539-333 ADDENDUM_1-2021.0322.pdf

ADDENDUM NO. 01

March 22, 2021

VA PROJECT # 539-333

CONSTRUCT 3RD FLOOR BUILDING #2 AND RENOVATE 1ST FLOOR

CINCINNATI VA MEDICAL CENTER

3200 VINE ST.

CINCINNATI, OHIO 45220

LEVIN PORTER ASSOCIATES, INC

3011 NEWMARK DRIVE

DAYTON, OHIO 45342

LPA PROJECT NO. 62125.00

TO ALL BIDDERS:

This addendum including all items listed hereinafter, shall become a part of the documents, shall be taken into account in preparing the Proposal, and shall become a part of the Contract. The work under each branch shall be in accordance with the original specifications unless excepted in this Addendum.

This Addendum consists of 2 pages plus (20 pages for specification 23 74 13) and (1) 30X42 drawing attachments:

ARCHITECTURAL

DRAWINGS

ITEM NO.1 Drawing No. 2.A202

A. Replace keynote 2.07 to read “REMOVE ROOFING SYSTEM INCLUDING ROOF MEMBRANE, INSULATION, AND FASTENERS. PATCH AND LEVEL CONCRETE DECK AS REQUIRED TO

PREPARE FOR NEW THIRD FLOOR FINISHES.”

MECHANICAL

SPECIFICATIONS

ITEM NO. 1 SPECIFICATION SECTION 23 74 13

A. Add section 2.2 AIR PURIFICATION SYSTEM – BIPOLAR IONIZATION.

DRAWINGS

ITEM NO. 2 Drawing No. M601 – Revised sheet attached.

A. Corrected quantity of AHU fans in FAN SCHEDULE.

B. Modified ‘AIR HANDLING UNIT 2-AHU5 LAYOUT’:

1) Corrected economizer section.

2) Added relief louvers to service vestibule.

3) Added Bipolar Ionization.

END OF ADDENDUM NO. 01

VA CINCINNATI PROJECT NO. 539-333

CONSTRUCT 3rd FLOOR BUILDING #2 AND RENOVATE 1st FLOOR

04-11

23 74 13 - 1

SECTION 23 74 13

PACKAGED, OUTDOOR, CENTRAL-STATION AIR-HANDLING UNITS

PART 1 - GENERAL

1.1 DESCRIPTION

A. Roof top air handling units including integral components specified herein.

B. Definitions: Roof Top Air Handling Unit (Roof Top Units, RTU): A factory fabricated assembly consisting of fan, coils, filters, and other necessary equipment to perform one or more of the following functions of circulating, cleaning, heating, cooling, humidifying, dehumidifying, and mixing of air. Design capacities of units shall be as scheduled on the drawings.

1.2 RELATED WORK

A. Section 13 05 41, SEISMIC RESTRAINT REQUIREMENTS FOR NON-STRUCTURAL

COMPONENTS: Seismic restraints for equipment.

B. Section 23 05 11, COMMON WORK RESULTS FOR HVAC: General mechanical requirements and items, which are common to more than one section of Division 23.

C. Section 23 05 41, NOISE AND VIBRATION CONTROL FOR HVAC PIPING AND

EQUIPMENT: Sound requirements.

D. Section 23 07 11, HVAC AND BOILER PLANT INSULATION: Piping and duct insulation.

E. Section 23 21 13, HYDRONIC PIPING and Section 23 22 13, STEAM AND

CONDENSATE HEATING PIPING: Piping and valves.

F. Section 23 82 16, AIR COILS: Heating and cooling coils and pressure requirements.

G. Section 23 34 00, HVAC FANS: Supply, return and exhaust fans.

H. Section 23 31 00, HVAC DUCTS AND CASINGS: Requirements for flexible duct connectors, sound attenuators and sound absorbing duct lining.

I. Section 23 40 00, HVAC AIR CLEANING DEVICES: Air filters and filters' efficiency.

J. Section 23 09 23, DIRECT-DIGITAL CONTROL SYSTEM FOR HVAC: HVAC controls.

K. Section 23 05 93, TESTING, ADJUSTING, AND BALANCING FOR HVAC: Testing, adjusting and balancing of air and water flows.

L. Section 23 05 12, GENERAL MOTOR REQUIREMENTS FOR HVAC AND STEAM

GENERATION EQUIPMENT: Types of motors.

M. Section 26 29 11, MOTOR CONTROLLERS: Types of motor starters.

N. Section 01 91 00, GENERAL COMMISSIONING REQUIREMENTS:

23 74 13 - 2

O. Section 23 08 00 – COMMISSIONING OF HVAC SYSTEMS: Requirements for commissioning, systems readiness checklists, and training.

1.3 QUALITY ASSURANCE

A. Refer to Article, Quality Assurance, in Section 23 05 11, COMMON WORK RESULTS

FOR HVAC.

B. Air Handling Units Certification

1. Air Handling Units with Housed Centrifugal Fans: The air handling units shall be certified in accordance with AHRI 430 and tested/rated in accordance with AHRI 260.

2. Air Handling Units with Plenum Fans:

a. Air Handling Units with a single Plenum Fan shall be certified in accordance with

AHRI 430 and tested/rated in accordance with AHRI 260.

b. Air handling Units with Multiple Fans in an Array shall be tested and rated in accordance with AHRI 430 and AHRI 260.

C. Heating, Cooling, and Air Handling Capacity and Performance Standards: AHRI 430, AHRI 410, ASHRAE 51, and AMCA 210.

D. Performance Criteria:

1. The fan BHP shall include all system effects for all fans and v-belt drive losses for housed centrifugal fans.

2. The fan motor shall be selected within the rated nameplate capacity, without relying upon NEMA Standard Service Factor.

3. Select the fan operating point as follows:

a. Forward Curve and Axial Flow Fans: Right hand side of peak pressure point.

b. Air Foil, Backward Inclined, or Tubular Fans Including Plenum Fans: At or near the peak static efficiency but at an appropriate distance from the stall line.

4. Operating Limits: AMCA 99 and Manufacturer’s Recommendations.

E. Units shall be factory-fabricated, assembled, and tested by a manufacturer, in business of manufacturing similar air-handling units for at least five (5) years.

1.4 SUBMITTALS:

A. The contractor shall, in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, AND SAMPLES, furnish a complete submission for all roof top units covered in the project. The submission shall include all information listed below. Partial and incomplete submissions shall be rejected without reviews.

B. Manufacturer's Literature and Data:

23 74 13 - 3

1. Submittals for RTUs shall include fans, drives, motors, coils, mixing box with outside/return air dampers, filter housings, blender sections, and all other related accessories. The contractor shall provide custom drawings showing total air handling unit assembly including dimensions, operating weight, access sections, diffusion plates, flexible connections, door swings, controls penetrations, electrical disconnect, lights, duplex receptacles, switches, wiring, utility connection points, unit support system, vibration isolators, drain pan, pressure drops through each component (filter, coil) and rigging points.

2. Submittal drawings of section or component only, shall not be acceptable. Contractor shall also submit performance data including performance test results, charts, curves or certified computer selection data; data sheets; fabrication and insulation details. If the unit cannot be shipped in one piece, the contractor shall indicate the number of pieces that each unit shall have to be broken into to meet shipping and job site rigging requirements. This data shall be submitted in hard copies and in electronic version compatible to AutoCAD version used by the VA at the time of submission.

3. Submit sound power levels in each octave band for fan(s) and at entrance and discharge of RTUs at scheduled conditions. Include sound attenuator capacities and itemized internal component attenuation. Internal lining of supply air ductwork with sound absorbing material is not permitted. In absence of sound power ratings, refer to Section 23 05 41, NOISE AND VIBRATION CONTROL FOR HVAC PIPING AND

EQUIPMENT.

4. Provide fan curves showing cubic feet per minute, static pressure, efficiency, and horsepower for design point of operation and at maximum design cubic feet per minute and 110 percent of design static pressure.

5. Submit total fan static pressure, external static pressure, for RTU including total, inlet and discharge pressures, and itemized specified internal losses and unspecified internal losses. Refer to air handling unit schedule on drawings.

C. Maintenance and operating manuals in accordance with Section 01 00 00, GENERAL

REQUIREMENTS. Include instructions for lubrication, filter replacement, motor and drive replacement, spare part lists, and wiring diagrams.

D. Submit written test procedures two weeks prior to factory testing. Submit written results of factory tests for approval prior to shipping.

23 74 13 - 4

E. Completed System Readiness Checklists provided by the Commissioning Agent and completed by the contractor, signed by a qualified technician and dated on the date of completion, in accordance with the requirements of Section 23 08 00 COMMISSIONING

OF HVAC SYSTEMS.

F. Submit shipping information that clearly indicates how the units shall be shipped in compliance with the descriptions below.

1. Units shall be shipped in one (1) piece where possible and in shrink wrapping to protect the unit from dirt, moisture and/or road salt.

2. If not shipped in one (1) piece, provide manufacturer approved shipping splits where required for installation or to meet shipping and/or job site rigging requirements in modular sections. Indicate clearly that the shipping splits shown in the submittals have been verified to accommodate the construction constraints for rigging as required to complete installation and removal of any section for replacement through available access without adversely affecting other sections.

3. If shipping splits are provided, each component shall be individually shrink wrapped to protect the unit and all necessary hardware (e.g. bolts, gaskets) shall be included to assemble unit on site (see section 2.1.A4).

4. Lifting lugs shall be provided to facilitate rigging on shipping splits and joining of segments. If the unit cannot be shipped in one piece, the contractor shall indicate the number of pieces that each unit shall have to be broken into to meet shipping and job site rigging requirements.

1.5 APPLICABLE PUBLICATIONS

A. The publications listed below form a part of this specification to the extent referenced.

The publications are referenced in the text by the basic designation only.

B. Air-Conditioning, Heating, and Refrigeration Institute (AHRI):

260-01 .................................. Sound Rating of Ducted Air Moving and Conditioning

Equipment

410-01 .................................. Standard for Forced-Circulation Air-Heating and Air-

Cooling Coils

430-09 .................................. Standard for Central Station Air Handling Units

AHRI-DCAACP ..................... Directory of Certified Applied Air Conditioning Products

C. Air Moving and Conditioning Association (AMCA):

210-07 .................................. Laboratory Methods of Testing Fans for Rating

23 74 13 - 5

D. Anti-Friction Bearing Manufacturer's Association, Inc. (AFBMA):

9-90 (R2008) ........................ Load Ratings and Fatigue life for Ball Bearings

E. American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE):

51-2007 ................................ Laboratory Methods of Testing Fans for Rating

F. American Society for Testing and Materials (ASTM):

A653/653M-02 ...................... Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-

Coated (Galvannealed) by the Hot-Dip Process

B117-07a .............................. Salt Spray (Fog) Testing

C1071-05e1.......................... Standard Specification for Fibrous Glass Duct Lining

Insulation (Thermal and Sound Absorbing Material)

D1654-08 ............................. Standard Method for Evaluation of Painted or Coated

Specimens Subjected to Corrosive Environments

D1735-08 ............................. Water Resistance of Coatings Using Water Fog Apparatus

D3359-08 ............................. Standard Test Methods for Measuring Adhesion by Tape

Test

E84-10.................................. Standard Test Method for Surface Burning Characteristics of Building Materials

G. Anti-Friction Bearing Manufacturer's Association, Inc. (AFBMA):

9-90 ...................................... Load Ratings and Fatigue life for Ball Bearings

H. Military Specifications (Mil. Spec.):

DOD-P-21035A-2003 ........... Paint, High Zinc Dust Content, Galvanizing Repair

I. National Fire Protection Association (NFPA):

NFPA 90A ............................ Standard for Installation of Air Conditioning and Ventilating

Systems, 2009

J. Energy Policy Act of 2005 (P.L.109-58)

PART 2 - PRODUCTS

2.1 ROOF TOP AIR HANDLING UNITS

A. General:

1. Roof top units (RTU) shall be fabricated from insulated, solid double-wall galvanized steel without any perforations in draw-through configuration. Casing is specified in paragraph 2.1.C. Galvanizing shall be hot dipped conforming to ASTM A525 and shall provide a minimum of 0.275 kg of zinc per square meter (0.90 oz. of zinc per square foot) (G90). Aluminum constructed units shall be provided subject to VA

23 74 13 - 6 approval and documentation that structural rigidity is equal or greater than the galvanized steel specified.

2. The contractor and the RTU manufacturer shall be responsible for insuring that the unit shall not exceed the allocated space shown on the drawings, including required clearances for service and future overhaul or removal of unit components. All structural, piping, wiring, and ductwork alterations of units, which are dimensionally different than those specified, shall be the responsibility of the contractor at no additional cost to the government.

3. RTUs shall be fully assembled by the manufacturer in the factory in accordance with the arrangement shown on the drawings. The unit shall be assembled into the largest sections possible subject to shipping and rigging restrictions. The correct fit of all components and casing sections shall be verified in the factory for all units prior to shipment. All units shall be fully assembled, tested and then split to accommodate shipment and job site rigging. On units not shipped fully assembled, the manufacturer shall tag each section and include air flow direction to facilitate assembly at the job site. Lifting lugs or shipping skids shall be provided for each section to allow for field rigging and final placement of unit.

4. The RTU manufacturer shall provide the necessary gasketing, caulking, and all screws, nuts, and bolts required for assembly. The manufacturer shall provide a local representative at the job site to supervise the assembly and to assure the units are assembled to meet manufacturer's recommendations and requirements noted on the drawings. Provide documentation that this representative has provided this service on similar jobs to the COR. If a local representative cannot be provided, the manufacturer shall provide a factory representative.

5. Gaskets: All door and casing and panel gaskets and gaskets between air handling unit components, if joined in the field, shall be high quality which seal air tight and retain their structural integrity and sealing capability after repeated assembly and disassembly of bolted panels and opening and closing of hinged components. Bolted sections shall use a more permanent gasketing method provided they are not disassembled.

6. Structural Rigidity: Provide structural reinforcement when required by span or loading so that the deflection of the assembled structure shall not exceed 1/200 of the span based on a differential static pressure of 1991 Pa (8 inches water gage) or higher.

23 74 13 - 7

B. Base:

1. Provide a heavy duty steel base for supporting all major RTU components. Bases shall be constructed of wide-flange steel I-beams, channels, or minimum 150 mm (6 inch) high 3.5 mm (10 Gauge) structural steel base rails. Welded or bolted cross members shall be provided as required for lateral stability. Contractor shall provide supplemental steel supports as required to obtain proper operation heights for cooling coil condensate drain trap and steam coil condensate return trap.

2. RTUs shall be completely self supporting for installation on a full perimeter roof curb as specified below.

3. The RTU bases not constructed of galvanized material shall be cleaned, primed with a rust inhibiting primer, and finished with rust inhibiting exterior enamel.

C. Prefabricated Roof Curbs:

1. Construction: Galvanized steel, full perimeter type with continuous welded corner seams, two inch wall thickness, treated wood nailer, 38 mm (1-1/2 inch) thick, 48 kg per cubic meter (3 pound) density rigid mineral fiberboard insulation with metal liner, built-in cant strip, (except for gypsum or tectum decks). For surface insulated roof deck provide raised cant strip to start at the upper surface of the insulation. Curbs shall be built for pitched roof or ridge mounting as required to keep top of curb level.

2. Curb Height: Minimum 600mm (24 inches) above roof deck/450 mm (18 inches) above finished roof surface.

D. Casing (including wall, floor and roof):

1. General: RTU casing shall be entirely double wall insulated panels, integral of or attached to a structural frame. Construction shall be such that removal of any panel shall not affect the structural integrity of the unit. Casing finished shall meet salt-spray test as specified in paragraph 2.1.C.10. All casing and panel sections shall be tightly butted and gasketed. No gaps of double wall construction shall be allowed where panels bolt to air handling unit structural member. Structural members, not covered by the double wall panels, shall have equivalent insulated double wall construction.

2. Double wall galvanized steel panels, minimum 100 mm (4 inches) thick, constructed of minimum 1.0 mm (20 gauge) outer skin and 1.0 mm (20 gauge) solid inner skin to limit wall, roof and floor deflection to not exceed an L/240 ratio when the unit casing

23 74 13 - 8 is pressurized to (±1245 Pa (±5 in. w.g.). Deflection shall be measured at the midpoint of the panel height. The outer (skin) and inner panels shall be solid.

Casing performance – Casing air leakage shall not exceed leak class 6 (CL = 6) per

ASHRAE 111 at specified casing pressure, where maximum casing leakage

(cfm/100 ft2 of casing surface area) = CL X P0.65.

Air leakage shall be determined at 1.25 times maximum casing static pressure up to

8 in.wg. Specified air leakage shall be accomplished without the use of caulk. Total estimated air leakage shall be reported for each unit in cfm, as a percentage of supply air, and as an ASHRAE 111 Leakage Class.

3. Blank-Off: Provide blank-offs as required to prevent air bypass between the AHU sections, around coils, and filters.

4. Insulation: Insulation shall be injected CFC free foam encased in double-wall casing between exterior and interior panels such that no insulation can erode to the air stream. Insulation shall be 100 mm (4 inch) thick, and 48 kg/m3 (3.0 lb/ft3) density with a total thermal resistance (R-value) of approximately 4.4 m.K/W (25.0 hr-ft2

OF/BTU). Units with less than 100 mm (4 inch) of insulation in any part of the walls, floor, roof or drain pan shall not be acceptable. The insulation shall comply with

NFPA 90-A for the flame and smoke generation requirements. Also, refer to specification Section 23 07 11, HVAC AND BOILER PLANT INSULATION.

Table 2.1.C.4

Outer Panel 0.9 mm (20 Gage) Minimum

Inner Panel 0.9 mm (20 Gage) Minimum

Insulation

Thickness

Density

Foam

100 mm (4 inch) Minimum

48 kg/m3 (3.0 lb/ft3) Minimum

Total R Value 4.4 m2.K/W (25.0 ft2.OF.hr/Btu)

Minimum

5. The thickness of insulation, mode of application, and thermal breaks shall be such that there is no visible condensation on the exterior panels of the AHU.

6. Casing panels shall be secured to the support structure with stainless steel or zinc-chromate plated screws and gaskets installed around the panel perimeter. Panels shall be completely removable to allow removal of fan, coils, and other internal

23 74 13 - 9 components for future maintenance, repair, or modifications. Welded exterior panels are not acceptable.

7. Access Doors: Provide in each access section and where shown on drawings. Show single-sided and double-sided access doors with door swings on the shop drawing submittal. Doors shall be a minimum of 100 mm (4 inches) thick with same double wall construction as the unit casing. Doors shall be a minimum of 600 mm (24 inches) wide, unless shown of different size on drawings, and shall be the full casing height up to a maximum of 1850 mm (6 feet). Doors shall be gasketed, hinged, and latched to provide an airtight seal. The access doors for fan section, mixing box, and coil section shall include a minimum 150 mm x 150 mm (6 inch x 6 inch) double thickness, with air space between glass panes tightly sealed, reinforced glass or

Plexiglas window in a gasketed frame.

a. Hinges: Manufacturers standard, designed for door size, weight and pressure classifications. Hinges shall hold door completely rigid with minimum 45 kg (100 pound) weight hung on latch side of door.

b. Latches: Non-corrosive alloy construction, with operating levers for positive cam action, operable from either inside or outside. Doors that do not open against unit operating pressure shall allow the door to ajar and then require approximately

0.785 radian (45 degrees) further movement of the handle for complete opening.

Latch shall be capable of restraining explosive opening of door with a force not less than 1991 Pa (8 inches water gage).

c. Gaskets: Neoprene, continuous around door, positioned for direct compression with no sliding action between the door and gasket. Secure with high quality mastic to eliminate possibility of gasket slipping or coming loose.

8. Provide sealed sleeves, metal or plastic escutcheons or grommets for penetrations through casing for power and temperature control wiring. Coordinate with electrical and temperature control subcontractors for number and location of penetrations.

Coordinate lights, switches, and duplex receptacles and disconnect switch location and mounting. All penetrations and equipment mounting shall be provided in the factory or in the field. All field penetrations shall be performed neatly by drilling or saw cutting. No cutting by torches shall be allowed. Neatly seal all openings airtight.

23 74 13 - 10

9. Roof of the unit shall be sloped to have a minimum pitch of 1/4 inch per foot. The roof shall overhang the side panels by a minimum of three inches to prevent precipitation drainage from streaming down the unit side panels.

10. Casing finished shall meet ASTM B117, 500-hour salt spray test, using 20 percent sodium chloride solution. Immediately after completion of the test, the coating shall show no sign of blistering, wrinkling, or cracking, no loss of adhesion, and the specimen shall show no sign of rust creepage beyond 1/8-inch on either side of scratch mark.

E. Unit floor shall be level without offset space or gap and designed to support a minimum of 488 kg/square meter (100 pounds per square foot) distributed load without permanent deformation or crushing of internal insulation. Provide adequate structural base members beneath floor in service access sections to support typical service foot traffic and to prevent damage to unit floor or internal insulation. Unit floors in casing sections, which shall contain water or condensate, shall be watertight with drain pan.

F. Condensate Drain Pan: Drain pan shall be designed to extend entire length of cooling coils including headers and return bends. Depth of drain pan shall be at least 43 mm

(1.7 inches) and shall handle all condensate without overflowing. Drain pan shall be double wall construction, Type 304 stainless steel and have a minimum of 50 mm (2 inch) insulation, and shall be sloped to drain. Drain pan shall be continuous metal or welded watertight. No mastic sealing of joints exposed to water shall be permitted. Drain pan shall be placed on top of casing floor or integrated into casing floor assembly. Drain pan shall be pitched in all directions to drain line.

1. An intermediate condensate drip pan shall be provided on stacked cooling coils and shall be constructed of type 304 stainless steel with copper downspouts factory piped to main condensate pan. Use of intermediate condensate drain channel on upper casing of lower coil is permissible provided it is readily cleanable. Design of intermediate condensate drain shall prevent upper coil condensate from flowing across face of lower coil.

2. Drain pan shall be piped to the exterior of the unit. Drain pan shall be readily cleanable.

3. Installation, including frame, shall be designed and sealed to prevent blow-by.

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G. Housed Centrifugal Fan Sections:

1. Fans shall be minimum Class II construction, double width, double inlet centrifugal, air foil, backward inclined or forward curved type as indicated on drawings, factory balanced and rated in accordance with AMCA 210 or ASHRAE 51. Provide self-aligning, pillow block, regreasable ball-type bearings selected for a B(10) life of not less than 40,000 hours and an L(50) average fatigue life of 200,000 hours per

AFBMA Standard 9. Extend bearing grease lines to motor and drive side of fan section. Fans shall be located in airstream to assure proper air flow.

2. Provide internally vibration isolated fan, motor and drive, mounted on a common integral bolted or welded structural steel base with adjustable motor slide rail with locking device. Provide vibration isolators and flexible duct connections at fan discharge to completely isolate fan assembly. Refer to Section 23 05 41, NOISE

AND VIBRATION CONTROL FOR HVAC PIPING AND EQUIPMENT, for additional requirements. Allowable vibration tolerances for fan shall not exceed a self-excited vibration maximum velocity of 0.005 m/s (0.20 inch per second) RMS, filter in, when measured with a vibration meter on bearing caps of machine in vertical, horizontal and axial directions or measured at equipment mounting feet if bearings are concealed. After field installation, compliance to this requirement shall be demonstrated with field test in accordance with Section 23 05 41, NOISE AND

VIBRATION CONTROL FOR HVAC PIPING AND EQUIPMENT and Section 23 05

93, TESTING, ADJUSTING, AND BALANCING FOR HVAC. Following fan assembly, the complete fan assembly balance shall be tested using an electronic balance analyzer with a tunable filter and stroboscope. Vibration measurements shall be taken on each motor bearing housing in the vertical, horizontal, and axial planes (5 total measurements, 2 each motor bearing and 1 axial).

H. Fan Motor, Drive, and Mounting Assembly (Housed Centrifugal Fans):

1. Fan Motor and Drive: Motors shall be premium energy efficient type, as mandated by the Energy Policy Act of 2005, with efficiencies as shown in the Specifications

Section 23 05 12, GENERAL MOTOR REQUIREMENTS FOR HVAC AND STEAM

GENERATION EQUIPMENT, and suitable for use in variable frequency drive applications on AHUs where this type of drive is indicated. Refer to Section 23 05 11, COMMON WORK RESULTS FOR HVAC, for additional motor and drive specifications. Refer to Specification Section 26 29 11, MOTOR CONTROLLERS.

23 74 13 - 12

2. Fan drive and belts shall be factory mounted with final alignment and belt adjustment to be made by the Contractor after installation. Drive and belts shall be as specified in Section 23 05 11, COMMON WORK RESULTS FOR HVAC. Provide additional drive(s) if required during balancing, to achieve desired airflow.

I. Plenum Fans:

1. General: Fans shall be Class II (minimum) construction with single inlet, aluminum wheel and stamped air-foil aluminum bladed. The fan wheel shall be mounted on the directly-driven motor shaft in AMCA Arrangement 4. Fans shall be dynamically balanced and internally isolated to minimize the vibrations. Provide a steel inlet cone for each wheel to match with the fan inlet. Locate fan in the air stream to assure proper flow. The fan performance shall be rated in accordance with AMCA 210 or

ASHRAE 51.

2. Allowable vibration tolerances for fan shall not exceed a self-excited vibration maximum velocity of 0.005 m/s (0.20 inch per second) RMS, filter in, when measured with a vibration meter on bearing caps of machine in vertical, horizontal and axial directions. After field installation, compliance to this requirement shall be demonstrated with field test in accordance with Section 23 05 41, NOISE AND

VIBRATION CONTROL FOR HVAC PIPING AND EQUIPMENT and Section 23 05

93, TESTING, ADJUSTING, AND BALANCING FOR HVAC. The fan wheel shall meet or exceed guidelines in AMCA 801-92 for dynamic balancing requirements.

The complete fan assembly balance shall be tested using an electronic balance analyzer with a tunable filter and stroboscope. Vibration measurements shall be taken on each motor bearing housing in the vertical, horizontal, and axial planes (5 total measurements, 2 each motor bearing and 1 axial).

3. The plenum fan(s) shall be driven by variable speed drive(s). Where multiple fans in an array are used, at least one back-up drive shall be provided. Use of a drive with bypass is not permitted for multiple fans in an array.

4. Multiple fans (if provided) shall be installed in a pre-engineered structural frame to facilitate fan stacking. All fans shall modulate in unison, above or below the synchronous speed within the limits specified by the manufacturer, by a common control sequence. Staging of the fans is not permitted. Redundancy requirement shall be met by all operating fans in an array and without the provision of an idle standby fan.

23 74 13 - 13

5. Fan Accessories

a. Fan Isolation: If multiple plenum fans are provided, provide an automatic back draft damper to isolate the fan not in operation due to failure.

b. Fan Airflow Measurement: Provide an airflow measuring device integral to the fan to measure air volume within +/- 5 percent accuracy. The probing device shall not be placed in the airflow path to stay clear of turbulence and avoid loss of performance.

6. AHU design is based upon a single plenum supply fan and a single plenum return fan. If multiple plenum fans in an array are preferred, any additional cost, including electrical cost, shall be borne by the HVAC Contractor at no additional cost to the

Government.

7. Fan Motor, Drive and Mounting Assembly (Plenum Fans): Fan Motors shall be premium energy efficient type, as mandated by the Energy Policy Act of 2005, with efficiencies as shown in Specification Section 23 05 12, GENERAL MOTOR

REQUIREMENTS FOR HVAC AND STEAM GENERATION EQUIPMENT and suitable for use in variable frequency drive applications. Refer to Section 23 05 11, COMMON WORK RESULTS FOR HVAC, for additional motor and drive specifications. Refer to Specification Section 26 29 11, MOTOR CONTROLLERS.

J. Mixing Boxes: Mixing box shall consist of casing and outdoor air and return air dampers in opposed blade arrangement with damper linkage for automatic operation. Coordinate damper operator with Section 23 09 23, DIRECT-DIGITAL CONTROL SYSTEM FOR

HVAC. Dampers shall be of ultra-low leak design with metal compressible bronze jamb seals and extruded vinyl edge seals on all blades. Blades shall rotate on stainless steel sleeve bearings or bronze bushings. Leakage rate shall not exceed 5 cfm per square foot at 1 inch water gage and 9 cfm per square foot at 4 inches water gage. Damper operators shall be furnished and mounted in an accessible and easily serviceable location by the air handling unit manufacturer at the factory. Damper operators shall be of same manufacturer as controls furnished under Section 23 09 23, DIRECT-DIGITAL

CONTROL SYSTEM FOR HVAC.

K. Blenders: Construction of the blender section shall be of welded aluminum 2 mm (0.081 inch) thick framing and turbulators. The mixer shall have no moving parts and shall contain a primary set of directional changing vanes, a secondary set of turbulator vanes, and a cone design for mixing of air streams. Certify blender performance to achieve no

23 74 13 - 14 more than a 5°F variation across the cross section of the AHU measured 12 inches downstream of the blender over a face velocity range of 1-4 m/s (200-800 FPM).

L. Filter Section: Refer to Section 23 40 00, HVAC AIR CLEANING DEVICES, for filter requirements.

1. Filters including one complete set for temporary use at site shall be provided independent of the RTU. The RTU manufacturer shall install filter housings and racks in filter section compatible with filters furnished. The RTU manufacturer shall be responsible for furnishing temporary filters (pre-filters and after-filters, as shown on drawings) required for RTU testing.

2. Factory-fabricated filter section shall be of the same construction and finish as the

RTU casing including filter racks and hinged double wall access doors. Filter housings shall be constructed in accordance with side service or holding frame housing requirements in Section 23 40 00, HVAC AIR CLEANING DEVICES.

M. Diffuser Section: Furnish a diffuser segment with perforated diffuser plate immediately downstream of housed centrifugal supply fan to assure uniform distribution of leaving air across the face of the downstream after-filters to create uniform velocity profiles across the entire opening. Bolt or weld diffuser plate to a sturdy steel support frame so that it remains rigid. Manufacturer shall include any diffuser section pressure loss in excess of diffuser plate and this value shall be included in unspecified internal losses when selecting fan.

N. Coils: Coils shall be mounted on hot dipped galvanized steel supports to assure proper anchoring of coil and future maintenance. Coils shall be face or side removable for future replacement thru the access doors or removable panels. Each coil shall be removable without disturbing adjacent components. Cooling coils shall be designed and installed to insure no condensate carry over. Provide factory installed extended supply, return, drain, and vent piping connections. Refer to Drawings and Section 23 82 16, AIR COILS, for additional coil requirements.

1. Water Coils.

2. Integral Face and Bypass Steam Coils: Provide integral vertical face and bypass dampers. Damper operators shall be furnished and mounted by the RTU manufacturer at the factory. Damper operators shall be of same manufacturer as controls furnished under Section 23 09 23, DIRECT-DIGITAL CONTROL SYSTEM

FOR HVAC.

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3. Steam Distributing Tube Coils

O. Humidifier: When included in design, coordinate the humidification requirements with section 23 22 13 STEAM AND CONDENSATE HEATING PIPING. Provide humidification section with stainless steel drain pan of adequate length to allow complete absorption of water vapor. Provide stainless steel dispersion panel or distributors as indicated, with stainless steel supports and hardware.

P. Sound Attenuators: Refer to Drawings, Specification Section 23 05 41, NOISE AND

VIBRATION CONTROL FOR HVAC PIPING AND EQUIPMENT, and Section 23 31 00, HVAC DUCTS AND CASINGS, for additional unit mounted sound attenuator requirements. RTU sound attenuators shall be factory installed as an integral part of

RTU.

Q. Discharge Section: Provide aerodynamically designed framed discharge openings or spun bellmouth fittings to minimize pressure loss.

R. Electrical and Lighting: Wiring and equipment specifications shall conform to Division 26, ELECTRICAL.

1. Vapor-proof lights using cast aluminum base style with glass globe and cast aluminum guard shall be installed in access sections for fans, mixing box, and any section over 300mm (12 inch) wide. A single switch shall control all lights in the unit with pilot light mounted outside of the unit. Wiring between switches and lights shall be factory installed. All wiring shall run in neatly installed electrical conduits and terminate in a junction box for field connection to the building system. Provide single point 115 volt - one phase connection at junction box.

2. Install compatible 26 watt compact fluorescent or equivalent LED bulb in each light fixture.

3. Provide a convenience duplex weatherproof receptacle next to the light switch.

4. Disconnect switch and power wiring: Provide factory or field mounted disconnect switch. Coordinate with Division 26, ELECTRICAL.

2.2 AIR PURIFICATION SYSTEM - BIPOLAR IONIZATION

A. The air handling unit shall contain a Plasma Generator with Bi-polar Ionization output as described here within.

B. The Bi-polar Ionization system shall be capable of:

1. Effectively killing microorganisms downstream of the bi-polar ionization equipment (mold, bacteria, virus, etc.).

23 74 13 - 16

2. Controlling gas phase contaminants generated from human occupants, building structure, furnishings and outside air contaminants.

3. Capable of reducing static space charges.

4. Effectively reducing space particle counts.

5. Keep the cooling coil free from pathogen and mold growth.

6. All manufacturers shall provide documentation by an independent NELEC accredited laboratory that proves the product has minimum kill rates for the following pathogens given the allotted time and in a space condition:

a. MRSA - >96% in 30 minutes or less

b. E.coli - > 99% in 15 minutes or less

c. TB - > 69% in 60 minutes or less

d. C. diff - >86% in 30 minutes or less

e. Noro Virus -> 93.5% in 30 minutes or less

f. Legionella -> 99.7% in 30 minutes or less

Manufacturers not providing the equivalent space kill rates shall not be acceptable. All manufactures requesting prior approval shall provide to the engineer independent test data from an independent lab confirming kill rates and time meeting the minimum requirements stated in section 2.2 B, points 6a, 6b and 6c. Products tested only on Petri dishes to prove kill rates shall not be acceptable. Products being sold under different trade names than those tested shall not be acceptable.

7. Capable of modular field assembly in six inch (150mm) sections.

C. The bi-polar ionization system shall operate in a manner such that equal amounts of positive and negative ions are produced. Uni-polar ion devices shall not be acceptable. Ionizers with positive and negative output (DC type) shall not be acceptable. All ionizers provided shall be AC type ionizers with one electrode pulsing between positive and negative.

1. Air exchange rates may vary through the full operating range of a constant

Volume or VAV system. The quantity of air exchange shall not be increased due to requirements of the air purification system.

2. Velocity Profile: The air purification device shall not have maximum velocity profile.

23 74 13 - 17

D. Humidity: Plasma Generators shall not require preheat protection when the relative humidity of the entering air exceeds 85%. Relative humidity from 0 -

100%, condensing, shall not cause damage, deterioration or dangerous conditions within the air purification system. Air purification system shall be capable of wash down duty.

E. Equipment Requirements:

1. Electrode Specifications (Bi-polar Ionization):

a. Each alternating current (AC) Ionization Bar with Bi-polar Ionization output shall include a minimum of eighteen carbon fiber cluster ion needles per foot of coil face width shall be provided. The entire cooling coil width shall have equal distribution of ionization across the face. Systems without ion needles at least 0.50” (12.5mm) apart shall not be acceptable. The plasma electrode shall require no more than 1.0” (25mm) in the direction of airflow for mounting. All hardware required for mounting shall be provided by the air purification manufacturer except self-tapping screws for the power supply. Bi-polar ionization tubes manufactured of glass and steel mesh shall not be acceptable due to replacement requirements, maintenance, and performance output reduction over time, ozone production and corrosion.

b. Electrodes shall be provided in 6.0” (150mm) increments, epoxy filled for an IP55 rating and utilizing brass connection hardware that is recessed into the connection joint once fully engaged and assembled.

c. Electrodes shall be energized when the main unit disconnect is turned on.

d. The ionization output shall be a minimum of 140 million ions/cc per inch of cooling coil width as measured 1 inch from the cold plasma needles.

e. Ionization bars shall be provided with magnet mounting kits to prevent penetration into cooling coils.

f. Ionization bars shall be constructed of UL 94VO and UL746C composite material.

g. If the ionization bars are mounted immediately downstream from a humidifier, protective rain covers shall be provided over the ionization bars by the installing contractor. The design of the cover shall be confirmed with the ionization manufacturer prior to installation.

23 74 13 - 18

F. Air Handler Mounted Units:

1. Plasma Generator(s) shall be provided in each AHU. The Plasma Generator shall be mounted and wired to the remote mount power supply using the cables provided by the air purification manufacturer. A 24VAC, 115VAC or 208-

230VAC circuit shall be provided to the plasma generator power supply panel.

No more than 15 watts shall be required per power supply. Each power supply shall be capable of powering up to 6 ionization bars or a total of 50 linear feet of bar(s). Each plasma generator shall be designed with fiberglass housing, liquid tight flexible conduit and a high voltage quick connector.

2. Where deemed necessary, an angled hat section to cover the ionization bars and deflect any direct condensation towards the floor and off the bars, shall be provided for the ionization bars mounted downstream of steam humidifiers.

G. Plasma Requirements:

1. Plasma Generators with Bi-polar ionization output shall be capable of controlling gas phase contaminants.

a. The Bi-polar ionization system shall consist of Bi-Polar Plasma Generator and power supply. The Bi-polar system shall be installed on the face of the cooling coil. The device shall be capable of being powered by 24VAC, 115VAC or 208-230VAC without the use of an external transformer.

Ionization systems requiring isolation transformers shall not be acceptable.

b. Ionization Output: The ionization output shall be controlled such that an equal number of positive and negative ions are produced (AC Ionizers only are acceptable). Imbalanced levels shall not be acceptable.

c. Ionization output from each bar shall be a minimum of 140 million ions/cc per inch of bar when tested at 1” from the ionization bar. Bars with needles spaced further apart than 0.5” shall not be acceptable.

d. Each plasma electrode shall be made from an all fiberglass composite, UL

94V0 and UL 746C rated material for prevention of corrosion and electrical insulation.

2. Ozone Generation:

a. The operation of the electrodes or Bi-polar ionization units shall conform to

UL 2998 as tested by UL proving no ozone output.

H. Electrical Requirements:

23 74 13 - 19

1. Wiring, conduit and junction boxes shall be installed within housing plenums in accordance with NEC NFPA 70. Plasma Generator shall accept an electrical service of 24VAC, 115 VAC or 208-230VAC, 1 phase, 50/60 Hz.

I. Control Requirements:

1. All Plasma Generators shall have internal short circuit protection, overload protection, and automatic fault reset. Systems requiring fuses shall not be acceptable.

2. The Plasma Generator power supply shall have internal circuitry to sense the ionization output and provide dry contact alarm status to the BMS as well as a local “Plasma On” indication light.

3. The ionization system shall be provided with a stand-alone, independent ion sensor designed for duct mounting to the ionization bar to monitor the ion output and report to the BAS system that the ion device is working properly.

Ion systems provided without an independent ion sensor, shall not be permitted. The control voltage to power the ion sensor shall be 24VAC to

260VAC and draw no more than 150mA of current. The sensor shall provide at minimum, dry contact status to the BAS and a BacNet interface.

4. The installing contractor shall mount and wire the Plasma device within the air handling unit specified or as shown or the plans. The contractor shall follow all manufacturer IOM instructions during installation.

5. A fiberglass NEMA 4X panel with Plasma On/Off Indicator Light (interfaced with stand-alone ionization detector), Ionization Output On/Off Indicator Light and an On/Off Illuminated Switch shall be provided to house the power supply.

PART 3 – EXECUTION

3.1 INSTALLATION

A. Install roof top unit in conformance with ARI 435.

B. Assemble roof top unit components following manufacturer's instructions for handling, testing and operation. Repair damaged galvanized areas with paint in accordance with

Military Spec. DOD-P-21035A. Repair painted units by touch up of all scratches with finish paint material. Vacuum the interior of air-handling units clean prior to operation.

C. Refer to specification Section 13 05 41, SEISMIC RESTRAINT REQUIREMENTS FOR

NON-STRUCTURAL COMPONENTS for seismic restraint requirements.

23 74 13 - 20

D. Leakage and test requirements for roof top units shall be the same as specified for ductwork in Specification Section 23 31 00, HVAC DUCTS AND CASINGS except leakage shall not exceed Leakage Class (CL) 12 listed in SMACNA HVAC Air Duct

Leakage Test Manual when tested at 1.5 times the design static pressure. Repair casing air leaks that can be heard or felt during normal operation and to meet test requirements.

E. Perform field mechanical (vibration) balancing in accordance with Section 23 05 41, NOISE AND VIBRATION CONTROL FOR HVAC PIPING AND EQUIPMENT.

F. Seal and/or fill all openings between the casing and RTU components and utility connections to prevent air leakage or bypass.

3.2 STARTUP SERVICES

A. The air handling unit shall not be operated for any purpose, temporary or permanent, until ductwork is clean, filters are in place, bearings are lubricated and fan has been test run under observation.

B. After the air handling unit is installed and tested, provide startup and operating instructions to VA personnel.

C. An authorized factory representative shall start up, test and certify the final installation and application specific calibration of control components. Items to be verified include fan performance over entire operating range, noise and vibration testing, verification of proper alignment, overall inspection of the installation, Owner/Operator training.

3.3 COMMISSIONING

A. Provide commissioning documentation in accordance with the requirements of Section

23 08 00 – COMMISSIONING OF HVAC SYSTEMS for all inspection, start up, and contractor testing required above and required by the System Readiness Checklist provided by the Commissioning Agent.

B. Components provided under this section of the specification shall be tested as part of a larger system. Refer to Section 23 08 00 – COMMISSIONING OF HVAC SYSTEMS and related sections for contractor responsibilities for system commissioning.

- - - E N D - - -

12 SERVICE VESTIBULE WITH RELIEF LOUVERS AND

GRAVITY BACKDRAFT DAMPERS SIZED AT MAX 500

FEET PER MINUTE.

SCALE: NONE

MAX. BHP VFD

2@4.4 2

0.4 ECM

2@8.8

1.6 NO

0.6 ECM

2.4 NO

0.4 ECM

- NO

- NO

AIR HANDLING UNIT NOTES

STEAM HUMIDIFIER SCHEDULE

AIR FLOW MEASURING DEVICE SCHEDULE

AIR FILTER SCHEDULE

HVAC DESIGN DATA

DUCT PRESSURE CLASS & LEAKAGE TABLE

FAN SCHEDULE

AIR HANDLING UNIT SCHEDULE

CHILLED WATER COOLING COIL SCHEDULE

STEAM HEATING COIL SCHEDULE

HVAC PUMP SCHEDULE

AIR HANDLING UNIT 2-AHU5 LAYOUT

2-PH5 2-PF5A

2-PF5B

TYP.

2-CC5

1 RETURN AIR OPENING.

2 6" HIGH BASE RAIL.

3 ACCESS SECTION.

4 ECONOMIZER SECTION.

5 24" WIDE ACCESS DOOR. SEE PLANS FOR UNIT HAND.

6 EXTEND FULL SIZE DRAIN PIPE TO ROOF DRAIN.

7 OUTSIDE AIR INTAKE DAMPERS.

SECTION VIEW

PLAN VIEW

8 BLENDER SECTION.

2-SF5

SUPPLY

AIR

9 SUPPLY AIR OPENING.

DISTANCE

ABSORP.

(MAX.)

2-SH5

HUMID.

NO.

2-AHU5

SYSTEM

18"

CFM

20,000

°F

Db

56.7 30

ON-OFF

VALVE

ENT. ENT.

PSIG

VALVE

CONTROL

STEAM

VALVE

ON-OFF &

CONTROL

LBS/HR

LBS/HR

TRAP

LEAVING AIR

UNIT

2-AFM5A

2-AFM5B

NO.

LOCATION

2-AHU5 SUPPLY FAN

2-AHU5 RETURN FAN

DUCT

SIZE

WxH

& TYPE

FAN SIZE

0.02"

DROP

S.P.

0.02"

MIN.

5,000

CFM

MAX.

10,000

9,500

2-AHU5

SYSTEM

2-AHU5

24.5" DDP

4,000

2-AFM5E 2-AHU5 OUTSIDE AIR DAMPER 64"X43" 0.02"20,000 2-AHU5N/A 4,000

NOTES:

2-PF5B 2-AHU520,000

HOUSING

SIDE ACCESS

0.5" 1.0" 500 1,2,4

RATING

MERV

NO.

FILTER

SYSTEMCFM

HOUSING

VELOCITY

TYPE

FACE

MAX.

NOTE

SEE

STATIC PRESSURE REQUIREMENTS BASED ON 500 FPM FACE VELOCITY. FINAL PRESSURE DROPS BASED ON VA'S

FILTER HOUSING TO BE PART OF AIR HANDLING UNIT ASSEMBLY.

HOUSING

1,2,320,0002-PF5A 2-AHU5

SIDE ACCESS

0.33" 0.66" 500

EFFICIENCY

35%

85%

RECOMMENDED CHANGE OVER PRESSURE DROP.

MAX. S.P. DROP (1)

INITIAL FINAL

DESIGN ALTITUDE: 499 FT.

Db ( °F)

OUTDOOR DESIGN TEMPERATURES

TELECOM CLOSETS

INDOOR AREA DESIGN CONDITIONS

OFFICES

92.8 74.5 0.5

SUMMER

% HUMIDITY

DEG. F Db WINTER DEG. F Wb SUMMER DEG. F Db SUMMER

Db ( °F)

81 60

% HUMIDITY

WINTER

7075 60ALL OTHER AREAS

NOTES:

7075 -UNOCCUPIED MODE (NOTE 1) -

REFERS TO OCCUPANCY STATUS FOR CONTROL OF AIR TERMINAL UNITS. REFER TO AIR1

TERMINAL UNIT SCHEDULE AND CONTROL SEQUENCES.

P/N

POSITIVE (P)

PRESSURE

NEGATIVE (N)SYSTEM

SYSTEMS

ALL

DUCT INVOLVED

SUPPLY AIR DUCTS FROM OUTLET OF AH-UNIT

AIR TERMINAL UNITS TO SUPPLY AIR DEVICES

SUPPLY AIR DUCTS FROM OUTLET OF

RETURN AIR DUCTS FROM CEILING REGISTERS

ALL DUCTWORK EXCEPT AS LISTED BELOW.

TO INLET OF AH-UNIT

GENERAL EXHAUST DUCTS

OUTSIDE AIR DUCTS

TO INLET OF AIR TERMINAL UNITS.

P

N

N

N

OR

P

RECTANGULAR

DUCT

SMACNA LEAKAGE CLASS

-3"

-2"

1"

-2"

A

A

A

A

CONST.

SMACNA

W.G.

4"

2"

CLASS

SEAL

SMACNA

A

CLASS

A 4 2

ROUND

DUCT

4 2

4 2

4 2

4 2

4 2

2-AHU5

2 MOTORS 1 HP AND ABOVE SHALL BE NEMA PREMIUM EFFICIENT TYPE.

NOTES :

2-SF5

NO.

FAN

LOCATION

20,000

CFM

4.9"

S.P.

FAN FAN

SWSI PLENUM FANS

DESCRIPTION

CF

TYPE

FAN

AFW

TYPE

22.5"

MIN.

DIA.

WHEEL

DRIVE

2,000

RPM

DIRECT

MAX.

460-3

VOLT.-NOM.

2@11

HP (2) PHASE

MOTOR

1,2,3,5

NOTE

SEE

SCHEDULED MAXIMUM BHP IS FOR SCHEDULED SP PLUS TEN PERCENT. IF UNIT COIL PRESSURE DROPS SUBMITTED ARE LESS THAN SCHEDULED, THEN THE SP REQUIREMENT MAY BE REDUCED ACCORDINGLY. MAXIMUM BHP MAY BE BASED ON THE REVISED SP PLUS TEN PERCENT.

3 REFER TO ELECTRICAL DRAWINGS FOR VARIABLE SPEED DRIVE ASSOCIATED WITH THIS FAN.

2-AHU52-RF5 19,000 1.9" CF AFW 20" 2,000 DIRECT 2@5.5 1,2,3,5

ROOF OF 3RD FLOOR2-EF10 2,000 RV BIW 1,650 DIRECT 0.5 416"1.0"

460-3

115-1

SONES

MAX.

4 PROVIDE ELECTRICALLY COMMUTATED (E.C.) MOTOR.

2-AHU5

NOTES:

POD ROOF

BUILDING 2 NORTH

LOCATION

NO.

UNIT

AREA SERVED

EXTERNAL STATIC PRESSURE REQUIRED AT DUCT CONNECTIONS TO INLET / OUTLET OF AHU. MEASUREMENTS SHALL BE TAKEN WITHIN 3 FT. OF INLET AND

OUTLET AT A POINT OF MAXIMUM ACCURACY.

TOTAL OF MAXIMUM PRESSURE DROPS OF COMPONENTS WHICH ARE SPECIFIED SEPARATELY, I.E. PREFILTERS, AFTER FILTERS, HEATING AND COOLING COILS, DIFFUSER PLATE AND SOUND ATTENUATOR. AIR FILTER PRESSURE DROP SHALL BE SELECTED AT MID-LIFE.

INTERNAL LOSS ALLOWANCE SHALL INCLUDE LOSSES DUE TO ENTRANCE AND EXIT OF AHU, MIXING BOXES, DIFFUSER SECTION (OTHER THAN DIFFUSER PLATE)

FAN INLET CONDITIONS, CASINGS, HUMIDIFERS, DAMPERS, ETC.

TOTAL FAN S.P = EXTERNAL STATIC PRESSURE + SPECIFIED INTERNAL LOSSES + UNSPECIFIED INTERNAL LOSSES.