DETAILED TENDER SPECIFICATIONS

“SUPPLY, INSTALLATION, TESTING AND COMMISSIONING OF PRECISION AIR

CONDITIONING SYSTEM FOR NEW PROPOSED TEM ROOM AT NZFP LAB BUILDING

AT NFC , HYDERABAD.”

1.0 General

1.1 These specifications cover supply, installation of Ducting, insulation, false ceiling, Supply,

Installation and Commissioning of PAC units at NFC, Hyderabad.

1.2 All items mentioned in these specifications shall be complete in all respects and any

component or, equipment not covered here but essential for proper design, operation

and maintenance shall be brought to the notice and included by the tenderer. The

successful tenderer shall take full responsibility for the guaranteed operation of the

system, as regards performance/reliability etc.

1.3 No foreign exchange or, import license for importing equipments, components, spares

or, raw materials against these specifications will be arranged or, provided by the

department. It shall be the responsibility of the tenderer for the supply of materials

from Indian and foreign sources as the case may be, and execute the contract within the

agreed time schedule. In case, the offer involves expenditure in foreign exchange this

fact shall be clearly indicated by the tenderer together with a statement as to how this

will be arranged by the tenderer.

1.4 Where found necessary, the department reserves the right to select reputed

manufacturers for any of the items, in the interest of the standardization, and therefore,

the successful tenderer shall supply the same of the particular make, if so required. It

may be noted that the items of supply included in the scope of this tender shall be of

standard make, or from reputed manufacturers subject to approval of the department.

1.5 The Nuclear Fuel Complex area slopes from the ridge of hills on the west towards the

east, the levels dropping by about 11 M in distance of 400 M. The altitude above MSL is

around 538 M.

2.0 Standards

2.1 Unless otherwise specified, the equipments/components shall be designed, assembled,

erected and tested in accordance with the relevant IS codes published by the Bureau of

Indian Standards, wherever available, in order that specific aspects under Indian

conditions are taken care of. In case, where suitable Indian standards are not available,

the item(s) shall conform to the generally accepted codes and practices.

2.2 The electrical equipments & installation shall also conform to the latest Indian Electricity

Rules, as regards safety, earthling and essential provisions specified therein for

installation and operation of electrical equipments.

2.3 All the items included in the scope of this tender shall comply with the statutory

requirements (if any) of the Government of India as well as the Government of Andhra

Pradesh. The entire equipment & installation shall also conform to the provisions of

statutory and other regulations in force, such as the Indian Factories Act, Indian

Explosives Regulations etc., whichever may be relevant to the items of works called for

in this tender. The successful tenderer at no extra cost, if so required, shall arrange

approval on drawings and/or, installation by the statutory authorities.

2.4 In case, where the offer deviates from the specified standards, the tenderer shall

indicate clearly in his offer the standards proposed to be adopted by him along with the

details thereof.

3.0 Workmanship

3.1 All items covered in the specifications shall be manufactured from the best materials

under first class workmanship.

4.0 Lubrication

4.1 All equipments shall be provided with efficient lubrication arrangement so that bearings

and other parts are not subjected to under wear and tear. Sufficient lubrication point

shall be provided, wherever necessary and all such points shall be easily accessible. The

tenderer shall indicate the name of the lubricant and quantity required thereof for a

period of one (1) year.

5.0 Safety

5.1 All moving and exposed parts shall be adequately guarded to prevent accidents to the

operators and other working in the vicinity.

5.2 The successful tenderer (i.e., the contractor) shall undertake to bear the primary

responsibility for the safety of the contract labourers and others who shall accompany

them (including children). The contractor shall have to make necessary arrangements

to ensure their safety. The successful tenderer, immediately after awarding the contract

shall, therefore, furnish a written undertaken to the department to that effect.

5.3 The contractor shall ensure completion of the entire work under safe working

conditions, as per “SAFETY CODE” prevailing at NFC.

6.0 Utilities

Power Supply: Three phase, 415/240 V, AC 50 Hz power supply will be available.

7.0 Miscellaneous:

Work related minor civil works, as may be required for erection of ducting etc. shall be

carried out by the contractor, e.g., making openings for duct passage, drilling, ,

chipping/grouting and making good after erection, etc.

7.1. Salient features or, brief description of the proposed AC works (including its objective):

As mentioned earlier, the proposed AC works comprises a) Supply ,Installation and

Commissioning of PAC units at required location. b) Supply and erection of air

distribution system including thermal insulation/ acoustic insulation which shall comply

to ASHRAE stnds. A brief sketch of Proposed TEM room, PAC plant room, duct layout is

also enclosed in line drg. Tenderer is requested to take care for proper selection of

materials & Machinery where ever not indicated.

7.2 Technical Specification for Precision Air Conditioning

1) Technical requirements of Precession AC is given under Section-A.

2) The precision AC unit has to cater necessary ambient atmospheric requirement of a

sensitive equipment fixed in TEM room having dimensions of 5.5 x 6 x 5.5. The required

environmental conditions for the TEM room are mentioned below:

Recommended indoor DB temperature 20°C

Allowable temperature change 20 ± 1°C

Allowable rate of change of

temperature

0.5°C/hr

Relative humidity at 20°C 45± 5 % , dew point should be below

18°C

Allowable speed of Air flow near the

supply air grill

25 m/min

Outdoor Conditions Should be considered as per NBC-2005

considering 0.4% annual cumulative

frequency for Hyderabad climate.

Air speed near TEM < 5 mts/min

3) The PAC has to run round the clock during complete year while maintaining above

environmental condition. Bidder is responsible for meeting these cooling requirements.

4) The PAC will be top discharge, I-COM control, 10TR sensible cooling capacity, 10000

cmh volumetric air flow capacity.

5) The unit shall have a redundancy of 1+1 i.e. 1 unit will be working while another will be

stand by.

6) Any down time in the PAC affecting the availability of equipment shall be considered

critical and liable to cause imposition of penalty & Rs.5000 per day. The penalty shall be

deducted from remaining invoices. The maximum value of penalty shall not exceed 5%

of the total contract value.

7) If the availability of the PAC is continuously below 75% over a period of 1 month, NFC

has right to terminate the contract in full without any cost implications.

8) The entire system requires 5 year comprehensive onsite maintenance (COM) support

after completion of 1 year guarantee period inclusive of all labor, spare parts,

consumables ,materials etc . COM also consist of diagnose of faults & rectify/repair and

replacement of faulty hardware/software units, parts, accessories , carrying out

preventive maintenance as per schedule, refrigerant charging etc . Pl refer Section C for

details.

9) The vendor shall have support centre in Hyderabad. The vendor shall furnish names,

locations, complete postal address, telephone numbers and FAX numbers of all technical

support centre after commissioning of PAC. Apart from that the bidder should meet the

following supporting requirement.

Service window 24*7

Telephone support 24*7

Response time: Onsite On call 24 hrs

Resolution 48 hrs

Spare turnaround time 48 hrs

10) The vendor shall ensure that a minimum stock of critical spare parts/units of the system

are maintained as spare stock at the site along with the spare parts list and

specifications.

7.3 TECHNICAL SPECIFICATION FOR THE OTHER ITEMS

INSULATION ON SHEET METAL DUCTING

The thickness of insulation used on ducting shall be as detailed below:

Insulated with 16 mm thick closed cell nitrile foam /cross linked polyethylene duly covered with

prelaminated Aluminum foil as vapor barrier tightly around the outer surface of ducting and

firmly tightened with wire straps. Nitrile foam should be self adhesive. the “k” value should not

exceed .034w/m°C and should be stable. The insulation should be fire retardant as per

standards and codes. All gaps and joints should be properly sealed using self adhesive aluminum

sealing tape.

The application of insulation should be carried out in workman like manner as detailed below

a) Duct surface to be cleaned thoroughly

b) To apply two coats of adhesive Compound.

c) To fix factory aluminum covered self adhesive type cross linked polyethylene/Nitrile

insulation of specified thickness and to be firmly tightened using wire straps.

d) Fix self-adhesive aluminum tape of 50 mm width on all longitudinal / Transverse

joints.

e) Finally fix PVC straps of 19mm width at every 300mm centre to centre.

ACOUSTIC LINING OF DUCT

The material to be used for duct lining shall be 15mm thick microban insulation with open

cell structure, 16 mm thick Armaround insulation .047W/mK thermal conduction, fire

retardent”O” class , resistant to chemical and microorganism and sound absorption of

class –D.

FALSE CEILING (CALCIUM SILICATE)

Providing and Fixing AEROLITE Light weight Calcium Silicate Ceiling Tiles – Tegular Edge of Texture-

QUADRA/FINE FISSURED/COSMOS OR any other design/pattern of size 595x595mm, having 100% RH –

HUMIDITY RESISTANCE, and Fire Performance - Incombustible as per BS 476, part 4, Noise Reduction

Coefficient of 0.15, sound attenuation of 32dB, Light reflectance above 85%, density of 450 Kg/m3,

Thermal Conductivity of 0.043 W/mo kC, to be laid on true horizontal level 24 mm exposed hot dipped

galvanized steel powder coated sections comprising of main ‘T’ runner suitably spaced at joints to get

required length and of size 3.6mtrx38mmx 24mm made of 0.33mm thick sheet spaced at 1200mm centre

and cross ‘T’ of size 1.2mtr x 30 24mm made of 0.254mm thick sheet, 1200mm long spaced between

main ‘T’ at 600mm centre to centre to form a grid of 600x1200mm and secondary cross ‘T’ of size

0.6mtrx30x24mm made of 0.254mm thick sheet to be interlocked at middle of the600x1200mm panel to

form grids of 600x600mm. The wall angle shall be 3.0mtrx22x0.457mm to be fixed all around the wall.

Main ‘T’ runners to be suspended from the ceiling using GI slotted cleats fixed to ceiling with 6mm dia.

And 50mm long dash fasteners, 4mm GI adjustable rods with galvanized level clips spaced at 1200mm

centre to centre along main ‘T’ , bottom exposed width of 24mm of all T- sections shall be pre-painted

with polyester paint, all complete at all heights as per specifications and drawings as directed by

Engineer-In-charge.

REFRIGERANT PIPING & INSULATION:

All refrigerant piping shall be in hard drawn high grade copper (18 Gauga) including all

connections. Tees, reducers, etc., required no.s of Refrigerant joints with insulation should be

provided for uniform flow of refrigerant through all indoor units. All refrigerant piping shall be

insulate with suitable thickness of closed cell elastomeric thermal insulation material. All joints

on the insulation should be sealed with good quality sticking compound. All joints should be

covered with 2” wide aluminum tape. Entire refrigerant piping inside the building should be

installed on the wall / ceiling with proper clamping arrangement and refrigerant piping out side

the building (i.e., on terrace, shafts) should be properly clamped on MS / GI brackets on the wall

of duct / shaft. Sufficient valving shall be included to allow compressor/s to be removed for

service & to allow the refrigerant to be pumped in to and contained in the condenser. The unit

shall be equipped with a liquid line shut off valve, filter drier, liquid line sight glass, and solenoid

valve & insulation where required to prevent condensation forming.

7.4 Ducting

SCOPE:

The scope of this section comprises the fabrication , installation, testing, air balancing and

commissioning of GI sheet metal supply and return air ducts .

Material:

The duct shall be 20 gauge , Galvanized steel sheet.

Ducts above 1250 mm width shall be suitably supported by MS angle. The duct support hangers

shall be made out of 16mm dia rod . the down rod shall have threading on end and bend hook

on the other end. The threading shall be made by die block/lathe.

Installation:

The duct fabrication and installation shall confirm to IS 655-1963(Revised). The contractor shall

provide and neatly erect all sheet metal work according to requirement to carry out intent of

these specifications and drawings and this work shall meet with the approval of the engineer in

all its parts and details. All necessary allowances and provisions shall be made by the Contractor

for beams, pipes, or other obstructions in the buildings, whether or not the same are shown on

the drawings. Where necessary to avoid beams or other structural work or plumbing or other

pipes or conduits, the ducts shall be transformed, divided or curved to one side, the required

area being maintained, all as approved or directed by the Engineer.

All metal work in dead or furred down spaces shall be erected in time to avoid delay

to other contractors on the building. Ducting over false ceiling shall be supported from the slab above, from beams. In no case shall a duct be supported from the ceiling hangers or be permitted to rest on a false ceiling.

If a duct cannot be run as shown on the drawings, the Contractor shall install one duct between the required points by any path available, subject to the approval of the Engineer. All ducts shall be rigid and adequately supported and braced wherever required with standing

beams, tees or angles or sample size to keep the duct true to shape and to prevent buckling, vibration or breathing. All joints shall be made tight and all interior surfaces shall be smooth. Bends shall be made with

radius not less than one half of the width of the duct or with scientifically designed interior

curved vanes, as approved. The vanes shall be so spaced that the aspect ratio of each of the

individual elbows formed by the vanes will be about five. Where metal ducts or sleeves terminate in brick or masonry openings, tight joints shall be made by means of closely fitting heavy flanged collars.

7.5 MS Supporting structure:

Ducting supports shall be designed to carry weight of ducts. The drg. shall be

submitted for approval for its load carrying capacity. For the duct supports trusses shall have

to be provided. It may please be noted that the duct support for road crossing shall be

erected at a ht of approx 6 mts. Necessary safety appliances and safety permit shall be taken

by the contractor. The painting shall be done as per the clause under painting.

7.6 DAMPERS :

Dampers shall be manufactured using the same materials as the ductwork. Round

dampers shall be single butterfly blade type, rectangular dampers shall be parallel blade

type. All dampers shall be designed for 30 inches WC pressure differential. Blade shaft shall

be designed to provide a 10:1 safety factor for operating torque requirements.

Leakage shall not exceed 3 cfm per square foot at 12” wc or 5.25 cfm per square foot at 30”

wc as required in this specification for isolation

7.7 A) VOLUME CONTROL DAMPERS (VCDs)

7.7.A! VCDs shall be fabricated of minimum thickness specified and shall be of robust

construction. VCDs shall be of single blade type for round duct and opposed blade

type for rectangular duct. VCDs shall have a locking device mounted outside the

duct to hold the VCDs in a fixed position without vibration. Fully open and fully

closed position shall be marked for easier operation of VCDs.

7.7.A2 VCDs shall be provided with Teflon or brass bushing for blade shaft

7.7 B) FIRE DAMPERS

Fire dampers shall be provided at the supply and return air path of the Packaged

AC. The Fire dampers shall be provided with approved make, fire and smoke of at

least 90 min. fire rating certified by CBRI Roorkee as per UL 555: 1973 or Indian

equivalent standards. Fire damper blades and outer frame shall be formed of 1.6 mm galvanized sheet

steel. The damper blade shall be in pivoted on both ends using chrome-plated

spindles in self-lubricated bronze bushes. Stop seals will be provided on top and

bottom of the damper housing made of 16 G galvanized sheet steel. For preventing

smoke leakage side seals will be provided.

7.8 DIFFUSERS AND GRILLES

7.8.1 The type and quantity of diffusers and grilles shall be provided, as specified. The

CONTRACTOR shall ensure that the diffusers and grilles offered are of requisite

capacity, throw and terminal velocity. Diffusers and grilles shall be fabricated from

Aluminum Powder coated with rust resistant primer

7.8.2 Whenever VCD is provided with diffusers or grilles it shall be located within the

duct collar. Diffusers and grilles shall be of flush or stepped pattern.

7.8.3 Ceiling diffuser shall be equipped with fixed air distribution grids, removable key

operated volume control dampers and anti-smudge rings. The extruded aluminum

diffusers shall be provided with removable central core and concealed key

operation for volume control damper.

7.8.4 FLEXIBLE CONNECTIONS

Where sheet metal duct connects to the intake or discharge of fan units, a flexible

connection of fire retarding double layer heavy duty canvas material of at least 150

mm width shall be provided. The material shall be attached to angle frames by

means of a steel band over the end of the flexible connection. The material shall be

secured between the band and the angle frame by bolting. Sleeve shall be made

smooth and the connecting duct work rigidly held by independent supports on

both ends. The flexible connection shall be suitable for fan intake and outlet

pressures.

8.0 MEASUREMENTS

8.1 DUCTING

Measurement for ducting shall be carried out on the basis of centre-line

measurements as described in following paras.

8.1.1 Duct work shall be measured on basis of external surface area of ducts. Duct

measurement shall be taken before the application of insulation if any. The

external surface area of duct shall be calculated by measuring the perimeter

comprising of width and depth, in the centre of each duct section and multiplying it

with overall length from flange face to flange face of each duct section and adding

up areas of all duct sections.

8.1.2 Surface area of the supply air plenums for linear and slot diffusers shall be added to

the duct quantities.

8.1.3 For tapered rectangular ducts, the average width and depth shall be used to

measure perimeter, whereas for tapered circular ducts, the diameter of section

midway between large and small diameters shall be adopted. The length of tapered

duct section shall be the centre-line distance between the flanges of the duct

section.

8.1.4 For special pieces like transformations, bends, offsets and branch connections,

mode of measurement shall be identical to that described above using the length

along the centre-line. End cover or closure shall be measured as per end duct cross-

section area (width × height).

8.1.5 The quoted unit prices for ducts shall include all wastage allowances,

reinforcement angles or flats, duct supports, flanges and gaskets for joints, nuts

and bolts, anchor fasteners, angles, channels, flexible connections at equipment

inlet and outlet, splitter dampers, access doors, turning vanes and straightening

vanes. These accessories shall neither be separately measured nor paid for.

8.2 DIFFUSERS

Areas shall be calculated by measuring cross-section area for air flow at discharge

or capture area excluding flanges. In case of supply air diffusers, VCDs shall form

part of unit prices quoted and shall not be separately measured or accounted.

Frame work for diffusers shall also be included in unit prices quoted.

8.3 LINEAR DIFFUSERS

Linear diffusers shall be measured by linear measurements only for each size or

width, and not by cross-section area. Linear measurement shall exclude mounting

flanges. Frame work for linear diffusers shall also be included in unit prices quoted

and shall not be measured separately. The supply air plenum for linear diffusers

shall be measured identical to ducting as described earlier.

8.4 SLOT DIFFUSERS

Slot diffusers shall be measured by linear measurements only and not by cross-

section area. Linear measurement shall exclude mounting flanges. Frame work for

slot diffusers shall also be included in unit prices quoted and shall not be measured

separately. The supply air plenum for slot diffusers shall be measured identical to

ducting as described earlier.

8.5 GRILLES

Area shall be calculated by measuring width and height, excluding flanges. In case

of supply air grilles, VCDs shall form part of unit prices quoted and shall not be

separately accounted. Frame work for grilles shall not be estimated separately and

shall also be included in unit prices quoted.

8.6 FLEXIBLE CONNECTION

Flexible connections other than those at the equipment inlet and outlet shall be

measured by their cross-section area perpendicular to air flow. Quoted unit prices

shall include necessary mounting arrangement, flanges, nuts and bolts and fire

treatment of requisite length of canvas cloth.

8.7 Painting shall not be separately measured or paid for. Various quoted unit prices

shall include painting wherever specified or required.

9.0 INSPECTION AND TESTING

Pl refer Section B.

10.0 BALANCING

10.1 The air distribution system shall be tested and balanced so that the requisite

temperature and air flow are maintained throughout the space to be air-

conditioned or ventilated.

10.2 During start-up phase, The CONTRACTOR shall make all arrangement for drilling or

plugging of all test opening or holes, adjustment of VCDs, adjusting of fan speed to

obtain specified flows, obtaining actual motor ampere readings, and all related

functions to ensure the proper operation of all systems.

10.3 Test holes for system commissioning shall be minimum 20 mm diameter to accept

a standard pitot tube of 8 mm diameter and each hole shall be fitted with an

effective removable type seal. The CONTRACTOR, in consultation with the

PURCHASER, shall decide location of test holes.

10.4 The CONTRACTOR shall provide all instruments required for testing and balancing

of air distribution system.

10.5 Complete air balance report shall be submitted for scrutiny and approval. Four

copies of the approved balance report shall be provided with completion

documents.

10.6 Splitter damper and VCD adjustments shall be permanently marked after air

balancing is complete so that these can be restored to their correct position if

disturbed at any time.

11. DATA TO BE FURNISHED BY THE CONTRACTOR AFTER THE AWARD OF CONTRACT

1. List of drawings and documents to be submitted for review, approval and

information with scheduled submission dates

2. Quality Assurance Plan (QAP)

3. Dimensioned general arrangement drawing showing all diffusers, grilles,

dampers, plenums, hoods, access doors, flexible connections and all other

accessories. Duct supports and transverse joint locations shall be marked on the

drawing.

4. Fabrication drawings for duct showing duct support and guide vane details.

5. Cross-sectional drawings of volume control dampers, with part list, materials of

construction and installation details

12.0 Information to be furnished with the tender

12.1 The tenderer shall submit the relevant literature/leaflets/catalogues in respect of the

material etc., offered for enabling the purchaser to assess the offers.

13.0 Scope of supply by successful tenderer

13.1 The successful tenderer shall supply all equipment and materials described in this tender

with such modifications and additions/deletions etc., as are mutually agreed upon.

13.2 Drawings & instruction manuals

After getting approval of the drawings by the Department, three sets of the following

shall be supplied by the contractor before commencement of the work at site

i) Approved drawings.

ii) Certified test-certificates in respect of various materials.

14.0 PREDESPATCH INSPECTION AND TESTINGS

14.1 Routine and type tests or, any other relevant test(s) in respect of the various items of

equipment/materials shall be conducted/performed at the contractors/suppliers’ works

before effecting dispatch to site. The tests shall be conducted in presence of the

departmental representative, if so desired by the department. The contractor shall,

therefore, be required to give prior intimation well in advance to the department of his

intention of carrying out such tests.

The following parameters shall be tested at manufacturers work for P/T AC units:

a) Run Rest of Blowers/fans, Nominal cooling capacity

b) Verification of Test certificates of individual components.

14.2 The following items can be delivered to site directly after submission of test certificate

and approval regarding material and performance as per relevant standards and as

specified in the Tender document.

i) PAC units

ii) Cable

iii) MCB/DB

iv) Earthing/cable trays

v) Small motors

vi) Dampers

vii) Gasket

viii) All SS & MS hardware

15.0 Installation, testing & commissioning

15.1 The successful tenderer will be responsible for providing all necessary tools, tackles and

instruments required for execution and testing of the plant and equipment.

15.2 Trial-run/performance tests, etc., for the system shall be conducted by the contractor

after completion of erection work. In case, the work does not meet the intent of the

specification, the same will be made good by the contractor so as to meet the specified

duty.

15.3 The various readings shall be taken (and results computed) by the contractor during the

performance tests of the system .

15.4 On completion of the work, the contractor shall furnish the following immediately.

i) Five (5) sets of “As executed drawings” along with tracing in ink.

ii) Five (5) sets of test-result sheet.

15.5 After Installation and commissioning the followings parameters will be tested at NFC for

acceptance.

All AC units with respect to

i) Nominal capacity

ii) Flow

iii) Temperature at outlet

iv) Efficiency

v) Noise, Vibration as per IS standards.

All grills

i) Velocity

ii) Temperature

iii) Noise as per IS standards.

The firm has to arrange all the testing instruments samplers, sample analyzer, Sling

psycho meter, flow meter, velocity meter, Pressure gages etc. In case of deviations in

values of acceptance parameters beyond reasonable limits , the firm has take all

necessary corrective action to meet the approved design values.

16.0 Deleted

17.0 Validity

17.1 The tender should be kept valid for acceptance for a minimum period of 90 (ninety) days

from the date of tender opening.

18.0 Guarantee

The entire installation shall be guaranteed by the contractor for a period of twelve (12)

months from the date of completion & handing over in all respects against any defect in

design, manufacture/workmanship.

18.1 The purchaser (Department) may increase or, decrease the quantity of any item or,

delete the item altogether and final order value will be on the basis of the unit price

quotation.

18.2 In case of variation in quantities of any item(s) of the work order, the payment shall be

made on the actual measurement basis.

19.0 Miscellaneous

The acceptable noise-level as specified for various AC units shall be measured as per

standards

20.0 Deleted

20.1 Special Notes

All security and safety rues applicable time to time in NFC shall be strictly followed by

the contractor with out fail. Violations of safety and security rules shall be viewed

seriously and penalty will be imposed for such violations.

20.2. Persons engaged shall be healthy and fit to work at height. Medical certificate to this

extent shall be furnished before commencement of work.

20.3 Generally work has to be done in general shifts by engaging required manpower. But to

meet target of completion, contractor can work in holidays and beyond general shift

hours with prior written permission.

20.4 Continuous supervising from contractor side is required for this work. So contractor is

required to depute one qualified supervisor exclusively for this job.

20.5 All works required for successful completion of job such as bending/folding/welding/civil

works etc. are also in the scope of the contractor.

19.6 Contractor shall consider all above points while quoting.

20.6 Prices and delivery

20.7 The prices for supply and erection shall be separately quoted as unit prices for

equipment/materials supplied and lump sum prices for services rendered (where

applicable) strictly on the prescribed proforma under “Schedule of Quantities”. The

prices should be F.O.R. site and ‘firm’ (inclusive of all taxes/duties & levies etc.). The

materials shall be securely packed for transport up to destination at site.

20.8 The purchaser (Department) may increase or, decrease the quantity of any item or,

delete the item altogether and final order value will be on the basis of the unit price

quotation.

20.9 In case of variation in quantities of any item(s) of the work order, the payment shall be

made on the actual measurement basis.

20.0 Painting:

21.1 As mentioned earlier, all exposed metallic surfaces are to be treated/protected with

appropriate anti-corrosion treatment.

21.2 Wherever 2 coats epoxy paint is called, it always means 2 coats of epoxy finish paint

only. At all places, 2 coats epoxy finish paint shall be coated over 2 coats of epoxy red

oxide zinc-chromate primer, using appropriate thinner (including surface preparation &

cleaning). Epoxy paint shall be of standard make with the consent/approval of the

department.

22.0 Approved list of "‘makes’ of various equipments & components and materials: (

Contractor has to supply/use following approved makes only)

1. Precision AC : Emerson-Liebert /Blue Star/climvete/uniflair/schultz 2. Brass/Copper fittings : Kim/Brassomatic 3. Motor : Siemens /Kirloskar/Crompton 4. Starter :Siemens / L&T/Hawels 5. Gauges : Gen. Inst. Co.Manometer India, Fiebig/Waree/Hguru 6. Paint :Berger/Jenson Nicholsan\Asian 7. Insulation :K-Flex/Armaflex/Vedoflex 8. "V" –belt : Fenner 9. Bearings : SKF/NGF 10. Filters :Air Breeze/ Aerosol/Trijama/Spectrum 11. Thermostatic Exp. Valve : Sporlan/ALCO/Danfoss 12. Damper : Airmaster/ Airbreeze/Cosmic 13. Centrifugal Fans : Accel/Nadi/Nicotra /Kruge r/GEC (Alstom) 14. Grille & Diffusers : Airmaster / Airbreeze/Cosmic 15. GI sheet : Sail/Tata / JINDAL 16. Control Switches : Siemens/ Kaycee. 17. Power & control cables : IOC, CCI, OPC, and NICCO Cables, Universal, Finolex, LAPP 18. Timers : Advani Orelikan, PLA, L&T

SECTION - A

Precision AC Units (air cooled) Technical Specification and scope of work Scope: This specification describes specific requirements of microprocessor based top discharge DX Precision Airconditioning system. Outdoor condensing unit shall comprise air-cooled condenser with fan. Indoor unit shall consist of filter section, P-I-D Controller, Electrical Power switch board, multi-rows deep copper cooling coil with aluminium fins, Dehumidification cycle, modular panel cabinet construction, cabinet insulation, fan section with dynamically balanced centrifugal fans with a motor and drive, humidifier, High technology scroll compressor, accessible refrigeration control. The system shall also be designed to control temperature and humidity conditions in rooms containing electronic equipment, with good insulation and vapour barrier. The manufacturer shall design and furnish all equipments to be fully compatible to fulfill requirements of HRTEM room as specified in the tender schedule and specification given below. SPECIFICATION OF 5 TR TOP DISCHARGE AIR COOLED DX TYPE PRECISION

AIRCONDITIONER

Indoor Unit

Power supply 415V, 3 phase, 50 Hz, a.c, 4 wire system

Compressor Hermetically sealed DIGITAL/inverter/microprocessor based Scroll Compressor mounted on vibration isolators

Cooling coil DX type fin & tube coil shall have internally grooved copper

tubing with slit fins

Blower motor IP54, Electronically commutated motor with speed protection via controller signal

Blower fan EC Backward curved centrifugal plug type fan with maintenance free design & construction

Nominal Air Flow 5000 CMH

External Static Pressure 50 mm of w.c

Safety device for Inbuilt internal thermal protector, over load trip, high-Low

compressor voltage trip, internal pressure relief valve, high pressure

cutout, low pressure cutout, anti-freeze cut out, etc

Control Panel Microprocessor based intelligent control panel with digital

Temperature & Relative Humidity controller and faults

diagnostic, alarm, indication as per detail specification given

below

Temperature controller Digital temp controller

Range : 18 - 24˚C

Sensitivity : ± 0.5 ˚C,

TC/RTD/thermistors type temperature sensors

RH controller

Factory installed inside the unit Low pressure steam injection type humidifier with high intensity Infrared quartz lamp with automatic water supply system and system should be able to prevent mineral precipitation.

Range : 20 – 60 %

Sensitivity : ± 1 %

Full capacity shall be achieved with in 10 sec from cold start.

Heater Strip heaters of required capacity to control temperature and

RH with thermal safety switches.

Condenser Air cooled condensers shall have internally grooved copper

tubing with anti corrosive coated aluminium fins suitable

for coastal area

Air Filters Micro fibre glass fine filter of rated efficiency shall be > 95%

down to 5 micron particle size, conform to the standards

EU9/MERV15

Refrigerant & oil Refrigerant R-407C & oil shall be required quantity as first

charging charge

Refrigerant Piping K type hard drawn copper piping between indoor and

outdoor units

Cabling Suitable Power, control and interlocks cabling and earthing

between indoor unit and Isolator switch and between indoor

unit and air cooled condensers (ODU) duly complete with all

fittings.

Sheet Metal Parts Indoor and outdoor units shall be power coated textured

finished

Detailed Specification: Cabinet Construction The frame shall be constructed of 2.5, 2.0 and 1.2 mm folded galvanised steel. The exterior panels shall be constructed of 1.2 mm zinc coated sheet steel and insulated with foam insulation. The cabinet shall be powder coated in Charcoal Grey colour and have a textured finish. The hinged front doors shall be removable and include captive 1/4 turn fasteners. The cabinet shall be constructed to provide ease of disassembly & reassembly for difficult access sites. Filtration Micro fibre glass fine filter of rated efficiency shall be > 95% down to 5 micron particle size, conform to the standards EU9/MERV15. The filter panels shall be an integral part of the system and with drawable from the front of the unit. Filtration shall be provided by deep V form, dry disposable media housed in a metal frame. DOP test certificates for these filters from the manufacturer shall be produced at the time of installation. EC Fans The fan section shall be designed for external static pressure of 50 mm of w.c. The unit shall be fitted with direct-driven, high efficiency, single inlet, backward curve, centrifugal 'plug' type fans, with aluminium nozzle(s) and impeller(s). The fan motors shall be Electronically Commutated (EC), IP54, with internal protection and speed regulation via controller signal. They shall be statically and dynamically balanced. Humidifier A Low pressure steam injection type humidifier with high intensity Infrared quartz lamp shall be factory installed inside the unit. Bypass air shall be used to enable moisture to be absorbed into the air stream without condensation. The humidifier shall be serviceable and removable from the front of the unit. Infrared Humidifier The humidifier shall be of the infrared type consisting of high intensity quartz lamps mounted above and out of the water supply. The humidifier pan shall be stainless steel and arranged to be removable without disconnecting high voltage electrical connections. The complete humidifier section shall be pre-piped, ready for field connection to water supply. The humidifier shall be equipped with an automatic watersupply system and shall have an adjustable water-overfeed to prevent mineral precipitation. A high-water detector shall shut down the humidifier to prevent overflowing. Full capacity operation shall be achieved within 10 sec from cold start. Electric Heater Electric heating shall be provided in a single stage. The elements shall be low watt density, 304/304 stainless steel fin tubular construction, protected by thermal safety switches. The heating system shall include dual safety protection through loss of air and manual reset high temperature controls, and GCD protected.

Digital /invertor/ microprocessor Scroll Compressor The compressor shall be of the high efficiency Compliant Scroll design, with an E.E.R. (energy efficiency ratio) of not less than 11.0 BTUH/watt (C.O.P. of not less than 3.25) at ARI rating conditions. The compressor shall be charged with polyolester (POE) oil and designed for operation on HFC R407C. Each compressor shall have internal motor protection and be mounted on vibration isolators. Refrigeration Circuit The refrigeration system shall be of the direct expansion type with two cooling stages and incorporate one hermetic digital scroll compressors, complete with crankcase heaters and rotalock connections. A hot gas bypass solenoid valve shall be used on single compliant scroll compressor models. The system shall include a manual reset high pressure control, auto reset low pressure switch, externally equalised thermal expansion valve, high sensitivity refrigerant sight glass, large capacity filter drier with rotalock connections and charging/access ports in each circuit. Thermal Expansion Valve To provide quick and accurate Refrigerant system set up and calibration the thermal expansion valve (TXV) shall be accessible to allow system set up and calibration while the unit is running. Evaporator Coil The evaporator coil shall be an A-Coil incorporating draw-through air design for uniform air distribution. The coil shall be constructed of enhanced surface aluminium fins mechanically bonded to enhanced surface internally grooved cross hatched copper tubes. The coil frame is fabricated from Hot dipped galvanized sheet metal and the stainless steel condensate drip tray. The evaporator drain tray shall incorporate double sloped gutters for condensate removal. Dehumidification - EC Fan Air, Water Cooled, Dual Cool and Free Cool Units A specific dehumidification cycle shall operate by reducing airflow to lower the surface temperature of the evaporator/cooling coil below the return air dew point condition. Air Cooled Systems The indoor evaporator unit shall include refrigerant piping, with a factory holding charge of Nitrogen. Each refrigeration circuit shall include rigidly mounted isolation valves in the discharge and liquid lines to aid servicing and installation. Field relief of the Schrader valve shall indicate a leak-free system. A 3 pole circuit breaker shall be factory fitted per refrigeration circuit for field connection of power to each remote air cooled condenser. Remote Air Cooled Condenser The factory matched air cooled condensers shall be the low profile, weatherproof type incorporating high efficiency, direct drive, external rotor motors with axial blade fans. The condenser shall be constructed from heavy duty aluminium and corrosion resistant components. Heavy duty mounting legs and all assembly hardware shall be included. Condensers shall be suitable for 24 hour operation and be capable of providing vertical or horizontal discharge. The condenser shall be fully factory wired to an input isolator and motor operable to 415 volt 3 phase 50Hz electrical service. The high performance heat exchanger condenser shall include mechanically expanded enhanced surface, internally grooved cross hatched copper tubes and anti corrosive coated aluminium fins for efficient heat transfer. Fan Speed Control Condenser The condenser fans shall be directly driven by 6 pole 690 rpm 415 volt 3 phase 50 Hz electric motors with an IP54 enclosure rating and class F insulation. The motors shall be equipped with permanently sealed ball bearings and high temperature grease. The motors shall be speed controlled to ensure stable operating conditions from -20°C to 45°C ambient by a factory fitted, direct acting pressure actuated electronic fan speed controller. The control system shall be complete with input isolator, transducers and electrical wiring.

Microprocessor Control with Graphic Display The microprocessor control unit shall be factory-set for intelligent control which uses "fuzzy logic" and "expert systems" methods. Proportional and Tunable PID shall also be user selectable options. Internal unit component control shall include the following:

Compressor Short Cycle Control - Prevents compressor short-cycling and needless compressor wear System Auto Restart - The auto restart feature will automatically restart the system after a power failure.Time

delay is programmable Sequential Load Activation - On initial startup or restart after power failure, each operational load is sequenced with a

minimum of one second delay to minimize total inrush current Predictive Humidity Control - Calculates the moisture content in the room and prevents unnecessary humidification

and dehumidification cycles by responding to changes in dew point temperature. Customer shall pre-select the desired grouping of display languages at the time of the order from the following choices: English, French, Italian, Spanish, German, Portugese, Russian, Chech and Chinese Service Contacts Menu shall allow display of local service contact details. Service Menus Shall be Defined as Follows: - Setpoints The control system shall allow programming of the following conditions:

o Temperature Setpoint 20ºC o Adjustable temperature hysterisis 0.1-1ºC o Humidity Set point 45-50% RH* o Adjustable humidity hysterisis 1-5% RH o Low/High Temperature Alarm 17-24ºC o Low/High Humidity Alarm 20-75% RH

* The microprocessor may be set within these ranges, however the unit may not be able to control to extreme combinations of temperature and humidity. The control system shall include the following settable features:

• Unit identification number. • Startup Delay, Cold start Delay and Fan Run on timers • Sensor Calibration. • Remote shutdown & general Alarm management • Compressor Sequencing. • Return temperature control. • Choice of Modulating output types.

Standby Settings/Lead-Lag Menu shall allow planned rotation or emergency rotation of operating and standby units. Timers/Sleep Mode Menu shall allow various customer settings for turning on/off unit.

Alarm Setup The microprocessor shall activate an audible, visual and general alarm in the event of any of

the following conditions: o High Temperature o Low Temperature o High Humidity o Low Humidity o Compressor Overload o Main Fan Overload o Humidifier Problem o High Head Pressure o Low Suction Pressure o Change Filter o Fan Failure o Unit Off

The unit shall also incorporate the following protections:

• Single phasing preventors. • Reverse phasing • Phase imbalancing • Phase failure � Overload tripping (MPCB) of all components

Audible Alarm The audible alarm shall annunciate any alarm that is enabled by the operator. Common Alarm A programmable common alarm shall be provided to interface user selected alarms with a remote alarm device. Remote Monitoring All alarms shall be communicated to the Liebert monitoring system with the following information: Date and time of occurrence, unit number and present temperature and humidity.

Sensor Calibration

Menu shall allow unit sensors to be calibrated with external sensors. Maintenance/Wellness Settings Menu shall allow reporting of potential component problems before they occur. Options Setup Menu shall provide operation settings for the installed components. System/Network Setup Menu shall allow Unit-to-Unit (U2U) communication and setup for teamwork modes of operation (up to 32 units). Teamwork Modes of Operation Saves energy by preventing operation of units in opposite modes multiple units. Auxiliary Boards Menu shall allow setup of optional expansion boards. Diagnostics/Service Mode Control input and output values and status shall be displayed to aid in unit diagnostics and troubleshooting. Control inputs shall be indicated as on or off at the front display. Control

outputs shall be able to be turned on or off from the front display without using jumpers or a service terminal. Each control output shall be indicated by an LED on a circuit board. Advanced Menus Factory Settings Configuration settings shall be factory-set based on the pre-defined component operation. Pressure Switch: Danfoss/Honeywell make safety pressure switches for HP and LP cutout pressure, low oil pressure, etc. Refrigerant Piping: Suitable size hot gas and liquid line copper tubes to interconnect indoor unit and outdoor units shall be K type high wall thickness (not less than 16 G) and hard drawn and shall conform to IS 10773 - 1995. All refrigerant piping shall be pressure tested to rule out any leak. Necessary oil traps, slopes shall be provided. The supplier shall prepare drawing for the refrigerant piping and it shall be approved by Engineer-in-charge. The refrigerant piping shall be properly supported and clamped. Liquid Line Drier: The liquid line, drier cum strainer (Non refillable “Catch All”) shall be provided to prevent entry of any contaminants and moisture into expansion valves. Suitable liquid line valve shall be provided. Refrigerant & Oil Charge: Refrigerant and oil are to be filled for required level. Refrigerant shall be R-407C or non CFC. Cabling: Power cabling between Packaged A.C units and main incoming Isolator shall be 16 mm2, 4 core PVC insulated, PVC sheathed, GI flat armoured, 1100V grade, Copper conductor UG,FRLS cable as per the IS: 1554 (Part-1).

Power cabling between Packaged AC unit to outdoor condensing unit and cabling to heater bank shall be 2.5 mm2, 4 core PVC insulated, PVC sheathed, GI flat armoured, 1100V grade,FRLS Copper conductor cable as per the IS: 1554 (Part-1).

All control type of control cabling, inter links, etc. shall be provided by contractor. Department will provide isolator with switch-fuse unit in one point at plant room for each Packaged AC units. Earth wire shall be 8 SWG copper solid conductors. The Packaged AC units and its ODUs shall be double earthed. All the cables shall be properly glanded and terminated with copper lugs (aluminium lugs should not use). All the cables shall be neatly dressed and clamped in suitable size GI cable tray.

SECTION - B

INSPECTION, TESTING AND COMMISSIONING

GENERAL

This chapter covers initial inspection and testing of compressor, condenser & indoor chilling unit at manufacturer’s works, Initial inspection of other equipments/ materials on receipt at site, final inspection, testing & commissioning of all equipment at site & description of testing requirements & procedure.

All equipment shall be tested at manufacturer's work as per latest relevant BIS specifications or in the absence of BIS specification, approved testing methods shall be followed and test certificates/ reports submitted to the Engineer-in-charge. The contractor shall intimate in advance the probable date of such tests to the Engineer-incharge to enable him / his representatives to witness the tests if he so desires. But under no circumstances shall this absolve the Contractor of his responsibility for Performance of the Equipment or System.

In addition to the above, all equipment and systems shall be tested after installation as required by various statutory authorities, certifying agencies and as required under various sections of these specifications / Special Conditions.

The Contractor shall leave necessary provisions required for fixing instruments, gauges, meters, etc. for testing the installation even if these are not shown on the drawings. All such instruments, services etc. needed for the tests shall be arranged by the Contractor at his own cost.

Notwithstanding approval of tests or equipment or materials by Engineer-in-charge, up to the tests in static state as described here-in above, the Contractor shall be required to perform site tests to prove correctness of ratings and performance of equipment, machines and materials supplied and installed by him, in dynamic state also.

All equipment shall be capable of performing the duties specified in these specifications without damage, distortion or failure of any component.

The performance of various equipments individually shall not be less than quoted ratings and consumption of power, fuel or other consumable shall not exceed the ratings quoted by the tenderer, when tested in dynamic state. All test instruments shall be calibrated for accuracy prior to taking the performance tests. All safety and control instruments shall be checked for proper operation, sequencing etc. and set points furnished to Engineer-in-charge.

In the event of short fall in rating of individual equipment/ materials or excessive consumption of power/ fuel etc. or non-fulfillment of performance of equipment/ materials or overall installation, in any way whatsoever, the Contractor shall at his own cost make good the defects by altering, repairing, replacing, augmenting etc. as required at his own cost and to the entire satisfaction of Engineer-in-charge and within reasonable time as may be decided by Engineer-in-charge.

INITIAL INSPECTION AT MANUFACTURER’S WORKS

a. Physical verification for materials, thickness and make shall be carried out as per contract before application of insulation.

b. Manufacturer’s test certificate for density shall be furnished.

Note: Accuracy of testing instruments shall be as mentioned in the final inspection procedure given below.

FINAL INSPECTION AND TESTING The Contractor shall intimate in writing to Engineer-in-charge as and when individual components of the installation are ready for hydraulic/pneumatic/ electrical, etc. tests required for further progress of erection. All such tests shall be carried out as per this specification and/or as directed by Engineer-in-charge and recorded in the presence of Engineer-in-charge/his representatives.

The Contractor shall intimate in writing to Engineer-in-charge, the proposed date of initial startup and request for ancillary requirements such as permanent power etc. to be made available to him for initial operation of his installation.

The Contractor shall, on approval of Engineer-in-charge, proceed with necessary pre-commissioning activities and tests and put the installation on initial operation and startup during which preliminary adjustments and balancing shall be carried out.

Testing shall be carried out for all three seasons.

Routine testing for summer, winter & Monsoon season, pressure testing for fabricated components shall be required.

Performance testing at site of complete Air conditioning plant as per various technical requirements, as stipulated in the Performance Testing Clause.

Based on preliminary observations during the initial operation described above, necessary modifications/repairs/replacements/ etc. if any shall be carried out by the Contractor to the entire satisfaction of Engineer-in-charge. On successful completion of initial operation, the Contractor shall proceed with trial runs. Unless otherwise indicated, the trial runs shall be carried out for minimum period of 3 days, each of 24 hours duration. In case of interruptions of a duration of more than 4 hours at a time, the period of trial runs shall be extended by 1 (One) day.

After successful trial operations, the Contractor shall proceed with preliminary testing performed during static phase, i.e. rooms or facilities are complete and ready for operation, with all services connected and functional, but without full/any occupancy or equipment in the rooms/facilities.

The preliminary test readings shall be recorded at intervals of not more than 1 hr for a period of minimum 3 days of 24 hours duration each day. Such readings shall be recorded in format approved by Engineer-in-charge.

Test readings taken in the static state of operation shall not be considered as performance tests, unless such tests are not deemed to be affected by factors which shall be present in the dynamic state. All such test readings shall be witnessed by the Engineer-in-charge or his authorised representatives.

Final performance tests shall then be carried out in dynamic state i.e. when rooms/facilities are in normal operation with all services and equipment functional and with normal occupancy of staff present and performing their normal functions.

Final performance test shall be carried out for a minimum period of 3 consecutive days of 24 hours duration each day, unless otherwise directed by Engineer-in-charge and for each equipment and overall system with test reading and observations being witnessed by Engineer-in-charge or his representatives.

The performance tests for Precision Air Conditioning System shall be carried out during peak summer and monsoon seasons. However, if these systems are required to be put into

operation for beneficial use of Client at a time other than peak summer or monsoon seasons, then, the equipment and overall installation shall be taken over by the Department and put into operation. The final performance tests, in any case, shall have to be carried out during peak summer and monsoon and witnessed by Engineer in-charge or his representative.

Pressure drops across compressor and condenser at specified flow rates shall be checked.

All instruments for testing shall be arranged by the Contractor and suitable provision made in the piping and/or equipment for installing the same.

DATE OF ACCEPTANCE

Subject to the guarantee Clause date of taking over the installation after 10 days of trouble free operation shall be the date of acceptance. Any undue wear and tear of components during the “Running in Period” shall be made good by the contractor free of charge.

GUARANTEES a) The guarantee shall cover each & every material whether manufactured by the contractor or not. The contractor shall replace the defective parts with new ones.

Replaced parts shall also be covered by a similar guarantee.

b) The replaced parts shall be of genuine make and subject to approval by the

Department.

c) The contractor shall guarantee the performance of the entire process, equipment and

pipeline for a period of one year from the date of handing over to the Department.

The three Seasonal Tests are successfully completed. Nothing extra shall be paid on this account.

REPORTS

Provide 3 copies of the complete balancing and testing reports to the Department. Report shall be neatly typed and bound suitable for a permanent record. Report forms shall contain complete test data and equipment data as specified.

FINAL DOCUMENTATION

The contractor shall leave the system operating in complete balance with water and air quantities as shown on drawings. Set stops on all balancing valves and lock all damper quadrants in proper position. Notify the department of any areas marginal or unacceptable system performance.

The above tests and procedures mentioned herein are for general guidance and information only, but not limited to the provisions of conditions of contract and design/performance criteria.

Upon commissioning and final handing over of the installation, the Contractor shall submit (within 4 weeks) to the Engineer-in-charge.

a.Comprehensive operation and maintenance manual and spare parts catalogue for all equipments.

b. As built drawings in hard copy and soft copy.

c. Test certificates, consolidated control diagram and technical literature on all controls.

d.Equipment warranties from manufacturer’s.

e. Rating charts for all equipment.

f. Log books as per equipment manufacturer’s standard format.

g. List of recommended spares and consumables.

h. Detailed circuit diagram, local diagram of various electrical components for control of all equipment provided.

i. Sequence operation notes explaining the sequence of operations when operation button is pressed.

Any special tools required for the operation or the maintenance of the plant shall be supplied free with the plant.

At the close of the work and before issue of final certificate of completion by the Engineer-in-charge, the contractor shall furnish a written guarantee indemnifying CDRI/EPI against defective materials and workmanship for the Defects liability period.

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Tender conditions for Participation in tendering:

1.0 Tenders will be issued to eligible DAE as well as non DAE contractors provided they

produce definite proof from the appropriate authority, which shall be to the

satisfaction of the competent authority, of having satisfactorily completed similar

works of magnitude specified below: -

One similar work not less than 80% of estimated cost

Two similar works not less than 50% of estimated cost

Three similar works not less than 40% of estimated cost

For the purpose of this clause ‘similar work’ means the works like “Supply, Installation,

Testing & commissioning of Precession/Package type AC system along with air

distribution"

2.0 For purchasing the tender/participating, the tenderer must also produce the

following

a) Solvency Certificate of at least 40% of estimated cost from Bankers or Equivalent in

support of financial standing taken after 1.4.2014.

b) List of works executed duly supported with certificates/testimonials from clients in

support of the similar works executed like “Supply, Installation, Testing &

commissioning of Precession/Package type AC system along with all air distribution"

executed during last 7 years ending 31st March 2015.

c) Audited balance sheet indicating value of works carried out /in progress, profit and

loss etc for last 5 years latest by March duly supported by returns filed to I.T.

department. The firm shall be profit making for the last 3 years.

3.0 The time allowed for carrying out the work will be 2 (Two) calendar months to be

reckoned from the 15th

day after the date of written orders to commence the work

or from the first date of handing over of the site, whichever is later, in accordance

with the phasing, if any, indicated in the tender documents.

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