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15820-3
VENTILATION FANS

Provide flexible duct connections on inlet and outlet of fan when fans are ducted.

Install fans on roof or exterior wall with flashing to prevent water and weather from
entering building.

Performance testing and balancing shall be in accordance with specification Section
15907-Testing and Balancing Heating and Ventilating Systems.

END OF SECTION

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15840-1

SECTION 15840

DUCTWORK AND DEVICES

PART 1 - GENERAL

1.1

1.2

1.3

1.4

1.5

DESCRIPTION

A. Work Included: Provide and install all required sheet metal and ductwork, setting of
control dampers, louvers, flexible connections, and devices as shown on the
Drawings or required to make the installation complete in accordance with the intent
of the Drawings and Specifications.

B. Related Work Specified Elsewhere:
1. "HVAC - General" is specified in this Division.
2. Pipe Sleeves and Seals are specified in Section 15092.
3. Sealants are specified in Section 07900.

C. Design Criteria: The drawings do not show every detail of fittings, hangers and
equipment which are necessary for the complete installation, but are provided to
show the general arrangement.

QUALITY ASSURANCE
A. Ductwork:

1. SMACNA "HVAC Duct Construction Standards - Metal & Flexible, 3rd
Edition," 2005.

2. ASHRAE Duct Construction Recommendations (5 percent maximum leakage

allowable).

3. SMACNA "Thermoplastic Duct (PVC) Construction Manual, 2nd Edition,"
1995,

4. SMACNA "Round Industrial Duct Construction Standards, 2nd Edition,"
1999,

SUBMITTALS TO THE ENGINEER

A. Submit manufacturer's certification for the type of material provided.

B. Submit all shop drawings to the Engineer as specified in the General Conditions of
the Construction Contract and as specified in Section 01340.

DELIVERY, STORAGE AND HANDLING
A. Deliver all ductwork and accessories as Work progress requires.
B. Store all material to prevent damage of any nature.

JOB CONDITIONS
A. Protection:
1. Protect all ductwork, and accessories from the accumulation of paint,
concrete, mortar, etc.
2. Keep the interior of duct system free from dirt, rubbish, etc.

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15840-2
DUCTWORK AND DEVICES

PART 2 - PRODUCTS

2.1 MATERIALS

A.

F.

All ducts, devices and accessories except PVC ducts and other ducts noted on

drawings shall be constructed to SMACNA 2-inch water gage (w.g.) classification

for both vacuum and pressure applications.

Ducts, devices and accessories shall be constructed of materials as noted below and

on the Drawings.

1. Galvanized Steel - Control Building

2. Aluminum 3003 alloy H14 temper per ASTM B209 or 5052 alloy H32
temper. - Grit Building, Sludge Processing Building

All longitudinal and traverse joints, seams and connections of supply and return

ducts operating at a static pressure less than or equal to 2 inches water gauge (w.g.)

shall be securely fastened and sealed with welds, gaskets, mastics (adhesives),

mastic plus embedded fabric systems or tapes installed in accordance with the

manufacturers installation instructions.

Insulation: Ducts requiring insulation shall use materials specified in the "Duct

Insulation" Section in this Division. Note that duct sizes shown are inside clear

dimension, not necessarily sheet metal size.

Diffusers, grilles, and registers:

1. All air devices shall be supplied by a single manufacturer.

2. Acceptable manufacturers:

Price.

Nailor.

Tuttle & Bailey.

Anemostat.

Titus.

Manufacturers with equivalent diffusion pattern, air throw, velocity, and

sound level.

Fire Damper: Equal to Ruskin DIBD2, Style B or Style C and UL listed.

moaoce

PART 3 - EXECUTION

3.1 INSTALLATION

A.

Elbows, vaned elbows, take-offs, branch connections, transitions, splitters, duct
volume dampers, fire dampers, flexible connectors, and access doors shall conform
to SMACNA Duct Construction Standards.

Install duct so that ductwork shall operate without chatter, vibration, and be air tight
so that no dust marks from air leaks will show at connections or outlets.

Field Changes to Ductwork: Design changes such as those required to suit the size
of factory fabricated equipment actually furnished to minimize losses in pressure
and performance due to sudden expansion and contraction. Use transitions in field
changes as well as modifications to connecting ducts.

Splitters and Dampers: Dampers shall have accessible operating mechanism, and
where operators occur in finished portions of the building, operators shall be
chromium plated with all exposed edges rounded. Splitter dampers shall be operated
by quadrant operators or 3/16-inch rod brought through the side of the duct with

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15840-3
DUCTWORK AND DEVICES

locking setscrew and bushing. Two rods are required on splitters over 8 inches.
Manual volume-control dampers shall be operated by locking type quadrant
operators. Dampers and splitters shall be two gages heavier than duct in which
installed. Unless otherwise indicated, multi-leaf damper shall be opposed blade type
with maximum blade width of 4 inches. Access doors or panels shall be provided
for all concealed damper operators and locking setscrews. Unless otherwise
indicated, provide the locking type quadrant operators for dampers, when installed
on ducts to be thermally insulated, with stand-off mounting brackets, bases or
adapters to provide clearance between the duct surface and the operator not less than
the thickness of the insulation. Stand-off mounting items shall be integral with the
operator or standard accessory of the damper manufacturer. Provide volume
dampers where shown on the Drawings.

Air Deflectors: Provide air deflectors in all square elbows, duct-mounted supply
outlets, takeoff or extension collars to supply outlets, and tap-in branch-takeoff
connections. Air deflectors shall be factory-fabricated and factory- or field-
assembled units consisting of curved turning vanes or louver blades for uniform air
distribution and change of direction with minimum turbulence and pressure loss.
Provide square elbows with curved vanes as shown on the Drawings. Devices shall
be of the same material as ductwork.

Fire Dampers: Provide fire dampers in all ducts penetrating fire walls and slabs, and
where duct systems serve two or more floors in accordance with the National Fire
Protection Association Standard No. 90A. Install dampers with sufficient tension to
prevent rattling or vibration. Fire dampers shall conform to the requirements of
Under-writers' Laboratories, Inc. Provide dampers where shown on the Drawings.
Duct Access Doors: Provide hinged doors at all automatic dampers, fire dampers,
coils, thermostats, temperature controllers, and other apparatus requiring service and
inspection in the duct system. Doors shall be 12 by 12 inches unless otherwise
shown on the Drawings. Where size of duct will not accommodate this size, make
the doors as large as practical. Install doors not less than 24 by 24 inches on each
side of each air-handling unit. Doors shall be rigid, and shall be provided with
airtight felt gaskets. Provide doors with hinges, pins and two fasteners of the same
material as the adjacent duct. Provide doors 24 by 24 inches or larger with fasteners
operable from both sides. Doors in insulated ducts shall be of the insulated type.
Unless otherwise shown on the Drawings, doors shall swing so that fan pressure or
suction holds the door closed.

Duct Sleeves and Prepared Openings:

1. Round ducts - 15 inches in diameter or less: Provide duct sleeves for all round
ducts 15 inches diameter or less passing through floors, walls, ceiling, or roof.
Install ducts larger than 15 inches diameter and all square and rectangular
ducts passing through floors, walls, ceilings or roof. Sleeves shall conform to
the requirements of Section 15092 except as noted below:

a. Sleeve shall provide one-inch clearance between the duct and the sleeve,
or one inch clearance between the insulation and the sleeve for insulated
ducts, except at grilles, registers, and diffusers.

2. Round ducts larger than 15 inches diameter and all rectangular ducts:

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15840-4
DUCTWORK AND DEVICES

a. Install ducts larger than 15 inches diameter and all square and
rectangular ducts passing through floors, walls, ceilings or roof through
prepared openings.

b. Provide one-inch clearance between the duct and the prepared opening,
or one-inch clearance between the insulation and the prepared opening
for insulated ducts, except at grilles, registers, and diffusers.

c. Space between the prepared opening and the duct or duct insulation shall
be packed with commercial grade twisted fireproof yarn. Seal the
annular space with polyurethane sealant, S-6, per Section 07900 for
standard penetrations. Penetrations through fire rated walls and floors
shall utilize Fyre-shield sealant, S-7, per Section 07900 in lieu of the
polyurethane sealant.

3. | The contractor shall be responsible for the proper size and location of sleeves
and prepared openings. The Drawings attempt to indicate approximate sleeve
and prepared opening sizes. The actual size is to be carefully coordinated with
concrete placement and other construction activities to ensure sufficient and
properly sized sleeves and prepared openings are provided. Due consideration
should be given to the need for increased opening sizes to accommodate
devices such as fire dampers or contractor selected equipment.

4. Provide duct sleeves and prepared openings for all duct mains and duct
branches. Branch takeoff connections to grilles, registers, and diffusers shall
be in accordance with SMACNA HVAC Duct Construction Standards - Metal
& Flexible 2nd Edition.

Duct Supports: Provide and install duct supports not less than two 1-inch by 1/16-
inch thick spaced one on each side of duct in accordance with SMACNA HVAC
Duct Construction Standards Metal & Flexible 2nd Edition. Supports on the risers
shall allow free vertical movement of the duct.
Support ducts and install to be completely free from vibration under all conditions
of operation. Attach supports only to structural framing member and concrete slabs.
Do not anchor supports to metal decking unless a means is provided and approved
for preventing the anchor from puncturing the metal decking. Where supports are
required between structural framing members, provide suitable intermediate metal
framing. Where C-clamps are used, use retainer clips.
Access Panels: Provide access panels for all concealed valves, controls, dampers,
duct access doors, and any item requiring inspection and maintenance. Provide
access panels of sufficient size.
Air Filters: Install air filters so that access space for servicing the filters is provided.
Install filters with suitable sealing to prevent bypassing of air.
Flexible Collars: Provide flexible collars in connections between fans and ducts or
casings and where ducts are of dissimilar metals, as shown on the Drawings and
were required. Make collars of neoprene coated glass fabric weighing
approximately 30 ounces per square yard. Securely fasten flexible connections by
stainless steel clinch type bands for round ducts. For rectangular ducts, install the
flexible connections locked to metal collars using normal duct construction
standards.

Flashings: Where ducts pass through exterior building walls and roofs, provide

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15840-5
DUCTWORK AND DEVICES

flashings and make waterproof. Flashing shall conform to Division 7.

Cleaning of Duct System: After completing installation of ductwork, clean the entire
system of rubbish, plaster, dirt and any other debris. After installation of equipment
and connections are made to fan, and before any grilles, outlets or registers are
installed, blow out the entire system with dampers and outlets wide open.

3.2 QUALITY CONTROL

A.

Tests: Upon completion and prior to acceptance of the installation, perform the

following tests:

1. Low Velocity Ductwork: Test and make substantially airtight all supply,
return, and exhaust ducts, plenums, and casings, at the static pressure
indicated for the system before covering with insulation or concealing in
masonry. Substantially airtight shall be construed to mean that no air leakage
is noticeable through the senses of feeling or hearing at all duct joints.

Preliminary Tests: Give the air supply and distribution system and its components

an operational test for a period of not less than 4 hours.

After preliminary test, adjust, test and balance the air supply and distribution system

to obtain air volumes as shown on the Drawings. Record final balanced air

quantities and submit to the Engineer for approval.

Provide necessary samples from installed ductwork as Engineer may require (not to

exceed 10) for inspection purposes. Patch all openings due to the removal of the

samples at no additional cost to the Owner.

3.3 SHEET METAL THICKNESS TABLES

A.

Minimum Sheet Metal Gauges for Rectangular Duct for both galvanized steel and
stainless steel ducts shall be according to SMACNA HVAC Duct Construction
Standards, 3rd Edition - 2005.

Wherever the tables allow for more than one choice of gage and reinforcement, the
Contractor shall select the gage reinforcement and reinforcement spacing that will
be used throughout the Contract and submit this information to the Engineer through
the submittal process specified in the General Conditions.

END OF SECTION

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15862-1

SECTION 15862

DAMPERS
PART 1 - GENERAL
1.1 DESCRIPTION
A. Work Included: Provide and install dampers and accessories where shown on the
Drawings.
B. Related Work Specified Elsewhere:
1. “HVAC General” is specified in this Division.
2. Electrical is specified in Division 16.
1.2 QUALITY ASSURANCE
A. Acceptable Manufacturers:
1. Greenheck
2. Air Balance, Inc.
3. Airstream
4. Louvers & Dampers, Inc.
5. Ruskin.
6. Or approved equal.
1.3 SUBMITTALS TO THE ENGINEER
A. Submit shop drawings in accordance with the General Conditions of the
Construction Contract.
1.4 DELIVERY, STORAGE AND HANDLING

A. Deliver as Work progress requires.
B. Protect in a suitable weathertight enclosure to prevent damage of any nature.

PART 2 - PRODUCTS

2.1

MATERIALS
A. Motor Operated Air Control Dampers:
1. Control Dampers:
a. Equal to Greenheck VCD-23 control damper.
b. Multi-blade, parallel or opposed blade as indicated.
c. Fully gasketed with a maximum allowable leakage of 8 cfm per square
foot of face area at 4 inches W.C. differential pressure.
d. Entire damper shall be constructed from aluminum 6063-TS5 structural
shapes and extrusions.
e. Bearings and blade shafts shall be non-corrosive.

B. Damper Operators:
1. |Manual operators supplied by damper or louver manufacturer.

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15862-2
DAMPERS

2. Motor operators and linkage to connect motor to damper linkage will be
furnished and installed by the Automatic Temperature Control (ATC)
Contractor.

3. Normal closed or open as noted, spring return, electric motor
operated. Modulating type as indicated in Section 15604.

C. Miscellaneous Connecting Sheet Metal:

1. | Galvanized steel or stainless steel to match adjacent duct.

2. Thickness: Per SMACNA

3. Joints, seams, connections, cross bracing, flanges and supports as required for
installation and recommended by SMACNA.

PART 3 - EXECUTION

3.1 INSTALLATION
A. Install dampers, operators and linkage in strict accordance with the manufacturer's
instructions and recommendations.
B. Insure all blades open, close, and seal properly.
C. Adjust weights on backdraft dampers.

END OF SECTION

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Jim Donchess
Mayor e City of Nashua

To: Board of Aldermen

From: Mayor Jim Donchess

Date: March 9, 2022

Re: Multi-Year Contract Award — Riverfront Landscaping

Pursuant to NRO: § 5-74/B: A contract that extends from the current fiscal year into succeeding

fiscal year(s) in which no funds have been appropriated nor otherwise designated for this purpose
shall be approved by the full Board of Aldermen before the contract shall become binding on the

City.

The Finance Committee has approved and placed on file the notification of the award of the
referenced contract at the March 16, 2022 meeting and as such | am requesting the full Board of
Alderman approve the following contract:

Item: 2022 Landscaping: seasonal maintenance at the Library to Pan
Am Pedestrian Bridge, Peddlers to Margaritas, upper edge of
BAE parking lot, and both sides of river behind 53-59 Main Street
to Cottonmill Bridge

Value: $180,000

Vendor: Doty Group

Purchasing Memo#: 22-248 dated March 9, 2022

Contract Term: 5/1/22 through 10/31/23
Thank you.

229 Main Street * PO Box 2019 * Nashua, New Hampshire 03061-2019
603.589.3260 * fax 603.594.3450 * NashuaMayor@NashuaNH. gov
www.NashuaNH. gov

15869-1

SECTION 15869

LOUVERS

PART 1 - GENERAL

1.1

1.2

1.3

1.4

DESCRIPTION

A.

B.

Work Included: Provide and install louvers and accessories where shown on the

Drawings.

Related Work Specified Elsewhere (When Applicable):

1. Caulking and flashing are specified in Division 7.

2. Sheet metal ductwork, air devices, automatic temperature control, etc., are
specified in the appropriate Sections in this Division.

3. Electrical is specified in Division 16.

QUALITY ASSURANCE

A.

B.

All louvers shall be certified by AMCA for air pressure drop, free area, and water
penetration.

Acceptable Manufacturers:

1. Greenheck

Ruskin Mfr. Co.

Air Balance, Inc.

Louvers & Dampers, Inc.

American Warming and Ventilating, Inc.

Airstream Inc.

Or equivalent.

NAW PYND

SUBMITTALS TO THE ENGINEER

A.

go

Submit shop drawings, manufacturer's literature, maintenance data and operating
instructions as stated in the General Conditions of the Construction Contract.

Submit free area, pressure drop, and water penetration data for each louver for
approval.

Submit AMCA certification for louver style.

Submit sample louver section with proposed finish for review and no exceptions
taken by the Engineer.

Submit scale drawings of each louver showing sizes, construction details, and
mullion locations.

DELIVERY, STORAGE, AND HANDLING

A.
B.

Deliver in manufacturer's unopened containers as job progress requires.
Store in unopened containers in weathertight building.

C. Exercise care in handling to avoid bending blades or frames, damaging finish and

other damage of any nature.

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