- Fan Type
Fan shall be rooftop centrifugal exhaust type with aluminum backward inclined centrifugal wheel. The inlet Venturi shall have round curved section to smoothly transit the air to the wheel cone. The wheel shall be statically and dynamically balanced to Level G2.5 as per AMCA204 standard.
- Quality Standards
The fan shall be tested in accordance with AMCA Standard 210 and 300 and AMCA licensed according to AMCA Publication 211 and 311 for sound and air performance. And each fan shall be affixed with AMCA sound and air performance Seal, The manufacturer must own the production license for industrial products and ISO9001 quality system authentication.
- Fan Material
The fan housing, wheel and curb shall be constructed of aluminum alloy. The exterior color of the fan shall be silver white to be harmony with the building.
Hood: The hood shall be rigid to bear heavy wind load and protect the fan from leaking of heavy rain or snow melting.
Motor, Drives and Wheel Support Panel: Motor and drives support panel shall use an anti-corrosion treated steel panel. Using the same material as that of the housing is prohibited. The column shall be aluminum stick to make sure the support is stable.
Internal Wiring Conduit: Fan shall be furnished with a conduit to lead the power supply wiring through the curb to the motor chamber (Limited to non smoke removal type).
Curb cap with Mounting Holes: The roof curb cap shall have pre-drilled holes at its side by which the fan could be fixed.
Galvanized Bird Screen: Galvanized bird screen shall be furnished to protect the fan discharge from birds when the fan is not running.
- Fresh Air Cooling Motor
Fresh air shall be induced into the motor chamber from the area without exhaust air to cool the motor. Fresh air shall be induced into the motor chamber via auxiliary wheel blades from the gap below motor cover.
- Transmission Device (Only for belt drive type)
Shaft: Fan shaft shall be heat treated through soaking furnace to reach the hardness level of HB250, and the surface shall be hard film corrosion treated. The fan shaft shall be balanced together with the wheel, and the shaft design speed shall at least exceed 25% of the maximum fan operation speed.
Pulleys: Fan pulleys shall be sized for a minimum of 150% of driven power. Pulleys shall be cast iron. Motor pulleys shall be adjustable for final system balancing. Conical (QD) type bushings shall be equipped for easy removal of the pulleys.
Bearing: Bearings shall be selected of metallic to avoid vibration directly applied to motor. The motor bearings shall be selected for a minimum (L－10) life in excess of 80,000 hours at maximum cataloged operating speed. Bearing type shall be permanently sealed, lubricable pillow block metal ball bearings.
Drive support: Drives shall be supported by powder coated heavy gauge steel and mounted on vibration isolators. The belt tension shall be adjusted through motor support plate to make sure the fan shaft and motor shaft always parallel.
- Explosion-proof Structure (Only for explosion-proof type)
Fan shall conform to Spark A explosion-proof structure according to AMCA99 Standard. Whole aluminum alloy structure and the motor shall adopt explosion-proof type. The whole fan should own CNEX certification and the manufacturer must own the production license for anti-explosion electric products.
- Fire fighting Certification (Only for smoke removal duty)
The fan shall be tested OK in complying with the General Usage Centrifugal Fan technical Specification (China National Standard JB/T 10563-2006). A test report issued by licensed authorities shall be provided. The fan must be tested according to China National Standard GA 211-2009, Fire Fighting Smoke Removal Fan High Temperature Testing Method, running continuously over 30 minutes when the main duct air temperature is 280 degrees centigrade. The high temperature resistance character must be qualified by presenting an official certificate.
Motor shall be carefully matched to the fan load, IP54, and insulation class F. Motor bearings shall be lubrication-free ball bearing type. Motor and drives shall be out of the air stream to avoid grease or dirt accumulation. Motor chamber shall be fixed through stainless steel clips for easy maintenance.
Permanently fixed aluminum nameplate shall be fixed on fan body clearly display fan mark, product model and serial number (i.e.: unique ID for each fan), so that the customer can use this number to find out the parts used.