2	CENTRAL REFRIGERATION & AIR CONDITIONING EQUIPMENT 	2	
2.1	GENERAL	2	
2.1.1	Scope	2	
2.1.2	References	2	
2.1.3	Products	3	
2.1.4    Quality assurance	3	
2.2	PACKAGE CHILLERS	4	
2.2.1	Air Cooled Package Chillers	4	
2.2.2	Water Cooled Package Chillers	6	
2.3	PACKAGED AIR CONDITIONERS	8	
2.3.1	Air Cooled Packaged Air Conditioning Units	8	
2.3.2	Water Cooled Packaged Air Conditioning Units                                              	10	
2.3.3     Variable Refrigerant Flow Air-Conditioners Units (VRF)	12	
2.4	COMPRESSORS	14	
2.4.1	General	14	
2.4.2     Reciprocating Compressors	16	
2.4.3    Rotary Compressors	17	
2.4.4     Scroll inverter compressors                                                                             	18	
2.4.5     Twin Rotary Inverter compressors                                           	18	
2.4.6     Scroll compressors                                                                                          	19	
2.4.7     Screw compressors                                                                                         	20	
2.5	CONDENSERS	21	
2.5.1	Air Cooled Condenser	21	
2.5.2	Water Cooled Condenser	23	
2.5.3	Evaporative Condensers	24	
2.5.4	Dual Condensing	24	
2.6	COOLER	23	
2.6.1	General	25	
2.7	COOLING TOWERS	26	
2.7.1	General	26	
2.8	PACKAGE COOLING TOWERS	27	
2.8.1	General	27	
2.9	REFRIGERATION ACCESSORIES	29	
2.10	MISCELLANEOUS	29	
2.10.1  Water Chemical Treatment	29	
  2.10.2  Water Softeners
	30	

2	CENTRAL     REFRIGERATION     &     AIR     CONDITIONING EQUIPMENT

2.1	GENERAL

2.1.1	Scope

1	This Part specifies the requirements of the design manufacture, construction installation testing and commissioning of central refrigeration and air conditioning equipment.
2	Related Sections and Parts are as follows: This Section
Part 1	General

Section 1	General
Section 10	Instrumentation, Control and Automation
Section 16	Structural Metalwork
Section 21	Electrical Works

2.1.2	References  

1	The following standards and organizations are referred to in this Part:
AHRI Standard 210/240 
AHRI Standard 340/360
AHRI Standard 365
AHRI Standard 550/590
AHRI Standard 450
AHRI Standard 480
AHRI Standard 440 
AHRI Standard 1230
ASHRAE Standard
ASTM B117
NEMA
EN 13053
EUROVENT
IEC
PED 97/23/CE
ISO15042:2017

2.1.3	Products
	
1	Materials and equipment furnished under these specifications shall be standard catalogue products of manufacturers regularly engaged in production of such materials or equipment and shall be the manufacturer’s latest standard design complying with the specification requirements and meets and capacity indicated in the Project Documentation. Where two or more units of the same class of equipment are required, these units shall be produces of a single manufacturer. However, the component parts of the system need not be the products of the same manufacturer while for water-cooled chillers the compressor shall be manufactured by the same manufacturer as the chiller.

2	Each major component of equipment shall have the manufacturer’s name address, and catalogue number on a nameplate securely affixed in a conspicuous place; the nameplate of a distributing agent only will not be acceptable.

2.1.4	Quality assurance   

(i)	Air Cooled Chillers shall be certified and rated according to the latest editions of AHRI Standards.
550/590 (I‐P) & 551/591 (SI) for Performance Rating of Chillers. 
Eurovent Certified Air Cooled Chillers acceptable for cooling capacity less than 250 T.R capacity.

(ii)	Water Cooled Chillers shall be certified and rated according to the latest editions of AHRI Standards.
550/590 (I‐P) & 551/591 (SI) for Performance Rating of Chillers.

(iii)	Package units shall be certified and rated according to the latest edition of AHRI Standard 340/360 or AHRI Standard 210 / 240 Performance Rating of Commercial and Industrial Unitary Air‐ Conditioning and Heat Pump Equipment or Eurovent Certified Package units acceptable.
(iv)	
Eurovent Certified Package units acceptable for cooling capacity less than 20 T.R. capacity.
(v)	Condensing Units shall be certified and rated according to latest edition of AHRI Standard 365 Performance Rating of Commercial and Industrial Unitary Air‐ Conditioning condensing units. 
Eurovent Certified acceptable for cooling capacity less than 20 T.R. capacity.
(vi)	VRF units shall be certified and rated or tested according to latest edition of AHRI Standard 1230 for VRF or equivalent Eurovent from accredited laboratory.   
(vii)	Water-Cooled Refrigerant Condensers, Remote Type shall be certified and rated or tested according to latest edition of AHRI Standard 450.
(viii)	Remote Type Refrigerant Cooled Liquid Coolers shall be certified and rated or tested according to latest edition of AHRI Standard 480.
(ix)	Coefficient of Performance (COP), Energy Efficient Ratio (EER) and Integrated Part Load Value (IPLV) for All Projects Require GSAS 3 Star and above shall confirm 10% more than ASHRAE Energy Standard 189.1-2017 and for all other projects, IPLV shall be above 5.5.
(x)	Acceptance Text / Performance test required for HVAC equipment, factory visit could be required for projects more than 500 TR or witness could be required.

The Lab-factory test shall comply with  the following test:
A- Factory acceptance test (FAT): to run test at electrical conditions, 3 phases, 50HZ, Electrical power kw.

B-Performance test to measure cooling capacity, electrical load and shall be run and tested at partial load and full load to calculate automatic reading for EER, COP, SEER or IPLV.
The lab-test must be certified with all tools and instrument having calibrated and adjusted to meet AHRI standards or equivalent.
Method statement of factory laboratory performance test to be submitted for ENGINEER ‘s Approval

2.2	PACKAGE CHILLERS

2.2.1	Air Cooled Package Chillers  

1	The air-cooled packaged chillers shall be factory assembled complete with piping and wiring and shipped with refrigerant charge and oil change.
2	The only required field connections shall be the system water piping, electrical power supply and external control cables when required.

3	The units shall be provided with lifting lugs for easy site handling.

4	All components shall be mounted on a continuous structural steel base resting on spring type vibration isolators. The isolators shall be proportional for the loads at all points under the unit.

5	The chiller control and starters shall be housed in a weatherproof and dust-proof enclosure with lockable door. The minimum rating for the enclosure shall be IP55.

6	The system shall be designed and supplied with the refrigerant as specified in the Project
Documentation.

7	The power supply cables and protective devices shall be rated as recommended by the manufacturer.

8	The chiller shall be selected to meet the capacities as detailed in the Project Documentation.

9	    The compressor type shall be Screw or as specified in the Project Documentation.

10	The chiller shall be in accordance with the latest QGEWC regulations.

11	The manufacturer’s details should be followed wherever possible.

12	Adequate space shall be provided for operating and maintenance purpose.

13	Air cooled chillers base, frame, and casing shall be protected with a corrosion-resistant coating capable of withstanding a 1000 hour salt-spray test according to ASTM B 117.

14	Refrigerant Circuits:

Refrigerant Type:  Classified as Safety Group A1 according to ASHRAE 34 such as R-134a.
Refrigerant Compatibility:  Chiller parts exposed to refrigerants shall be fully compatible with refrigerants, and pressure components shall be rated for refrigerant pressures.
Refrigerant Circuit:  Each shall include a thermal- or electronic-expansion valve, refrigerant charging connections, a hot-gas muffler, compressor suction and discharge shutoff valves, a liquid-line shutoff valve, a replaceable-core-filter-dryer, a sight glass with moisture indicator, a liquid-line solenoid valve, and an insulated suction line.
Pressure Relief Device:
(i)	Comply with requirements in ASHRAE 15 and in applicable portions of ASME Boiler and Pressure Vessel Code:  Section VIII, Division 1, or equivalent European PED standard.  
(ii)	ASME-rated, spring-loaded pressure relief valve; single- or multiple-reseating type, or equivalent European PED standard.  
15                 Evaporator:  Shell-and-tube design.
Flooded type with fluid flowing through tubes and refrigerant flowing around tubes within the shell / direct expansion Refrigerant in tubes, Water in shell. 
(iii)	Code Compliance:  Tested and stamped according to ASME Boiler and Pressure Vessel Code:  Section VIII, Division 1, or equivalent European PED standard.  
Shell Material:  Carbon steel.
Shell Heads:  Removable carbon-steel heads located at each end of the tube bundle.
Fluid Nozzles: Terminated with mechanical-coupling or flanged end connections for connection to field piping.
Tube Construction:  Individually replaceable copper tubes with enhanced fin design, expanded into tube sheets.
16	The units having capacity (200 TR) and above shall have a minimum of two compressors and able to operate even in case that one compressor is out of order. Each compressor shall be provided with independent refrigerant circuit for better redundancy. 
17    Electrical Power 
Factory-installed and -wired switches, motor controllers, transformers, and other electrical devices necessary shall provide a single-point, field-power connection to chiller.
Wiring shall be numbered and color-coded to match wiring diagram.
Chillers higher than 250 TR, the maximum allowed Inrush current shall not exceeds 10% of the running current. 
and chillers required to be supplied with Variable frequency drive or Inverter for starting and capacity control. 
or alternative subject to HVAC and Electrical Engineer Approval for alternative 
The chillers power factor shall be greater than 0.95. 
18        Control
Standalone microprocessor control.
Enclosure:  Share enclosure with electrical power devices or provide a separate enclosure.
Operator Interface:  Multiple-character digital or graphic display with dynamic update of information and with keypad or touch-sensitive display located on front of control enclosure. In either imperial or metric units. The Units controls and starters shall be housed in a weatherproof and dust-proof enclosure with lockable door. The minimum rating for the enclosure shall be IP55.
19	Air cooled chiller of each model proposed shall be factory performance tested at actual design condition. The chillers to be selected randomly by Engineer. All chillers proposed for the project shall be tested in the event of performance test failure.
20	Chillers shall be suitable for operation with Primary variable primary speed pumps without tripping or failures.
21	Spare Parts List:  
	Air Cooled Chillers	Qty	
1	Condenser Fan With Motors	1 per chiller < 300 T.R 
2 per chiller > 300 T.R	
2	Solenoid Valve Coil	1 per chiller Model	
3	Electronic Expansion Valve 	1 per chiller Model	
4	Filter Drier Core 	1 per chiller < 300 T.R 
2 per chiller > 300 T.R	
5	Temp Sensors 	1 per chiller 	
6	Compressors Circuit Breaker 	1 per chiller Model	
7	Condenser Fan Circuit Breaker 	2 per chiller 	
8	Control Circuit Breaker 	1 per chiller 	
9	Contactors 	2 per chiller 	
10	Accessories	As per manufacturer recommendation	

Spare parts List could be amended according to the manufacturer recommendation and Engineer approval.
 
Tools and spare parts supplied under this clause shall be provided in original packing, clearly labelled, and referenced.

Spare Parts furnished under this clause shall not be used during the maintenance period without the written permission of the owner (Contractor shall procure spare parts, tools etc., fulfill his obligations to operate and maintain the system in the contract period)

2.2.2	Water Cooled Package Chillers 

1	The water-cooled packaged chillers shall be factory assembled complete with piping and wiring and shipped with refrigerant charge and oil change.

2	The associated condenser capacity shall be matched with the capacity of the chillers.

3	The only required field connections shall be the system water piping, electrical power supply and external control cables when required.

4	The units shall be provided with lifting lugs for easy handling.

5	All components shall be mounted on a continuous structural steel base resting on vibration isolators. The isolators shall be proportional for the loads at all points under the unit.

6	The chiller control and starters shall be housed in a weatherproof and dust proof enclosure with lockable door. The minimum rating for the enclosure shall be IP55.

7	The system shall be designed and supplied with the refrigerant as specified in the Project
Documentation.

8	The power supply cables and protective devices shall be rated as recommended by the manufacturer.

9	The chiller shall be selected to meet the capacities as detailed in the Project Documentation.

10	The compressor type shall be centrifugal or as specified in the Project Documentation.

11	The chiller shall be in accordance with the latest QGEWC regulations.

12	The manufacturer’s details should be followed wherever possible.

13	Adequate space shall be provided for operating and maintenance purpose.

14	The units having capacity (1700 TR) and above shall have a minimum of two compressors and    able to operate even in case that one compressor is out of order , single compressor could be approved subject to the engineer approval. 

15	Chillers shall be suitable for operation in series counterflow arrangement.

16	Chillers shall be suitable for operation with Primary variable primary speed pumps without tripping or failures.

17	A water cooled chiller of each model proposed shall be factory performance tested at actual design condition. The chillers to be selected randomly by Engineer. All chillers proposed for the project shall be tested in the event of performance test failure.

18	Spare Parts List  

	Water Cooled Chillers	Qty	
1	Solenoid Valve Coil	1 per chiller Model	
2	Electronic Expansion Valve 	1 per chiller Model	
3	Filter Drier Core 	1 per chiller < 1000 T.R 
2 per chiller > 1000 T.R	
4	Temp Sensors 	1 per chiller 	
5	Compressors Circuit Breaker 	1 per chiller Model	
6	Control Circuit Breaker 	1 per chiller 	
7	Contactors 	2 per chiller 	
8	Accessories	As per manufacture recommendation	

Spare parts List could be amended according to the manufacturer recommendation and Engineer approval.
 
Tools and spare parts supplied under this clause shall be provided in original packing, clearly labelled and referenced.

Spare Parts furnished under this clause shall not be used during the maintenance period without the written permission of the owner (Contractor shall procure spare parts, tools etc., fulfill his obligations to operate and maintain the system in the contract period)

2.3	PACKAGED AIR CONDITIONERS

2.3.1	Air Cooled Packaged Air Conditioning Units 

1	The air-cooled packaged Air Conditioning Units shall be factory assembled complete with piping and wiring and shipped with refrigerant charge and oil change.
	
2	The only required field connections shall be the system ductwork, electrical power supply and external control cables when required.

3	The units shall be provided with lifting lugs for easy site handling.

4 	    All components shall be mounted on a continuous structural steel base resting on vibration        isolators. The isolators shall be proportional for the loads at all points under the unit.
5	The Packaged Air Conditioning Units controls and starters shall be housed in a weather proof 

	and dust proof enclosure with lockable door.  The minimum rating for the enclosure shall be IP55.

6	The system shall be designed and supplied with the refrigerant as specified in the Project
Documentation.

7	The power supply cables and protective devices shall be rated as recommended by the manufacturer.

8	The Packaged Air Conditioning Units shall be selected to meet the capacities as detailed in the Project Documentation.

9	The compressor type shall be as specified in the Project Documentation.

10	The  Packaged  Air  Conditioning  Units  shall  be  in  accordance  with  the  latest  QGEWC
regulations.

11	The manufacturer’s details should be followed wherever possible.

12	Adequate space shall be provided for operating and maintenance purpose.

13	Refrigerant Circuits:
	
Refrigerant: Classified as Safety Group A1 according to ASHRAE 34 such as R 410A. 
Refrigerant Compatibility: package units parts exposed to refrigerants shall be fully compatible with refrigerants, and pressure components shall be rated for refrigerant pressures.
Refrigerant Circuit:  Each shall include thermal expansion valve, refrigerant charging connections, compressor suction and discharge shutoff valves, a liquid-line shutoff valve, a filter-dryer, a sight glass, a liquid-line solenoid valve, and an insulated suction line.

14 	Minimum G3/G4 or MERV-5/MERV-7 (According to Engineer Approval), 50mm thick pleated fiberglass media throwaway filters in filter rack.

15 	Casing: Galvanized-steel construction 0.9 mm minimum with enamel paint finish, removable panels or access doors with neoprene gaskets for inspection and access to internal parts, minimum 25 mm thick thermal insulation, knockouts for electrical and piping connections, exterior condensate drain connection, and lifting lugs.

16	Indoor Fan: Forward curved, centrifugal, belt driven with adjustable motor sheaves, grease-lubricated ball bearings, and motor.

17	The units having capacity (10 TR) and above shall have a minimum of two compressors and able to operate even in case that one compressor is out of order.

18      Electrical Power: 
	Factory-installed and -wired switches, motor controllers, transformers, and other electrical devices 
          necessary shall provide a single-point, field-power connection. Wiring shall be numbered and color-coded to match wiring diagram.

19        Control

	Standalone microprocessor control for package unit nominal capacity above 100 KW.
	Factory built- in, in the outdoor unit control panel weather protected, with self –diagnostic function for easy reading and maintenance. all service information should be displayed ,
The control system consists of a microprocessor, controller and a user interface remote controller. 
The controller to be provided with built in anti-recycle timer to prevent compressor short cycling, sequential control of compressor, condenser motor and evaporator motor, Intelligent control to ensure balance usage of compressor in the system, and sensor fault indication.
  
	Enclosure: Share enclosure with electrical power devices or provide a separate enclosure.

20      Third Party performance test

          3rd party performance test report from accredited laboratories to be submitted as evidence of performance  @ 35 C, 46 C

21       Spare Parts List.
	Package Units	Qty	
1	Condenser Fan	5% of total units in the project	
2	Fan Motor	5% of total units in the project	
3	Thermostat (Room Temp Sensor)	5% of total units in the project	
4	Filter Dryer	5% of each units in the project	
5	Contactor	10% of total units in the project	
6	Filter Drier Core 	1 per package unit	
7	Compressors Circuit Breaker 	1 per model	
8	Condenser Fan Circuit Breaker 	1 per package unit	
9	Condenser Fan With Motors 
	1 per package unit	
10	Electronic Expansion Valve	1 per package < 10 T.R 
2 per package > 20 T.R	
11	Accessories	As per manufacturer recommendation	
	
Spare parts List could be amended according to the manufacturer recommendation and Engineer approval.
 
Tools and spare parts supplied under this clause shall be provided in original packing, clearly labelled and referenced.

Spare Parts furnished under this clause shall not be used during the maintenance period without the written permission of the owner (Contractor shall procure spare parts, tools etc., fulfill his obligations to operate and maintain the system in the contract period)

2.3.2	Water Cooled Packaged Air Conditioning Units

1	The water-cooled packaged Air Conditioning Unit shall be factory assembled complete with piping and wiring and shipped with refrigerant charge and oil change.

2	The associated condenser capacity shall be matched with the packaged Air Conditioning
Units requirements.

3	The only required field connections shall be the condenser system water piping ductwork, electrical power supply and external control cables when required.

4	The units shall be provided with lifting lugs for easy site handling.

5	All components shall be mounted on a continuous structural steel base resting on vibration isolators. The isolator shall be proportional for the loads at all points under the unit.

6	The Packaged Air Conditioning Units controls and starters shall be housed in a weatherproof and dust proof enclosure with lockable door. The minimum rating for the enclosure shall be IP55.

7	The system shall be designed and supplied with the refrigerant as specified in the Project
Documentation.

8	The power supply cables and protective devices shall be rated as recommended by the manufacturer.

9	The Packaged Air Conditioning Units shall be selected to meet the capacities as detailed in the Project Documentation.

10	The compressor type shall be as specified in the Project Documentation.

11	The units shall be in accordance with the latest QGEWC regulations.

12	The manufacturer’s details should be followed wherever possible.

13	Adequate space shall be provided for operating and maintenance purpose.

2.3.3	VARIABLE REFRIGERANT FLOW AIR-CONDITIONERS UNITS (VRF): 

1	The VRF Units shall be factory assembled complete with piping and wiring and shipped with refrigerant charge and oil change.
	
2	The only required field connections shall be the electrical power supply.

3	The units shall be provided with lifting lugs for easy site handling.

4	All components shall be mounted on a continuous structural steel base resting on vibration isolators. The isolators shall be proportional for the loads at all points under the unit.

6	Variable refrigerant air-conditioning-heat pump systems shall be installed to provide heating or cooling to the areas via individually controlled room units on the same refrigeration circuit.

7	Variable refrigerant air-conditioning-heat pump system shall be based on one modular outdoor air cooled condensing unit connected via a single refrigerant circuit comprising suction and liquid pipe work for indoor units and/or air handling units, of different types and capacities.

8	Refrigerant pipe work circuit shall be designed to satisfy the distance between the outdoor condensing unit and the farthest indoor unit and/or air- handling unit on the circuit and may 

	incorporate the level difference without the necessity for any oil traps.

9	Operation of the variable refrigerant air-conditioning-heat pump system shall permit either cooling or heating of each indoor unit or all of the indoor units serving a common room. Each indoor unit or group of indoor units shall be able to set temperature independently via a local remote controller, an Intelligent Controller, an Intelligent Manager and/or a BMS interface.

10	Outdoor Units base, frame, and casing shall be protected with a corrosion-resistant coating capable of withstanding a 1000-hour salt-spray test according to ASTM B 117.

11	Refrigerant Circuits:
	
	Refrigerant: R 410A or R 32.
	Refrigerant Compatibility: package units parts exposed to refrigerants shall be fully compatible with refrigerants, and pressure components shall be rated for refrigerant pressures.

	The units shall be fitted with all key components such as twin rotary Inverter or scroll Inverter compressor(s), electronic expansion valve(s), oil separator(s), suction accumulator, high pressure switches, inverter driven fan motors, safety thermostat, over current relay, inverter overload protection, fuses, necessary solenoid valves, liquid shutoff valves, gas line shut off valves, short re-cycling guard timer and all necessary sensors for optimized, safe and trouble free operation. Shall be fitted with an in built Earth Leakage protection.

12	Each outdoor unit shall have all inverter driven compressor(s) electronically controlled and capable of changing the speed linearly to follow the variations in cooling or heating load. 

13	The outdoor units having nominal capacity (10 TR) and above shall have a minimum of two compressors and able to operate even in case that one compressor is out of order.

14	The VRV / VRF system shall have the ability to sustain refrigerant piping lengths of up to 165m with a level difference up to 50m between indoor units and condensing unit if the outdoor unit is located above the highest level indoor unit. An option shall be available to increase the level difference of the pipe work to 90m between indoor units and condensing unit if the outdoor unit is located above the lowest level indoor unit. Manufacturer shall submit live computer model to check the pipe lengths.

15 	Electrical Power, The unit shall be provided with all necessary factory assembled terminal block where in the power supply should pass through a noise filter to DC reactor with safety device to protect from rush current to the inverter board for smooth linear compressor operation along with built in controls such as but not limited to H.P switches, HP&LP sensors, over current protection thermal switch, magnetic contactors for the compressors and fan motors.

16  Control
Standalone microprocessor control module as a standard product.
Factory built- in, in the outdoor unit control panel weather protected, with self –diagnostic function for easy reading and maintenance. A four – digit LCD display should give all service information, fault history and must constantly monitor all operation of respective outdoor and connected indoor units, room’s thermostats either in cooling or heating mode and interlocked with BMS. 
Enclosure:  Share enclosure with electrical power devices or provide a separate enclosure for remote mounting in the field.
Operator Interface:  Multiple-character digital or graphic display with dynamic update of information and with keypad or touch-sensitive display located on front of control enclosure.  In either imperial or metric units.
The Units controls and starters shall be housed in a weatherproof and dust proof enclosure with lockable door.  

17               Third party performance test
3rd party performance test report from accredited laboratories to be submitted as evidence of performance  @ 35 C, 46 C

18      Spare Parts List
	VRF (outdoor unit)	Qty	
1	Compressor Assy.	1 per model	
2	Compressor Capacitor	1per model if the total cooling capacity > 500 T.R	
3	Fan motor	1per model if the total cooling capacity > 500 T.R	
4	Fan Capacitor/ CMPSR	1per model if the total cooling capacity > 500 T.R	

Spare parts List could be amended according to the manufacturer recommendation and Engineer approval.
 
Tools and spare parts supplied under this clause shall be provided in original packing, clearly labelled and referenced.

Spare Parts furnished under this clause shall not be used during the maintenance period without the written permission of the owner (Contractor shall procure spare parts, tools etc., fulfill his obligations to operate and maintain the system in the contract period)

2.4	COMPRESSORS

	General
	
1	Compressors shall be tested and rated in accordance with ISO Standard 917 or equivalent and guaranteed to operate at published capacities.

2.4.1	Centrifugal Compressors

2	Shall be serviceable, hermetically sealed requiring no shaft seals, or required stages and consisting of the following:

3	Impeller

(a)	shall be made of non-ferrous, cast aluminium alloy or approved alloy or approved 

equivalent material

(b)	shall be dynamically and statically balanced after fabrication and tested minimum 25 %
overspeed

(c)	shall be sufficiently rigid to prevent any vibration at operating speed

(d)	The impeller operating speed shall be below first critical speed

(e)	Impellers shall be connected to the motor by a gear train or equivalent approval.

4	Casing

(a)	all external parts shall be constructed of steel, high-strength ductile iron casting or approved equivalent material
(b)	O-ring gaskets shall be used between casings

5	Lubrication System

(a)     shall  be  of  the  forced-feed type  and  shall  provide oil  at  the  proper temperature to all parts requiring lubrication

(b)     on   units   providing   forced-feed   lubrication   prior   to   starting,   a   differential  oil pressure cut-out interlocked with the compressor starting equipment shall allow the compressor to operate only when the required oil pressure is provided to the bearings

(c)	the lubrication system shall be complete with the following: (i)	pressure relief valves
(ii)	oil piping

(iii)	gauges

(iv)	thermometers

(v)	oil pressure switches

(vi)     oil cooler designed for use with chilled water, condenser water or directly cooled by refrigerant

(vii)	oil filter

(viii)	oil reservoir

(ix)     oil  heater,  of  a  size  to  prevent  oil  from  absorbing refrigerant during shut- down, thermostatically controlled. It shall not be required if the system is designed to prevent the refrigerant from contact with the oil and guaranteed not to absorb oil during prolonged shutdowns.

6	Capacity Control

(a)   the compressor shall be provided with temperature or pressure-actuated capacity reduction to the pre-rotation vane or suction damper type to provide automatic capacity modulation from 100 to 10 percent capacity

(b)     hot gas by-pass automatically controlled shall be provided if required to maintain stable operation.

7	Gear Transmission

(a)    the gear transmission shall be of the self-aligning type, having sufficient capacity to transmit the maximum compressor load under all operating conditions without objectionable noise or vibration

(b)     the gears shall be double helical type, and the teeth shall be continuously flooded with filtered oil

(b)	the bearings shall be of the pressure lubricated type, and suitable for both gears and pinions.

8	Motors

(a)    The motors shall be of the hermetically sealed, refrigerant-cooled type, the winding specifically insulated for use with refrigerant
(b)     The motors shall be designed for continuous operation at nameplate rating, provided with a load limit mechanism and solid state sensors in motor winding to provide positive thermal and current overload protection

(c)     The motor starter shall be contained in a weatherproof enclosure, completely pre-wired to the motor.

9	Lifting device

(a)	An eyebolt or approved equal device to permit lifting compressor shall be included:

2.4.2	Reciprocating Compressors

1	Clarification

(a)     reciprocating compressors may be of the open or semi-hermitic serviceable type, or of the welded hermetic type, with the motor and compressor contained within the same pressure vessel and the motor shall be in contact with the refrigerant

(b)     reciprocating compressors shall be capable of operating at partial load conditions a continuous operating down to the lowest step of unloading

(c)	reciprocating compressors shall be designed for use with a fluorocarbon refrigerant.

2	Drivers and Starters

(a)	open type compressor

(i)      open type compressor may be driven by an external motor, directly through a coupling or indirect through a belt-drive or gearbox. Starting of open type compressors shall be across the line or in accordance with the manufacturer’s recommendations.

(b)	hermetic type compressors

(i)      hermetic type compressors shall be direct driven by either a standard motor and across the line starter or a reduced voltage starter
(ii)      the motor insulation and rubber materials shall be compatible with refrigerant and oil mixtures.

3	Lubr

(a)	ication System

reciprocating compressors shall be provided with a forced feed lubrication system by	
		means of eccentric gear-pump, vane pump or piston pump. The lubrication pumps shall be equipped with bleed provisions on the discharge side to vent the pump and to prevent excessive pressures, and with a strainer or oil filter in the suction line	
	(b)	small reciprocating compressors may be lubricated by a splash. The crankcase shall be filled with oil up to the bottom of  the main bearings or  to the middle of the crankshaft main bearings. At each revolution the crankshaft or the eccentric shall splash the oil around the inside of the compressor.

	
4	Features: Reciprocating compressors shall be provided with the following features:- (a)	capacity control for unloaded start and noted capacity steps
(b)	suction strainer
(d)	hot gas muffler

(e)	replaceable bearings

(f)	suction and discharge stop valves

(g)	oil level sight-glass

(h)	suction and discharge refrigerant gas pressure gauges

(i)	high and low gas pressure adjustable safety control

(j)	vibration isolators

(k)	oil safety switch

2.4.3	Rotary Compressors 

1	Description

	(a)	rotary  compressors  shall  be  designed  and  rated  in  accordance  with  ASHRAE
recommendations or equivalent		
	(b)	rotary compressors used for household refrigerators , window type air conditioners using R-32 refrigerant or R-410 refrigerants shall be of the rolling piston or rotating vane type.	
	(c)	rotary  compressors  shall  be  designed  to  have  a  high  volumetric  efficiency  and an acceptable sound level, particularly where they are intended for use in homes	
	(d)	rotary  compressors  shall  have  a  rigidly  constructed  shaft  to  meet  deflection allowances and cast iron bearing with a hardened, steel journal rotary compressors shall have tow blades, designed for maximum reliability, and constructed to limit the deflection under load to no more than 0.05 mm per/m of blade length. The slots shall be hardened, steel journal	
	(e)	the journal shall be ground round and honed or polished	
	(f)	Rotary compressor shall be equipped with a check valve at the suction inlet to close automatically when the compressor stops to prevent high-pressure gas from migrating into the evaporator.	
2	Lubr	ication System	
	(a)	rotary compressors shall be provided with a good lubricating system to circulate an ample supply of clean oil to all working surfaces, bearings, blades, slots, and seal faces	
	(b)	oil grooves shall have outlets to permit free flow of the excess lubricant, and to flush particles into the sump.	

3	Drivers and Starters

(a)	rotary  compressors  shall  be  equipped  with  a  standard  split-phase  motor  or  a permanent split-capacitor motor in accordance with the manufacturer’s recommendations.

2.4.4 Scroll Inverter - Compressors  

1 Description
  Hermetically closed scroll type compressors used for VRF units using R 410 A or R32.    
The compressors should be equipped with the technology, providing the minimization or elimination of refrigerant backflow within the scroll structure al low load conditions.
The motor windings shall have specially constructed, in order to achieve the safe and smooth operation to avoid hazards due to the continuously changing of frequency and voltage. The compressors shall be protected by an electrical crankcase heater to prevent oil condensation at low ambient temperatures.
		
Compressors should be integrated sound absorbing jacket.
2 Lubrication 
The oil supply in the compressor will have to be on the high-pressure side, ensuring optimum lubrication of all moving parts. Therefor a separate lubrication system will not be required for the moving parts of the compressor, since the oil in the centre of the crankshaft will be transported across the surface of the rotating parts from the centre to the perimeter. This optimizes the performance of the compressor and minimizes stress and wear, extending its lifetime. The compressors’ motors will have a cooling system using compressed gas, to avoid sudden changes in temperature resulting in significant stresses on winding and bearings.
 Compressors will alter the rotation speed linearly and consume energy in accordance with cooling and heating loads, ensuring operational autonomy and independent temperature control in each room. DC inverter compressors shall vary their speed separately controlling the volumetric flow more accurately, with lower power consumption, resulting in higher efficiencies at all loads and connection ratios.
For protecting the compressor from frequent start-stops, provide an appropriate timer.

3 Motors 

DC inverter driven motor and be able to continuously change the frequency, resulting in a change motor RPM to the volumetric refrigerant flow from the compressor, in order to accurately and fast respond to the required load. The change in frequency should be done incrementally, but in enough steps so the change of delivered capacity can be approximated as linear. The minimum number of capacity steps will have to be no less than 100.

 2.4.5    Twin Rotary Inverter-Compressors:     

1  Description

Twin rotary compressors for air conditioners shall be hermetic type, utilising inverter drive technology.  The compressor shall be using R410 A / R 32 refrigerant. 
The rotary compressor shall have a rolling piston that makes an eccentric motion within a round cylinder and a vane that divides the compression chamber. The twin rotary compressor equipped with two compression cylinders, located 180 C from each other and DC brushless motor with the shaft in perfect balance ensure reduced vibration.
The connection of the compression chamber with the discharge port is made by opening the discharge valve, which is designed to open when the pressure within the compression chamber reaches a set level for discharge.  The compressor shall therefore have a varying compression ratio based on system load and should not be of a fixed design utilising mechanical reed valves to compensate for over compression issues during low load demand.
The twin rotary compressor shall be equipped with accumulator as part of itself to maximize the reliability. The compressor shall have ability to add a protection device such as thermal plug. 

2. Lubrication

The twin rotary compressor shall have a suitable lubricating system that enables the correct volume of oil to circulate freely to all working parts. 
The compressor shall have motor in the upper part and thereby can separate the oil in the discharge gas using centrifugal force of the motor to minimize the amount of oil circulating in the refrigeration cycle.
The lubrication (Synthetic) oil of the compressor shall be fed between rotors and cylinder, which ensures for maximum compressor efficiency and minimize wear & tear. It shall be easy to supply oil to the moving parts positioned at lower portion of the compressor. 
There shall be an oil detection circuit in both singular and modular systems.
A crankcase heater(s) shall be factory mounted on the compressor(s).

3. Motor

The twin rotary compressor shall have a DC brushless motor with neodymium rare earth permanent magnet and a concentrated type stator.
Electrical insulation classification of the motors shall be class “E” type.
DC inverter drive motor shall be able to make changes in real time to the operational HZ in increments of 2Hz, in order to accurately and quickly respond to the required load. The change of frequency shall be done incrementally, but enough steps so the change of delivered capacity can be approximately linear. The minimum number of capacity steps will have to be no less than 100 or equivalent to achieve required part load efficiently.

2.4.6	Scroll Compressors      

1	Description

	(a)	Fully hermetic scroll type compressors, designed and  rated  in  accordance  with  ASHRAE recommendations or equivalent.		
	(b)	Scroll compressors used for package and split air conditioners , using R-407C refrigerant , R-410 refrigerants , R134A or R32.
	
	(c)	Suction gas-cooled hermetic scroll low sound superior efficiency compressor

	
	(d)	Design of high precision, high acceleration capability bearings with low friction & low heat generation; and cast-iron housing for better compressor alignment. 	
	(e)	Compressor shall be equipped with operating oil charge, crank case heater, crank case oil sight glass, inherent motor protector, and short cycling delay timer protection	
2	Lubr	ication System	
	(a)	Scroll compressors shall be provided with a good lubricating system to circulate an ample supply of clean oil to all working surfaces, bearings, blades, slots, and seal faces	

3	Drivers and Starters

(a)	A fully hermetic, 100% suction gas-cooled, squirrel cage induction motor drive.

(b)	Direct drive compressor, 2900 rpm (50power supply cycle). Motor shall be protected by internal thermal protection.

2.4.7	Screw Compressors             

1 Description

Screw type Semi-hermetic compressors used for household refrigerators R 134A. Compressors shall be equipped with a discharge valve as part of the compressor.

Compressors shall start unloaded with the unit microprocessor to load the compressor to match the system load.

Compressor shall have an Oil level switch, high efficiency suction strainer, crank case heater. 

Capacity control shall utilize an infinitely step less modulating slide valve for chiller below 250TR and VFD/Inverter for chillers above 250TR to modulate capacity to match load requirements. Each compressor should have its own VFD/Inverter

Compressor shall be supported by rubber in shear vibration isolators and provided with ample space around it for service and removal.

Compressor shall be equipped with a built-in low-pressure protection through a pressure transmitter connected to unit controller.

Single or Double walled pressure compensated rotor housing, which is extremely stable and results in additional sound attenuation.

 
2 Lubrication

Optimized oil management with built-in directly flanged on integral mesh or cyclonic type oil separator.

Pressure relieved bearing chamber ensures minimum refrigerant dilution in the oil.

3 Motor 
Direct drive Compressor, suction gas cooled 2 pole motor. Motor shall be protected by a solid-state motor protector feeding from imbedded motor temperature sensors on all three phases.

Large volume motor suitable for solid state soft starter for chillers below 250TR or VFD/Inverter for chillers above 250TR with integrated embedded sensors in each winding.

Intelligent electronics including thermal motor temperature monitoring, phase sequence monitoring, manual reset lock-out and discharge temperature.

2.5.1 Air Cooled Condenser

2.5	CONDENSERS 

1	Air-cooled condenser shall be rated to AHRI Standard or equivalent and guaranteed to operate at published capacities.

2	Air-cooled condenser shall be suitable for remote installation for computer room D.X system  in a weather protected casing, or for use with self-contained air conditioners.

3	The air-cooled condenser shall be a complete factory-fabricated and factory assembled unit consisting of the following:

4	Coils shall be as follows:

(a)	The tubes shall be Seamless copper

(b)	The fins: shall be Aluminum

(c)	Condenser coils for installation in salt air or corrosive atmosphere shall be constructed of copper tubes and aluminum fins with galvanized steel end sheets. Alternatively the condenser coils shall be provided with protective coating as specified. (Such as copper tube / copper fins).
	
(d)	Condenser Coating: 

Units that will be installed at a distance of 2000 meters from the sea or less shall be protected with high quality post dipped coating such as heresite / Blygold / Fingaurd / Electrofin / E-Kote coating or equivalent to ensure complete coverage of all coil and tube surfaces. Post dipped coating to be complete with five years special warranty from supplier. 
Fins with coating process shall achieve and pass Neutral salt spray test for 5000 Hrs for chillers and 3000 Hrs for D.X systems according to ASTM Standard.

Units that will be installed at a distance 2000 up to 5000 meters from the sea shall be protected with high quality post dipped coating such as heresite / Blygold / Fingaurd / Electrofin coating / E-Kote or equivalent to ensure complete coverage of all coil and tube surfaces. Post dipped coating to be complete with five years special warranty from supplier. 
Fins with coating process shall achieve and pass Neutral salt spray test for 3000 Hrs for chillers and 1000 Hrs for D.X systems according to ASTM Standard.

Units that will be installed at a distance more than 5000 meters from the sea shall be protected with high quality pre coating such as polyurethane fins / Hydrophilic fin / Gold fin / Blue fins or equivalent.
Pre coating shall achieve and pass Neutral salt spray test for 500 Hrs according to ASTM Standard.

Exception : Condenser for window units and split units installed at a distance less than  5000 meters from the sea shall be protected with high quality pre coating such as polyurethane fins or equivalent

black color coatings are not acceptable unless Test of Black coating @ Radiation Temperature 80 oC during June and August or equivalent to confirm units able to operate in case of standby and start up 11 AM up to 12 PM  

5	Fans

(a)   propeller type or centrifugal type directly connected to the motor shaft with a fan guard. 

(b)	fans shall be statically and dynamically balanced

6	The Housing shall consist of:

(a)	the frame and supports shall be constructed of galvanized angle iron

(b)	the casing shall be constructed of hot dip galvanized steel

(c)	vibration isolators

7	EC Motors
	
(a)     totally enclosed, fan-cooled or TEAO for all installations where motor is exposed to the weather or in an air stream.

(b)	open drip-proof type within an enclosure to be fully protected from the weather

(c)	thermal protection shall be of the manual or automatic reset type

8	Condenser Controls. One of the following methods of controlling condensing temperature shall be provided:

(a)	air volume control

(i)    thermostat or pressure switch type with a control relay shall be provided to modulate fan discharge dampers and maintain adjustable pre-set refrigerant condensing temperatures

(ii)      a solid state variable speed fan motor controller may be provided in lieu of volume dampers to control the airflow over the coil

(iii)     a condenser with multiple fans may be provided with a fan cycling control to cycle one of two, or two of three fans act in response to outdoor ambient temperatures.

(b)     condenser  flooding.  On  a  decrease  in  refrigerant  discharge  pressure,  a  head pressure sensitive valve shall start to throttle the liquid flow from the condenser outlet and thereby increase the amount of liquid in the condenser. The liquid leaving the condenser shall be reheated by hot gas to increase the temperature of the sub-cooled liquid sufficiently to maintain a balanced pressure temperature relationship in the receiver.

9	Liquid Receiver or equivalent approval 

A liquid receiver of a minimum capacity of 125 % of the refrigerant charge shall be supplied and connected to the refrigerant circuit, complete with

(a)     inlet and outlet service valves

(b)     charging connections

(c)     relief valve

An air-cooled condenser may be used for refrigerant storage in lieu of separate receiver, provided that the condenser storage capacity is 20 percent in excess of the fully charged system.

2.5.2	Water Cooled Condenser

1	Water cooled condenser shall be rated in accordance with AHRI Standard 450 , ASME Construction Standard or equivalent and guaranteed to operation at published capacities. Fouling factor shall be a minimum of 0.00025 in accordance with AHRI Standard 550.

2	Shells and Tubes

(a)	the welded steel shells and copper tubes shall be rolled into grooved holes in tube sheets

(b)	the  tube  shall  be  removable without  affecting  tube  sheet  or  causing  leakage  of adjacent tubes

(c)	the  tube  sheets shall be  made of  carbon steel suitable for withstanding working pressure

(d)     intermediate tube sheet supports shall be installed prevent tube vibration.

3	Water Boxes

(a)	the water boxes shall be made of high grade carbon steel or material of equivalent strength and suitable for the specified pressure

(b)	water boxes shall have the following: (i)	separable cover with eyebolt (ii)	vent and drain connections
(iii)	connected to shell in a manner to prevent shell exposure to water

(iv)	grooved suitable for Victaulic connection / flanged water nozzles for main piping connections

(v)	tappings for thermometers, control bulbs and gauges

(vi)	piping connections shall be arranged to permit cleaning without removing the piping.

4	Baffles

(a)	to prevent direct impingement of refrigerant gases upon tubes

(b)	to uniformly distributes gas refrigerant over length of condenser

(c)	non-corrodible  baffle  sheet  to  segregate  and  collect  non-condensable  gases  for compression purging. Purge connections non-corrodible materials

(d)	purge and recovery unit connection to remove non-condensable gases and water vapour.

5	Condenser Controls capacity control by means of restricting water flow through condenser using one of the following two methods.

(a)	two-way	throttling	valve	to	maintain	condensing	pressure	in	once-through applications utilising city or well water

(b)	three-way valve to direct water around the condenser as the condensing  temperature is lowered. This system is most often used with a cooling tower.

2.5.3	Evaporative Condensers

(a)	draw   through   or   blow-through   type   sized   and   installed   in   accordance   with
ASHRAE recommendations consisting of the following:

(i)	galvanized steel casing and basin with overflow and drain connection

(ii)	frame made of angle iron

(iii)	removable galvanized steel eliminators

(iv)	access panels of adequate size for maintenance

(v)	make-up water float valve

(vi)     fan with adjustable pitch belt drive with belt guard and weather protection cover for motor.  Fan shaft shall be epoxy coated, zinc chromatised or approved equal finish

(vii)    condensing coil with a liquid sub-cooler made of hot-dip galvanized steel, copper tubing or iron pipe

(viii)	recirculating pump factory installed and piped to bronze non-clog spray nozzles

(ix)	galvanized steel piping

(x)	flanged collars for duct connections for indoor installations

(xi)	water bleed system

(xii)    capacity control can be obtained as a modulating discharge damper to vary air flow across the coil or a multi-speed fan motor to vary airflow across the coil.

2.5.4	Dual Condensing

1	Dual condensing systems shall consist of a heat rejection and an auxiliary heat recovery condenser to extract heat from refrigerant and reject some of that heat to a warm circuit.

2	Heat  Rejection Condenser. The  heat  rejection  condenser shall  be  of  the  water-cooled condenser type, as described in clause 2.9 or of the air-cooled condenser type as described in the Clause 2.8.

3	Heat  recovery  Condenser.  The  heat  rejection  condenser  shall  be  of  the  water-cooled condenser type as described in Clause 2.9.

2.6	COOLER

2.6.1	General

1	Cooler shall be designed and rated in accordance with AHRI Standard 480.

2	Shell and tube type and performance is based on a fouling factor to 0.0000176 for non-ferrous tubes, and 0.000176 for steel tubes, consisting of the following:-

3	Shells and Tubes see Clause 2.9.2.

4	Water Boxes

(a)     water   boxes   made   on   high-grade   carbon   steel   or   material   or   equivalent strength suitable for specified pressure, provided at each end for an odd number of passes and one end for an even

(b)	water boxes shall have the following specifications : See Clause 2.9.3.

5	Baffles

(a)	to prevent direct impingement of liquid on tubes

(b)	to distribute liquid refrigerant uniformly.

6	Eliminators

(a)	non-ferrous

(b)	to prevent liquid refrigerant from entering compressor.

7	Anti-freeze thermostat

8	Insulation with a vapour barrier

2.7	COOLING TOWERS

2.7.1	General

1	Cooling  towers  shall  be  designed,  constructed and  rated  in  accordance with  ASHRAE Recommendation 21 - Equipment.

2	Field-assembled  Cooling  Towers.  Filed  assembled  cooling  towers  shall  consist  of  the following :

3	Framework

(a)     Steel   framework   bolted,   reinforced  and   interconnected  so   that   stresses  are transmitted directly to the tower foundation
(b)	Bolts, nuts, washers and corners shall be made of hot-dipped galvanized steel

(c)     Roof  framing  designed  for  additional  loads  of  fan,  fan  motors,  gear-reducer  if required, fan-casing, and other loads during erection or normal operation.

4	Casing.  Casing shall be water and-air tight made heavy duty FRP section.

6	Partitions

(a)	full height of tower

(b)	water and air tight

7	Water Distribution

(a)	distribution system for each cell.

(b)	header system with branches, spray arm and nozzles.

(c)	nozzles made of non-clogging cast bronze or polyethylene type.

8	Collection Basin

(a)     concrete basins

(b)	overflow and cleanaout

(c)	drain connector.

9	Access. To fan deck, gear and fan, water distribution area and basin.

10	Fans

(a)	propeller type with adjustable pulley

(b)     gear  speed  reducer,  if  required,  with  a  stainless  steel  shaft,  flexible  coupling and extension pipe to permit filling, draining and sampling of the oil level out-side fan housing with an oil sight-glass

(c)	totally enclosed fan cooled type motor

(d)	removable wire screen, hot-dipped galvanized steel.

11	Vibration Eliminators. Vibration eliminators with an isolation efficiency of a minimum of 70 percent.

12	Corrosion Protection. Interior and exterior corrosion protection coating and lining.

13	Eliminators.  Removable  made  of  asbestos  neoprene  honeycomb  or  approved  equal materials, and supported by galvanized steel channel sections.

14	Fill Material. Made of polyvinyl chloride film-type or approved equal materials supported at close centres by galvanized steel structural members.
15	Bleed-off and Make-up Water. The cooling tower shall be provided with a controlled bleed-off feature to minimise scale formation and to inhibit corrosion and with a make-up water connection controlled by a large-diameter seamless type copper float to maintain automatically the water level in the sump at a predetermined level.

2.8	PACKAGE COOLING TOWERS

2.8.1	General

1	Package cooling towers shall be factory-assembled of the counterflow or crossflow  through design, with centrifugal or propeller fan assemblies built completely into the pan, with all moving parts factory-mounted and aligned. 
                Cooling tower can be factory or site assembled (knock down) for cooling towers exceeds 1000 TR 
               The packaged cooling tower shall consist of the following:

2	Pan Section

(a)     the  pan  section shall  consist of  a  steel  framework  and  a  sloped stainless steel 316 L or equivalent .

(b)     the  pan  section  shall  be  provided  with  access  door,  stainless  steel  strainer with perforated openings smaller than spray nozzle orifices, waste water bleed-off line with valve, and a make-up valve with a large diameter float arranged for easy adjustment.

3	Fan Assembly

(a)     the  fan    shall  be  of  the  propeller  or  centrifugal  type.  The  housing  of  the  fan shall have compound curve inlet rings for efficient air entry and a discharge cover within the pan to prevent water from entering the fan

(b)     the   fan   shaft   shall   be   mounted   in   heavy-duty,   grease-packed,   self-aligning ball bearings

(c)     Direct drive with gear box is required or equivalent  V-belt   drives   shall   be   designed   for   not   less   than   150   percent   of   motor nameplate horsepower. Drives and all moving parts shall be completely enclosed by removable screens made of stainless steel or hot-dipped galvanized steel.

4	Surface Section

(a)     the  heat  transfer  section  shall  be  removable  from  the  pan  made  of  stainless steel 316 L for units that will be installed at a distance more than 8000 meters from the sea or other approved material supported such as coated hot deep galvanized  steel frame for units that will be installed at a distance less than 8000 meters from the sea, and waveformed or honeycomb in shape for optimum heat transfer.

5	Water Distribution

(a)     water distribution shall be evenly spread over the tower’s fill area through gravity or sprayhead tree, consisting of stainless-steel 316 L header and removable branches with replaceable spray nozzles made of plastic or approved equal materials. The nozzles shall be held in place with snap-in rubber grommets to provide quick removal of individual nozzles or branches for cleaning or flushing.

6	Eliminators

(a)     eliminators  shall  be  removable  in  easily  handled  sections  made  of  stainless steel or other approved material.

7	Fan Motors

(a)	fan motors shall be of the encapsulated epoxy-insulated drip-proof type.

8	Quality Assurance 

Certified by CTI Standard STD 201 and/or in accordance with C.T.I. performance test Code C.T.I. ATC-105. 

Cooling tower thermal performance according to CTI STD 201, "Certification Standard for Commercial Water-Cooling Towers Thermal Performance."

2.9	REFRIGERATION ACCESSORIES

1	Combination filter with a dryer in the refrigerant line, so arranged that cartridges can be replaced when the refrigerant circuit is changed.

2	Combination sight-glass and moisture indicator.

3	Solenoid valve in the refrigerant line and in the oil bleeder lines from flooded evaporators.

4	Expansion valve on refrigerant line at coil inlet with the bulb located immediately after the coil outlet.

5	Strainer in suction line on steel piping systems to protect pressure-regulating devices.

6	Strainer in refrigerant line to protect expansion valve.

7	Refrigerant charging connection in the liquid line.

8	Liquid suction interchange in the liquid line.

9	Muffler in the hot-gas line in the downward flow risers or in the horizontal lines near the compressor.

10	Oil trap (separator) in the discharge line.

2.10	MISCELLANEOUS

2.10.1	Water Chemical Treatment

1	After preliminary design, the Contractor shall submit to the Supervising Agency a complete analysis of local water or actual water samples at the site. This information shall be accompanied by a description of each system to be treated with anticipated make-up rates and other available data.

2	Make-up rates of chemicals and water quality requirements for each system shall be in accordance with the ASHRAE recommendations and the chemical analysis.

3	Water Treatment Firm

(a)	the Contractor shall engage a water treatment firm which shall : (i)	supervise installation and application of water treatment
(ii)      supply  required  treatment  chemicals  and  instructions  for  application  and control of initial cleaning of all piping systems

(iii)	supply testing equipment and reagent

(iv)     instruct the Contractor on installation of chemical feeding equipment before start-up

(v)     demonstrate  the  proper  application  of  treatment  materials  to  be  used, operation of feeding equipment as installed and operation of testing equipment required

(vi)     collect  samples  of  each  treated  system  for  analysis  at  laboratory  and submit result, with comments

(vii)    provide   written   proposals   detailing   services   to   be   performed   for   an extended service period of one year from date of start-up.

4	Condenser Water System

(a)     chemicals.      Selection  of   treatment  chemicals  for   the   cooling  tower   system shall  be  based  upon  characteristics  and  solids  content  of  make-up  water  as follows :

(i)      chemical  formulation to control corrosion and scale as directed by raw water analysis or sea water analysis where applicable and equipment operating conditions, is to be introduced to system through automatic treatment equipment

(ii)     this formulation shall be a non-metallic blend of corrosion and scale inhibitors capable of producing desired treatment results without supplementary acid feed

(iii)    biological fouling liquid formulation as dictated by water analysis and local environmental conditions to be slug-fed to system

(iv)     cycles of concentration are to be maintained at a level consistent with raw water analysis and operating conditions

(v)     biocides shall be added if  significant amount of algae or slime are detected after system operation. Compounds of mercury, copper or arsenic are not permitted.

(b)	Equipment

(i)      diaphragm chemical proportioning pump shall be furnished to pump algae inhibitors.  The pump shall include suction strainer, check valve and associated piping including corporation stop injection assembly

(ii)      water meter shall be located in the cooling tower make-up line and shall be sized for combined peak flow of evaporation and bleed-off

(iii)     automatic re-set timer unit and counter-unit shall be assembled as a package to modulate chemical feed and bleed in proportion to tower make-up water

(iv)	a solenoid bleed valve and Y-strainer shall be furnished.

5	Chilled Water System

(a)     Chemicals. Treatment shall consist of a buffered nitride-based product, maintained in circulating water systems at 700 - 1000 PPM sodium nitride.

(b)     Equipment. By-pass chemical pot feeders, consisting of cast iron and steel body, easy to fill.

2.10.2	Water Softeners

1	Water softeners shall be fully automatic downflow, pressure-type water softeners, having capacities as indicated in the Project Documentation.

2	Piping.  Piping shall be copper tubing with brass or wrought copper solder joint fittings, or as required in the Project Documentation.

3	Tank

(a)    softener tank shall be made of riveted or welded stainless steel construction in accordance with the relevant ISO Standards and/or ASME Code

(b)     the shell shall be designed and tested at 50 percent greater pressure than the working pressure

(c)     the tank and both sides of false bottoms shall be lined with plastic, rubber or equivalent corrosion-resistant material

(d)	upper head and lower side of each tank shall be provided with access openings.

4	Collector System

(a)     a suitable device shall be provided within the softener tank for collecting softened water and distributing wash water. The device shall be deflector-plate type, or false- bottom type, or other approved equal type

(b)     the underdrain system shall distribute the backwash water in a manner that will not cause channelling of the gravel and exchange material.

5	Deflector-plate Type

(a)     the deflector-plate type collector shall be made of cast iron, or corrosion-resistant steel, securely fastened to the bottom of  the tank and arranged for discharge around the circumstance of the plate or through radial slots in the plate. The deflector-plate type require a gravel bed

(b)     pipe connection for softened-water outlet or backwash inlet shall be on the underside between deflector and tank bottom.

6	False-bottom Type

(a)     the false-bottom type collector shall consist of a false bottom with strainers attached thereto and therefore does not require a gravel bed.

(b)	strainers and fasteners shall be made of corrosion-resistant metal.

7	Gravel Bed

(a)     the gravel supporting bed shall be placed immediately above the underdrain system of all types except the false-bottom type collector

(b)	the gravel shall be washed and free from any foreign materials

(c)     the gravel bed shall be properly graded to prevent loss of exchange material during normal operation and back-washing.

8	Exchange Material

(a)     exchange material shall be quartz sand, washed, processed and not less than 0.35 mm in size and with uniformity coefficient not higher than 1.2

(b)     exchange material shall not require dosing or adding of any chemical mixture or solution to the water to be treated or to the water used for back-washing or regeneration other than common salt, NaCI.

9	Brine-storage Tank

(a)     one brine-storage tank shall be provided for each water softening unit, made of steel, reinforced and lined with enamel or other approved brine-resistant material, provided with an automatic, float-controlled water control valve, located in an independent float chamber, inside the tank.

END OF PART