SECTION 15860

CENTRIFUGAL FANS

PART 1 GENERAL

SECTION INCLUDES

Backward inclined centrifugal fans.

Forward curved centrifugal fans.

Airfoil centrifugal fans.

Radial centrifugal fans.

Tubular centrifugal fans.

Inline centrifugal fans.

Utility/vent sets.

Motors and drives

Fan Accessories.

RELATED WORK

Section 15170 - Motors.

Section 15242 - Vibration Isolation.

Section 15290 - Ductwork Insulation.

Section 15855 - Air Handling Units With Coils.

Section 15890 - Ductwork.

Section 15910 - Ductwork Accessories: Backdraft dampers.

Section 16180 - Equipment Wiring Systems: Electrical characteristics and wiring connections.

REFERENCES

AFBMA 9 - Load Ratings and Fatigue Life for Ball Bearings.

AFBMA 11 - Load Ratings and Fatigue Life for Roller Bearings.

AMCA 99 - Standards Handbook.

AMCA 210 - Laboratory Methods of Testing Fans for Rating Purposes

AMCA 300 - Test Code for Sound Rating Air Moving Devices.

AMCA 301 - Method of Calculating Fan Sound Ratings from Laboratory Test Data.

NEMA MG1 - Motors and Generators.

NFPA 70 - National Electrical Code.

SMACNA - HVAC Duct Construction Standards - Metal and Flexible.

SUBMITTALS

Submit under provisions of Section [01300.] [________.]

Shop Drawings: Indicate assembly of centrifugal fans and accessories including fan curves with specified operating point clearly plotted, sound power levels for both fan inlet and outlet at rated capacity, and electrical characteristics and connection requirements.

Product Data: Provide data on centrifugal fans and accessories including fan curves with specified operating point clearly plotted, sound power levels for both fan inlet and outlet at rated capacity, and electrical characteristics and connection requirements.

Manufacturer's Installation Instructions.

OPERATION AND MAINTENANCE DATA

Submit under provisions of Section [01700.] [________.]

Maintenance Data: Include instructions for lubrication, motor and drive replacement, spare parts list, and wiring diagrams.

DELIVERY, STORAGE, AND HANDLING

Deliver, store, protect and handle products to site under provisions of Section [01600.] [________.]

Protect motors, shafts, and bearings from weather and construction dust.

ENVIRONMENTAL REQUIREMENTS

Do not operate fans for any purpose until ductwork is clean, filters in place, bearings lubricated, and fan has been test run under observation.

EXTRA MATERIALS

Furnish under provisions of Section [01700.] [________.]

Provide [two] [____] sets of belts for each fan.

PART 2 PRODUCTS

MANUFACTURERS

[__________________________________] Product [_________].

[__________________________________] Product [_________].

[__________________________________] Product [_________].

Substitutions: Under provisions of Section [01600.] [________.]

GENERAL

Performance Ratings: Conform to AMCA 210 [and bear the AMCA Certified Rating Seal.]

Sound Ratings: AMCA 301, tested to AMCA 300 [,and bear AMCA Certified Sound Rating Seal.]

Fabrication: Conform to AMCA 99.

Performance Base: [Sea level] [________] conditions.

Temperature Limit: Maximum [300] [600] [____] degrees F ([150] [315] [____] degrees C).

Static and Dynamic Balance: Eliminate vibration or noise transmission to occupied areas.

Performance

Air Flow: [_____] cfm ([_____] L/sec) at [_____] in wg ([_____] Pa).

Motor: [_____] hp, [_____] volt, [single] [three] phase, 60 Hz.

WHEEL AND INLET

Backward Inclined: Steel [or aluminum] construction with smooth curved inlet flange, heavy back plate, backwardly curved blades welded or riveted to flange and back plate; cast iron [or cast steel] hub riveted to back plate and keyed to shaft with set screws.

Forward Curved: [Black enameled] [Galvanized] steel construction with inlet flange, back plate, shallow blades with inlet and tip curved forward in direction of airflow, mechanically secured to flange and back plate; steel hub swaged to back plate and keyed to shaft with set screw.

Airfoil Wheel: Steel construction with smooth curved inlet flange, heavy back plate die formed hollow airfoil shaped blades continuously welded at tip flange, and back plate; cast iron [or cast steel] hub riveted to back plate and keyed to shaft with set screws.

Radial: Steel construction with [inlet flange,] heavy [reinforced] back plate, plate blades [with reinforcing gussets] [and] [wearing strips] welded or riveted to back plate [and flange]; cast iron [or cast steel] hub riveted to back plate and keyed to shaft with set screws.

HOUSING

Heavy gage steel, spot welded [for AMCA 99 Class I and II fans, and continuously welded for Class III], adequately braced, designed to minimize turbulence with spun inlet bell and shaped cut-off.

Factory finish before assembly with enamel or prime coat. For fans handling air downstream of humidifiers, [provide two additional coats of paint.] [fabricate of galvanized steel.] [Prime coating on aluminum parts is not required.]

Provide bolted construction with horizontal flanged split housing [, where indicated].

Fabricate plug fans without volute housing, with steel cabinet, lined. Refer to Section 15290.

BEARINGS AND DRIVES

Bearings: AFBMA 9, [L-10 life at 50,000 hours] [L-50 life at 100,000 hours] heavy duty pillow block type, self-aligning, grease-lubricated ball bearings, or AFBMA 11 [L-10 life at 120,000 hours] [L-50 life at 400,000 hours] pillow block type, self-aligning, grease-lubricated roller bearings.

Shafts: Hot rolled steel, ground and polished, with key-way, protectively coated with lubricating oil, and shaft guard.

V-Belt Drive: Cast iron or steel sheaves, dynamically balanced, keyed. Variable and adjustable pitch sheaves for motors 15 hp (11.2 Kw) and under, selected so required rpm is obtained with sheaves set at mid-position. Fixed sheave for 20 hp (15 Kw) and over, matched belts, and drive rated as recommended by manufacturer or minimum 1.5 times nameplate rating of the motor.

Belt Guard: Fabricate to SMACNA Standard; of 12 gage (2.8 mm) thick, 3/4 inch (20 mm) diamond mesh wire screen welded to steel angle frame or equivalent, prime coated. Secure to fan or fan supports without short circuiting vibration isolation, with provision for adjustment of belt tension, lubrication, and use of tachometer with guard in place.

ELECTRICAL CHARACTERISTICS AND COMPONENTS

Electrical Characteristics:

[____] hp ([____] kW).

[____] volts, [single] [three] phase, 60 Hz].

[____] amperes maximum [fuse size] [circuit breaker size] [overcurrent protection].

[____] percent minimum power factor at rated load.

Refer to Section 16180.

Motor:	[Refer to Section 15170.] [NEMA MG1, [____].]

Wiring Terminations:	Provide terminal lugs to match branch circuit conductor quantities, sizes, and materials indicated. Enclose terminal lugs in terminal box sized to NFPA 70.

ACCESSORIES

Fixed Inlet Vanes: Steel construction with fixed cantilevered inlet guide vanes welded to inlet bell.

Adjustable Inlet Vanes: Steel construction with blades [supported at both ends] [cantilevered] with two permanently lubricated bearings, variable mechanism [out of air stream] terminating in single control lever with control shaft for double width fans [and locking quadrant].

Discharge Dampers: [Parallel] [Opposed] blade heavy duty steel damper assembly with blades constructed of two plates formed around and welded to shaft, channel frame, sealed ball bearings, with blades linked out of air stream to single control lever.

Inlet/Outlet Screens: Galvanized steel welded grid.

Access Doors: Shaped to conform to scroll, with quick opening latches and gaskets.

Scroll Drain: 1/2 inch (13 mm) steel pipe coupling welded to low point of fan scroll.

PART 3 EXECUTION

INSTALLATION

Install in accordance with manufacturer's instructions.

Install fans as [indicated,] [specified,] with resilient mountings and flexible electrical leads. Refer to Section 15242.

Install flexible connections specified in Section 15910 between fan inlet and discharge ductwork. Ensure metal bands of connectors are parallel with minimum one inch (25 mm) flex between ductwork and fan while running.

Install fan restraining snubbers as [indicated.] [required.] Refer to Section 15242. Adjust snubbers to prevent tension in flexible connectors when fan is

operating.

Provide [fixed] sheaves required for final air balance.

Provide safety screen where inlet or outlet is exposed.

Pipe scroll drains to nearest floor drain.

Provide backdraft dampers on discharge of exhaust fans and as indicated. [Refer to Section 15910.]

CENTRIFUGAL FAN SCHEDULE

Drawing Code	F-1	F-2	F-3	F-4

Manufacturer

Model

Fan Type

Wheel Type

Class

Arrangement

Size

Air Flow Capacity

Static Pressure

Drive

Motor hp

Sound Power

Discharge

1st Octave

2nd Octave

3rd Octave

4th Octave

5th Octave

6th Octave

7th Octave

8th Octave

Inlet

1st Octave

2nd Octave

3rd Octave

4th Octave

5th Octave

6th Octave

7th Octave

8th Octave

Accessories

END OF SECTION