MD ANDERSON Project No. XX-XXXX
MD ANDERSON PROJECT NAME
A/E Project No.
Month, 00, 0000
The fan array system shall consist of multiple, direct driven, arrangement 4 plenum fans constructed per AMCA requirements for the duty specified, (Class I, II or III). Unless otherwise noted, each air handling unit fan array shall consist of (2) ‘A’ & ‘B’ controlled fan array halves which are either equally split or controlled in a “checkered board” arrangement. Each ‘A’ & ‘B’ fan array shall be controlled by its own VFD.
All fans shall be selected to deliver the specified airflow quantity at the specified operating total static pressure and specified motor speed. The fan array shall be selected to operate at a system total static pressure that does not exceed 90% of the specified fan’s peak static pressure producing capability at the specified fan/motor speed.
Each fan/motor “cube” shall include an 11 gage; A60 galvanized steel motor support plate and structure. The fan air inlet cone and motor support structure shall be powdered coated for corrosion resistance. All motors are standard T-frame pedestal mounted type, (TEAO) or (TEAC), selected at the specified operating voltage, rpm, and efficiency as specified or as scheduled elsewhere. All motors are to be compatible for inverter duty, with sealed bearings and also include an isolated bearing or shaft grounding. To ease the replacement of the assembled fan/motor, the motor shall not exceed the nominal rating of 10 horsepower.
The fan array shall produce a uniform airflow and velocity profile within the airway tunnel of the air handling unit not to exceed the specified cooling coil and filter bank face velocity when measured 12 inches from the intake side of the fan array intake plenum wall and at a distance of 48 inches from the discharge side of the fan array intake plenum wall.
Each fan/motor cube shall be equipped with a metal grating fan outlet guard. The manufacturer of the array shall be responsible to determine if the addition of vibration isolators are required to meet the vibration requirements within this specification.
Each fan array shall also include a motor removal rail located on the discharge side of the fan array. An I-beam rail with a trolley shall span the full internal width of the unit or each fan array section shall include at least one jib hoist assembly to facilitate motor removal from any fan cube.
Each fan cube shall be provided with a backdraft damper to isolate the inlet side of the fan/motor cube that is fails on standby or is being removed from the fan array. The function shall prevent air bypass through a fan cube when not in operation. The backdraft damper shall be constructed of extruded aluminum frame and blades with low friction bearings for long life, continuous operation.
Each fan array shall include at least one fan assembly with a complete airflow measuring station to indicate airflow in CFM. The flow measuring system shall consist of a flow measuring station with static pressure taps and total pressure tubes located at the fan inlet cone. The flow measuring station shall provide an analog to digital CFM readout using a 4-20ma or 0-10 volt output control signal for use in the BAS.
Plug Fan (PF) SWSI Minimum Class II Fans: single width single inlet arrangement 4 as indicated on the Drawings. Fan wheel has a minimum of 12 blades made from extruded aluminum as a hollow airfoil in shape, and welded to the center and wheel side plates. The fan Inlet cone is made from spun aluminum material. Fan wheel shall be keyed to the shaft.
The University of Texas
CUSTOM AIR HANDLING UNITS WITH FAN ARRAY SYSTEMS
MD Anderson Cancer Center
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