SALEH&HEGAB

HVAC WORKS

PART A - SCOPE OF WORK AND GENERAL REQUIREMENTS

1. SCOPE OF WORK AND SYSTEM DESCRIPTION1.1GENERAL:

a.The general conditions and amendments shall form part of these specifications with the same force and effect as though repeated herein and in case of discrepancy, the engineer's decision will be applied.

b. The scheme covered under these specifications and related A/C drawing calls for the supply and installation, setting to work, testing, commissioning and delivering in perfect operating condition as maintaining the complete installation for a period of one year after acceptance and handing over of the complete installation.

c. The contractor will be responsible to provide all equipment, materials and labour necessary to ensure excellent installation and perfect operation whether such equipment, materials and labour are detailed under these specification and drawings or not.

d.The right to make any change in location of pipes, ducts, grilles, diffusers, boxes, fitting or equipment up to the time of installation is reserved for the engineer with no extra charges.

e.The contractor shall include for all equipment, material, labour, etc., required for the complete installation and to ensure best operating conditions, whether such are detailed under these specifications and attached drawings.

f.Where equipment are manufactured under license, the tenderer should enclose with his offer a written assurance from the license (the principal manufacturer) for the design and quality of equipment produced by the license. This assurance should be submitted along with each offer without which offers will not be considered for adjudication of the tender.

g.Installation and workmanship shall be of the highest order in a neat substantial and workmanlike manner and executed by an approved and registered A/C contractor. The whole installation shall be approved by the employer or the engineer before the acceptance and prior to issue of a taking over certificate.

h.All builders works including float foundations, cutting, opening, wooden frame, etc. required for the A/C installation shall be carried out by the contractor whether details of such works are mentioned or not and as shown in the drawings. The float foundation insulation material shall be of an approved acoustic and vibration isolation material of the kinetic type 2" thick all as described and approved by the engineer. builders works detailed drawings to be submitted showing all opening sizes in concrete beam, shafts in cupboards and exact location and size of float foundations on roof to be approved by the engineer before concrete castings.

1.1.1 NOTICE TO BIDDERS

A. These specifications and accompanying drawings are to be considered as supplementing each other and as such are intended to serve jointly as the basis upon which the contractor shall establish a contract price, and upon which he shall base his performance of required work.

B. It is the intent of these specifications and drawings to call for finished work ,tested, complete, and ready for operation.

C. Design responsibility : The contractor shall accept complete design, responsibility for the heating, ventilation, refrigeration and air conditioning system complete with all related control and electrical works to meet the design criteria.

D. These drawings and specifications are presented to the contractor, with the understanding that he is expert and competent in the preparation of contract bid prices on the basis of information such as is contained in these documents, which do not include assurance as to their complete accuracy and validity in all details, and which may depend, for proper execution upon interpretation by owner's representatives during the course of construction.

E.For the above reason, the contractor shall understand that his submission of an unqualified proposal commits him to perform all work expressed and implied in the drawings and specifications without additional compensation. He shall further understand such submission commits him without extra compensation, and within the scope of the contract, the following :

1.To provide, if required by the owner's representative, the items or arrangements of greater quantity, better quality, or higher cost in the event that a disagreement with regard to such items occurs between the drawings and specifications, or within either one.

2.To abide by the rules and regulations of all authorities (utility companies, code enforcement bureaus, etc.) having jurisdiction over the work.

3. To subcontract, or otherwise arrange to have any work, called for in the drawings and specifications, which does not come within the jurisdiction of the local heating ventilating and air conditioning trade unions, by done such persons whose performance of the work will not create jurisdictional or other disputes which might delay the completion of the project.

4.To provide any small items of work not specifically called for, but required to complete the intended installations.

5.To coordinate his work or adjust same to that of other trades involved in the project, so that conflicts in space do not occur.

6. To coordinate his work or adjust or suit site or any other existing conditions.

F.Prior to submitting proposal, the contractor shall take cognizance of his responsibilities as outlined above, and shall notify the party contracting for the work if any conditions exist which make it impossible for him too stand behind his unqualified proposal as a firm commitment, covering all work intended and implied.

Unless the contractor provides proper notification to the contrary, it will be considered that he has acceptable the conditions under which he has been required to develop his proposal. In particular, it will be assumed that he has had adequate time to prepare his proposal and to furnish any qualifications to same he deems necessary. It will also be assumed that he has had adequate access to these site of the project, adequate opportunity to inspect any existing conditions and adequate opportunity to investigate the drawings, specifications and other documents pertaining to the installations of other trades, which may affect his work.

G. The HVAC contractor when submitting his proposal, shall notify the party contracting for the work of any portion of these specifications and accompanying drawings tending to create delays in the performance of the work.

H. The contractor shall notify the party contracting for the work of these or other influencing conditions when submitting his proposal. If possible, the contractor shall quote a separate figure indicating the additional amount, if any necessary to adjust the work, as specified, to avoid delays, in the event that no such notification is received, prior to an acceptance of the contractor's proposal, it will be construed that the specifications and accompanying drawings have nothing which would tend to delay the work.

1.2 SCOPE OF WORK

1.2.1 GENERAL

The work in this division of the specification the provision of all labour supervision, materials equipment, accessories, services and tests, necessary for a complete system as indicated on the final drawings and as set forth in this specification, delivered to the employer in perfect operating condition and guaranteed for one full year of perfect operation as well as maintaining the complete installation for a period of one year after acceptance handing over the complete works.

The contractor shall provide equipment and systems to meet the design criteria specified. No additional cost shall be allowed for the exchange of any component part of any system if the original fails to provide the design condition when subject to test.

1.2.2 SYSTEM EQUIPMENT

The system shall include but not limited to the following :

A. CHILLED WATER PIPING

Black steel piping, valves, fittings, connected to all AHUs and FCUs from ground up to roof as shown on the drawings .

B.AIR HANDLING UNITS & AIR DISTRIBUTION SYSTEM:(Code No. 15720)

Fresh air - air handling units are located on the mechanical rooms of the main building.

C.FAN COIL UNITS : (Code No. 15760)

FCUs shall serve all rooms as per drawings .

D. exhaust systems : (Code No. 15830)

All exhaust fans (and fresh air fans) are located as shown on the drawings.

E. Sheet metal work : (Code No. 15820, 15850)

For all system requiring duct work, access doors, volume dampers non return dampers, fire dampers, air outlets, diffusers & grilles( slot linear and square ), fresh air louvers, sand trap louvers , insulation , galvanized sheet metal jacketing...etc.

F. Insulation : (Code No. 15810)

for all supply and return piping and duct work and jacketed as per specs .

G. Electric motors and starters : (Code No. 15915)

This contractor shall install all motors and starters and motor control panels. Electrical contractor shall provide only the main feeders to the motor control panels.

1.2.3 description of the system

The HVAC system is centralized chilled water system for all the building. The chilled water shall be generated by existing water cooled chillers.

The chilled water shall be distributed from ground floor to the different air handling units serving, and also the fan coil units.

2. codes, standards, permits and inspections

A.All work shall meet or exceed the latest requirements of all national, state, and other authorities exercising jurisdiction over construction work at the project.

B.All required permits and inspection certificates shall be obtained, paid for and made available and the completion of the work.

C.The following latest issue of publications listed below, but referred to by basic designation only, form a part of the specification.

ASHRAEAmerican society for heating, ventilating and air conditioning engineers .

AIAAmerican insurance association

AGAAmerican gas association

IEEEInstitute of electrical and electronics engineers

ASAAmerican standards association

ASHRAEAmerican society of heating, refrigerating and air

conditioning engineers

ASMEAmerican society of mechanical engineers

ASTMAmerican society for testing and materials

AWSAmerican welding society

AWWAAmerican water working association

AMCAAir moving and conditioning association

NECNational electrical code

NEMANational electrical manufacturers association

ULUnderwriters laboratories, inc.

SMACNASheet metal and air conditioning contractors national association, inc.

NFPANational fire protection association.

3. Design conditions

The scheme shall be based on the following design conditions

a. Location : north latitude 27 17\

b. External condition

Summer : 105 F DB and 78F WB

Winter: 50 oF DB.

c. Internal condition

Summer : 77 F DB, 50 % + 5% R.H

Winter : 72 F DB

d. Noise level

The A/C contractor shall be responsible for any objectionable noise caused by the A/C system being transmitted to the air conditioned areas. All equipment and all system components shall be selected and installed to function quietly. Sound level in all rooms shall not exceed 40 decibels measured on scale "A" by an approved sound level meter and at 3 ft. distance from air outlets. Attenuators shall be selected accordingly (if required).

PART-B TESTING, COMMISSIONING, BALANCING, HANDING OVER AND MAINTENANCE

1.INSPECTION AND TESTING DURING MANUFACTURE:

1.1GENERAL:

Routine tests for various equipment shall be carried out and any material or works which do not comply with the specifications or do not pass the specified test, shall be replaced or made good at the contractor's expense.

The contractor shall also submit original copies of all type test certificates for various equipment and if the engineer is not satisfied with the results of any type test, then such type test shall be repeated at the contractor's expense.

Where the contract provides for tests on the premises of the contractor or of any sub-contractor, the contractor shall provide such assistance, labour, materials water, electricity, fuel, stores, apparatus, instruments etc. as may be required to carry out such tests efficiently, at no extra cost.

1.2TEST CERTIFICATES:

All main results, tests certificates and performance curves shall be supplied in triplicate for all tests carried out pursuant to the provision of the contract. These results and test certificates as well as the performance tests shall be supplied for all tests whether the engineer has attended them or not .

Information contained in these certificates and curves shall be sufficient to identify the related appliances or equipment and shall be marked with the reference of the contract.

1.3SAMPLES:

The contractor shall supply free of charge the sample. for inspection/tests required by the engineer to enable him to determine the quality of the equipment/material supplied and all the tests shall be made at the expense of the contractor. should a tested or inspected sample not meet the requirements of the related specification, the engineer may refuse any equipment containing this sample.

All approved samples shall be kept under the custody of the engineer till the completion of the project and shall be returned to the contractor, thereafter.

2.INSPECTION AND TESTING ON SITE:

2.1GENERAL :

Upon completion of the installation, but before insulation and covering are applied, all piping, duct work, and equipment shall be inspected and pressure tested and proved absolutely tight in the presence of the engineer.

The contractor shall notify the engineer in writing five (5) days before the date after which he will be ready to make such tests on site.

All equipment, instruments, facilities, log sheets, test forms, labour, tools etc. required to properly conduct the tests shall be furnished by the contractor. All tests must be to the satisfaction of the engineer and approved by him.

2.2EQUIPMENT AND PIPE PRESSURE TESTING:

Each system of piping shall be tested after portions of Mechanical work are completed. Any revisions made in piping system after installation will subsequently necessitate retesting of such affected portions of piping system.

Defective material or defects in workmanship that develop during tests shall be remedied and the system shall be retested. The contractor shall be responsible for any damages during testing.

Piping shall be tested in accordance with the American standard code for pressure piping by maintaining the required pressure during the test. use water pumps for all water pressure tests.

Piping for air-conditioning system shall be subjected to test pressure of not less than 1 1/2 times the system pressure, and a duration of 4 hrs. min. Equipment or other piping system components with a working pressure below test pressure shall be isolated from the system during testing and then tested to the required working pressure.

2.3DUCT LEAKAGE TESTING:

All duct work shall be field-tested during construction prior to insulation or concealing in masonry, shafts or above false ceiling. Low pressure duct systems shall be constructed to mean that no air leakage is noticeable, and shall be visually tested (smoke test).

List duct lengths shall not be in excess of 30 meters for risers and 45 meters for horizontal ducts.

Duct risers and branches shall be individually tested. each riser and branch shall be isolated from remainder of system by seals, plugs or caps.

Risers installed in shafts shall be tested in sections to allow erection of shaft wall and duct insulation. Adequate duct tightness shall be based upon a maximum leakage factor of 1 % . Leakage factor allowable shall be based upon the total operating air volume m3/hr. of section of duct under test.

2.4ELECTRICAL EQUIPMENT TESTING:

All electrical equipment shall be cleaned and adjusted on site before application of power.

The following tests shall be carried out:

A)wire and cable continuity tests.

B)Insulation resistance tests, phase to phase and phase to earth, on all circuits and equipment, using a 500 volt megger. The megger reading shall be not less than one meg. ohm.

C)Earth resistance between conduit system and earth must not exceed half (1/2) ohm.

D)Phasing out and phase rotation tests.

E)Operating tests on all protective relays to prove their correct operation before energizing the main equipment.

Any leaks or faults discovered during such tests shall be remedied at once by the sub-contractor at his own expense and the tests repeated until the engineer is satisfied that the section under tests is sound, and the engineer's decision whether the test is sound or not shall be final.

After each test a signed certificate of approval shall be obtained from the engineer.

2.5VISUAL CHECKING:

1.Checking to ensure that the plant and components are complete according to the as built drawings.

2.Checking the external suitability, such as complete paint work, enameling, clean lines of ducting, equipment and plant accessibility of maintenance.

3.Checking the construction of the whole of the ducting and piping systems, with accessories (air silencers, intake and outlet insulation etc.) mounting fixtures, weather-protection gratings, inspection openings, etc. including builders work construction.

4. Checking the installation and mounting of equipment and accessories.

5.Checking the construction of all components of the control system to ensure a technically correct and complete installation.

6.Checking clean lines of the air filters and also the availability of replacement elements and air resistance indicators.

7.Checking the sealing of openings to and from rooms.

8.Checking the ventilation and air-conditioning ceiling installations (assembly, demountability, acoustic lining and insulation).

The above visual checking shall be performed by the contractor and in the presence of the engineer. contractor to submit check list for each inspection and shall be approved by the engineer.

3.CLEANING AND ADJUSTING

Pipes shall be cleaned free of scale and thoroughly flushed of all foreign matter. Temporary by-pass shall be provided for all water coils to prevent flushing water from passing through coils. All strainers and valves shall be thoroughly cleaned. The ducts, plenums, and casing shall be thoroughly cleaned of all debris and blown free of all small particles of rubbish and dust and then shall be vacuum cleaned before installing outlet faces. equipment shall be wiped clean, with all traces of oil, dust, dirt or paint spots removed. Temporary filters shall be provided for all fans that are operated during construction, and new filters shall be installed after all construction dirt has been removed from the building, and the ducts, plenum and casings and other items specified herein before have been vacuum cleaned. It shall be the responsibility of the contractor to maintain the system in this clean condition until final acceptance. Bearings shall be properly lubricated with oil or grease as recommended by the manufacturer. Belts shall be tightened to proper tension. Control valves and dampers and other miscellaneous equipment requiring adjustment shall be adjusted to setting indicated or directed. Fans shall be adjusted to the speed indicated by the manufacturer to meet specified conditions.

4.TOTAL SYSTEM TESTING, ADJUSTING AND BALANCING (TAB):

4.1GENERAL :

Total system testing, adjusting and balancing shall be done by and on the responsibility of the contractor, who will employ an independent company specialized in testing and balancing of air conditioning systems to test regulate and adjust air distribution systems, water distribution systems and equipment and apparatus connected thereto to conform to capacities indicated on the drawings. The testing company should have past experience in this type of work and has satisfactorily tested and adjusted at least three systems of comparable types and sizes.

The testing company will not be accepted if it has any affiliations with contractors or manufacturers.

Testing company should be certified by the associated air Balance council (AABC) or approved equal. Qualified companies who are not members of AABC will also be considered.

4.2GENERAL REQUIREMENTS:

a)Give the engineer seven days notice before conducting the tests and carry out all tests in the presence and to the complete satisfaction of the engineer.

b)Include for all testing and commissioning, the provision of the necessary instruments and equipment and the supply of supervisory staff and skilled and unskilled labour. Demonstrate the accuracy of the instruments if required. Test after erection of the installations or sections of the installations or plant items to show that they comply with the requirements of the contract documents and to the satisfaction of the engineer. Perform the tests in the presence of the engineer.

c)Where necessary, test the installations in section to suit building progress. The number of tests required will be at the discretion of the engineer.

d)Demonstrate to the complete satisfaction of the engineer that the installation or any portion thereof, which has been set to work, complies with the requirements of the specification.

e)Rectify any defects of workmanship, materials and performance, maladjustment, non-compliance with this specification, or other irregularities which become apparent during the tests at no additional cost to the employer. After rectification, repeat tests, at the contractor's expense until the whole is proved free from defects and in complete working order to the complete satisfaction of the engineer. All system shall be left sound and correct.

f)The testing company shall visit the job site when fabricated ductwork is delivered and when hanging is in the very early stages and the installation is well along but before any closing-in, to verify to his satisfaction that all fittings, air volume control devices and water regulating valves are of the proper type or properly fabricated and are installed as per specifications and that he will be able to balance the systems as required herein.

g)The contractor shall furnish any special fittings or devices in the piping or duct systems as may be required by testing agency's instrumentation to obtain the required data. Artificial resistance, equal to dirty filters, shall be added to the clean filter bank by partially blanking off the filter face area.

h)Prior to any air volume testing, any furred spaces, chases, shafts, etc., which are to handle air directly without the use of sheet metal ductwork, shall be tested for leakage. First seal or otherwise prevent the leakage of air through cracks or porous materials in these spaces. All voids around piping, conduit, ductwork or other services which pierce the construction shall be caulked air-tight. Before making final duct connections and register installations to such spaces, all such openings shall be sealed off. The testing agency shall provide a source of metered air to apply approximately twice the static pressure, as determined by the engineer, to the space. The leakage of air into or out of the space shall be recorded. Leakage shall not exceed 2 % of the design air volume to be handled in the shaft or plenum spaces.

i)Air volume at each inlet and outlet shall be adjusted to within 5 % of that shown on the drawings. All test data shall be recorded.

j)Upon completion of the work submit three copies of the complete test and balancing reports.

k)Permanently mark the settings of all valves, dampers and other adjustment devices in a manner that will allow the settings to be restorted. Set and lock any balancing device which is provided with a memory stop.

1)The performance of all components of equipment shall be tested under all possible variations of loads, flow conditions, temperatures, etc. which can be simulated on the job by utilizing any of the heating or cooling equipment.

m)All testing and or balancing shall be performed in accordance with national standards for total system balance (latest edition) as published by the associated air balance council (AABC).

4.3SUBMITTALS:

Submit to the engineer for approval the name of the firm the contractor proposes to use for work, plus the name, experience and qualifications of the test and balancing engineer.

The selected firm shall submit to the engineer:

1.Detailed procedures.

2.Agenda.

3.Certified test reports signed by test and balance supervisor who performed TAB work. In addition, have report certified by the engineer.

Include identification and types of instruments used and their most recent calibration date with submission of final test report.

Include in maintenance manuals, coples of certified test reports.

4.4JOB CONDITIONS:

Don't proceed with testing, adjusting and balancing work until work has been completed and is operable. Ensure that there is no latent residual work still to be completed, and the system has started-up. Start-up shall include the following:

1.All equipment operable in safe and normal condition.,

2.Temperature control systems installed complete and operable.

3.Proper thermal overload protection in place for electrical equipment.

4.Air systems:

a.Final filters clean and in place. If conditions warrant, the contractor shall install temporary media in addition to the final filters.

b.Duct systems clean of debris.

c.Correct fan rotation.

d.Fire and volume dampers in place and open.

e.Coil fins cleaned and combed.

f.Access doors closed and duct and caps in place.

g.All outlets installed and connected.

h.Duct systems leakage shall not exceed the rate specified.

5.Water system:

a.Flushed, filled and vented.

b.Correct pump rotation.

c.Proper strainer baskets clean and in place.

e.Service and balance valves open.

4.5INSTRUMENTS:

Have in possession the required instrumentation to obtain proper measurements. Properly maintain and transport instruments in such a manner as to provide protection against damage due to vibration, impact, moisture or any other condition that may render them inaccurate.

Have instruments calibrated within a period of six months prior to starting the Project. Maintain proof of calibration with the instrument. Recalibrate instruments upon completion of the work when required by the engineer to prove reliability.

Use only instruments which have the maximum field measuring accuracy and are best suited to the function being measured.

4.6PATCHING MATERIALS:

Except as otherwise indicated, use same products as used for installation for patching holes in insulation, ductwork and housings which have been cut or drilled for test purposes, including access for testing instruments, attaching jigs, and similar purposes.

At engineer's option, plastic plugs with retainers may be used to patch drilled holes in ductwork and housings.

Refer to other relevant sections of the HVAC installation for materials to be used for patching of holes in insulation, ductwork and housings which have been cut or drilled for test purposes.

5.FUNCTIONAL AND PERFORMANCE TESTS:5.1WATER SYSTEM

After adjustments to the coils are made, settings at pumps, chillers and boilers shall be rechecked and readjusted if required.

Pressure gauges shall be installed on each coil, then the pressure drop through the coil at set flow rate shall be recorded for full cooling operation. The pressure drop across the by-pass valve shall be set to match the coil full flow pressure drop. This prevents unbalanced flow conditions when coils are on full by-pass.

The following items shall be rechecked and recorded at each cooling equipment:

-Inlet water and air temperatures.

-Leaving water and air temperatures.

-Pressure drop of each coil.

-Pressure drop across each valve.

-Pump operating suction and discharge pressures and final total discharge head.

-Rated and actual running amperage of pump motor.

-Water metering device readings.

Interlocking devices shall be checked to make sure that the refrigerating compressors shall not start unless, chilled water pumps are running.

Differential pressure switches or flow switches shall be checked to make sure that the refrigerating compressors cannot start unless a sufficient volume of water is flowing through the chiller. The same procedure shall be followed to check the boiler performance.

Lubricating oil pumps shall be checked to make sure that in case the refrigerating compressor stops for any reason, the lubricating oil pumps shall continue to run until the compressor comes to a standstill.

Automatic controls shall be checked to make sure that the refrigerating compressor will stop running in the event of:

-Failure of lubricating oil supply

-Unduly high refrigerant discharge pressure

-Unduly low refrigerant suction pressure.

-Unduly low water temperature leaving the chiller.

The manual switches at the switching cabinet shall be tested together with the associated operation and fault lamps.

Water chillers shall be tested for capacity at the set design conditions.

5.2AIR SYSTEMS:

Thermostats setting adjustment shall be tested together with the air heaters and air-coolers.

The performance of differential-pressure switches at filters shall be checked.

After adjustments at supply and return air systems are made, the following items shall be rechecked and readjusted if required:

-Blower RPM and motor full load amperes.

-System static pressures, suction discharge.

-System recirculated air and outdoor air, DB and WB temperatures.

Air flow pattern shall be tested for freedom from draughts during a heating period, and during a cooling period in the occupied areas by means of an air flow tester.

Room inside conditions (for each room) DB and WB temperatures should be checked and recorded.

The automatic back-draft dampers at roof fans and the operation of damper positioning motors shall be tested.

The manual switches and the main disconnection switches external to the main air-distribution and extraction equipment shall be tested together with the associated operation and fault lamps.

5.3SOUND TEST: (Code No. 15070)

Tests to demonstrate compliance with sound level requirements shall be conducted in selected areas of the buildings. Readings shall be measured in decibels on the "A" scale of an approved sound level meter.

Readings shall set forth the total random sound level of the selected area with the system in operation, as compared to total background sound level with the system not in operation.

If sound levels are above the specified levels, adjustments shall be made to bring the sound level within the range. If this cannot be done with the equipment as installed, recommendation shall be made to correct the sound level to within the specified range.

Sound level readings shall be taken at air diffusers, grilles, or registers, approximately 1.5 meters above the floor, on a line approximately 45 degrees to the center of diffusers, grilles or registers.

5.4RELIABILITY TESTS:

After satisfactory completion of total system balance, the contractor shall be responsible for running reliability tests for all plant and equipment.

During the reliability tests, the independent balancing and testing company will provide spot check readings as requested by the engineer and sufficient additional readings to confirm that system balance is being maintained.

The reliability tests shall be made under the full responsibility of the contractor, and he shall provide full time skilled operators for running the plant during the whole test period.

Each reliability test shall last for a period of 31 consecutive days during which time the whole of the plant under test shall operate continuously without adjustment for repair to the satisfaction of the engineer. In the event of any repair or adjustment having to be made other than the normal running adjustment, the test shall be void and the installation shall be re-tested after the readjustments or repairs have been completed. A test shall not be void due to circumstances outside the control or the contractor.

The whole reliability tests of the refrigeration and cooling plants shall take place during the period between 30th may and 1st. September and for heating plants during the period between 1st. November and 15th march.

All log sheets for recording the test results shall be prepared by the contractor and approved by the engineer. Daily log sheets duly filled shall be submitted to the engineer the following day for review and approval.

6.HANDING OVER AND MAINTENANCE6.1TRAINING OF EMPLOYER'S PERSONNEL

The contractor shall be responsible for training a number of persons who will be selected by the engineer in the correct and careful operation, control and maintenance of all the HVAC services provided under the contract before the works are handed over to the employer. The training shall be carried out by the qualified commissioning staff of the contractor for each particular service and shall be continued throughout the period proceeding the taking over unless the specifications call for more extended period or as mutually agreed between the employer and the contractor.

6.2CERTIFICATE OF COMPLETION OF WORKS

As soon as the works have been completed in accordance with the contract Documents (except in minor respects that do not effect their use for the purpose) and have passed the reliability tests successfully, the engineer shall issue a certificate of completion in which he shall certify the date on which the works have been so completed and have passed the said tests and the engineer shall be deemed to have taken over the works on the date so certified, but the issue of a certificate of completion shall not operate as on admission that the works have been completed in every respect.

In the event of the works being divided into two or more sections, the engineer shall be entitled to take over any section or sections before the other or others, and thereupon a certificate of completion shall be issued in respect thereof.

If, by reason of any default on the part of the contractor, a certificate of completion has not been issued in respect of the works after the date fixed by the contract for the completion of the works, the engineer shall be at liberty to use the works or any portion thereof in respect of which a certificate of completion has not been issued, provided that the works or the portion so used as aforesaid shall be reasonably capable of being used without harm to the equipment (except normal wear and tear) and that the contractor shall be afforded reasonable opportunity of taking such steps as may be necessary to permit the issue of the certificate of completion.

The period of maintenance for the HVAC Works shall commence from the date of certificate of completion for the building works or part thereof as appropriate, provided the HVAC services are operated on that date. In the event that operation of the HVAC services is delayed beyond the date of certificate of completion for the building works or part thereof, then the period of maintenance in respect of the HVAC services or part thereof shall commence from the date of their actual operation.

6.3MAINTENANCE (DEFECTS LIABILITY) PERIOD

The contractor shall during the maintenance period of two (2) years, replace, repair, with utmost speed, and at his own expense, any part of the plant or work performed or furnished under the HVAC services in the contract which may prove defective in design, erection, operation performance, workmanship, or from any act or omission of the contractor that may develop under the conditions provided for by the contract and under proper use of the works or any section thereof, as the case may be, have or has been taken over by the engineer.

If any defects be not remedied within the time stipulated by the engineer and to his full satisfaction, the employer may proceed to do the work at the contractor's risk and expense.

If the repairs, replacements, or renewals are of such a character as may affect the efficiency of the works or any portion thereof, the engineer may within one (1) month of such repair, replacement or renewal give to the contractor notice in writing requiring that tests at site be made, in which case sush tests shall be carried out as provided.

Until the maintenance certificate shall have been issued, the contractor shall have the right of access, at all reasonable working hours, at his own risk and expense by himself and his duly authorized representative whose names shall have been communicated previously in writing to the engineer, to all parts of the works for the purpose of inspecting the working thereof, and to the records of the working and performance thereof, for the purpose of inspecting the same and taking notes therefrom. subject to the approval of the engineer. which shall not be unreasonably withheld, the contractor may at his own risk and expense make any tests which he considers desirable.

Before the termination of the maintenance period, the contractor shall, upon the request of the engineer, assume responsibility for dismantling of any defective part of the plant and apparatus indicated by the engineer. If such dismantling, however, necessitates the interruption of service of the works, such period of interruption shall not affect the extent of the maintenance period.

The contractor shall obtain and submit to the engineer any guarantee or certificate of warranty available from the manufacturers but only as supplementary to the contractor's own guarantees and in no way invalidating them.

6.4MAINTENANCE COMPLETION CERTIFICATE

The maintenance completion certificate shall be issued after completion of the maintenance period.

The contractor shall be responsible in the last routine check preceding the end of the maintenance period to demonstrate that the complete HVAC system is in satisfactory working order.

Verification of dimensions:

The CONTRACTOR shall visit the premises to thoroughly familiarize himself with the details of the work and working conditions and verify all dimensions in the field, and shall advise the CONSULTANT of any discrepancy before performing any work. the CONTRACTOR shall be specifically responsible for the coordination and proper relation of his work to the building structure and to the work of all trades.

Workmanship:

Materials and equipment shall be installed in accordance with the approved recommendations of the manufacturer to conform to the contract documents. The installations shall be accomplished by workmen skilled in this type of work.

Nameplates:

Each major item of equipment shall have the manufacturer's name, address, and catalog or model number on a plate securely attached to the item. In lieu of nameplate, the manufacturer's name or trademark may be cast intergrally or stamped, or otherwise permanently marked.

Safety Requirements:

Belt, pulleys, chains, gears, couplings, projecting setscrews, keys and other rotating parts so located that personnel can come in close proximity thereto, shall be fully enclosed or properly guarded. Items such as catwalks, ladders, and gaurdrails shall be provided where indicated for safe operation and maintenance of equipment.

Reference Standards:

A.The following latest issue of publications listed below, but referred to by basic designation only, form a part of the specification.

B.Sheet Metal and air conditioning contractors national association, inc. (SMACNA).

1.Low Pressure duct construction standards (LPDCS).

2.High Pressure duct construction standards (HPDCS).

3.Fire Damper and heat stop guide for air handling system.

4.Duct Liner application standards (DLAS).

5.Testing, Balancing and adjusting of environmental system.

C.National Fire protection association codes (NFPA).

1.NFPA 90A, Air conditioning and ventilating systems.

2.NFPA 91, Blower and exhaust systems.

D.Underwriter Laboratories, Inc. (UL).

E.Air Movement and control association, Inc. (AMCA).

F.American National standards Institute standards (ANSI).

G.American society of testing materials standards (ASTM).

H.Air Diffusing council (ADC).

I.American society of heating, refrigerating and air conditioning engineers (ASHRAE).

J.American Refrigeration institute (ARI)

Shop Drawings and Product Data:

A.Shop drawings, material and equipment submittal, and layout drawings shall be submitted per the requirement of the contract documents. the submittals shall include illustrations, schedules, performance curves, charts, instructions, brochures, diagrams, catalog cuts and any other information necessary to demonstrate the requirements, and operation of a complete system, and compliance to the contract requirements: model numbers alone will not be acceptable. The information shall also include the name and address of the nearest service and maintenance organization that regularly stock repair parts. submittals, which shall be submitted for approval at the same time, shall be those required by the contract documents and also those for material and/or equipment which function as parts of an integrated system. Submittals for departures from the contract drawings, shall include details of such departures, and reasons for such departures. where such departures required piping or equipment to be supported other than as shown, details shall be submitted that include loading and type and kind of frames, brackets, or other necessary supports.

Approved departures shall be made at no increase in contract sum.

B.Submit shop drawings showing details of unit construction, supports, reinforcement, access doors, configuration and accessory installation for construction where these are field conditions, or CONTRACTOR options permitted by the specifications.

C.Submit shop drawings for fans with complete information on fan construction and performance. Include a complete set of performance curves for each fan.

D.Submit shop drawings for coils which show coil compliance with specified and indicated requirements, which include actual air leaving conditions compared to indicated requirements and applicable drawings showing installation position for coil to be drainable as specified.

E.Submit shop drawings of ductwork and plenums. Show details of joint construction, supports, reinforcement, access doors, fitting configuration and accessory installation for construction where these are field conditions or specified options.

F.Submit a schedule of proposed air diffusion devices, indicating type location, air quantity, neck or jet velocity, pressure drop, throw and diffusion range. Identify air diffusion devices using contract drawing designations.

G.Submit shop drawings which include tabular or graphic performance covering useable range for the system unit filters provided.

H.If deviations from contract documents are deemed necessary by the CONTRACTOR, SUBMIT with the shop drawings details of such deviations, including changes in related portions of the project and the reasons therefore for approval.

PART-C PRODUCTS

1. AIR HANDLING UNITS : (Code No. 15720)

1.1GENERAL:

The air handling unit shall consist of the required number of different factory assembled sections, described below to handle each air handling unit's specific demands given in the equipment schedules and as shown on the drawings. Unit fan and coil performance shall be certified in accordance with the ARI standard 430 for central station AHUs or other approved standard which required no lower quality than mentioned.

The design shall allow access of the housed components from the inspection side of the unit. The various unit sections shall be all made in a right-hand or left-hand version with respect to inspection panels as seen in the direction of the air flow.

The floor mounted air handling unit shall be mounted on a common, torsionally - rigid base frame of galvanized steel of height not less than 4 inches and high enough to enable easy mounting of the water trap for draining the condensate from the air cooler. The bottom frames of the unit sections shall be bolted to the base frame. The width and length of the base frame shall be selected to suit the size and combination of unit sections of the relevant unit. The water trap shall be fitted and installed at the base frame.

Air handling units installed outside shall be made of weather proof casings.

The tabulated fan static pressure shown in the equipment schedules are approximate and given for guidance. the contractor must calculate the system static pressure and provide the required fan and motor HP.

1.2 CASINGS

Casings shall be of double-skin air tight design with 1 inch thick mineral wool or glass fiber insulation and ASTM A525-71, G90- hot-dipped galvanized steel sheet with baked enamel finish. The insulation material shall provide good thermal insulation, heat transmission factor max. 0.29 Btu/hr-ft2 - F. and shall give good sound attenuation and meet NFPA-90A flame spread and smoke generation requirements.

The different sections are to be jointed by means of sturdy clamping strips.

The casing design shall allow completely smooth inside and outside surfaces for easy service and cleaning.

Inspection panels with access doors shall be provided wherever necessary for servicing the housed components. The access doors shall be tightly sealed and higned, and shall be provided with quick - release fasteners. All access doors and in fill poanels shall close upon a 1 inch side x 1/2 inch thick rubber gasket secured to the panel landing member. The extended panel edge and return angle shall provide an air tight air seal.

The casings are to withstand an internal pressure of minimum 4" of water and an internal vacuum of 6" of water. Where the total head developed by the fan is higher than 3" of water the casings shall be designed to withstand at least 125 % of the maximum head which can be developed by the fan.

1.3FAN SECTION

1.3.1General :

Medium pressure Fans (3" W.G. and above total static pressure Centrifugal fan to be of backward curved DIDW type complete with fan motor, belt drive, flexible connections and base-frame with slide rails. Fan wheels to be statically and dynamically balanced. Fans to be selected for their maximum efficiency. Impeller tip sped and outlet velocity shall ensure quiet running at all operating speeds. Shaft bearing to be of the permanent lubricated, self-aligning type. Minimum required efficiency to be 80 %, pillow block regreasable ball type selected for an average life of 200,000 hours at design operating conditions per ANS1/A

All metal parts to be well protected against corrosion and shall be factory finished coating. Pulleys suitable for use with V-belt drive to be fitted to motor and fan shafts.

Fan pulleys to be of the variable pitch type.

Fan motor position shall be adjustable by means of slide rails. Sufficient allowance in fan horsepower calculations should be made in order that design air quantities are obtained towards the end of the useful filter life when the pressure drop across the air filter is maximum.

1.3.2 Low Pressure Fans

To be same as above except fan wheels could be forward curved type.

1.3.3 Fan Drive and Guards

Fan drives shall be multiple of V-belts and pulleys secured to the fan and motor shaft by keys fitted into mechanical key ways. the motor sheave shall be of adjustable type. the v-belts shall be of the anti-static type suitable for operations in temperatures up to 50 c. The V-belt drives shall be capable of transmitting the rated wattage output of the motor with one belt removed.

Drive and pulley guards shall be readily removable to permit belts to be changed. adequate access shall be provided in the guard to allow tachometer readings and belt tension to be tested.

1.3.4 FAN MOTOR

Each motor shall be rated at least 130 % of the fans rating when running at the specified duties and suitable for operating in an ambient air temperature of 50 c. Fan motors shall be squirrel cage, totally enclosed fan cooled type wond for 380 volts, 3 phase, 50 Hz electrical supply. The motor winding shall be provided with 3 Nos. of thermistor type overheating cutouts.

All motors shall be suitable for horizontal foot mounting and shall be complete with slide rails and belts adjusting bolts.

1.4.COOLING / COIL SECTION

The coil shall be constructed from seamless copper tubes of 5/8" with profiled aluminum fins, with aluminum fine spaced at not more than 10 fins/inch. the headers and water connections shall be made of copper.

Plugged tapings for venting and drainage shall be fitted on the coil. Venting and drainage connection to be executed as specified elsewhere in the specifications.

Cooling coils shall be drainable and shall have untrapped circuits. An internal condensate pan of stainless steel sheet with drain connection to the inspection side of the unit shall be provided. The drain line shall be provided with a "U" trap suitable for the operating static pressure of the fan.

The coil shall be designed to operate with a face velocity up to max. 550 ft/min., and number of rows shall not exceed 8.

Maximum pressure drop on the water side shall not exceed 16 feet w.g. and scheduled values on the air side (but not more than 0.4 inches w.g.).

Where coil height exceeds 40" it shall be splited into two coils with intermediate drain pans with drop tubes at either end to drain condensate to the main drain pan without flooding the lower coil.

The sides of the units shall be removable for withdrawal of the coil.

The coil shall be designed for a maximum working pressure of 150 psi. Each coil shall be factory tested at a minimum pressure of 300 psi.

The coils shall be designed and tested in accordance with the American national standards institute safety code for mechanical refrigeration (ANSI 89.1).

1.5AIR FILTER SECTIONS

Each air handling unit shall be provided with complete set of air filters sections as indicated on the drawings and/or Particular specifications.

The filters shall be installed with gaskets and clips to maintain a positive pressure seal between filer and frame in order to prevent leakage, by-pass unfiltered air and facilitate installation.

Filters shall be installed in such a manner that they can be quickly and easily removed and that no special tools are required. filters can be arranged in straight bank or v-arrangement installation.

Filter-sections shall be equipped with removable access panels or doors for replacement and service of the filters.

1.6ACCESS SECTIONS

Access sections shall have hinged doors on both service sides and shall be suitable for installation between any two components. Access sections shall be provided, where necessary for inspection or maintenance purposes.

1.7EMPTY SECTIONS

Empty sections shall be provided to form a plenum on the discharge side of fans or, where necessary for erection of the thermostats.

1.8INTAKE DAMPER SECTIONS

Intake damper sections with contra-rotating blades of a torsionally rigid double-skin casing. The bearing shall be of glass-fibber reinforced nylon. The damper shall be fixed to a connection frame for jointing directly to the unit casing.

Dampers shall be sectionalized to limit blade length of not more than 1250 mm. In order to prevent excess blade warping and assure tight closure.

1.9MIXING SECTIONS

The mixing sections shall consist of two dampers of equal size with parallel-rotating blades to guarantee effective mixing. The blades shall be made of a torsionally rigid double-skin construction of galvanized steel sheet. The bearings shall be of glass fibber reinforced nylon. Dampers shall be sectionalized to not more than 1250 mm.

The dampers shall be manually operated or motor driven as specified elsewhere.

1.10MISCELLANEOUS COMPONENTS

a)Vibration Isolators

Vibration Isolators bases shall be rubber-in-shear, spring, springs under intertia base or special units from low fan rpm and usually critical applications unless otherwise specified elsewhere.

b)Pressure differential

A permanent easily read inclined type manometer with suitable range to be fitted across each filter sections supply and return air fan.

2.FAN COIL UNITS (Code No. 15760)

2.1GENERAL

Fan coil units shall be supplied and installed as shown on the drawings. The units shall be of 3 or 4 rows coil type. Coils to be suitable for chilled water application, their ratings, duties and types shall be as tabulated in the equipment schedule. The fan coil units shall be selected at medium speed to give the required capacities.

They shall generally be in accordance with the following specification.

2.2CABINETS

All fan coil units as listed in the equipment schedule and drawings shall be with cabinet or concealed type without cabinet .

2.3COIL

Cooling coils shall be constructed of heavy gauge copper tubes and copper or aluminum fins. The fin spacing shall not exceed 12 fins per inch. Tubes shall be mechanically expanded to the fins. Each coil shall be provided with manual air vent of an approved type. An insulated drain pan fitted with a drain connection shall be provided to receive all condensation and drip from internal fittings.

2.4FILTERS

Filters shall be 1" thick air filter and shall be of the heavy duty, cleanable type having non-ferrous metal wool or other well proven material arranged in a solid frame. The air filter to be located remotely in the return air opening provided in the return air plenum.

2.5FAN

The fan shall be of the multi-blade centrifugal type with balanced wheel directly coupled to an electric motor and shall operate at a static pressure as tabulated elsewhere. Noise level generated shall be within the specified limits.

2.6FAN MOTOR

Fan motor shall be of the open type suitable for 220 V single phase A.C. 50 cycles with thermal protection and shall be silent in operation.

Motors shall be of 3 speed type with permanent split capacitor starting and shall generally comply with electrical specification.

2.7CONTROLS

Each unit shall be complete with manually selected 3 speed fan control switch with "off" position. The switch shall be suitable for wall mounting for high level and concealed type units. For floor mounted units the switch shall be an integral part of the unit.

3.SUPPLY AND EXTRACT FANS (Code No. 15830)3.1GENERAL

Fans shall be used for either supply or extract with capacities and characteristics as indicated in the equipment schedules or drawings and to be selected for minimum noise level.

Fan shall be provided complete with drive and motor, the fan and motor assembly shall be factory built dynamically and statically balanced to provide vibration free operation and shall clearly indicate the direction of rotation.

Fans shall be constructed in conformity with AMCA or approved equal standard and have certified ratings based on tests performed in accordance with AMCA or equivalent. Certified acoustical and fan curve performance data shall be provided at the actual speeds required showing static pressure, total pressure, fan power and mechanical efficiency and sound power level plotted against air-volume.

Fan motor shall be squirrel cage induction type, totally enclosed, where motor is outside the air stream it shall be fan cooled (T.E.F.C).

Fan motor shall be suitable for operation on 50 cycles, 380 volts, 3 phase or 50 cycles, 220 volts, single phase as shown on the fan's schedules.

Motor RPM shall not exceed 1500 unless otherwise specifically indicated in the fan's schedules. Motor class of insulation shall be suitable for the fan application or as given in the project documents.

Fan and motor shall be treated to withstand the corrosive atmosphere such as battery rooms, laboratories applications etc.

The tabulated static pressure shown in the fan schedule are approximate and given for guidance. The contractor must calculate the system total static pressure and provide the required fan motor HP.

3.2 CENTRIFUGAL FANS:

Fans shall be either double inlet double width or single inlet single width as indicated in the project documents.

Fans having a static pressure of 3" WG and above shall be back-ward curved mild steel sheet blades and fans below 3" WG static pressure can be of the forward curved mild steel sheet blades types.

Fans shall be with or without cabinet housing and available in right-hand or left-hand version as indicated in the project documents. The side plates of the cabinet type housing shall be rectangular with provision of impeller removal. The housing shall be provided with a bolted access inspection door for the large units.

Bearings shall be of the self-aligning self-cooling babbitted sleeve type with adequate oil reservoirs or self-aligning ball type with accessible grease fittings.

Fan shaft shall be turned and ground to size from mild steel bars and by-pass shall be provided with screwing wheels and driving pulleys.

Fan motor shall be either unit mounted or mounted on the same base of the fan with the possibility of motor base adjustment.

Motor pulley and pulley shall be adjustable to provide not less than 20 percent speed variation except for fans with variable inlet vanes.

Fan drive shall be V-belts and pulleys secured to the fan and motor by keys fitted into key ways. The motor pulley shall be of the adjustable type. The v-belts shall be of the anti static type suitable for operation in temperatures up to 55 C.

3.3CENTRIFUGAL DUCT MOUNTED FANS:

Fan wheel shall be airfoil, centrifugal duct mounted type with non - overloading characteristics, high efficiency and quiet operation. The fans shall be of the heavy duty type and durable construction, provided with shut-off dampers to automatically close when the fan is not running.

The casing shall be hot dipped galvanized cylindrical and flanged at each end provided with an inspection cover to provide access for blades angle adjustment. The unit shall be also provided with flexible connection, mounting flanges and vibration isolators.

Fan blades shall be of the die-aluminum. Bearings shall be of the permanently lubricated type.

Fan motor shall be either directly coupled to the fan shaft or provided with v-belt drive, fan motor shall be explosive proof.

3.4 Axial fans (duct mounted)

- Provide either adjustable die cast impeller blades with motor integral part of hub design or die formed blades with belt drive and motor mounted outside air stream.

-Extend lubrication fittings to outside of fan casing proceed terminal box.

- Provide flanges on housing for connection of ductwork. When not connected to duct work, provide inlet cones.

- Provide easy access to fan wheel for varying blade angle setting during air balancing.

- Fans operating at over 1.5 inch W.G (374 pa) shall be of vane-axial design for improved operating efficiency.

- Provide variable inlet vanes where indicated.

3.5WALL OR GLASS MOUNTED EXHAUST FANS:

Fans shall be of axial type for glass and wall mounting complete with gravity exhaust louvers, mounting collar and inlet fan guard. Axial blades shall be die formed steel or aluminum, welded to a heavy gauge hub. Entire fan assembly shall be factory finished to be rust resistance. Fans shall be suitable for 220 volt, 50 Hz, service fans shall be rated as specified on drawings.

3.6 FAN SECTION (FRESH AIR FAN)

3.6.1 Centrifugal fan to be of forward or backward curved DIDW type complete with fan motor, belt drive, flexible connections and base-frame with slide rails. Fan wheels to be statically and dynamically balanced. Fans to be selected for their maximum efficiency. Impeller tip speed and outlet velocity shall ensure quiet running at all operating speeds. Shaft bearing to be of the permanent lubricated, self-aligning type. Minimum efficiency to be 80 %.

All metal parts to be well protected against corrosion and shall be factory finished coating. Pulleys suitable for use with V-belt drive to be fitted to motor and fan shafts.

Fan pulleys to be of the variable pitch type.

Fan motor position shall be adjustable by means of slide rails. Sufficient allowance in fan horsepower calculations should be made in order that design air quantities are obtained towards the end of the useful filter life when the pressure drop across the air filter is maximum.

3.6.2 Fan Drive and Guards

Fan drives shall be multiple of V-belts and pulleys secured to the fan and motor shaft by keys fitted into mechanical key ways. the motor sheave shall be of adjustable type. the v-belts shall be of the anti-static type suitable for operations in temperatures up to 50 deg. C. The V-belt drives shall be capable of transmitting the rated wattage output of the motor with one belt removed.

Drive and pulley guards shall be readily removable to permit belts to be changeadequate access shall be provided in the guard to allow tachometer readings and belt tension to be tested.

3.6.3 FAN MOTOR

Each motor shall be rated at least 130 % of the fans rating when running at the specified duties and suitable for operating in an ambient air temperature of 50 c. Fan motors shall be squirrel cage, totally enclosed fan cooled type wond for 380 volts, 3 phase, 50 Hz electrical supply. The motor winding shall be provided with 3 Nos. of thermistor type overheating cutouts.

All motors shall be suitable for horizontal foot mounting and shall be complete with slide rails and belts adjusting bolts.

3.6.4AIR FILTER SECTIONS

3.6.4.1FILTER SECTION & ACCESSORIES :

Each air handling unit shall be provided with complete set of air filters sections as indicated on the drawings and/or Particular specifications.

The filters shall be installed with gaskets and clips to maintain a positive pressure seal between filer and frame in order to prevent leakage, by-pass unfiltered air and facilitate installation.

Filters shall be installed in such a manner that they can be quickly and easily removed and that no special tools are required. filters can be arranged in straight bank or v-arrangement installation.

Filter-sections shall be equipped with removable access panels or doors for replacement and service of the filters.

3.6.4.2DRY TYPE CLEANABLE (WASHABLE) PANEL FILTERS:

Shall be of metallic type, constructed of galvanized steel and designed to provide maximum arrestance, large dust holding capacity and low resistance.

The filter media shall be constructed of layers of crimped corrugated wire screen and expanded galvanized steel to provide large filtering area and shall be held in a heavy gauge galvanized steel from capable to withstand shock and abuse.

The filter shall be sized for maximum air velocity of 350 fpm with initial press drop of not more than 0.1" WG and average arrestance of 75 % .

Return air filters shall be 2" thick and fresh air filters 4" thick.

3.6.5 ACCESS SECTIONS

Access sections shall have hinged doors on both service sides and shall be suitable for installation between any two components. Access sections shall be provided, where necessary for inspection or maintenance purposes.

3.6.6 EMPTY SECTIONS

Empty sections shall be provided to form a plenum on the discharge side of fans or, where necessary.

3.6.7 INTAKE DAMPER SECTIONS

Intake damper sections with contra-rotating blades of a torsionally rigid double-skin casing. The bearing shall be of glass-fibber reinforced nylon. The damper shall be fixed to a connection frame for jointing directly to the unit casing.

Dampers shall be sectionalized to limit blade length of not more than 1250 mm. In order to prevent excess blade warping and assure tight closure.

3.7 CENTRIFUGAL CEILING FAN

All units shall be AMCA certified performance rating seal and the UL label.

Grille shall be white plastic with grill screw concealed from view .

Grille shall have a minimum of 80 % free area .

Motors shall be shaded pole, sleeve bearing type supported by one piece, die

formed steel suspension brackets in combination with rubber isolation dampers, with no metal - to - metal contact .

Terminal box shall be mounted in the housing with receptacle , plug and cord inside the cabinet .

Motor and fan assembly shall be removable from install ceiling ventilator .

Duct flanges shall be pre assembled to housing .

Flexible ducts : corrugated , Aluminum or fabric supported by helically wound steel wire or flat steel strips .

3.8CENTRIFUGAL CEILING VENTILILATOR

The exhaust fans shall be of the direct driven type with white plastic framand grille unit. Rugged steel housing of reinforced construction, attained by use of heavy gauge steel, durable finish over phospatized steel resists rusting and corrosion, inside is painted a dark color to be virtually inisible through grille. The fan wheel shall be statically and dynamically balanced. Blades, finns. Motor and fan wheel shall be mounted on vibration isolators.

3.9SMOKE EXHAUST FAN

1-All fans will work in case of fire / smoke situation.

2-All fans shall have provision for manual start / stop from remote point (base room).

3-In case of fire / smoke situation in the building , smoke detector thru fire alarm panel shall active all fans simulatenous. Provided necessary interface between fire alarm panel and building mangement system.

-Fan shall be high performance heat and smoke exhaust ventilator developed specification in the event of fire.

-Fan shall be suitable for conveyance of hot smoke gases of maximum 300 (C for 30 minutes.

6-Fan shall be constructed from materials which are resistive to atmospheric corrosion. Stainless steel and aluminum alloy shall be mainly used and mild steel components wherever used shall be galvanized and painted.

7-The base and body of the ventilator shall be of aluminum alloy spinnings.

They shall be joined by aluminum alloy extrusion.

8-Base shall be supplied with turdoums for curb mounting .

9-Impeller shall be axial flow type made from mild steel.

-Motor shall be totally enclosed air steam cooled . Moror shall be class F insulation.

-Electrical connection shakll be made into a terminal box mounted on to side of motor.

-Top and buttom shutter, centrifugal latch , top and bottom guard body and motor mounting brackets shall be provided.

-Use fire resistant wiring between the main supply , the starter controls and the fan unit.

The main supply should be connected to emergency power supply.

4.AIR FILTERS: (Code No. 15820)

Air filters shall be used for outdoor air and recirculoted air and shall be tested in accordance with ASHRAE Test standards 52 - 76.

4.1DRY TYPE CLEANABLE (WASHABLE) PANEL FILTERS:

Shall be of metallic type, constructed of galvanized steel and designed to provide maximum arrestance, large dust holding capacity and low resistance.

The filter media shall be constructed of layers of crimped corrugated wire screen and expanded galvanized steel to provide large filtering area and shall be held in a heavy gauge galvanized steel frame capable to withstand shock and abuse.

The filter shall be sized for maximum air velocity of 350 fpm with initial press drop of not more than 0.1" WG and average arrestance of 75 % .

Return air filters shall be 2" thick and fresh air filters 4" thick.

This type of filters may be used as a pre-filter to a higher efficiency filter.

4.2BAG FILTERS:

It shall be of dry, extended surface pocket type consisting of 16 gauge galvanized steel holding frame and replaceable filter. Holding frames shall be predrilled for convenient assembly into banks and shall be installed to provide service from the dirty air side. Holding frames shall be equipped with factory installed special high temperature gaskets and heavy duty rotary spring type latches which fasten across the corners of the filter to force the filter firmly against the gaskets. Replaceable air filters shall consist of rigid rust-resistant metal headers to which individual pockets of filter media are attached. The media shall be made from ultra-fine fiberglass supported on the air leaving side by a protective media backing.

The bag filter shall be designed for a face velocity of 500 FPM. The required average efficiency is 80 - 85 %

The following table shows the initial and final press drops for different efficiency ranges:

Efficiency Dust spot as Per ASHREA 52 - 76

Permissible Initial Pr drop (Inches of WG)

Recommended final Pressure Drop (Inches of WG)

40 - 45

0.30

1

50 - 55

0.35

1.2

60 - 65

0.40

1.2

80 - 85

0.45

1.2

90 - 95

0.65

1.2

4.3 HEPA FILTER HEPA is designed for 90 FPM average face velocity at initial 0.47 W.G. and has arated efficiency of 99.99% at 0.3 micron or larger, permitting temporary connection of tubing for D.O.P leak testing.

4.4 Project Air Filters

Primary Air Filter (G4)

Bag Filter (F7)

-Heavy duty construction.-High performance media.-Type: high performance disposable plated-Application: pre filter for high efficiency and absolute filter.-Minimum efficiency ( 35%-Media: mixture of cotton and synthetic fibre.-Recommended final pressure drop: 250 pa-High mechanical strength.-Rigid, water resistant and carboard frame.-Fully supported media bonded on to wiresupport rigid.-Bonded into case to eliminate air by-pass.

-Ultra fin glass fiber.-Minimum efficiency EN 779 ( 85%.-High efficiency with lower overall operating resistance.-Recommended final pressure drop:250 pa -Max pressure drop 450 pa. -Type: extended surface multi pocket bag filter-Media = glass fibre.-Header frame: galvanized steel.

Hepa Filter (H13)

-Minimum efficiency (MPPS): ( 99.95% -Media: pleated glass paper.-Separator: hot melt beads.-Sealant = polyurethane.-Frame: medium density fibre (MDF) board.

-Recommended final pressure drop: 500 pa

5.AIR INLETS AND OUTLETS (Code No. 15850)

5.1GENERAL

All air inlets and outlets shall be made of extruded aluminum alloy, polyester powder coated, oven baked and with a suitable colour to the satisfaction of the engineer.

All air inlets and outlets shall be tested by an approved laboratory and certified by ADC (Air Diffusion council) or an approved equivalent.

5.2LINEAR SLOT TYPE DIFFUSER

The diffuser should have a fully adjustable deflection blades which allow the air pattern to be controlled along with the ceiling, straight down or at some intermediate setting.

Every slot is individually adjustable and equipped with 2 deflector vanes of a special design to minimize the internal turbulence obtaining and ideal air pattern adjustable over 180 (

Supply linear slot diffusers shall be equipped with volume control damper. The damper shall be attached to the rear side of the diffuser and shall have a black finish.

Supply linear slot diffusers shall be equipped with equalizing grid of extruded aluminum with black finish.

Both supply and return slot linear diffusers must be equipped with acoustic plenum easily mounted on the slot diffuser.

The plenum is made out of galvanized sheet steel with or without a damper . The plenum has to be rigidly insulated.

5.3DIFFUSERS

Diffusers shall be square or rectangular suitable for ceiling installation and duct work application as shown on project drawings. They shall be provided with rubber gasket or foam tape at the outer edge of the frame to produce a positive air seal at the mounting surface. They shall be produced with removable core and provided with equalizing grids. Face plates shall be furnished with concealed hinges and clips. Duct collars connecting duct of diffuser shall be air tight and not interfere with the volume control damper.

-Supply air diffuser shall be equipped with opposed blade volume damper adjustable from the face of the diffuser without removing the core.

5.4TRANSFER GRILLE

It shall consist of two closely spaced grilles with connection collar. The grille shall have fixed deflection blades set at an angle of 35 and parallel to long dimension with mounting frame. The free area of the transfer grille shall not be less than 65 % of the total face area.

5.5DOOR GRILLES

The frame shall be separated from the blades by an extruded rigid PVC track which shall be an integral part of the frame. The blades shall be of v-shape, mounted in the PVC track and spaced 1/2 " on centers.

5.6DISC VALVE

Disc valves shall be used for exhaust air and shall consist of valve disc fitted to valve seat by means of an adjustable valve spindle, complete with separate mounting frame and connecting socket including sealing ring. front section shall be produced in stove-enameled sheet steel and rear parts shall be made of galvanized sheet steel.

5.7SAND TRAP LOUVERS

Sand trap louvers must have a high degree of separation of sand and large dust particles even in case of high dust concentrations. It must be self-cleaning and maintenance free . The sand is drained by using vertical sections and holes.

Sand trap louvers frame and blades shall be made of extruded aluminum alloy , polyester powder coated , oven baked with a suitable colour to satisfaction of the engineer.

6.SOUND ATTENUATORS

6.1GENERAL

Sound attenuators whether rectangular or cylindrical shall be rated in a laboratory in accordance with ASTM E477, Standard Method of testing Duct liner materials and air flow performance. This procedure shall include ratings for acoustical performance in terms of net insertion loss, in dB, press, drop and aero-dynamic loss. Proper location of the silencer in the duct system is of importance in order to avoid breakout of fan noise to occupied areas if unsilenced duct is installed above these areas. The preferred location for silencers is in the fan room or in ducts upstream of occupied areas in supply systems and downstream of occupied areas in return air systems.

6.2RECTANGULAR BAFFLE TYPE ATTENUATORS

The baffles shall be enclosed in an outer reinforced casing of galvanized sheet steel and provided with sealing strips at both ends. Each baffle shall be of a perforated sheet steel casing with a mineral wool fill. The inlet ends of the baffles shall be rounded to ensure a low pressure drop.

6.3CIRCULAR ATTENUATORS

The attenuator shall be of a tube of perforated sheet steel enclosed in a casing and end plates made of galvanized sheet steel. The space between the tube and the casing shall be filled with mineral wool. silencers of more than 250 mm. Diameter shall be provided with one center baffle.

7.DAMPERS (Code No. 15820)7.1VOLUME CONTROL DAMPER

Volume control Dampers shall be provided in duct work to regulate and balance air systems, since dampers on the air inlets and outlets shall be used only for fine or secondary regulating or balancing. The damper shall be fabricated in accordance with SMACNA Duct construction standards.

Single blade dampers shall be used for blade widths up to 12" provided that there is sufficient length of straight duct after the damper to ensure equal flow before the next take off or outlet. Where the damper width is over 12", multiplied dampers shall be used. Multiplied damper styles shall be generally, parallel blades for two position operation and opposed blades for modulating position. The blades shall be constructed of galvanized sheet, suitably stiffened by forming or other method, and assembled in prime coated or galvanized channel frame with suitable hardware. The bearings shall be of bronze or oil impregnated nylon.

Locking and indicating quadrant regulator shall be provided for each damper. The indicating quadrant shall be clearly marked to indicate close, 1/4 , 1/2 , 3/4% and open positions. On insulated ducts, quadrant regulators shall be mounted on stand off mounting brackets or bases. For motor operated damper, the motor-operator shall be electric or pneumatic as indicated in the project documents.

7.2MOTORIZED VOLUME DAMPER

A substantially constructed, motorized damper of the multiple blade type (200 mm, maximum blade width) shall be fitted where required or shown on the drawings with galvanized steel interlocking blades, sleeves, bearings, or as required for volume control purposes, and galvanized steel frame. Blades shall be fabricated from 1.5 mm., steel with seamed edge and a maximum length of 1200 mm. Operating rods and linkage for connection to an electric damper motor shall be provided.

7.3GRAVITY SHUTTERS

Dampers of the back draft type shall be constructed of parallel blades, balanced to open automatically when the fan starts and to close tightly when the fan stops. The blades shall be constructed of galvanized steel or aluminum with interlocking edges provided with rubber strips to prevent ratting. Blades to be supported on galvanized steel or aluminum frame.

7.4FIRE DAMPERS

Shall be fabricated in accordance with NFPA 90A and Ul 555 or equivalent and shall be as follows:

To be provided in ducts and openings in shafts, floor, fire walls, fire partitions and fire rated ceilings.

In horizontal ducts, fire dampers may be single or of the multiplied type. in vertical ducts only single-bladed.

Galvanized sheet steel housing provided with angled flanges on both sides.

The damper shall be of 1.6 mm. thick sheet steel or steel/mineral fiber/steel sandwich of equivalent fire resistance, thermally released.

Fire dampers shall be equipped with fuse plug, positioning leavers, fittings and position indicator accessible from outside.

8.DUCT WORK: (Code No. 15810)8.1DUCT MATERIAL

All ducting shall be made of galvanized steel sheet to ASTM A 525, lock-foaming quality, having zinc coating of 1.25 OZ. per sq. ft. (382 g/sq.m.) for both sides in conformance with ASTM A90 and of tensile strength in range of 28/33 tons per square inch.

8.2LOW PRESSURE RECTANGULAR DUCT WORK:

Gauges of G.I. sheeting, type of joints, bracing etc. used for the manufacture of low press. ducting shall be as per SMACNA recommendation:

All transformation pieces of ducting shall have slope of 1 in 7, where it is not possible to maintain this, a maximum slope of 1 in 4 shall not be exceeded.

All the side outlet take off (outlet collars) shall have a throat radius of not less than the width of the take off and to be fitted with fixed turning vanes.

All Tees, bends and elbows shall be constructed in such a way that the radios will not be less than 1 1/2 times width of duct on centerline. Where this is not possible turning vanes shall be provided.

Duct sizes shall be increased gradually, not exceeding 15 degrees divergence wherever possible. Divergence upstream of equipment shall not exceed 30 degrees, convergence downstream shall not exceed 45 degrees.

Easements shall be provided where low pressure ductwork conflicts with piping and structure. Where easements exceed 20 percent duct area, duct shall be split into two maintaining original duct area.

8.3TURNING VANES

Shall be fabricated in accordance with SMACNA standards.

Turning vanes shall be as follows:

Factory or site-fabricated using factory-fabricated vane spacing rails.

Turning vanes shall be provided in all square elbows, take-off or extension collars to supply outlets and tap-in branch take-off connections.

Turning vanes shall be reinforced by rods or sectional construction.

Turning vane arrangements and thickness shall be as shown in the following table:

SINGLE VANE SCHEDULE

TYPE

Space Between

Radius

Gauge

Small

1 1/2"

2"

24

Large

3 1/4"

4 1/2"

22

8.4ACCESS DOORS

Air tight access doors with rubber linings shall be installed in all ducts at fans, filters, heaters, fire dampers and volume dampers for inspection, cleaning and maintenance purposes.

The opening in the ductwork shall be properly stiffened at the edges, with frames revited or welded to the duct. the access door shall be as follows:

All access doors mounted on insulated ducts shall be of sandwiched type, having the same insulation thickness as that of the duct, with cam lock handles.

Max

DIM

NO. OF HINGES

NO. OF

HANDLES

GAUGE

DOOR

BACK

FRAME

12X12

2

1

26

26

24

16X20

2

2

24

26

22

24X24

3

2

22

26

22

8.5FLEXIBLE CONNECTIONS

Flexible connections shall be fitted on all suction and discharge connections of fans and air conditioning units, for preventing transmission of vibration through the ducts to occupied spaces.

Flexible connections shall be flame proof factory, fabricated from chemically impregnated canvas. Connections shall fit closely and be secured in an air-tight fashion to duct work, fans and apparatus by means of angle iron or flat iron frames. The unclamped section of the flexible connection between the apparatus and the ductwork shall be not less than 6" in length. Flexible connections shall not be painted.

8.6SUPPORTS AND HANGERS

Installation of supports and hangers shall be as follows:

Supports and hangers shall be attached only to structural framing members and concrete slabs. They shall not be anchored to metal decking unless a means is provided and approved for preventing the anchor from puncturing the metal decking.

Supports shall generally comprise galvanized steel sections, and where heavy items of equipment occur within ductwork additional support shall be provided as necessary.

Duct work hung from inserts or from clip angles shall be secured with expansion bolts in shear.

Supports for horizontal ducts shall be PER SMACNA STANDARD.

Design of supports for vertical ducts will be dictated by site conditions and spacing may be greater than for horizontal ducts.

Supports for vertical ducts shall be angles and channels made of galvanized or painted black steel.

8.7FLEXIBLE DUCTS

For connections between branches, risers or mains to mixing units, air outlets and inlets or for combination lighting air distribution units. Flexible ducts to be manufactured from vinyl or anosol bonded to glass fabric zine-coated flexible metal, or constructed of two - element sprial construction composed of a corrosion - resistant metal, supporting spiral and coated fabric or approved equal materials with a mineral base.

8.8DUCT TEST HOLES

Test Holes shall be factory fabricated, air tight flanged fittings with screw cap. for insulated ducting extended neck fittings to clear insulation shall be provided.

9.THERMAL INSULATION AND FINISHING:-9.1General Requirements:

Thermal insulation shall be of on approved material with thermal conductivity not higher than 0.29 Btu/hr.ft. 2 f. inch measured at an average temperature of 100F.

The thermal insulation shall be non-corrosive to the metal, water repellent, fire retardant, sustenance to vermin and easily cut and fitted to shape during application.

The insulation shall be provided with approved fire retardant vapor barrier jockey to prevent moisture penetration to the insulation. Vapor barrier shall also be applied to all joints and edges.

The insulation shall be fixed into the material surface by means of an approved adhesive compound that has no corrosion effect on the metal, and thoroughly applied to the metal surface and insulation.

The insulation and finishing shall be carried out by skilled lobour, and before thermal insulation is applied, oll metal surfaces shall be thoroughly cleaned and treated with approved corrosion inhibitor.

Insulation shall be applied in such a manner that air circulation within the insulation or between the insulation and pipe, duct or equipment is completely prevented. Pipe insulation shall fit snugly on the pipe and duct insulation shall be adhered to the duct surface with special adhesive.

All insulation joints shall be firmly butted together, made absolutely tight and finished smooth.

Vapor barrier jackets shall have 5 cm minimum overlaps. Longitudinal overlaps on exposed work shall be made towards ceiling or wall.

All insulation shall be made continuous through sleeves, openings and pipe hangers. The hanger shall be of size to fit around the insulation and jacketing.

Insulation shall be applied in such a manner as to permit expansion and contraction of the metal without causing damage to insulation or surface finish.

Openings made in the insulation shall be provided with metal frames to protect the edges of the insulation, and vapor sealed.

9.2Pipe Work Insulation:

Chilled, Hot, condenser Water, Refrigerant Pipes, valves, strainers, etc., and fittings shall be insulated with rigid fibber glass of not less than 6 lb/ft3 density or equivalent, performed sectionally and split longitudinally into two halves with factory applied reinforced aluminum foil coating with following thickness:

INSULATION MATERIAL THICKNESS

Service

Pipe Size

Up to 2"

2 1/2 - 6"

8" & above

1. Chilled/Hot water Pipe exposed to sun

1"

2"

3"

2. Chilled/Hot water pipes in non A/C areas.

1"

1 1/2"

2"

3. Chilled/Hot water pipes in A/C areas.

1/2"

1"

1 1/2"

4. Condenser water (cold) pipe from cooling tower to condenser exposed to sun

1"

1"

1"

5. Condensate drain pipe

1/2"

1/2"

--

6. Refrigerant (suction pipe only) inside building.

1"

1"

--

7. Refrigerant (suction pipe only) exposed to sun.

1 1/2"

2"

--

The insulation shall be secured to the piping by adequate number of non-corrodable straps 2 nos./3 ft. drawn tight and neatly cut. The straps shall not in any way cut the insulation or vapor seal. Wires shall not be accepted.

All insulated pipes running inside A/C plant room or inside air handling unit rooms and other machinery rooms or where they are exposed to view, shall be cladded with anodized 0.4 mm. thick aluminum sheets neatly installed. No pointing is required above the aluminum clodding. Coloured arrows and indications shall be used as specified else where.

All insulated pipes inside tunnels, shafts, and above false ceiling shall be cladded with 0.3 mm. thick smooth PVC sheet.

Pipes running underground or in trenches below ground level, whether back-filled or not, shall be specially trea