HVAC QUESTION AND ANSWER:1.
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SAES-K-001-Design and Installation of Heating, Ventilating and Air Conditioning Systems.
SAES-K-002 Air Conditioning Systems for Essential Operating Facilities
SAES-K-003 Air Conditioning Systems for Communication Buildings
SAES-K-100 Saudi Aramco Mechanical (HVAC) Code
SAES-K-101 Regulated Vendor List for HVAC Equipment
SAEP-379-Quality Issues Notification
SAEP-380-Equipment Deficiency Report
Any conflicts between this standard and other applicable Saudi Aramco Engineering
Standards (SAESs), Saudi Aramco Materials System Specifications (SAMSSs), Industry
Standards, Codes, Forms, and Saudi Aramco Standard Drawings (SASDs) shall be
resolved in writing by the Company or Buyer Representative through the Manager,
Consulting Services Department, Dhahran.
9. 27-SAMSS-011 Fire Dampers; Smoke Dampers & Combination Fire-Smoke Damper
10. 27-SAIP-01 HVAC Inspection Requirements Saudi Aramco Engineering Report
11. AMCA 99 Standards Handbook
12. AMCA 210 Laboratory Methods of Testing Fans for Rating
13. ANSI B31.5(American National Standards Institute) Refrigeration Piping
14. GI-0002.710 Mechanical Completion & Performance Acceptance of Facilities
15. American Society of Heating, Refrigerating & Air-Conditioning Engineers, Inc.
16. NADCA(National Air Duct Cleaners Association) General Specifications for the Cleaning
of Commercial Heating, Ventilating and Air Conditioning Systems
17. NEBB(National Environmental Balancing Bureau) Testing, Adjusting and Balancing of
Environmental Systems
18. NFPA 70(National Fire Protection Association ) National Electrical Code
19. NFPA 90A Installation of Air Conditioning and Ventilating Systems
20. SMACNA 2002(Sheet Metal and Air Conditioning Contractors' National Association, Inc. )
HVAC Systems-Testing, Adjusting and Balancing, 3rd edition
21. SMACNA 2005 HVAC Duct Construction Standards-Metal and Flexible, 3rd edition
22. SMACNA 2002 Fire, Smoke and Radiation Damper Installation Guide for HVAC Systems,
5th edition
23. International Mechanical Code, 2012(IMC)
24. Uniform Mechanical Code, 1997(UMC)
25. UL 181A(Underwriters Laboratories) Closure Systems for Use with Rigid Air Ducts
26. UL 181BUnderwriters Laboratories) Closure Systems for Use with Flexible Air Ducts and
Air Connectors
Definitions:1. AHRI: Air-Conditioning, Heating and Refrigeration Institute.
2. Air, Standard: Dry air at a pressure of 101.35 kPa (29.92 in Hg.) at 20°C (68°F)
temperature.
3. Air-Conditioning, Comfort: The process of treating air to control its temperature,
humidity, cleanliness, and distribution to meet the comfort requirements of the
occupants of the conditioned space
4. Air-Conditioning Unit, Packaged: An air-conditioning unit having the means of air
cooling, air heating, air circulation, air cleaning, and the controls thereof, in the
same cabinet with the condensing unit.
5. Air Conditioning, Split: Air Conditioning system consisting of equipment provided in
more than one enclosure, usually with supply air distribution equipment housed
separately from the refrigeration equipment.
6. Main Duct - is the duct that serves the system’s major or entire flow
7. Sub-Main Duct - is the duct that serves two or more branch-mains.
8. Branch-Main Duct - is the duct that serves two or more branch ducts.
9. Branch Duct - is the duct supplying a single terminal
10. Air-Handling Unit: Device usually connected to ductwork, to move air, which also
may clean and temper the air.
11. Air Terminal Device: is a generalized term used mainly for grilles, diffusers, weather
louvers, displacement units and Chilled Beams that are commonly used to supply,
extract or transfer air in a building. An Air Terminal Device, or ATD, is mounted in
any of the surfaces of a room with the function of directing supply or exhaust air in
such a way that comfortable and clean conditions are maintained in the occupied
zone of the treated space.
12. British Thermal Unit (BTU): A BTU is a unit of heat energy. It is defined as 252.9957
calories (777.65 ft – lb) and it is the heat required to raise the temperature of one
pound of water from 59°F to 60°F.
13. Building Management System (BMS): BMS is a description for products, software,
and engineering services for remote and centralized automatic controls, monitoring
and optimization, human intervention, and management to achieve energy efficient, economical, and safe operation of building services equipment
14. Chilled Water: Water used as a cooling medium at below ambient temperature.
15. Coil: A cooling or heating element made of pipe or tubing.
16. Constant Volume System: Operates on the principal of supplying a constant volume
of air to a single zone of conditioned space. Capacity control of this type of system is
achieved by varying the amount of heat removal from (or addition to) the air stream.
17. Cooling Tower: A cooling tower is a heat rejection device, which extracts waste heat
to the atmosphere though the cooling of a water stream to a lower temperature.
18. Cycle, Refrigerating: A sequence of thermodynamic processes through which a
refrigerant passes, in a closed or open system to absorb heat at a relatively low
temperature level and reject heat at a relatively higher temperature level.
19. Damper: A device used to vary the volume of air passing through a confined cross
section by varying the cross sectional area.
20. Dehumidification: Removal of water vapor from air by chemical or physical methods.
21. Diffuser: An outlet discharging supply air in various directions and planes.
22. Grill: A covering for any opening through which air passes.
23. Register: A grille equipped with a damper or control valve.
24. Duct: A passageway made of sheet metal or other suitable material, not necessarily
leak tight, used for conveying air or other gas at low pressures
25. Evaporation: Change of state from liquid to vapor.
26. Fan Coil Unit: Fan and a heat exchanger for cooling and/or heating, assembled
within a common casing.
27. Fins Per Inch (FPI): The number of fins in a coil per 25.4 mm (1 inch).
28. Humidity: Water vapor within a given space.
29. HVAC System: The equipment, distribution systems, and terminals that provide,
either collectively or individually, the processes of heating, ventilating or air
conditioning to a building or portion of a building.
30. Louver: Device comprising multiple blades which, when mounted in an opening,
permits the flow of air but inhibits entrance of other elements in a reverse direction.
31. Plenums: A compartment or chamber to which one or more air ducts are connected
and that forms part of the air distribution system.
32. Air-Handling Unit Room Plenum - An individual room containing an air-handling
unit(s) used to gather air from various sources and combine the air within the room
for returning to the air-handling unit.
33. Raised Floor Plenum - The space between the top of the finished floor and the
underside of a raised floor where used to supply air to the occupied area, or to
return or exhaust air from the occupied area.
34. Pressure Gauge: Pressure above atmospheric.
35. Psychrometry: The branch of physics relating to the measurement or determination
of atmospheric conditions, particularly regarding the moisture mixed with the air.
36. Refrigerant: The fluid used for heat transfer in a refrigerating system, which absorbs
heat at a low temperature and a low pressure of the fluid and rejects heat at a
higher temperature and a higher pressure of the fluid, usually involving changes of
state of the fluid.
37. Sound Attenuation: The reduction in sound power.
38. Suction Line: A tube or pipe that carries refrigerant vapor from the outlet of the
evaporator to the compressor inlet.
39. Temperature, Dry Bulb: The temperature of a gas or mixture of gases indicated by
an accurate thermometer after correction for radiation.
40. Temperature, Wet Bulb: Thermodynamic wet bulb temperature is the temperature
at which liquid or sold water, by evaporating into air, can bring the air to saturation
adiabatically at the same temperature.
41. Ton of Refrigeration (TR): The refrigerating effect equal to 3516 watts (12,000
Btu/hr).
42. VAV (Variable Air Volume): Operates on the principal of constant supply air
temperature at varying supply airflow rate
43. BACNET: A Data Communication Protocol for Building Automation and Control
Networks
44. Data Center: A building or portion of a building whose primary function is to house a
computer room and its support areas
45. Hybrid Cooled Communication Shelter: Hybrid Cooled Communication Shelter is a
Communications Shelter where grid power is not available and the cooling is
provided by both passive cooling method and DC powered air conditioning units
where the type of power supporting the air conditioning is DC type generated by
solar system
46. Passively Cooled Communication Shelter: Passively Cooled Communication Shelter
is a Communications Shelter where grid power is not available and the cooling is
provided without the need for power source by natural heat transfer through an
internal heat exchanger, accumulator and external heat exchanger. This system
utilizes the difference in temperature between day and night times to cool the
shelter.
47. Telecommunications Equipment Rooms: An environmentally controlled centralized
space for telecommunications equipment that usually houses a main or
intermediate cross-connection for telecommunications distribution cables
48. Telecommunications Room: Telecommunication Room (TR) is considered to be
floor-serving facilities that provide a connection point between backbone and
horizontal distribution pathways.
49. SAP: Systems, Applications & Products in data processing.
50. HEPA: High Efficiency Particulate Air
51. 9COM: “Commodity Classification Code”.
52. ACD: Agreed Completion Date
53. NCR Originator: Individual who creates the NCR in SAP QM module.
54. LBE: Logbook Entries (First level of reporting quality deficiency using Manual Logbook or
the Quality Management Information System, QMIS).
55. NCR: Non Conformance Report (Issued by Saudi Aramco through SAP QM). An NCR can
be issued directly without going through the LBE stage
56. Worksheet (WS): Mechanism for reporting MAJOR violations or escalating pending
NCRs as stipulated in this Procedure. It is also a mechanism for escalating NCRs
unapproved by PMT in the SAP system within working days of issuance per SAEP-381.
57. Corrective action: An action taken to eliminate the causes of an existing nonconformity.
58. Equipment Deficiency Report (EDR): SAP notification (type Q4) listing equipment
deficiencies with sufficient detail reflecting procurement document, specifications, the
equipment manufacturer and investigation result.
59. Responsible Inspection Office Inspector(RIO)
60. HVAC units re-circulating or recycling indoor air within a room (such as through the
wall window units, fan coil units or mini-split direct expansion units) shall not be
used within the following facilities unless prior written approval has been obtained
from the HVAC Standards Committee:
4.3.1.10.1 Communication rooms, e.g., TER; TR or Computer Rooms
Exception: Precision HVAC equipment.
61. All Building Management Systems (BMSs) shall be BAC net compatible as per SAES-K011.
62. For selection of air cooled units but not limited to the following:
63. Package Air Cooled Units
64. Air Cooled Condensers
65. Air Cooled Chillers
66. HVAC systems shall be capable of maintaining dry bulb temperature and relative
humidity (if applicable) within the performance range given in Table 1 unless stricter
indoor design conditions are required.
67. In remote locations, the use of water chillers is restricted to locations where
adequate water supply for system make-up is available.
68. HVAC units shall automatically shut down when fire alarm system is activated, in
accordance with SAES-M-100, NFPA 90A and NFPA 101.
69. For all electric resistance heaters airflow switches shall be provided.
70. All outdoor air supply and exhaust systems, vents, and ventilators shall be equipped
with motorized dampers interlocked with the AHU that will automatically shut down
when the system or spaces served are not in use.
71. Fans with motors greater than ¾ HP (0.5 kW) shall have automatic controls capable
of shutting off fans when not required.
72. Adequate access space shall be provided for the removal of any coil or other
equipment component, as per equipment manufacturer's recommendation.
73. The refrigerant lines of split condenser/compressor or compressor/evaporator units,
separated by more than 3 m (9.84 feet), shall be sized in accordance with ASHRAE
Fundamentals Handbook, Refrigerant Line Sizing section or as per HVAC equipment
manufacturer recommendation.
74. Potable water make-up connection for all chilled water piping systems shall be
equipped with an isolation / shut-off valve.
75. An analog type flow meter shall be installed in the make-up water line of the chilled
water system to monitor water loss. Flow meter resolution readings range shall be in
liters or gallons only.
76. The make-up water connection shall also include a reduced pressure type backflow
preventer, manufactured and certified to AWWA C511 standard.
77. Chilled water piping shall be disinfected / chlorinated in accordance with Saudi
Aramco Sanitary Code (GI-0151.006) before being put into service.
78. Dissimilar metal piping connections, shall comply with the following:
79. Be exposed and accessible, this shall include valved connections.
80. Provided with insulating unions or insulating flange sets.
81. All piping components for chilled and cooling water piping system components such
as valves, flanges, etc., shall have a minimum pressure rating of 1035 kPa gauge (150
psig).
82. 2-way control valves are to be used in water coils with variable flow.
83. 3-way control valves are to be used in water coils with constant flow.
84. Globe Valve
85. By-Pass Valves
86. Flush Valves
87. Control Valves
88. Balancing Valves
89. Pressure gauges shall be installed on direct expansion air cooled condensing units at
the following locations:
90. On the suction side of positive displacement compressors, complying with
manufacturer's recommendations.
91. On the discharge side of positive displacement compressors, complying with
manufacturer's recommendations.
92.
On the oil side capable of measuring oil pump discharge pressure, complying with
manufacturer's recommendations
93. Flexible pipe connectors shall not be used to correct misaligned piping installation.
94. Toilet rooms’ exhausts require the following: a) A mechanically operated exhaust
system capable of providing a minimum of four (4) air changes per hour. b) Exhaust
shall be directly to the outside with a point of discharge of at least 1.5 m away from
any openable window or door, and a minimum of 1m above and 3 m away from any
fresh air intake.
95. Re-circulation of air from rooms such as Telecommunication Equipment Rooms
(TER), battery / UPS rooms, toilet rooms, janitor closets, locker rooms, etc., that
houses equipment or materials that emit harmful; flammable or toxic fumes or gases
are not allowed.
96. Noise shall comply with SAES-A-105, “Noise Control”
97. Automatic fire dampers shall not be used in laboratory hood exhaust systems.
98. Fire detection and alarm systems shall not be interlocked to automatically shut
down laboratory hood exhaust fans.
99. All HVAC equipment shall be identified by mark/tag numbers and shall be listed with
such identification on the HVAC Equipment Schedule of drawings.
100. An identification tag or name plate made of Brass, 316 stainless steel or better,
and shall be attached to each equipment unit, securely with stainless steel or Monel
fasteners.
101. The compressor capacity of packaged, air cooled, reciprocating water chillers
shall not exceed 50 tons.
102. Each condensing unit shall be complete with all operational equipment, including
solenoid valve, sight glass with cover, and cartridge type filter on liquid lines. It shall
be mounted on a base frame
103. Number of rows per coil shall not exceed 10 rows.
104. Fin spacing of condenser coils shall not be closer than 12 fins per inch.
105. Copper fins on copper tubes shall be used for all condenser coils within ½ km of
sea. Evaporator coils shall also have copper fins on copper tubes when introducing
20% or more outside air within ½ km of sea or within an industrial area.
106. Chilled water piping shall be insulated with closed cell material having an R value
not less than 20°F-ft²-hr/Btu.
107. Valves and fittings shall be insulated with a foam-in place insulating material.
108. Pipe penetrations through wall / floors or roof slabs shall maintain the same
thickness of the insulation material used.
109. Chilled Water Piping System – Dark Blue Color with white label and directional
flow arrow, and shall be spaced not more than 3 meters apart.
110. Condenser / Cooling Water Piping System – Dark Green Color with white label
and directional flow arrow and shall be spaced not more than 3 meters apart.
111. Underground piping, shall be provided with: a) Identification markings, e.g.,
directional flow arrows and label b) Identification markings shall be spaced not more
than1 meters apart c) Identification markings shall be sized as per the table above.
112. AHU’s shall be tested, certified and in compliant with AHRI 430.
113. Exception: Not applicable for air handlers having less than 5000 cfm and DX Units.
114. AHUs shall consist of filters, cooling / dehumidifying coil, fan and the following,
as required: a) Mixing box b) Humidifier c) Electric heater d) Face and bypass
dampers
115. Electric Heater; controls and other electrical devices used to control the air
handlers shall be UL Listed.
116. AHUs casings shall be manufactured, pre-painted backed enamel finish, 18 gauge
minimum galvanized steel with structural steel frame and bracing. Casing panels
shall be insulated with: a) Closed cell insulating material meeting NFPA 90A for flame
and smoke spread rating shall be used for single wall panels. b) For double wall
panels fibrous material may be used
117. Outside air/return air mixing plenum shall include opposed blade dampers for
both the return and outside air streams. Automatic proportioning dampers shall be
provided between the outside air and return air. Mixing plenum shall include baffles
or other provisions to insure complete mixing of outside and return air streams at all
flow rates.
118. Casings shall include doors to provide maintenance and removal access for all
fans, motors, coils, filters, and humidifiers. Access doors or frames shall have
resilient gasketing material to prevent air leakage. Access doors shall have corrosionresistant hinges and positive latches.
119. Casing filter mounts or filters shall have seals to prevent air bypass.
120. Drain pans shall extend completely under the coil sections and shall have
minimum 1-¼ inch threaded drain connections. Drains pans shall be sealed, double
wall steel construction with rigid glass fiber insulation and Type 316 stainless steel
inner pan. Slope drain pans toward drain connection. Drain pans shall drain
completely.
121. Fans shall be air-foil, backward-inclined, backward curved, or forward-curved
and shall conform to AMCA 99 and AMCA 210 requirements. In variable air volume
(VAV) systems a variable speed fan shall be provided. Propeller fans may be used for
exhaust services.
122. Fans installed in parallel within a common system shall have back draft dampers,
which open when the fan motor is energized. All exhaust fans shall have back draft
dampers which shall close when fan is off.
123. Compressor motors, 10 tons and larger, shall have a separate overload relay
protection, as described in Article 440 of the National Electric Code (NEC). This
protection shall be in addition to other built-in compressor motor protection devices.
124. Condenser fan motors, 25 tons and larger units, shall have a separate overload
relay protection, as described in Article 440 of the National Electric Code (NEC). This
protection shall be in addition to other built-in compressor motor protection devices.
125. Each fan powered by a motor of 5 HP or larger shall have a variable-speed drive
that automatically change the fan speed to control the leaving fluid temperature or
condensing temperature/pressure of the heat rejection device.
126. Heating equipment / EDH shall be UL listed and selected for the type of service
required.
127. Pre-insulated double wall flexible ducts may be used at the connection of air
diffusing devices, in accordance with the requirements of NFPA 90A. Flexible ducts
shall not exceed 1. Foot (0.3 meter) in overall length and shall not have more than 1
bend no greater than 45°.
128. Turning vanes, as per SMACNA HVAC Duct Construction Standards, shall be
provided in all rectangular elbows of low velocity systems.
129. Diffusers, registers, grilles and other similar air terminal devices shall not be
installed directly on to main, sub-main and branch-main ducts. Branch ducts shall be
provided to these air terminal devices, having a minimum length of two duct sizes.
Exception: For commercial, public and unmanned industrial areas such as PIBs,
storage, etc., where noise level is not critical this requirement is not applicable.
130. All materials in return air plenums shall be noncombustible or limited
combustible and shall meet the requirements of 2.3.10 of NFPA 90A.
131. Ducts shall be insulated in accordance with the International Mechanical Code,
Saudi Aramco Mechanical (HVAC) Code (SAES-K-100) and the following: All return air
ducts, located outdoors or exposed to unconditioned air, shall be insulated. All
Supply ducts shall be insulated. All exposed insulated ducts shall be protected in
accordance with 4.8.13.5. Return air ducts shall be insulated. Exception: Insulation is
not required for return air ducts which are located in a ceiling space, where both
sides of the ceiling space are exposed to conditioned air and the ceiling space is not
used as a return air plenum.
132. Internal duct lining of fibrous material shall not be used. Only NFPA rated closed
cell material shall be permitted with prior approval of the HVAC Standards
Committee Chairman. Exception: Fibrous Internal lining complying with UL 181 is
permitted for air terminal boxes and air handling units. This liner shall include
protective coating to prevent erosion, corrosion, and growth of molds, bacteria and
fungus. Lining shall be installed in accordance with the latest requirements of
SMACNA – Duct Liner Installation Metal nosing or sleeves shall be installed over
exposed duct liner edges that is opposite to the direction of airflow.
133. Refrigerant suction lines shall be insulated from the evaporator to the
compressor.
134. Chilled water lines shall be insulated with closed cell type PVC nitrile rubber
insulation (such as Armaflex or an approved equivalent). Fiberglass shall not be used
for chilled water lines.
135. Insulation installed or exposed outdoors shall be metal cladded or protected by
an approved and acceptable method from moisture and sunlight degradation.
136. Identification. External duct insulation and factory- insulated flexible duct shall
be legibly printed or identified at intervals not greater than 36 inches (914 mm) with
the name of the manufacturer, the thermal resistance R-value at the specified
installed thickness and the flame spread and smoke-developed indexes of the
composite materials.
137. All fans shall be isolated from their ducts by flexible connections.
138. Provisions shall be made to control equipment induced vibration. The use of
vibration isolators between equipment and foundations and/or building structures is
required to minimize transmitted vibration. Fan casing and air handling units shall be
attached to ducts with flexible connectors.
139. Reciprocating compressors shall be vibration isolated from the unit, and frame
shall have vibration isolation (such as a vibration pad) between equipment and
equipment base.
140. All piping and ductworks crossing building construction joints shall be provided
with a flexible connection to sustain any structural or building settlements due to
expansion or contraction and seismic effects.
141. Dirty pre-filter pressure drop shall not be greater than 125 Pa (0.50 in WC) or
final filter pressure drop greater than 250 Pa (1.00 in WC).
142. Built-up central HVAC systems shall be provided with pre-filters and final filters.
143. Pre-filters and final-filters shall be upstream of coils and fans.
144. Each supply or return sub-main duct; main-branch duct and branch duct takeoffs shall be equipped with a volume damper.
145. Volume damper for sub-main and main-branch ducts take-offs shall be opposed
blade type with blade linkages outside the air stream and with a locking quadrant
damper for rectangular ducts.
146. Volume dampers shall be located a minimum of two duct sizes away from fittings.
147. Fire, smoke and combination fire-smoke dampers shall be UL Classified in
accordance with all the requirements of UL555 for Fire Dampers; UL555S for Smoke
Dampers and UL 555 & 555S for combination fire-smoke dampers.
148. Fire dampers shall be securely mounted in rated fire separation wall, ceiling or
floor, such that ducts can break away without lessening fire separation rating.
149. Fire and smoke dampers shall be manufactured and installed in accordance with
the latest issue of SMACNA, “Fire, Smoke and Radiation Damper Installation Guide”.
150. Inspection / access doors shall be provided to allow access to all fire dampers
and other maintainable accessories and shall be located either adjacent or
accessible to the device that will require resetting and maintenance.
151. Fire, Smoke and Combination Fire-Smoke damper shall be installed in an
unobstructed and accessible location. This location shall allow free access for
periodic functional testing, maintenance and replacement without any interruption
or dismantling of other utilities such as cables, ducting, piping, cable-trays, etc.
152. Psychometric charts shall be shown on one of the HVAC drawings for each HVAC
system of 10 tons and larger. This psychometric chart shall include, as a minimum,
the data required by paragraph 4.3.4 of this standard.
153. HVAC sequence of operation shall be shown on one of the HVAC drawings, for
each HVAC system of 10 tons and larger.
154. Air handlers, refrigeration condenser units, pumps, or any equipment mounted
outside, shall be mounted on a concrete housekeeping pad, at a minimum of 100
mm (4”) above the floor or a minimum of 150 mm (6”) above unpaved ground.
155. Roof mounting of HVAC equipment is prohibited. Exception: Packaged rooftop
units, especially manufactured for rooftop installation, or HVAC equipment located in
penthouse may be used for other than residential HVAC systems. Provision of
approved permanent stairs or a permanent jib crane sized to handle the heaviest
single component shall be provided.
156. Access doors shall be provided to every valve, coil, filter, damper or mechanical
device for inspection and/or adjustment and be within reachable distance. Access
doors for fire dampers shall be positioned so that dampers can be reset and fusible
links replaced, if necessary.
157. Equipment clearance shall be provided with a minimum of 1 m clearance on
each side of equipment with openable panel or controls, unless equipment
manufacturer requires greater clearances. Adequate space shall be provided for coil
removal.
158. All HVAC Equipment shall be properly grounded in accordance with NFPA 70,
National Electrical Code.
159. pressure type, anti-siphon valve shall be used on the raw water hose bib and
shall be provided within close proximity (not to exceed 10 feet) of HVAC equipment
that require periodic washing
160. After installation, all field-erected refrigerant piping, regardless of the quantity of
refrigerant charge, shall be pressure-tested in accordance with the requirements of
the Uniform Mechanical Code (UMC) and ASHRAE STD 16. The required test
pressure shall be maintained for a minimum of 10 minutes. Exemption: Factory
charged and sealed refrigerant tubing.
161. After installation, dehydrate system by placing a vacuum of 1.7 kPa (0.5 in. Hg)
absolute pressure. Hold vacuum for 24 hours or cycle vacuum and dry nitrogen
purge according to manufacturer's recommendations. Charge system with quantity
and type of refrigerant as per manufacturers' requirements
162. Air-cooled condenser unit shall be mounted level. Vertical air-cooled condensers
shall be provided with wind deflectors.
163. Evaporators of air handling units shall be mounted a minimum of 150 mm (6 inch)
off the floor, to allow room for condensate trap.
164. Drain Pan a) A corrosion resistant drain pan shall be provided under each
evaporator coil. b) The evaporator drain pan shall have a trapped drain pipe,
attached to the bottom or to the side of the drain pan, flush with the bottom plate. c)
The drain pan shall slope towards the drain outlet. d) The drain pipe trap shall have a
water seal height equal to or larger than the fan's External Static Pressure (ESP) but
not less than 50 mm (2”).
165. The drain pipe shall discharge to the nearest floor drain, in accordance with the
requirements of ASHRAE Equipment Handbook. Exception: HVAC units installed
outside of buildings may discharge condensate onto the ground or roof, but not onto
walkways.
166. Record data on waterside and air side of all air handling units, fans, coils, water
chillers, condensers, etc. Data shall include all water and airflow, motor, starter
heaters, manufacturer, nameplate data.
167. Balance air distribution system within + 10% of air quantities shown on project
drawings and record actual readings taken.
168. All TAB activities shall be performed and supervised by the NEBB certified
engineer /personnel.
169. The TAB report shall be reviewed and approved by the concerned HVAC
maintenance/operation organization. After which, random points may be selected
by the concerned organizations for re-measurement to verify the accuracy of the
TAB report.
170. Testing and balancing instruments shall be of types described in NEBB or AABC
manuals. Instruments shall be calibrated every six months. Calibration shall be in
accordance with NEBB and AABC procedures.
171. Alarms shall be provided for all HVAC systems covered by this standard to
provide warning of power loss (from the normal supply) and failure of any portion of
the HVAC system.
172. All alarm devices shall be independent of the normal power supply of the HVAC
system.
173. In buildings which are located in Class I, Zone 2 or Class I, Division 2 areas, the
HVAC system shall be designed to prevent the entry of flammable vapors or gases in
accordance with the requirements of NFPA 496, Chapter 5, “Pressurized Control
Rooms
174. These buildings shall be capable of maintaining an internal building pressure of
not less than 0.25 inch water gauge.
175. All motorized isolation dampers, gas detectors, sensors and HVAC Direct Digital
Controllers (DDCs) relevant to the operation of the pressurization system shall have
an independent emergency power supply in addition to the normal power supply.
176. All electrical devices (e.g., Motorized Isolation Dampers, Exhaust Fans, Fan
Motors) shall be UL listed.
177. Failure of the building pressurization system, as measured in 5.5.5 above, shall
signal a visible and audible alarm.
178. Gas detectors shall be installed in the outside air intake stream to detect toxic or
flammable gases.
179. Battery rooms shall be air conditioned to maintain a temperature of 22.5°C ± 2°C
(72.5°F ± 3.6°F).
180. Battery rooms shall be ventilated to the outside of the building at a minimum
rate of one air change every three hours.
181. Air shall not be recycled from battery rooms.
182. The bottom of the ventilation air inlet into the battery room shall not be higher
than 150 mm above the floor, and the air outlet shall be located in the ceiling or its
upper edge flush with the ceiling if it is located in a wall. Air inlets and outlets shall
be located to provide effective cross ventilation over the batteries
183. No false ceilings are allowed in battery rooms.
184. Pockets for collection of flammable gas within battery room ceilings shall be
avoided. However, if not possible, then means shall be provided to withdraw any
collected flammable gas from the highest point within each ceiling pocket.
185. Battery room exhaust fans shall be spark resistant and certified for use in battery
room applications.
186. Differential pressure gauges shall be provided across the filter assemblies.
187. When it is confirmed by the Proponent and/or Process Engineering Division that
the concentration of corrosive gases in the local plant environment will exceed the
G1 classification level, chemical filters shall be provided to limit the concentration of
gases inside rooms containing electronic equipment, to G1 classification level.
188. The HVAC systems of Communication Facilities and Data Centers shall be
designed for indoor air dry bulb temperature and indoor air relative humidity as per
Table 1.
189. HVAC Systems of Communication Facilities and Data Centers shall have fresh air
make-up filters (where fresh air make-up is used) and internal air recirculation filters.
190. Humidity control is not required in battery rooms.
191. Recirculation of conditioned air is prohibited within the battery room.
192. HVAC equipment in battery room shall be acid and hydrogen fumes resistant and
shall be of explosion proof type.
193. Standby exhaust fan shall be provided in Battery Room to ensure continues
ventilation.
194. For Communications Facilities direct expansion (DX) type HVAC systems shall be
used.
195. For Communication Facilities and Data Centers, Computer Room Precision Type
air conditioning units shall be used.
196. All fresh air intakes shall have the following:
197.
Sand trap louver
198.
Filter
199.
Bird screen
200.
Differential pressure gauge
201.
Volume damper
202. Communication Facilities and Data Centers that have recirculation precision type
air conditioning units with no fresh air make up shall be provided with separate
pressurization air conditioning unit to provide the required pressurization.
203. Indoor air temperature and humidity levels shall be recorded on a digital
recorder in each Communications Facility or Data Center.
204. The temperature and humidity measurements shall be performed at 1.5 m (±0.3
m) above the floor and 0.1 m (±0.3 m) away from the equipment
205. Automatic change over between the operating and standby units weekly, and/or
in the event of operating unit failure.
206. Remote alarms to NOCC (Network Operations Control Center) in case of any
HVAC equipment failure and/or any other alarms in the HVAC equipment.
207. Battery room shall be equipped with Hydrogen gas detector.
208. All pipe and fittings intended for condensate drain piping shall be of the
Drainage Waste and Vent (DWV) type material.
209. Duct material for Supply, Return and Exhaust ducts and other air terminal
devices, i.e., Volume Dampers, Air Diffusers, Grilles, etc., installed within a corrosive
environment, such as battery rooms or any rooms emitting corrosive gas or vapor,
shall either be coated with an anti-corrosive coating prior to insulation or the ducts
shall be made of 316L stainless steel material or better.
210.
Table 1 – Inside Design Conditions
Offices, schools, theaters
Shops, houses, apartments, trailers,
dining halls and store
Computer rooms, control rooms,
communication facilities, process,
interface buildings, analyzer houses
Unattended equipment rooms (excluding
communication rooms)
Unattended electrical substations
24
24
22
29
35
Table 2 – Maximum Duct Air Velocities
Main Duct
Supply (Ft/min)
2,000
Main Duct
Return (Ft/min)
1,500
Branch Duct
Supply (Ft/min)
1,500
Branch Duct
Return (Ft/min)
1,000