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READ AND **REMOVE THIS PAGE** BEFORE PLACING

THE SPECIFICATION SECTION IN THE CONTRACT

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[DIVISION 15: MECHANICAL]{.underline}

SECTION 15786 ‑ SPLIT SYSTEM AIR CONDITIONER

USE: Furnishing and installing a building air conditioning system.

**NOTES TO SPECIFIER:**

A. Options within paragraphs are identified by enclosure in brackets;
blank spaces enclosed by brackets \[\_\_\_\_\_\] provide for information
to be inserted, as appropriate, to individual projects.

B. **TO AVOID CONFLICTING REQUIREMENTS AND COSTLY MISTAKES,** the
specifier must edit (delete, substitute or add to the text). The
remaining paragraphs must be renumbered.

C. DELETE FOR FINAL COPY: Notes to the Specifier, located between lines
of asterisks; all \[brackets\], [underlining]{.underline}, **boldface**,
and *italics*, within the paragraphs; and this page. (Open Reveal Codes
\[alt F3\] to do this accurately.)

D. [To Edit "(Footer B)":]{.underline} (Corel 8). **ENTIRE FOOTER SHOULD
BE BOLDED.** Click in the footer and delete the "Project Name (ftr B)"
text and replace it with the **Name of the Project (upper and lower
case)**. Replace date with current MM/YY (WITHOUT BRACKETS).

E. The Guide Specifications are intended to be continuously reviewed and
revised. User's technical comments are appreciated. Also, other related
or similar specification that are written "from scratch" that could
benefit others, or other questions can be sent to NSTC A/E Group, ST
110, or call (303) 987-6868.

A. Section 01010: Summary of Work

(Required.)

B. Section 01300: Submittals

(When Contractor‑furnished materials are used, this section must be
included.)

C. Section 01700: Contract Closeout

(Must be used when training of Government employees is required.)

D. Section 15010: Basic Mechanical Requirements

(Must be used when Division 15 specifications are used.)

DRAWING DATA REQUIRED: Location and detail drawings as needed.

REQUIRED SPEC MODIFICATIONS:

[GENERAL NOTES]{.underline}

A. Whenever entire articles, paragraphs, or subparagraphs are not
applicable, the articles, paragraphs, or subparagraphs should be
deleted; when necessary, reletter or renumber articles, paragraphs, or
subparagraphs.

B. THIS GUIDE IS NOT INTENDED AS A SUBSTITUTE FOR READING THE ENTIRE
SECTION.

[TECHNICAL NOTES]{.underline}

A. 1.1A: Select applicable words.

B. 1.1B: Select or add applicable specification sections. Do not list
specification sections from Division 15.

C. 1.4B: Insert number of copies of the manufacturer\'s descriptive data
required. Normally 5 copies are required. Distribution after review is
normally 1 copy to the COR, 3 copies to the Contractor, and 1 copy to
the project file.

D. 1.4C: Insert number of copies of the manufacturer\'s installation
instructions required. Normally 5 copies are required. Distribution
after review is normally 1 copy to the COR, 3 copies to the Contractor,
and 1 copy to the project file.

E. 1.4D: Insert number of copies of the manufacturer\'s operating and
maintenance instructions required. Normally 5 copies are required.
Distribution after review is normally 1 copy to the COR, 3 copies to the
Contractor, and 1 copy to the project file.

G. 2.1A: Insert cooling and heating capacities. Select applicable
phrase.

H. 2.1B: Select applicable word.

I. 2.1C: Insert applicable requirements.

J. 2.1C1: Select \[horizontal\] when required.

K. 2.1C7: Insert heater requirements.

L. 4.1 and 4.2: When a \"lump sum\" Contract is used, delete the title
PART 4: MEASUREMENT AND PAYMENT, and both articles from this section.
Measurement and payment will be addressed in Part 4 of Section 01010
-Summary of Work.

**REVISIONS OF THIS SECTION:**

CSI format, editorial changes: 12/01

Metric:

Technical Update: 01/91

SECTION 15786

SPLIT SYSTEM AIR CONDITIONER

[PART 1: GENERAL]{.underline}

1.1 SUMMARY:

A. Section Includes: \[Furnishing\] \[and\] \[installing\] air cooled
condensing units and air handling units with a direct expansion
evaporator section \[and\] \[an\] \[electric coil\] \[gas fired\]
\[heating section\].

1.2 REFERENCES:

A. Air Conditioning and Refrigeration Institute:

ARI 210‑81 Unitary Air-Conditioning Equipment

ARI 270‑84 Sound Rating of Outdoor Unitary Equipment

ARI 410‑87 Forced-Circulation Air‑Cooling and Air-Heating Coils

ARI 430‑89 Central Station Air-Handling Units

B. National Fire Protection Association:

NFPA 90A-89 Installation of Air Conditioning and Ventilating Systems

C. Underwriters\' Laboratories, Inc.:

UL‑900-87 Test Performance of Air Filter Units

1.3 SYSTEM DESCRIPTION:

A. Requirements: The work includes equipment, piping, insulation,
controls, and related appurtenances for air conditioning and
ventilation. Completion must result in a complete and operable system.

1.4 SUBMITTALS:

A. General: Submittals shall be according to Section 01300 ‑ Submittals.

B. Manufacturer\'s Literature: Submit \[[ ]{.underline}\] copies of the
manufacturer\'s descriptive data for units to be used on this project.

C. Installation Instructions: Submit \[[ ]{.underline}\] copies of the
manufacturer\'s installation instructions for the units to be used on
this project.

D. Operating and Maintenance Instructions: Submit \[[ ]{.underline}\]
copies of the manufacturer\'s operating and maintenance instructions for
the units to be used on this project.

E. Shop Drawings: Submit \[[ ]{.underline}\] copies of shop drawings for
the major assemblies and major components to be used on this project.
Shop drawings shall show wiring and controls. A bill of materials shall
be furnished with the shop drawings. Drawings shall be \[same\]
\[larger\] scale as the full size Contract Drawings.

1.5 QUALITY ASSURANCE:

A. Manufacturer Qualifications: A company regularly engaged in the
manufacture of air cooled condensing units and air handling unit, and
who issues\'s a complete catalog of data on such products. \[The
manufacture shall have parts and service available to commence
correction of the deficiency, within \[\_\_\_\_\] hours after verbal
notification by the Contracting Officer, through factory
representatives, franchised dealers, or factory certified maintenance
service shops.

B. Testing Requirements: The units shall be tested for proper operation
at the factory.

C. Labeling Requirements: Units shall be Underwriter\'s Laboratories,
Inc. (UL). listed and labeled.

[PART 2: PRODUCTS]{.underline}

2.1 EQUIPMENT:

A. General: The capacity of the unit shall be \[[ ]{.underline}\] Btuh
(nominal) of cooling or greater with air entering the condenser at 95
degrees F, and a saturated suction temperature at compressor of 40
degrees F. Saturated condensing temperature shall not exceed 124 degrees
F. The unit shall be designed for operation down to at least 35 degrees
F outdoor air temperature entering condenser with standard controls. The
heating capacity shall be \[[ ]{.underline}\] Btuh input. Units shall be
designed for operation on 208 V, 3‑phase, 60 Hz power. The unit control
system shall provide protection against evaporator freeze up. The unit
shall be rated in accordance with ARI Standard 210. \[AHU motor driver
shall be adjustable sheave.\] \[AHU motor drive blower shall be variable
speed direct drive.\]

B. Condensing Unit: The condensing unit compressor shall be of
serviceable hermetic \[reciprocating\] \[rotary\] design. Compressor
shall operate at 1,750 rpm or lower. The compressor shall have external
spring isolators and shall have an automatically reversible oil pump.
Maximum input to the compressor shall not be more than 10.2 kW at the
conditions specified. The compressor shall unload in response to suction
pressure down to at least 33% of full load capacity in at least three
steps for partial load operation. Compressor shall be located in a
section separated from condenser fans and coils. Multiple compressor
units shall have step‑start fans and coils. Compressor motors shall have
part‑winding start. A crankcase heater shall be provided. Provide oil
pressure switch shutdown protection for compressors.

1\. Condenser coil shall be of nonferrous construction. Coil shall have
aluminum fins, mechanically bonded to seamless copper tubes. Coil shall
be circuited for subcooling.

2\. Unit shall have at least two direct driven propeller‑type fans
arranged for vertical discharge. Condenser fan motors shall have
inherent protection, and shall be of the permanently lubricated type,
resiliently mounted. Each fan shall have a safety guard. Controls shall
be included for cycling fans for intermediate season operation.

3\. Controls shall be factory wired and located in a separate enclosure.
Safety devices shall consist of high and low pressure switches and
compressor overload devices. Unit wiring shall incorporate a positive
acting timer to prevent short cycling of compressor if power is
interrupted. Timer shall prevent compressor from restarting for
approximately 5 minutes after shutoff. Units shall have a transformer
for 24 volt control circuit.

4\. Casing shall make unit fully weatherproof for outdoor installation.
Casing shall be of galvanized steel, zinc phosphatized, and finished
with baked enamel or an equivalent finish approved by the Government.
Openings shall be provided for power and refrigerant connections. Panels
shall be removable to provide access for servicing.

5\. Only one liquid line, one suction line, and one power supply
connection shall be required for each unit.

C. Air Handling Unit: Air handling unit shall provide \[[
]{.underline}\] cfm at \[[ ]{.underline}\] inch water gauge external
static pressure (ESP) for normal cooling operation. In addition to the
ESP, the fan shall provide all internal pressure losses incurred by
items such as the unit casing, a wet cooling coil, heating coil and
filter. The fan motor driver shall be of standard NEMA frame size and
shall provide at least \[[ ]{.underline}\] operating speeds. The normal
driver cooling operation shall be at 1,750 rpm and shall be provided by
a \[[ ]{.underline}\] hp driver minimum. The lower speed fan operation
shall be for providing recirculation air and outdoor air for ventilation
during the heating season. The lower motor speed shall be the value
required to enable the air handling unit to provide \[[ ]{.underline}\]
cfm at \[[ ]{.underline}\] inch water gauge ESP. The AHU components
shall be capable of operation at an ambient temperature of \[[
]{.underline}\] degrees F and the fan motor shall be supplied with a
NEMA class \"B\" or higher temperature insulation system. Totally
enclosed belt guards shall be provided and shall comply with the
Occupational Safety and Health Administration (OSHA) regulations.

1\. \[Horizontal\] Cooling coils shall be of nonferrous construction
with aluminum fins mechanically bonded to seamless copper tubes. All
tube joints shall be brazed with phoscopper or silver alloy.

2\. Evaporator fan section shall have forward‑curved blades,
double‑inlet fans mounted on a common shaft. Fans shall be statically
and dynamically balanced and supplied with permanently lubricated
bearings.

3\. The casing shall be made of galvanized steel and finished with baked
enamel or an equivalent finish approved by the Contracting Officer.
Access panels shall be provided for maintenance of the equipment. A
one‑piece drain pan shall be provided under the complete coil section,
with drain connections on both sides. One drain connection shall be
connected to a floor drain as shown on the drawings. The other drain
connection shall be sealed. The complete unit shall be insulated with
one‑inch thick 3/4 pcf foil‑faced fiberglass insulation.

4\. The unit construction shall be such that a horizontal return and
discharge may be achieved. Provisions shall exist so that the unit may
be suspended from structure above the unit or supported from structure
below the unit. Vibration isolators shall be used to isolate AHU
generated vibrations from the structure supporting the units.

5\. Filters shall be supplied with the unit, shall be standard size and
not less than one‑inch thick. Filters shall have either a Class 1 or
Class 2 rating according to UL 900.

6\. Provide optional filter adapter for installing filters.

7\. Each AHU shall be supplied with an electric heater of \[[
]{.underline}\] kW \[([ ]{.underline}Btuh)\] capacity for tempering the
mixture of return and outdoor air. The heater and controls shall provide
for five stages (4 kW increments) of heating.

8\. Provide low voltage heating/cooling thermostat with 24‑hour clock,
night and weekend setback, and manual overide. Voltage rating shall
match system control voltage.

[PART 3: EXECUTION]{.underline}

3.1 EXAMINATION:

A. Verification of Conditions: The Contractor shall be responsible for
inspecting equipment prior to installation.

3.2 INSTALLATION:

A. Location: Install equipment as close as possible to the locations
shown on the drawings. Equipment shall be installed according to
applicable NFPA standards and the manufacturer\'s installation
instructions.

B. Connections: Connections, flexible duct connections, and duct
transitions shall be as shown on the drawings. Flexible conduit and
wiring connections shall be used on the AHU if local codes permit. A
flexible connection shall be used at the drain connection.

C. Controls: The units shall be controlled as described in Section 15975
‑ Electric Temperature Control System.

D. Mounting: Mount AHU in the location shown on the drawings using
vibration isolators. Unit shall be mounted so as to provide access to
hanger brackets and removable panels housing equipment and electrical
connections. Piping shall not be run under the unit. Mounting shall
provide for easy replacement of filters. Filters shall be in place prior
to operation of the unit.

E. Acoustical Barrier: An acoustical barrier at least twice the size of
the base area of the unit shall be installed under the unit to attenuate
sound radiation. The barrier shall be constructed of one‑inch, 6‑lb
density insulation.

3.3 DEMONSTRATION:

A. Requirements: Upon completion of installation and after circuitry has
been energized, the Contractor shall demonstrate capability and
compliance of system with requirements. Malfunctioning units shall be
corrected and retested by the Contractor to demonstrate compliance with
the specifications.

3.4 TRAINING OF GOVERNMENT EMPLOYEES:

A. Requirements: See Section 01700 - Contract Closeout.

[PART 4: MEASUREMENT AND PAYMENT]{.underline}

4.1 METHOD OF MEASUREMENT:

A. Units: The work described in this section will not be measured for
payment.

4.2 BASIS OF PAYMENT:

A. Payment: No direct payment for the work described under this section
will be made. The Contractor shall include consideration for this item
in the bid price for other items of the Contract.

END OF SECTION