFFERENCE IN AIR VOLUME ON THE SUCTION AND DISCHARGE OF THE VENTILATOR?

air velocity at a given distance away from the fan. For example: one foot (305 mm) away from the suction end of a 12” (305 mm) fan, the air velocity will drop by 90 per- cent compared to only a three percent drop on the supply side. No. The given air volume is the same whether the ventilator is used as an exhauster or blower. However, there is a significant difference in the
30dd DECIBEL LEVELS Sound data on COPPUS products are based on tests conducted with units op- erating at published speeds. No attach- ments for attenuating sound were used [dBA levels recorded at 5’ (1.5 m)].
Suction10% of X Supply10% of x FAN Air velocity is reduced as the distance from the fan increases on both the inlet (exhaust) and outlet (delivery) sides. However the rate of reduction in air velocity is significantly greater on the inlet side of the fan. d = diameter of the fan face x = air velocity of the fan face