H26.REV

SHEET METAL WORK

NOTE: FINAL COPY: MAY, 1987.

Part 1 -	GENERAL

1)	WORK INCLUDED

A.	Work included in this Section includes the providing of labor, materials, equipment and services necessary for a complete and safe installation in accordance with the contract documents and all applicable codes and authorities having jurisdiction for the following

1.	Ductwork.

2.	Supports.

3.	Casings, plenums, and equipment housings.

4.	Dampers.

5.	Accessories.

B.	Definitions:

1.	Seam: locks or weld applied longitudinally to close section of duct, e.g.: longitudinal seam, spiral seam

2.	Joint: abutting connection between duct sections for continuity of air passage, e.g.: cross joint, transverse joint, coupling

3.	Reinforcement: hardware applied to strengthen duct, e.g.: girth angles, tie rods, fasteners (not connectors), etc

4.	Stiffening: folding, bending, beading, crossbreaking or corrugating of sheets to achieve strength through shape, e.g.: pocket lock secures joint and is transverse stiffener, with girth angle and/or fasteners applied (not connectors), joint or stiffener is reinforced

5.	Static pressure classifications:

NOTE: REMINDER. CALCULATE DUCT PRESSURES AND VELOCITIES. SEE TABLE 1-1 IN SMACNA DUCT CONSTRUCTION STANDARDS FOR PRESSURE - VELOCITY CLASSIFICATION FOR DUCTWORK, BECAUSE TOTAL PRESSURE DECREASES IN THE DIRECTION OF FLOW, A DUCT CONSTRUCTION PRESSURE CLASSIFICATION EQUAL TO FAN OUTLET PRESSURE CANNOT ECONOMICALLY BE IMPOSED ON THE ENTIRE DUCT SYSTEM. SPECIFY PRESSURE FROM FAN TO A CLEAR BREAKOFF POINT. FOR EXAMPLE "SUPPLY FAN TO DUAL MIXING BOXES" OR "SUPPLY FAN TO VAV BOXES". IF CLEAR BREAKOFF POINT CANNOT BE SPECIFIED, INDICATE ON DRAWINGS. THE ABOVE SMACNA STANDARD DESIGNATES THE 1 IN. W.G. PRESSURE CLASS AS APPLICABLE WHEN DESIGNERS DO NOT SELECT PRESSURE CLASSIFICATIONS FOR SPECIFIC SYSTEMS. EXCEPTION: 2 IN. W.G. IS PRESELECTED FOR VARIABLE VOLUME DUCT UPSTREAM OF BOXES

a.	Except as noted: = = STATIC PRESSURE = --------------- = PRESSURE CLASS OPERATING PRESSURE = -------------- ------------------ = 2 IN. W.G. UP TO 2 IN. W.G. = 6 IN. W.G. OVER 2 IN. UP TO 6 IN. W.G. = 10 IN. W.G. OVER 6 IN. UP TO 10 IN. W.G. =

b.	Based on the following:

(1)	Single duct systems: static pressure at respective point in ductwork during normal operation

(2)	Dual duct systems: static pressure at beginning of fan discharge duct

(3)	Variable volume systems: static pressure at beginning of fan discharge duct

NOTE: EXTENT OF DUCTWORK ABOVE 2 IN. W.G. PRESSURE CLASS SHOULD BE SHOWN ON THE DRAWINGS AND/OR SPECIFIED

c.	Extent of ductwork above 2 in. w.g. pressure class and equipment

(1)	Single duct constant volume systems: as noted

(2)	Variable volume systems: from fan discharge to variable volume units, or as noted

(3)	Dual duct systems: from fan discharge to mixing boxes, or as noted

d.	Pressure class ---- in. w.g.

(1)	Systems No.'s.

2)	RELATED WORK AND REQUIREMENTS

A.	Requirements of GENERAL CONDITIONS, DIVISION NO. 1 and Section GENERAL PROVISIONS FOR HEATING, VENTILATING, AND AIR CONDITIONING WORK apply to all work in this Section

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE ONLY SECTIONS DIRECTLY AFFECTING WORK OF THIS SECTION

B.	Related work in the following Sections:

1.	AIR HANDLING SYSTEM EQUIPMENT.

2.	MECHANICAL VENTILATING SYSTEM.

3.	INSULATION.

4.	VIBRATION ISOLATION.

5.	NOISE CONTROL.

6.	------.

NOTE: DELETE REFERENCES TO STANDARDS AND MANUALS NOT PERTINENT TO PROJECT

3)	REFERENCE STANDARDS

A.	All work shall conform with the following:

1.	Sheet Metal and Air Conditioning Contractors National Association, Inc. manuals (SMACNA) except where details or notes on drawings indicate otherwise

a.	HVAC Construction Standards Metal and Flexible

b.	Fire Damper and Heat Stop Guide for Air Handling Systems

NOTE: UNLESS REQUESTED OTHERWISE, THE AABC MANUAL SHALL BE USED FOR BALANCING. DELETE REFERENCES TO SMACNA & NEBB BALANCING MANUALS

c.	HVAC Systems Testing Adjusting and Balancing.

ALANCING

2.	National Environmental Balancing Bureau Manual: Procedural Standards for Testing - Balancing - Adjusting of Environmental Systems; referred to as NEBB Manual

3.	Associated Air Balance Council Manual: National Standards for Total System Balance; referred to as AABC Manual

ALANCING

NOTE: FOR INDUSTRIAL QUALITY EXHAUST SYSTEMS.

XHAUST

4.	American Conference of Governmental Industrial Hygienists: Industrial Ventilation - A Manual of Recommended Practice; referred to as ACGIH Industrial Ventilation Manual

5.	Sheet Metal and Air Conditioning Constractors National Association Inc. (SHACNA) Rectangular Industrial duct construction standards

XHAUST

B.	The most recent edition of all references shall be used.

C.	The aforementioned references shall be superseded by notes and details on drawings and in the Specification

D.	American National Standard Institute (ANSI).

E.	National Fire Protection Association Standards: refered to NFPA 90A, NFPA90B etc

F.	Underwriters Laboratories (UL) Standard for Safety: referred an UL 181, UL555, etc

G.	Underwriter Laboratory (UL) Standard UL 723 (ASTM-E-04): Maximum 25 flamespread rating and maximum 50 fuel contributed and smoke developed rating

H.	Published Specifications' standards, tests or recommended methods of trade, industry or governmental organizations apply to work in this Section

I.	Where two or more references conflict, the most stringent, as determined by the Engineer, shall take precedence

J.	Comply with all applicable national, state and local codes and refer to Section GENERAL PROVISIONS FOR HEATING, VENTILATING, AND AIR CONDITIONING WORK for additional Reference Standards

4)	QUALITY ASSURANCE

A.	Refer to Section GENERAL PROVISIONS FOR HEATING, VENTILATING, AND AIR CONDITIONING WORK for Guarantee and other Quality Assurance requirements

5)	SUBMITTALS

A.	Submit ductwork shop drawings for approval:

1.	Coordinated layout duct drawings that differ from ductwork shown on contract drawings

2.	Mechanical equipment room plans and sections showing all equipment, curbs, and accessories

3.	Minimum 3/8 inch scale, double line, showing sizes, transverse joints, transitions, elevations, clearances and accessories; sections where required

B.	Subject shop details and catalog cuts of:

1.	Ductwork construction, including gauge and bracing schedule

2.	Casing and plenum construction.

3.	Supports.

4.	Dampers.

5.	Turning vanes.

6.	Fire and smoke damper construction and installation.

7.	Access doors.

8.	Louvers.

9.	Hoods.

10.	Flexible connections.

11.	Other accessories.

NOTE: FOR LARGER, QUALITY PROJECTS.

12.	Submit each set of details and catalog cuts submitted in a 8-1/2 inch x 11 inch binder

C.	Samples: Submit 12 inch x 12 inch flat piece of sheet metal, showing installation of acoustical duct lining and nosing

D.	Submit name and qualifications of proposed test and balance organization and description of system testing and adjustment procedures

Part 2 -	PRODUCTS

1)	BASE BID MANUFACTURERS

A.	Flat oval and round duct and fittings: United Sheet Metal Div., United McGill Corp

B.	Flexible ducts: General Environment Corp., H. K. Porter Co., Wiremold Co., Clevaflex Div., Clevepak Corp. and The Flexaust Co

C.	Fire dampers: Air Balance, Inc., Ruskin Mfg. Co., Airstream Products Co., Inc. and American Warming and Ventilating Inc

D.	Duct sealants: Benjamin Foster Corp. Minnesota Mining Manufacturing Co. (3M), United Sheet Metal Div., United McGill Corp., Miracle Adhesives, Corp. and Hardcast, Inc

E.	Double wall casings: Industrial Acoustics Co., Keene Corp., Noise Control Div. and United Sheet Metal Div. and United McGill Corp

NOTE: DELETE IF LOUVERS ARE FURNISHED UNDER GENERAL CONSTRUCTION WORK

F.	Louvers: Air Balance, Inc., Arrow United Industries, Carnes Corp., Ruskin Mfg. Co. and American Warming and Ventilating, Inc

NOTE: CHECK APPLICABILITY OF EACH FIRM FOR PROJECTS OUTSIDE N.Y.C.

G.	Air balancing and testing firms: Air Balancing and Testing Corp., Air Conditioning Test and Balance Co., National Air Balance Co. Inc., Bal-Test Corp. and Systems Testing & Balancing Corp

H.	Mechanical Duct Coupling Systems: Ductmate Industries, Inc.

2)	MATERIAL

A.	Metal sheets shall be as follows:

1.	Galvanized steel shall be in accordance with ASTM 5261; black or galvanized as herein after specified.

2.	Aluminized steel Type 2 shall be in accordance with Military Specification 4174a, Type II, except waive Rockwell B80 max.

3.	Aluminum shall be in accordance with ASTM B209-64,2,1.4.

4.	Aluminum commercial sheet shall be 16,000 psig tensile.

5.	Stainless steel sheets shall be in accordance with AISI Types 302, 309 and 315. Concealed ducts shall be finish No. 2B or No. 3. Exposed ducts shall be finish No. 3 or No. 4

B.	Copper shall be in accordance with Federal Specification QQ-C-567, light cold rolled (cornice) temper. Stainless steel shall be in accordance with Federal Specification QQ-S-766c, Class 3041. Lead shall be in accordance with Federal Specification QQ-L-301a, Grade C, 0.24 inch thick

NOTE: USE OF CEMENT ASBESTOS AND FIBROUS GLASS DUCT MATERIAL IS PROHIBITED

3)	DUCTWORK

A.	Ductwork shall be galvanized steel, except as noted, in accordance with SMACNA HVAC Duct Construction Standard, 1985, except as noted. Provide gauges, construction and reinforcement as follows

1.	Pressure class 2 inch w.g.

a.	Sheet metal gauge and reinforcement shall be in accordance with SMACNA Table 1-5 and 1-10 thru 1-13 and based on a minimum of 2 inch w.g. duct pressure clase regardless of possible lower pressures. Round ductwork shall be spiral or longitudinal seam. Cross breaking shall be as required for rigid support

NOTE: EDIT MAXIMUM PRESSURES IN THE FOLLOWING PARAGRAPHS.

2.	Pressure classes 6 inch w.g. to ----- inch w.g.

a.	Rectangular ductwork: For pressure 2 inch w.g. to 6 inch w.g. Sheet metal gauges and reinforcement in accordance with Pressure Class 6 inch w.g.-SMACNA - Table 1-8; based on 6 inch pressure, regardless of possible lower pressure. For pressure above 6 inch w.g. to 10 inch w.g. sheet metal gauges and requirements shall be in accordance with SMACNA - Table 1-9; based on 10 inch pressure, regardless of possible lower pressures. Ducts to 60 inch wide and within 30 ft from fan discharge shall be next heavier listed gauge thickness to that indicated in SMACNA's. Duct Construction Standard. Use Tables 1-10 thru 1-13 for reinforcements

(1)	Joints shall be welded flange, flanged joint and companion angle flanged joint only. Inside slip (Fig T9), double S slip (Fig T8 & T80), standing seam (Fig T-15 and T-16) and pocket lock (Figs T17, T18 and T19) will not be permitted. Fittings and/or joints of two different gauges, connected joint rating shall meet more stringent conditions

b.	Round ductwork shall be spiral seam construction only. Gauges shall be in accordance with SMACNA Duct Construction Standard and fittings in accordance with SMACNA Duct Construction Standard, except as noted

(1)	Joints: Interior slip coupling beaded at center, fastened to duct with screws and with sealing compound applied continuously around joint before assembling and after fastening. Wrap joints with 3 inch wide duct tape

B.	Watertight construction where noted with edges bent 1/2 inch for watertight seal. Longitudinal seam sealant shall be similar to 3M Brand No. 800; Alcoa, Aluminastic Type C, or solder. Stiffeners shall be plug or spot welded. Transverse joints shall be bolted companion angles with 1/4 inch cadmium plated bolts with 6 inch minimum on centers and gasket

NOTE: COORDINATE THE USE OF MASONRY, CONCRETE ETC AIR SHAFT WITH THE PROJECT MANAGER. THE USE OF AIR SHAFTS OTHER THAN METAL MUST BE APPROVED

C.	Airtight construction where noted with longitudinal seams soldered. Stiffeners shall be plug or spot welded. Transverse joints shall be bolted companion angle with 1/4 inch cadmium plated bolts with 6 inch minimum on centers and gasket. Exposed, uninsulated ductwork shall be flush flat seam. Provide airtight concrete, masonry and other construction materials for plenums and shafts only where noted

NOTE: WHERE BUDGET DEMANDS LOWER COST WITH REASONABLE LONGEVITY OF MATERIAL, ALUMINIZED STEEL, TYPE 2 MAY BE THE CHOICE OVER PLAIN ALUMINUM, GALVANIZED STEEL AND STAINLESS STEEL. THE MATERIAL HAS A LONGEVITY OF FOUR TO FIVE TIMES OVER GALVANIZED STEEL OF THE SAME GAUGE AND IS A GOOD SUBSTITUTE FOR STAINLESS STEEL ON HIGH PRESSURE SYSTEMS, WHERE ALUMINUM CANNOT BE USED. IN PRICE, IT STANDS BETWEEN ALUMINUM AND GALVANIZED STEEL

NOTE: SELECT MATERIAL FOR DUCTWORK INSTALLED WITHIN SHAFTS OPEN TO THE WEATHER AS IF EXPOSED TO WEATHER

D.	Ductwork exposed to weather, except as noted shall be as follows:

AL1

1.	Aluminum.

2.	Aluminized steel - Type 2.

3.	Copper.

4.	Stainless steel.

AL1

5.	Watertight.

E.	Outside air, exhaust and relief duct shall be as follows:

AL2

1.	Aluminum.

2.	Aluminized steel - Type 2.

3.	Copper.

4.	Stainless steel.

AL2

5.	Extent:

NOTE: LIST ANY EXCEPTIONS.

a.	Within 10 ft of louvers.

b.	Louvers to casings.

c.	Louvers to preheaters.

6.	Watertight.

F.	Shower exhaust duct for 15 ft from registers shall be as follows

AL 3

1.	Aluminum.

2.	Aluminized steel - Type 2.

3.	Copper.

4.	Stainless steel.

AL 3

5.	Watertight.

G.	Discharge duct from coiling towers shall be as follows

AL 4

1.	Aluminum.

2.	Aluminized steel - Type 2.

3.	Stainless steel.

AL 4

4.	Watertight.

H.	Discharge duct from evaporative condensers shall be as follows:

AL 5

1.	Aluminum.

2.	Aluminized steel - Type 2.

3.	Stainless steel.

AL 5

4.	Watertight.

I.	Ductwork at duct humidifiers shall be as follows:

NOTE: DO NOT SELECT ALUMINUM AT STEAM HUMIDIFIERS.

AL 6

1.	Aluminum.

2.	Aluminized steel - Type 2.

3.	Copper.

4.	Stainless steel.

AL 6

5.	Watertight.

6.	Minimum 2 ft upstream.

7.	Minimum 10 ft downstream.

NOTE: CHECK LOCAL CODES ON USE OF PLASTIC MATERIALS; WHILE PLASTICS MAY NOT BE PERMITTED INSIDE BUILDINGS, THEY CAN BE USED OUTDOORS. REVIEW WITH DEPT CHIEF ENGINEER

J.	Fume hood exhaust ductwork, provide as follows:

EXHAUST

1.	Stainless steel.

2.	Fiberglass-reinforced polyster resins.

3.	Plastic (resin or acid resistant material) coated steel

4.	Plastic (polyvinyl chloride).

5.	Poly-vinyl coated steel (PVS).

EXHAUST

6.	Welded or sealed watertight and airtight.

NOTE: FOR HIGHLY CORROSIVE FUMES, PARTICULATES, OR MEDIUM AND HIGH PRESSURE SYSTEMS WHERE INDUSTRIAL QUALITY CONSTRUCTION IS DESIRED: (REVIEW ACGIH MANUAL)

7.	Construction shall be in accordance with ACGIH Industrial Ventilation Manual

NOTE: FOR EXHAUST DUCTWORK WITH HIGH PRESSURE.

8.	Construction shall be in accordance with SMACNA rectangular industrial duct construction standards

K.	Canopy fume hoods shall be as follows:

1.	ACGIH Industrial Ventilation Manual, unless noted otherwise

NOTE: CHECK LOCAL CODES FOR THICKNESS.

TYPE

2.	Furniture steel shall be No. 16 USSG, shop coat of prime lead base paint

3.	Stainless steel No. 16 USSG.

TYPE

4.	Internal angles and seams.

5.	Bolts shall be countersunk.

6.	Size, configuration and support shall be as indicated.

L.	Water wash paint spray exhaust duct shall be as specified for watertight ductwork of respective pressure classification and pitch to

PITCH

1.	Point of inlet.

2.	Drain.

PITCH

3.	Provide drain flanges at low points and pipe to service sink or floor drain. 1 inch and smaller shall be copper, Type L. 1-1/2 inch and larger shall be galvanized steel

M.	Boiler breeching: Provide black steel, welded or riveted airtight and refer to Section "Boiler Plant"

NOTE: IN GENERAL, DIESEL GENERATOR EXHAUST IS MADE OUT OF PIPE, BUT AT TIMES DUE TO LIMITING SPACE CONDITIONS, IT IS NECESSARY TO PROVIDE RECTANGULAR EXHAUST

N.	Diesel engine rectangular exhaust duct shall be minimum 3/16 inch thick black steel with continuous arc welded construction including connection to pipe exhaust and with 2 inch x 2 inch x 1/4 inch angle reinforcing 4 ft on centers

O.	Kitchen range hood exhaust duct including fan discharge to atmosphere shall be provide as follows

NOTE: IF ALL DUCTWORK IS INSIDE BUILDING.

BLACK

1.	No. 10 USSG black steel.

NOTE: NYC CODE REQUIREMENTS ALL DUCTWORK MUST BE WELDED AND THICKEER BLACK STEEL IF SOME DUCTWORK IS OUTDOORS. CHECK LOCAL CODE FOR OTHER AREAS

2.	Black steel of following gauges and thicknesses. Inside building shall be No. 10 USSG. Outdoor ductwork to 7 sq ft shall be 1/8 inch, above 7 sq ft to 12.5 sq ft shall be 3/16 inch, and over 12.5 sq ft shall be 1/4 inch.

BLACK

3.	All seams, joints and penetrations shall be liquidtight continuous external arc welded, except where the duct stub collar of the hood is connected to the exhaust duct. Connection to the hood shall be continuous liquidtight external arc welded or in accordance with NFPA 96, 1984

4.	Angle reinforcing shall be minimum 1-1/2 inch x 1-1/2 inch x 3/16 inch at maximum 4 ft on centers and in accordance with SMACNA Rectangular Industrial Duct Construction Standards shall be mounted

5.	Cleanout doors on horizontal ducts shall be mounted maximum 20 ft apart and in change of direction. Cleanout doors on horizontal duct shall be mounted on side of duct. Bottom edge shall be not less than 2 inch above bottom of duct. Cleanout doors at vertical ducts shall be mounted at base. Door and frame shall be same gauge as duct. Hinges shall be Ventlock No. 260, extra heavy zinc plated. Latches shall be Ventlock No. 140, cast zinc. Gaskets shall be between door and frame. Gaskets shall be 1/8 inch double thickness rated for 2000 deg F. Cleanout door size shall be maximum 24 inch x 24 inch and minimum shall be 24 inch one side, and other side shall be 2 inch less than duct height

P.	Wet exhausts duct from kitchen equipment shall be as follows

AL 7

1.	Aluminum.

2.	Aluminized steel - Type 2.

3.	Stainless steel.

4.	Copper.

AL 7

5.	Watertight.

Q.	Dishwasher exhaust duct shall be as follows:

DISHW

1.	Stainless steel.

2.	Aluminum and stainless steel from dishwasher to ceiling.

DISHW

3.	Watertight.

NOTE: CHECK LOCAL CODE REGULATIONS FOR DUCT SYSTEM REQUIREMENTS AND MATERIAL FOR DUCTWORK

R.	Paint spray booth (water wash type) exhaust duct shall be as follows

SPRAY

1.	Galvanized steel.

2.	Aluminum.

SPRAY

3.	Soldered watertight.

4.	Construction in accordance with ACGIH Industrial Ventilation Manual

S.	Swimming pool supply and exhaust, provide as follows:

POOL

1.	Aluminum.

2.	Stainless steel.

POOL

T.	Underground ductwork, provide as follows:

UNDER

1.	Galvanized steel, factory coated with PVC - 0.004 inch outside, similar to United Sheet Metal Uni-Coat

2.	Galvanized steel, concrete encased.

3.	Concrete pipe.

UNDER

U.	X-Ray Rooms ductwork or as noted shall be lead shielded.

4)	FLEXIBLE DUCTS

NOTE: NYC SHEET METAL CONTRACT LIMITS LENGTH OF FLEXIBLE DUCT. CHECK CAREFULLY WITH BUILDING CODE FOR ALLOWABLE SMOKE AND FLAME SPREAD RATINGS

A.	Flexible duct shall be constructed in accordance with NFPA 90A; U.L. 181 Class 1 (maximum flame spread: 25, maximum smoke developed: 50). Performance and installation shall be in accordance with SMACNA HVAC Duct Construction Standards, Metal and Flexible. Maximum length shall be 18 inch with no intermediate seams

NOTE: FOR ECONOMY PROJECTS.

FLEX

B.	Flexible duct for class 2 inch w.g. shall be polyester reinforced aluminum foil over corrosion resistant wire helix, similar to Wiremold WC

NOTE: FOR QUALITY PROJECTS.

C.	Flexible duct for pressure class 2 inch w.g. shall be high temperature copolymer impregnated glass fabric, locked to cold rolled flat steel spiral, similar to Wiremold 57

NOTE: INSTALL MAXIMUM PRESSURE.

FLEX

FLEX1

D.	Flexible duct for pressure classes 6 in w.g. to ----- inch w.g. shall be high temperature copolymer impregnated glass fabric, locked to cold rolled flat steel spiral, similar to Wiremold 57

NOTE: FOR HIGH QUALITY PROJECTS. REVIEW COST BEFORE SPECIFYING INSTALL MAXIMUM PRESSURE

E.	Flexible duct for pressure classes 6 in w.g. to ----- inch w.g. shall be corrugated aluminum construction, bendable, self-supporting and mechanically interlocked to be totally leak proof under operating conditions without use of adhesives, similar to Clevaflex Type 12

NOTE: FOR CONNECTION TO DIFFUSERS IN OPERATING ROOMS.

FLEX1

F.	Flexible duct for operating rooms shall be corrugated stainless steel construction, bendable, self-supporting and mechanically interlocked to be totally leak proof under operating conditions without use of adhesives, similar to Clevaflex Type SS

G.	Insulated type where noted shall be the same as flexible ducts. Duct shall be factory preinsulated with fiberglass blanket and foil-scrim-kraft or equivalent U.L. Class 1 vapor barrier facing. Thickness and density shall be in accordance with the requirements of Section Insulation

H.	Flexible duct will be permitted only at connections to:

1.	Terminal boxes at high pressure side and from unit to outlet

2.	Single linear slot air terminal.

3.	Combination lighting - air distribution units.

4.	Ceiling outlet below supply duct to compensate for misalignment

I.	Flexible duct connections to oval collars shall be with preshaped oval ends. Secure flexible duct with clamps and sealer or screws, sealer and tape for metal flexible ducting. Attach to rectangular supply air duct with low entrance loss, bellmouth type connector on air inlet end. Flexible shall not lay across lighting fixtures or other surfaces; provide hanger supports as required

5)	CASINGS, HOUSINGS AND PLENUMS

A.	Pressure class 2 inch w.g. shall be galvanized steel unless otherwise noted

WALL

1.	Single wall, minimum No. 16 USSG.

2.	Double wall, with insulation core. Outer panel, minimum No. 18 USSG. Inner panel, minimum No. 22 USSG and

SOLID

a.	Solid.

NOTE: WHEN SOUND ATTENUATION IS REQUIRED. REVIEW WITH DEPT CHIEF ENGINEER

b.	Perforated, except solid for cooling coil section to downstream of coil pans

SOLID

c.	Core shall be 2 inch thick, fiberglass or rock mineral wool, 2-1/2 lb minimum density

NOTE: APPLICABLE IF PERFORATED PANELS ARE SPECIFIED.

d.	Refer to section Noise Control. Plenums shall be similar to Industrial Acoustics Quiet-Flow Plenum

WALL

3.	Provide same construction for floor and ceiling of casing

4.	Provide for outdoor air intake plenums, exhaust plenums open to weather, and blow through units from fan discharge to leaving side of coil, as follows

TYPE

a.	Aluminum; single wall, watertight.

b.	Stainless steel; single wall, watertight.

TYPE

NOTE: INSERT MAXIMUM PRESSURE.

B.	Pressure classes 6 inch w.g. to ----- inch w.g. materials and wall shall be as specified for pressure class 2 inch w.g. For galvanized steel cellular deck, provide flat sheet on one side and where insulated, insulation shall be applied to flat side. Casings shall be as follows

NOTE: INSERT MAXIMUM PRESSURE.

1.	Pressure classes 3 inch w.g. to ----- inch w.g.

a.	-----.

b.	-----.

6)	SOUNDLINED DUCTWORK

A.	Refer to Section "NOISE CONTROL".

B.	Duct dimensions noted on drawings are clear inside dimensions

7)	ELIMINATORS

A.	Eliminators shall be constructed, as follows:

NOTE: ELIMINATORS SHOULD BE SHOWN ON DRAWINGS FOR SYSTEMS WHERE REQUIRED

GAUGE

1.	No. 24 USSG stainless steel.

2.	No. 24 USSG galvanized steel.

3.	No. 24 USSG aluminized steel - Type 2.

4.	No. 24 B&S gauge aluminum.

GAUGE

5.	Eliminators shall be in accordance with SMACNA Duct Construction Standards except as noted with 3 bends, 3 hooks and 45 deg deflection. Nominal 6-1/2 inch front to back and maximum 2 inches apart. Eliminators shall be removable. Provide separate sections vertically to match coil banks and provide top, bottom and intermediate supports. Locate over rear end of drain pan. Provide eliminators as noted

NOTE: LOCATE AND IDENTIFY ALL REQUIRED FIRE DAMPERS ON HVAC DRAWINGS. IT IS THE RESPONSIBILITY OF THE ENGINEER, NOT THE CONTRACTOR, TO DETERMINE THE INDIVIDUAL LOCATIONS WHERE FIRE DAMPERS ARE REQUIRED. COORDINATE SMOKE DAMPERS REQUIREMENTS WITH AUTOMATION

8)	FIRE DAMPERS

A.	Fire Dampers shall be UL listed and rated for 1-1/2 hour fire rating and 3 hour ratings where required, in conformance with NFPA 90A and authorities having jurisdiction. Horizontal ducts shall be gravity drop type and vertical ducts shall be spring loaded type

NOTE: FOR NYC PROJECTS ONLY.

1.	Dampers shall be approved by New York City Board of Standard and Appeals.

AMP

2.	Dampers multibladed, equipped with fusible link with blade housing out of air stream where noted

3.	Dampers shall be multi-bladed, with blade housing out of air stream and equipped with fusible link

AMP

4.	Fusible link shall be UL listed, with temperature rating not greater than 50 deg F above highest air temperature in duct.

5.	Fire Dampers shall be similar to Air Balance, Inc. Model 119 (319 for 3 hour rated)

6.	Stainless steel construction shall be Type 304 where installed in stainless steel or aluminum ductwork

B.	Install in accordance with U.L. 555, NFPA 90A and local authority requirements

NOTE: REVIEW DETAILS IN SMACNA FIRE DAMPER AND HEAT STOP GUIDE. ALL DETAILS WILL BE ACCEPTABLE, UNLESS SUPERSEDED BY ANOTHER DETAIL ON DRAWINGS OR A NOTE IN THIS SPECIFICATION

1.	Installation details in SMACNA Fire Damper and Heat Stop Guide, 1981, shall apply unless noted otherwise. Details on drawings are intended to supersede similar details in the Guide. Figures 8, 10, 11 and 12 in the Guide are not acceptable. Breakaway connections permitted shall be in accordance with Schedule 2, SMACNA Fire Damper and Heat Stop Guide

C.	Provide fire dampers as noted and in ducts and openings in the following

1.	Shafts.

2.	Floors.

3.	Fire walls.

4.	Fire-Resistance partitions.

5.	Fire rated ceilings.

6.	Exit corridor walls.

D.	Provide access door in duct adjacent to each fire damper.

NOTE: FOR NYC PROJECTS IF SYSTEM HAS BRANCH DUCT CONNECTING TO RANGE HOOD EXHAUST DUCT. FOR RANGE HOOD EXHAUST HAVING SELF-EXTINGUISHING SYSTEM. CHECK LOCAL CODE REQUIREMENTS

E.	Range hood exhaust system fire dampers shall be single blade, black steel, minimum No. 10 USSG, pivoted type weighted for gravity closure with continuous steel angle stop and closure. Angle shall be 1 inch x 1 inch x 1/8 inch weld to inside of duct to provide complete perimeter seal of closed damper. Steel pivot rod shall be 1/2 inch diameter set in bronze bushings with external weighted arm and steel cable

NOTE: FOR RANGE GOODS WITH SELF-EXTINGUISHING SYSTEM AS CO2.

a.	Fire Dampers in range hood exhaust duct shall confine fire extinguishing gases released into duct. Connect external cable with fusible link to pressure operated trip provided with self extinguishing system. Normally open damper shall automatically close on activation of hood extinguishing system

b.	Fire dampers shall be located at point of connection of branch duct

9)	VOLUME DAMPERS

A.	Volume dampers shall be single and multi-blade as specified. For galvanized steel ductwork, provide galvanized steel dampers except as noted. For other ductwork, provide dampers same material as ductwork. Provide single bladed dampers up to 6 inch width and opposed blade multi-blade dampers above 6 inch width

1.	Single and multiblade volume dampers shall be in accordance with SMACNA HVAC. Duct construction with blades of the same material as ductwork, end bearings, and dial regulator. Provide single bladed damper up to 6 inch width and multi-opposed blade above 6 inch. Damper end bearings shall be similar to Ventlock 609 dial regulator, with locking device shall be similar to Ventlock 635. For insulated ducts dial regulator with locking device shall be on collar to clear insulation similar to Ventlock No's 637, 638 or 639 as required to meet insulation thickness

NOTE: LOCATIONS OF VOLUME DAMPERS MUST BE INDICATED ON THE DRAWINGS

2.	For internally lined ductwork: Provide 2 internal saddles to protect lining

3.	For low pressure duct, provide opposed blade on branch ducts as noted. For high pressure duct provide opposed blade, factory fabricated. Refer to Section "AIR DISTRIBUTION SYSTEM EQUIPMENT". Damper levers shall be accessible

4.	Provide volume dampers at following locations:

a.	In all duct splits and branch connections of supply, return, and exhaust systems

b.	At duct splits above 36 inch depth.

c.	Ducts connecting to common plenums.

d.	Ducts serving single outlet.

e.	At open return duct in hung ceiling.

f.	As noted.

NOTE: INSERT MAXIMUM PRESSURE.

10)	SPLITTER DAMPERS

A.	Splitter dampers constructed of the same material as ductwork shall be provide where noted. Splitter dampers are an acceptable substitute for volume damper in low pressure, low velocity systems, at duct splits up to 36 inch depth for branches serving more than one outlet. Damper edges shall be close-hemmed, but not flattened

11)	RELIEF DAMPERS

A.	Relief dampers shall be 16 gauge galvanized steel frames with minimum

gauge aluminum blades integral stiffening ribs, stainless steel ball bearings, adjustable counter weight and concealed linkage

12)	AUTOMATIC DAMPERS

A.	Install automatic dampers supplied by automatic control system manufacturer. Notch end of rod and label duct or casing to indicate open and closed position

13)	GLASS INSPECTION PANELS

A.	Glass Inspection Panel where noted and in access doors at electric coils in air handling units shall be 12 inch x 12 inch panel, except as noted. Panels shall be wireglass, gasketed and watertight

14)	CONDENSATE DRAIN PANS

A.	Drain Pans shall be as follows:

DRAIN

1.	No. 20 USSG stainless steel.

2.	No. 18 B&SG aluminum.

DRAIN

3.	Supports shall be galvanized steel.

4.	Extend under coil casing.

a.	Upstream: minimum 12 inch.

b.	Downstream: minimum 30 inch.

5.	Provide additional intermediate drain pans for each coil mounted more than one section high

a.	Minimum 3 inch upstream.

b.	Minimum 8 inch downstream.

c.	Pipe to lowest drain pan.

6.	Extend on sides to wall of casing and to receive condensate from piping and controls

15)	ACCESS DOORS

A.	Access doors shall be in accordance with SMACNA HVAC Duct Construction Standards, except as noted. In ductwork doors shall be insulated or noninsulated the same as duct. Two 2 inch x 2 inch butt hinges, except where sliding or 4 latch removable type is required. Latch shall be similar to Ventlock No. 100. Provide 20 inch x 14 inch access doors except for ducts less than 16 inch: one dimension 20 inch and the other dimension 2 inch less than duct width. Provide larger sizes where required for access

NOTE: LOCATION OF ACCESS PANELS AND DOORS SHOULD BE INDICATED ON DRAWINGS

1.	Provide access doors in following locations:

a.	Coils in ducts: entering and leaving side.

b.	Electric heaters in ducts: entering and leaving side

c.	Automatic dampers: linkage side.

d.	Main balancing dampers.

e.	Smoke dampers.

f.	Fire dampers.

g.	Smoke detection heads.

h.	Duct humidifiers.

i.	Filter banks.

j.	Fan bearings enclosed in ducts.

k.	Inlet side of each single width centrifugal fan.

l.	Inlet and outlet sides of each tubular centrifugal and axial fan

m.	On both sides of ducts where necessary to provide maintenance accessibility to equipment on the other side

B.	For insulated casings, plenums and equipment housing, provide insulated doors, 20 inch x 56 inch. Doors shall be larger size where required for maintenance, such as filter removal. Doors shall be complete with latches, similar to Ventlock No. 310 and gasket all sides

NOTE: COORDINATE WITH ELECTRICAL DEPT.

1.	Provide disconnect switch to break circuit when door is open for electric heating coils and electric filter chamber

2.	Provide access door in each side wall at following locations

a.	Fan enclosures.

b.	Coil banks.

c.	Eliminators.

d.	Filters.

e.	Dampers.

f.	Humidifiers.

g.	Intake and exhaust plenums.

h.	Enclosed motors and drives.

C.	Provide temporary closures to maintain openings straight and square, and to prevent entry of debris

16)	FLEXIBLE CONNECTIONS

A.	Flexible connections for ductwork shall be in accordance with SMACNA HVAC Duct Construction Standards, Metal and Flexible, except as noted. Flexible connections with metal collars shall be installed with 2 inch slack in fabric and minimum movement of 1 inch. Provide flexible at connections to fans, building expansion joints, at connection between copper and stainless steel ductwork and at penetrations of mechanical equipment room walls.

1.	Provide neoprene coated glass fabric, 30 oz per sq yd with sewn and cemented seams, similar to Vent Fabrics, Inc. For kitchen exhaust, provide wire imbeded glass cloth with sewn seams as manufactured by Vent Fabrics

17)	TURNING VANES

A.	For galvanized steel ductwork, provide galvanized steel or painted black steel, except as noted. For other ductwork, provide same material as ductwork. Turning vanes shall be in accordance with SMACNA HVAC Duct Construction Standards, except as noted

1.	Install at square duct elbows and as noted on drawings. Max unsupported vane length shall not exceed 48 inches. Provide separate equal size sections for greater lengths. Refer to turning vane detail. Single vane and short radius vanes are not acceptable

18)	ACCESSORIES

A.	Provide the following in accordance with SMACNA Duct Manual, except as noted

1.	Belt guards: Frames shall be minimum No. 18 USSG steel with heavy gauge expanded metal; painted and shall be in conformance with OSHA regulations. Provide openings for tachometer measurements

2.	Goosenecks: Refer to detail.

3.	Cap flashing shall be the same material as duct; where copper, use 24 oz minimum

NOTE: COORDINATE WITH FACTORY FABRICATED TYPE IN "AIR HANDLING EQUIPMENT" SECTION

4.	Weather hoods, intake or exhaust: Provide round or rectangular as noted with 180 degree change in direction and with 1/2 inch wire mesh screen with a free area two times duct area

NOTE: DETERMINE IF LOUVER AND BLANK-OFF PANELS ARE FURNISHED UNDER GENERAL CONSTRUCTION WORK BY ARCHITECT OR UNDER HVAC WORK. DETERMINE MATERIAL AND FINISH

B.	Louvers:

LOUVER

1.	Connect to louvers furnished under General Construction Work

2.	Provide louvers: Louvers shall be extruded aluminum, equivalent to No. 12 B&SG, 6063-T5 alloy, 4 inch deep stationary blades on 45-deg angle, similar to Air Balance, Inc., Model 401

a.	Provide aluminum wire screen, No. 14 gauge, 1/2 inch mesh, secured to removable "U" frame bolted to louver and mount on interior face of exhaust air discharge louver. Mount on exterior face of outside air intake louver

b.	Louvers shall bear the AMCA Certified Rating Seal and shall be tested in accordance with AMCA Standard 500

LOUVER

3.	Provide blank off panels for unused portions of louvers. Panels shall be double wall construction with 0.032 inch aluminum, and 2 inch thick, internal glass fiber insulation in accordance with SMACNA. HVAC Duct Construction Standards

C.	Provide minimum No. 16 USSG diffuser plates for blow-through air handling units. Material shall match casing

D.	Open ducts in hung ceiling: Provide No. 16 USSG, 3/4 inch square mesh, screen over each opening; with 1 inch wide galvanized steel enclosing frame and flanged duct opening to receive frame. In lieu of screen and volume damper, provide register or grille plus opposed blade volume damper

E.	Provide duct sleeves. Sleeves shall be minimum 20 gauge USSG galvanized sheet steel unless otherwise indicated. Round sleeves through bearing walls or partitions shall be black steel pipe, Schedule 30, or 40

1.	Clearances:

a.	Non-insulated duct: Provide 1 inch between duct and sleeve on all sides

b.	Insulated duct: Provide 1 inch between insulation and sleeve on all sides

c.	Grilles, registers and diffusers: Provide no clearance

2.	Provide closure collars for exposed ducts on each side of wall or floor opening. Collars shall be galvanized sheet metal, minimum 4 inch wide, and fit tight against surface and around duct or insulation. Install with nails 6 inch on center

F.	Framed openings: Provide clearances and closure collars the same as for Duct Sleeves

G.	Duct-mounted automatic controls and monitoring devices: Mount on mechanical equipment all devices related to automatic controls, monitoring and fire protection work. Coordinate to obtain such devices from other contractors when they are not provided under Mechanical Work. Devices shall include, but not be limited to

NOTE: ADD OTHER SPEC SECTIONS AND DEVICES THAT MAY BE SUPPLIED BY OTHERS

1.	Automatic dampers.

2.	Smoke dampers.

3.	Duct-mounted smoke detectors.

4.	All equipment in Section AUTOMATIC CONTROLS.

5.	All equipment in Section AUTOMATION SYSTEM.

H.	Angles, tie rods and shapes for reinforcing joints shall be in accordance with SMACNA HVAC Duct Construction Standards, except for the following

1.	Reinforcing angle spacing shall not exceed 24 inch spacing and applied to four sides for following distances from fan inlet and outlet for each system.

a.	Ten feet for fans with wheel diameter to 27 inches.

b.	Twenty feet for fans with wheel diameters exceeding 27 inches.

2.	Galvanized and aluminum sheets: Provide galvanized steel

3.	Stainless steel sheets: Provide stainless steel.

4.	Copper sheets: Provide stainless steel, brass or bronze

I.	Screws and rivets: Provide the same material as sheet, except as noted. On aluminum sheets, provide cadmium plated or stainless steel. Zinc or cadmium plated will be permitted on galvanized sheets. Minimum screw size shall be No. 10; maximum spacing shall be 10 inch. Minimum rivet size shall be 4 lb; maximum spacing shall be 6 inch

J.	Duct sealants:

1.	Provide sealing compound for brush applications, similar to 3M Brand No. 800 and other applications, similar to 3M Brand No. 900. Provide tape, similar to 3M No. 474. For gaskets, provide continuous, reinforced, inert self-conforming type, 1/8 inch thick and width to match angle connection, similar to 3M Weatherban 1202-T ribbon sealer

K.	Refer to Installation for supports, hangers, inserts and attachments and the following special construction

1.	Stainless steel ductwork.

2.	Aluminized steel - Type 2 ductwork.

3.	Copper ductwork.

4.	Spiral seam round or flat oval ductwork.

5.	Lead shielding for ductwork.

Part 3 -	EXECUTION

1)	INSTALLATION

A.	Install in accordance with SMANCA HVAC Duct Construction Standards, except as noted. Unequal elbows are not permitted. Rectangular duct sections may be joined by use of acceptable mechanical coupling systems and installation shall be in accordance with manufacturer's recommendations, except use metal clips only (PVC will not be permitted). Provide system similar to the Ductmate System

1.	Sealing:

SEAL

a.	Pressure class 2 inch w.g. shall be in accordance with SMACNA HVAC Duct Construction Standards except that tape shall not be used.

NOTE: THE FOLLOWING SHALL BE CONSIDERED FOR QUALITY INSTALLATIONS. REVIEW WITH CLIENT AND CHIEF ENGINEER. SMACNA DUCT STANDARDS REFERENCE 'CLASS C'

b.	Pressure class 2 inch w.g.: Seal all longitudinal seams, transverse joints, fastener penetrations and fitting connections. Tape shall not be used. SMACNA duct standards reference 'Class C'

NOTE: INSERT MINIMUM PRESSURE AND MAXIMUM PRESSURE.

c.	Pressure class --- inch w.g. to ----- inch w.g.: Seal all longitudinal seams, transverse joints, fastener penetrations, fitting connections and duct wall penetrations

SEAL

d.	The installer shall verify in writing that the shelf life of all sealants products have not been exceeded

2.	Inserts and attachments:

NOTE: USE UNLESS REQUIREMENTS OF LOCAL CODE EXCEED THIS SPEC AND GOVERN. SPECIFICATIONS FOR INSERTS ARE BASED, GENERALLY, ON STEEL AND CONCRETE CONSTRUCTION. SOME OF THESE VARIATIONS ARE OUTLINED BELOW DECK: WELDING, BOLTING OR SCREWING CLIP ANGLES TO Q DECK. THESE METHODS MUST BE CHECKED WITH ARCHITECT METAL DECK: SIMILAR TO ABOVE CONCRETE CONSTRUCTION: CHECK TYPE OF INSERTS WITH STRUCTURAL ENGINEER THROUGH ARCHITECT STEEL CONSTRUCTION: WITH FIREPROOF CEILING IN LIEU OF FIREPROOFING INDIVIDUAL STEEL MEMBERS CINDER ARCH CONSTRUCTION: INSERTS MAY BE SPECIAL. IN ADDITION, EXPANSION BOLTS IN SHEAR OR TENSION MAY NOT BE ACCEPTABLE. CHECK. KITCHEN EXHAUST DUCTS, BREECHING, FIREPROOFED DUCTS, DUCTS WITH PLASTER AND DUCT WEIGHTS WHICH ARE HEAVIER THAN NORMAL DUCT CONSTRUCTION WILL REQUIRE HEAVIER SUPPORTS

a.	Locate and set inserts prior to the pouring of concrete floor slab. Subsequent attachments to concrete floor slabs and beams shall be made with expansion shields with a safety factor of four, based on manufacturers listed capacities

b.	Overhead supports shall be from bottom flanges of steel beams and sides of concrete beams, with bolts in shear rather than in tension. Attachment of hangers to bottom of overhead slab shall be limited to ducts with a maximum side dimension of 18 inches

c.	Provide anchors, similar to Phillips Drill Co. "Red Head". Beam clamps shall be used on exposed steel beam construction

3.	Hangers, horizontal ducts:

a.	To 2 sg ft in area: provide galvanized steel strap hangers, minimum 1 inch x 1/16 inch, maximum 8 ft - 0 inch spacing

b.	2 to 4 sq ft in area: galvanized steel strap hangers, minimum 1 inch x 1/8 inch, maximum 8 ft 0 inch spacing

c.	Strap hangers shall be bent 2 inch under the bottom corner of rectangular ducts. One screw shall secure 2 inch portion of hanger to bottom of duct. Straps shall be secured to side of duct with a minimum of two screws and more, as necessary, to provide a maximum screw spacing of 12 inch. Side-of-duct screws shall be located not more than 2 inch from top and bottom of duct

d.	4 to 10 sq ft in area: provide galvanized steel trapeze angles from steel threaded rods with a maximum 6 ft - 0 inch spacing

e.	Over 10 sq ft in area: provide galvanized steel trapeze angles from steel threaded rods with a maximum 4 ft - 0 inch spacing

f.	Provide stronger supports to match larger and heavier ducts; provide cross-bracing, angle iron hangers, as required for rigid and adequate supports

g.	In mechanical rooms: provide black steel painted or galvanized, vertical angles or rods and horizontal angles across ductwork

4.	Hangers:

a.	Vertical ducts: At each floor, provide minimum 2 supports per duct fastened to duct and spanning shaft opening. Fasten supports to floor or structural construction. Maximum screw spacing shall be 12 inch on center and maximum shall be four screws per riser.

b.	Angles and channels: Provide painted black steel or galvanized. Where angles are specified, channels of equivalent strength, material and protective coating will be permitted. Where more than one duct is supported by a common set of angles, support size shall be determined by sum of width dimensions

c.	Supports: Provide as follows, except increase supports as required for load and span where span of angles exceed 6 ft or floor-to-floor height exceeds 14 ft

(1)	Duct width to 30 inch: Provide angle size: 1-1/4 inch x 1-1/4 inch x 1/8 inch

(2)	Duct width, 31 inch to 54 inch: Angle size shall be 2 inch x 2 inch x 3/16 inch

(3)	Duct width, 55 inch to 90 inch: Angle size shall be 2 inch x 2 inch x 1/4 inch

NOTE: USE AS A GUIDE FOR SUPPORTS OF KITCHEN EXHAUST, ETC. SPECIFICATIONS SHALL BE WRITTEN TO COVER ACTUAL SITUATION ON EACH PROJECT. MINIMUM STRUCTURAL CHANNEL 3.0 IN., 4.1 LB/FT. WEIGHT INFORMATION SHALL BE FORWARDED TO ARCHITECT AND/OR STRUCTURAL ENGINEER

5.	Vertical kitchen exhaust, fireproofed and plastered ducts: Provide minimum 3 inch, 4.1 lb/ft, steel channels fastened to slab, welded to building structural steel or as acceptable. Supports shall be bolted or welded to ducts

B.	Support of casings, equipment housings and plenums: Bottom angle of casing to rest on continuous gasket on concrete foundation and structural platform. Caulk all seams and joints. Wrap casing sheets around corners. Provide stays and bracing as required. Casing shall form complete enclosure

1.	Where insulated, provide:

a.	Single wall, with internal insulation.

b.	Double wall.

c.	For insulation, refer to Section Insulation.

2.	Drain pans, cooling coil condensate:

a.	Refer to Section "INSULATION" for insulation under drain pans

b.	Pitch to galvanized steel drain connection.

c.	Pipe to drain through water seal, minimum 5 inch.

3.	Seal openings around ducts through partitions, walls and floors (not in shafts) with mineral wool or other non-combustible material

C.	Special materials and construction.

NOTE: FOR EXPOSED DUCTWORK IN FINISHED AREAS WHERE APPEARANCE IS IMPORTANT. CHECK WITH ARCHITECT AND DEPT CHIEF ENGINEER BEFORE USING

1.	Flush flat seam ductwork: Provide for all exposed uninsulated ducts and transverse joint detail shall be as indicated. Provide sheet metal 2 gauge numbers heavier than required for pressure classification with normal (standing) seam construction. Provide all joints and seams, smooth and aligned with no projections. For internal reinforcing, at transverse joints and on 2 ft centers, provide on ducts 31 inch to 60 inch wide, single vertical stay at duct midpoint, on ducts 61 inch to 90 inch wide provide 2 vertical stays at duct third (1/3) points and for ducts over 90 inch wide provide 3 vertical stays at ducts quarter (1/4) points. For vertical stays: provide 10 USSG galvanized steel, free of burrs and rough edges with both ends bent and fastened to top and bottom of duct

NOTE: WHERE RECOMMENDED FOR NOISE ABATEMENT BY ACOUSTICAL CONSULTANT

2.	Double wall rectangular ductwork: For all ductwork in fan rooms, except exhaust and relief air ducts, provide ductwork made up of insulated panels, as follows

a.	Outside sheet shall be the same gauge as single wall ductwork. Inside sheet shall be 2 gauge numbers lighter than outside sheet. Sections over 24 inch long: provide internally braced with Z-bars, pop riveted, 6 inch on centers to inside and outside sheets. Panels shall be assembled with slide locks. Seams shall be brazed at corners and spot brazed on 12 inch centers

b.	Transverse joint connections: Provide continuous 1/8 inch thick neoprene gaskets, full thickness of insulated panel and between butted sections of ducts. Covering strips, shall be No. 18 USSG, 2-1/2 inch wide strips completely around ducts, covering transverse joints and with edges slightly broken for stiffening. Strips shall be fastened to duct with sheet metal screws, 8 inch on centers. Screws shall penetrate outer sheet of panels only

c.	Solder shall be 50-50 hard bar type. Caulking shall be similar to #M "Weatherban" (polysulphide rubber, thiokal base, caulking compound). Gaskets shall be similar to 3M EC-1202

3.	Stainless steel ductwork: Provide the following as specified for respective pressure classification

a.	Sheet metal gauge, except minimum No. 16 USSG where welded. Where watertight is noted, joints and seams may be brazed with Eutectic Eutecrod No. 157 low temperature alloy wire

b.	Joints, seams and stiffening.

c.	For stiffening angles, rivets and hardware, provide stainless steel. Provide welded or brazed watertight joints and seams in sections where moisture may collect with welding or brazing ground smooth and pitch ductwork and provide drains as specified herein for watertight ductwork. Provide connections between stainless steel and other materials made with insulating fabric gaskets. Exposed ductwork in finished spaces shall be polished to match finish of equipment

4.	Aluminized steel - Type 2 ductwork: Provide sheet metal gauge and joints, seams and stiffening as specified for respective pressure classification

a.	Stiffening angles: For ductwork exposed to weather, provide galvanized steel, riveted or bolted with gasket separator under angles. Paint cut edges with Rustoleum primer and final costs

b.	Provide cadmium plated steel or stainless steel rivets, bolts and hardware. Make watertight joints and seams in sections where moisture may collect, and pitch ductwork and provide drains as specified herein for watertight ductwork. Where ductwork is exposed to weather, apply sealing compound to all joints and seams

5.	Copper ductwork: Provide joints, seams and stiffening as specified for galvanized steel ductwork, except stiffening angles shall be brass or steel with lead separators full area of angle between ductwork and stiffeners

a.	Weights:

(1)	To to 30 inch wide: 20 oz.

(2)	31 inch to 36 inch wide: 24 oz.

(3)	37 inch to 48 inch wide: 26 oz.

(4)	49 inch to 72 inch wide: 28 oz.

b.	Provide copper rivets and hardware. Provide solder watertight joints and seams in sections where moisture may collect and pitch ductwork and provide drains as specified herein for watertight ductwork. Make connections between copper and steel work with insulation rubber fabric gaskets

6.	Aluminum ductwork: Provide as specified for respective pressure classification and in accordance with SMACNA recommendations on aluminum duct, except as noted. Construction shall be of equivalent Brown & Sharpe (B&S) gauges. Seal all seams watertight. Separate aluminum ducts, casings, plenums, housings and louvers from direct contact with concrete by resilient gasketing or caulking compound

NOTE: REVIEW WITH CHIEF MECHANICAL ENGINEER BEFORE INCLUDING THIS ARTICLE. SPIRAL SEAM FLAT OVAL DUCTWORK IS MANUFACTURED FROM SPIRAL SEAM ROUND DUCTWORK. SEE UNITED SHEET METAL CO., INC. BULLETIN NO. F07 FOR ECONOMICAL SIZES. DUE TO MACHINE LIMITATIONS, WIDTHS UNDER 21 IN. NOT YET AVAILABLE. 12 FT LENGTHS AVAILABLE. DO NOT USE FOR PRESSURE CLASS UP TO 2 IN. W.G., NYC. UNION. REGULATIONS DO NOT PERMIT FOR PRESSURE CLASS UP TO 2 IN. W.G. BUT DO PERMIT FOR PRESSURE CLASSES 3 IN. TO 10 IN. W.G. TO 20 IN. ROUND EQUIVALENT PERIMETER. POSITIVE PRESSURE ONLY, NOT SUITABLE FOR NEGATIVE PRESSURES. THIS ARTICLE SUITABLE FOR PRESSURE CLASSES 2 IN. W.G. TO 10 IN W.G

7.	Spiral seam flat oval ductwork: For ductwork, provide spiral seam construction, galvanized steel of gauges as recommended by SMACNA HVAC Duct Construction Standards, except as noted. For joints, provide interior slip coupling beaded at center, fastened to duct with screws and with sealing compound applied continuously around joint assembling and after fastening. Wrap joints with 3 inch wide duct tape. Provide stiffening with full width reinforcement of both flat, major axis surfaces. Stiffeners on both flat surfaces extending beyond major axis shall be secured with threaded rods

a.	For pressure class 2 inch w.g. stiffening shall be as follows

(1)	Up to 26 inch wide: none.

(2)	27 inch to 34 inch: 1 inch x 1 inch x 1/8 inch angle, maximum 6 ft. centers

(3)	35 inch to 52 inch wide: 1-1/2 inch x 1-1/2 inch x 3/16 inch angles, maximum 6 ft centers

(4)	53 inch to 60 inch wide: 1-1/2 inch x 1-1/2 inch x 3/16 inch angle, maximum 4 ft centers

(5)	61 inch wide and larger: 2 inch x 2 inch x 3/16 inch angle, maximum 2 ft centers

b.	For pressure class 3 inch to 6 inch w.g. stiffening shall be as follows

(1)	Up to 34 inch wide: 1-1/2 inch x 1-1/2 inch x 1/8 inch angle, maximum 6 ft centers

(2)	35 inch to 40 inch wide: 1-1/2 inch x 1-1/2 inch x 3/16 inch angle, maximum 6 ft centers

(3)	41 inch to 45 inch wide: 2 inch x 2 inch x 3/16 inch angle, maximum 6 ft centers

(4)	46 inch to 60 inch wide: 2 inch x 2 inch x 3/16 inch angle, maximum 4 ft centers

(5)	61 inch wide and larger: 2 inch x 2 inch x 3/16 inch angle, maximum 2 ft centers

c.	For pressure class 10 inch w.g. stiffening shall be as follows

(1)	Up to 26 inch wide: 1-1/2 inch x 1-1/2 inch x 1/8 inch angle, maximum 6 ft centers

(2)	27 inch to 40 inch wide: 1-1/2 inch x 1-1/2 inch x 3/16 inch angle, maximum 6 ft centers

(3)	41 inch to 52 inch wide: 2 inch x 2 inch x 3/16 inch angle, maximum 4 ft centers

(4)	53 inch wide and larger: 2-1/2 inch x 2-1/2 inch x 3/16 inch, maximum 2 ft centers

d.	Within 30 ft of fan: Provide stiffeners of sizes specified, maximum 2 ft centers

e.	Provide fittings in accordance with SMACNA HVAC Duct Construction Standards, except as noted. Fittings shall be continuous weld, beaded end connections designed for flat oval ductwork. Provide radius type elbows with centerline radius

(1)	times duct width. For branch connections, provide lateral, conical tees, similar to United Sheet Metal Co., Inc

NOTE: CHECK FOR ANY OTHER SPECIAL AREAS.

8.	Lead shielded ductwork: Provide lead shielded ductwork in and around x-ray room, as noted. Sheet lead in contact with concrete, mortar or plaster shall have surfaces coated with heavy bituminous or latex material. Joints shall be lapped minimum of 1 inch and soldered to form complete continuous seal. Provide shielding construction, materials and equipment in conformance with applicable requirements of National Bureau of Standards, Handbook 60, Medical X-Ray Protection. Shielding shall be installed in such manner that X-ray absorption at any point is not less than above requirements or adjacent lead protection. Lead lining shall be securely installed, free of waves, lumps or wrinkles and with as few joints as possible

2)	FIELD QUALITY CONTROL

A.	Testing, adjusting and balancing (TAB) shall be performed by an approved independent TAB Contractor. Contractor qualification shall be Associated Air Balance Council (AABC) membership or National Environmental Balancing Bureau (NEBB) certification. Qualifications of the firm, persons responsible for supervising and performing the work, and the Registered Professional Engineer who will certify the report, shall be submitted for approval. Refer to Section "BALANCING AIR AND WATER SYSTEMS"

B.	Procedure shall be in accordance with the AABC National Standards for Total System Balance. Work shall include, but not be limited to the following

1.	Balance and adjustment of air distribution systems.

2.	Test of systems to certify compliance with requirements of authorities having jurisdiction for ventilation and proper functioning of operating devices

C.	Before testing examine air handling systems: For filters, provide clean filters, free of air bypass and functioning as specified. Lubricate moving equipment

D.	Other inspection and maintenance items for proper system operation

1.	Air handling equipment: Demonstrate equipment performs as noted. Adjust, variable type pulleys, variable inlet vanes and volume and control dampers. Replace fixed pitch pulleys as required to balance systems. Pulleys shall be supplied as specified in Section Air Handling System Equipment

2.	Air distribution: Adjust dampers and registers to deliver or remove indicated air quantities for registers, diffusers and terminal units within plus or minus 10 percent in proper pattern so that there are no drafts. Take Pitot readings in main trunk ducts in conjunction with inlet and outlet readings

E.	Leakage testing shall be in accordance with AABC National Standards

F.	Test reports: Submit six (6) copies in bound folders with accompanying sketches

1.	Report forms shall be:

a.	SMACNA, AABC or NEBB type.

b.	Apparatus test reports.

c.	Outlet test reports.

2.	Additional report information: Submit method of balancing and details of instruments used, including serial numbers and last date of calibration. Submit copies of air velocity and pressure readings with duct layout showing where readings were taken. Submit minimum and maximum air flow readings as measured for

a.	Outside air.

b.	Return air.

c.	Relief air.

d.	Exhaust air.

e.	Each terminal unit.

3.	Submit Pitot readings.

G.	Certification: Report shall be certified by an independent Registered Professional Engineer not affiliated with construction phase of the project. Certification shall include checking of air measurement calculations, factors, and procedures