hvac vrf installation method statement

7/25/2019 HVAC VRF Installation Method Statement

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COMMINT NIGERIA LIMITED

HVAC INSTALLATION METHOD STATEMENT

1. Introduction

The fxing o all air conditioning equipment, installation o all rerigerant pipework, duct work, insulation work, drain pipe work and ull commissioning shall

be perormed by Commint Nigeria Limited, a specialist V! installer who is

authori"ed to install #$%&%N equipment'

%n the course o installation Commint Nigeria Limited will apply the best

practice methodology in carrying out its duties and will strictly adhere to the

ollowing(

)') etain the responsibility to ad*ice o any aspects which, based upon

experience, would appear to be inappropriate and+or likely to lead to

operational problems'

)' -ealth . /aety at 0ork $ct )123, and all other rele*ant attendant

legislation, particularly the management o -ealth . /aety at 0ork

egulations )11, 4ersonal 4rotecti*e 5quipment at 0ork egulation )11

and the Construction, #esign and 6anagement 7C#68 egulation )113'

)'9 5nsure that all personnel are in possession o the appropriate personal

protecti*e equipment to comply with the 4ersonal 4rotecti*e 5quipment

egulations )11'

)'3 5nsure that all personnel are ully competent in the work they are taskedto perorm and any claim to stated qualifcations are *alid'

)':5nsure that all personnel are instructed to comply with the pre*ailing site

rules'

)'; 6ust use calibrated and regularly checked tools' 5lectrical tools will be

calibrated and checked annual

)'2


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utili"ed to minimi"e >oints on site' !urthermore all o the ollowing points should be

adhered to'

') $ll copper pipes up to ) )+?@ 7? mm8 outside diameter 7A+#8 shall be abricated

rom rerigerant quality tube to B/ 5N )331()111' Tube shall be ully annealed up

to 2+?@ 7 mm8 outside diameter 7A+#8 only' Tube shall be deli*ered to siteinternally degreased and shall be stored in clean dry conditions with ends sealed

until required or installation'

' $ll due consideration and allowances shall be taken to keep pipe work clean and

dry during the installation works, ensuring that all pipe work unfnished ends are

capped o at all times'

'9 The number o >oints bends and sets are to be kept to a minimum' Butt >oints

will not be acceptedD properly swaged >oints must be ormed' Bends and sets are to

be machine pulled to an appro*ed radius where possible'

'3 !lared >oints must only be used when connecting to the manuacturer

equipment'

': 4ipe work to be properly fxed and supported using a recogni"ed industry

appro*ed support system'

'; Bra"ing shall be carried out in accordance with British erigeration $ssociation

/pecifcation or Bra"ing and B/ )393(==3' Bra"ing rods shall be cadmium ree

and conorm to B/ 5N )=33()111' $t all times, when bra"ing, a small amount o dry

nitrogen must be purged through the pipe to pre*ent oxidation and scaling

internally' $ny component susceptible to heat during the bra"ing process that may

be damaged must be protected' /ot solder shall ne*er be used or >ointing o

rerigeration pipe work'

';') $ll completed 3)=$ systems will be strength and leak tested with dry

nitrogen as per itemi"ed below and B/ 5N 92?' % the system is ound to be leak

ree, the fnal pressure readings or both strength and leak testing are to be

witnessed by either the main contractor, the consultant or endEuser and recorded

in the test result Log Book'

) bar, /trength test or a period o time that is acceptable to show any signs o

deormation to the pipe work'

) bar or fnal leak test or minimum 3 hours' 4ressure testing signage will be

clearly *isible on site during testing periods'

';' $ll completed 3)=$ systems will be leak tested with dry nitrogen as

below and B/ 5N 92?' % the system is ound to be leak ree, the fnal pressure

readings or leak testing are to be witnessed and entered into the log Book


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)8 9'= bar 7N8 6inimum o 9 minutes'

8 ):'= bar 7N8 6inimum o 9 minutes'

98 )'= bar 7N8 6inimum 3 hours'

'2 An completion o strength+leak testing an e*acuation is to be carried out tomm -g 7 Torr8'This will eliminate the risk o any moisture being present within the

pipe work installation' %t is recommended that a triple e*acuation process be carried

out as below and this should then be ollowed by a pressure rise test'

; /teps 5*acuation

)8 5*acuate the system to )= Torr rom both ser*ice *al*es' /ystem maniold

gauges Fmust not@ be used to measure a *acuum' $ Torr gauge must be used at all

times'

8 Break the *acuum with A!N 7N8 into Fsuction@ ser*ice *al*e to ) bar'

98 5*acuate to : torr rom Fdischarge *al*e@'

38 epeat step '

:8 5*acuate to lowest pressure *acuum pump will achie*e 7 torr or ) hour

minimum8'

;8 4ressure rise test to be carried out or a minimum o 9= minutes'

$. Drain i!e "or#

$ condensate line shall be installed to each an coil unit' This shall be installed and

insulated as per the standard specifcation' 6inimum si"e o condensate pipes to be

):mm plastic and insulated' Condensate shall be pumped rom each an coil, drains

to run )(?= minimum alls'

9') 4ipe work will be adequately supported in such a manner as to permit ree

mo*ement due to expansion and contraction'

9' 4ipe work should be graded to all throughout, run to waste, and should be

accessible or cleaning'

9'9 An completion, a leak and unction test must be carried out'

9'3 Gra*ity drains will be installed whene*er possible'

%. E&ectrica& 'or#


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The contractor shall include or the design and installation 7unless otherwise

specifed8, including connecting all items o mechanical equipment' The Contractor

shall pro*ide and install all wiring, cables, conduit, trunking, cable trays, termination

points, local means o isolation, control wiring etc', to mechanical plant items to

ensure that all items o equipment and controls ully unction in accordance with

manuacturersH recommendations and the current %55 0iring egulations, C%B/5Codes o 4ractice, British /tandards and


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smoke or toxic umes' %nsulating materials should be o Class FA@ rating as defned

by the Building egulations'

:') Thermal insulation will be ftted to all the pipe work installations detailed herein'

$ll materials used will be JnonEcombustibleH Class FA@' $ll insulation materials,

adhesi*es and fnishes, will be suitable in all respects or continuous use withoutdegradation throughout the range o operating temperatures and within the

en*ironment indicated'

:' The materials and method o installation will comply with all rele*ant British

/tandards Codes o 4ractice'

:'9 The material will consist o Kexible C!C ree, elastomeric black oam with a

closed cell structure'The outer surace o the oam will be an inherent *apor barrier'

:'3 %n all cases where pipes pass through fre compartment walls, fre resistant and

nonEKammable insulation+oam will be packed between the pipe slee*e and the

pipe' $ll insulation will be supplied at the thickness specifed in rele*ant -V$C

standards'

*. Duct"or#+ Gri&&e) and Di,u)er)


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;'2 $ll ductwork systems will be ftted with sucient *olume control dampers to

enable system balancing' To pre*ent noise regeneration fnal trimming to )=M only

o airKows to be carried out using the opposed blade dampers ftted to terminal

de*ices'

;'? !ire dampers are to be ftted to ductwork passing through designated frebarriers, these dampers to be ftted with -5V$C installation rames where passing

through structural walls'

;'1 !lexible ducting shall be used to orm the fnal connection to the air terminal

de*ice' The maximum length not to exceed )': meters and incorporate a change in

direction o not greater than 1=I'

;')= !lexible ducting will be manuactured rom aluminum+polyester+aluminum

laminate enclosing a high tensile steel wire helix' 0here required Kexible ducting

will be o the insulated type with an outer >acket o reinorced aluminum laminate

gi*ing a Class FA@ rating'

;')) oints between Kexible and rigid ductwork to be secured by worm dri*e clip

with the rigid ductwork spigot incorporating a JswagedH end'

;') %nsulation will be applied to the ollowing ductwork systems( E !resh air intake

ductwork, *entilation return air ducts passing through unheated spaces E $ll

conditioned air ductwork 7unless an architectural eature and adequate control is

pro*ided to pre*ent condensation orming on the ductwork8'

;')9 %nsulation shall be either ockwool duct wrap minimum :mm thick, or

phenolic oam, with reinorced aluminum oil *apor barrier gi*ing a Class FA@ rated

fnish and a thermal conducti*ity o ='=)?0+6+O&' The insulation is to be applied in

accordance with the manuacturerHs recommendations' $ll >oints to be securely

taped with 2:mm wide sel adhesi*e aluminium tape and urther secured with wire

loops at )'=m inter*als'

;')3 $ll ductwork will be ftted with identifcation bands and directional arrows in

accordance with B/ )2)=()1?3'

;'): $ir terminal de*ices will be selected to pro*ide the required air Kows+throws or

the system design, are to pro*ide a draught ree en*ironment in all operating

conditions and take into account the acoustic requirements o the installation'

Generally terminal neck *elocities will not exceed 9':m+s to pre*ent noiseregeneration'

;'); $ll outdoor duct work will be insulated with a :=mm thick ockwool duct wrap

minimum or phenolic oam , with reinorced aluminum oil *apor barrier gi*ing a

Class FA@ rated fnish and a thermal conducti*ity o ='=)?0+6+O&, with additional

aluminum cladding as anti weather'


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-. reco//i))ioning

The ollowing items must be checked prior to any systems being switched on'

2') $ marked up scale site drawing showing all V! units and rerigeration pipework, address settings 7or units and remote controllers and BC branch connections8

and model+serial numbers must be produced'

2' City 6ulti %ndoor


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?') Connect 6onitor Tool and check system connect inormation is correct i'e'

Autdoor

hvac vrf installation method statement

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