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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 15781 ‑ COMPUTER ROOM AIR CONDITIONING UNITS

USE: Furnishing and installing computer room air conditioning units.

**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.

**DRAWING DATA REQUIRED:**

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

B. 1.1B: Select or add applicable references.

C. 1.3A: Select applicable specification section.

D. 1.3B: 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.

E. 1.3C: 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.

F. 1.3D: 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. 1.3E: Insert number of copies of shop drawings 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.

H. 1.3F: Insert number of copies of the testing procedure required.
Normally 3 copies are required. Distribution after review is normally 1
copy to the COR, 1 copies to the Contractor, and 1 copy to the project
file.

I. 1.3G: Insert number of copies of Certificates of Conformance
required. Normally 3 copies are required. Distribution after review

J. 2.1A: Insert altitude.

K. 2.1B: Select applicable data.

L. 2.1C: Insert Federal Standard Color.

M. 2.1K: Select or add applicable features.

N. 2.1M: Select or insert applicable type of electrical service.

O. 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: 02/91

SECTION 15781

COMPUTER ROOM AIR CONDITIONING UNITS

[PART 1: GENERAL]{.underline}

1.1 SUMMARY:

A. Section Includes: Furnishing and installing computer room air
conditioning units.

1.2 REFERENCES:

A. ab American Society of Heating, Refrigerating, and Air Conditioning
Engineers:

ASHRAE 52‑76 Testing Air-Cleaning Devices Used in General Ventilation
for Removing Particulate Matter

1.3 SUBMITTALS:

A. General: Submittals shall be according to \[Section 01300 -
Submittals.\] \[and\] \[Section 1365 - Certificates of Conformance.\]

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

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

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

E. Shop Drawings: Submit \[\_\_\_\_\] copies of shop drawings for the
major assemblies and major components to be used on this project. Shop
drawings shall show wiring, piping, connections, valves, strainers,
thermostatic devices, 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.

F. Testing Procedure: Submit \[[ ]{.underline}\] copies of the testing
procedure to be used to demonstrate proper operation of the computer
room HVAC system. This procedure shall be submitted for approval; 6
weeks prior to the scheduled testing of the system.

G. Certificates of Conformance: Submit \[\_\_\_\_\] copies of written
certification from the supplier of the Contractor-furnish items to be
used on this project that they conform to the requirements of this
specification section.

1.4 QUALITY ASSURANCE:

A. Manufacturer Qualifications: A company regularly engaged in the
manufacturer of the size and type of unit specified and who issues a
complete catalog of data on such products.

B. Labeling Requirements: The units shall be Underwriter\'s Laboratories
Inc. (UL) listed.

1.5 WARRANTY:

A. Requirements: Furnish a written warranty from the manufacturer
covering the computer room air conditioning unit according to Section
01700 - Contract Closeout. The warranty period shall extend for a
minimum of one year.

[PART 2: PRODUCTS]{.underline}

2.1 EQUIPMENT:

A. Type: Provide and install packaged, air cooled, factory assembled,
prewired unit, consisting of cabinet, condenser, fans, motors,
compressors, cooling and heating coils, filters, humidifier and
controls. The indoor cabinet shall contain two complete independent
refrigeration circuits. The D‑X cooling coil circuits shall be
interwoven so that the entire finned area is used for cooling by either
of the two compressors. An outdoor air cooled condenser shall also be
supplied. The condenser shall also have two separate refrigeration
circuits. Each circuit shall balance the heat rejection of the
corresponding compressor. The computer room indoor unit shall be a
downflow unit. An infrared humidifier shall be provided. Electric reheat
shall be provided. Unit shall be designed to operate at an altitude of
\[[ ]{.underline}\] ft.

B. Performance: Provide an air cooled computer room air conditioning
units with matched air cooled condenser, having a total capacity of
\[107,000\] btu/hr cooling \[5650\] cfm of air entering evaporator at 72
degrees F DB 60 degrees F WB and 50% RH with air entering condensing
unit at 95 degrees F. A minimum of \[107\] MBH sensible heat cooling
shall be provided under these conditions. Each evaporator blower shall
provide \[\_\_\_\_\_\] cfm air at an external static pressure of 0.50
inch wg minimum. The fan motor shall be \[2.0\] H.P., minimum. Each unit
shall have a total of \[56,000\] Btu electric reheat capacity with at
least 3 stages of reheat. The humidifier shall be capable of evaporating
\[17\] pounds of water per hour, minimum.

C. Indoor Section: The indoor section shall be completely internally
pre‑piped and pre‑wired, and shall include removable panels and
insulated with 1 inch thick, 1‑1/2 lbs density fiber insulation. The
unit and access panel shall be painted the color of
\[\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.\] Downflow air
shall be used to pressurize the raised floor and shall maintain room
condition of 70 degrees F DB, and 50% RH.

D. Compressors: Compressors shall be heavy‑duty, cast iron, manual reset
high pressure switches, serviceable, semi‑hermetic type with vibration
isolators, oil level sight glasses, thermal overloads, suction line
strainers, 1750 rpm and pumpdown controls.

E. Indoor Air Fans: Fans shall be multiple draw through belt‑driven
type, forward‑curved and double inlets, lifetime lubricated, and
self‑aligning ball bearings. Fan motor shall have an adjustable mount
and a variable pitch drive pulley.

F. Evaporator Coil: Coil shall be \"A\" Type with copper tubes, aluminum
fins and a stainless steel drip pan designed for high sensible heat
factor and shall have split distribution to supply both refrigerant
circuits uniformly under all load conditions. The drip pan shall be
piped to a building drain.

G. Humidifier: Humidifier shall be infrared type and of all stainless
steel construction and easily serviceable for cleaning. An automatic
water supply system with high and low water level audible and visual
alarms shall be provided.

H. Reheat: Reheat shall be electric and shall provide 14 kw to maintain
room dry bulb conditions when system is calling for full
dehumidification.

I. Electric Panel: Panel shall be prewired according to UL
specifications and serviceable by removing the front cover. Each circuit
shall be overcurrent protected and motor circuits shall contain starters
and/or contractors.

J. Filters: Filters shall be deep‑pleated and removable and shall have a
minimum capacity of 30% efficiency according to ASHRAE 52‑76.

K. Control System: The control system shall be microprocessor based. The
system shall be provided with two 0.43 inch high, seven segment LED
numerical display to allow observation of room temperature and humidity
and each setable function. (Temperature setpoint, temperature
sensitivity, humidity setpoint, humidity sensitivity). Normal operating
modes (Heating, Cooling, Humidification, Dehumidification) shall be
indicated by colored LED\'s on the unit‑mounted display panel. A
compressor sequence switch shall be provided to change the lead‑lag
sequence of the compressors. The control system shall monitor unit
operation and activate an audible and visual alarm in the event the
following faction preset alarm conditions:

High Temperature

Low Temperature

High Humidity

Low Humidity

High Head Pressure

Change Filters

Loss of Air

Humidifier Problem

Field Accessible Local Alarm

Manual Override Activated

L. Condensers: Condensers shall have ample capacity to handle the
compressors\' total heat rejection and maintain adequate condensing
temperature in all seasons down to ‑30 degrees F ambient drybulb.
Air‑cooled condenser shall have multiple direct driven propeller fans
with a speed control device on one fan motor and a low
temperature‑actuated shut‑off switch on remaining motors to provide head
pressure control. The low temperature package shall include insulated
receivers, pressure relief valve, three‑way head pressure control
valves, check valves, an roto lock valves for each circuit.

M. Electrical Requirements: The computer room air conditioning unit
shall be provided to operate on \[208 volt, 3 phase, 60 Hz\] system
electrical service.

[PART 3: EXECUTION]{.underline}

3.1 INSTALLATION:

A. Installation on Raised Floor: Coordinate installation of computer
room air conditioning unit with computer room raised floor installer.

B. Drainage Connections: Provide adequate drainage connections for
humidifier flushing system.

C. Manufacturer\'s Instructions: Install units according to the
manufacturer\'s instructions.

3.2 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.

3.3 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