Below is a precise method statement that covers the installation of HVAC Ducting Outlets i.e. Grills and Diffusers.
Scope of work includes all the ductwork for the project covering the outlets as per the approved schedule.
Project manager is overall responsible for the control of all related activities including the quality of work and health and safety of all workers/employee’s at the site.
Site mechanical engineer in coordination with supervisors shall be responsible for implementation of this method statement and all relevant project specifications and any regulatory requirements.
QA/QC engineer shall make sure the workmanship is of good quality and all specification requirements are fulfilled at all stages of the activity.
Proper safety harness to be used and secured as applicable while working on height.
All employees working on the project shall wear personal protective equipment according to the nature of the job.
Housekeeping of good standard shall be maintained on the site , all cut materials, and debris shall be removed on daily basis.
Tools & Equipment’s
Below is list of necessary tools and equipment for performing the ductwork and accessories installation.
Setting out Markers
Drill Machine / Hammer
PPE for all workers
Step Ladder / Scaffolding
Method of Grills & Diffuser Installation
Site supervisor will ensure that approved shop drawings, material submittals and all necessary documents including installation methods are available at the time of installation.
Before issuing the materials from store it shall be ensured that all grills diffusers and other duct accessories are approved by the consultant.
Any defective, damaged or unapproved material shall be returned to supplier or kept separately in a quarantine.
Ceiling Installation of Grilles & Diffusers
Unless otherwise specified, all installation shall be in accordance to approved shop drawings and contract specifications.
Drawing plans, schematics, and diagrams indicate general location and arrangement of Grilles & Diffusers, the installation shall be done as per the final approved coordination and ceiling drawings.
During the installation make sure the availability of space for future maintenance and cleaning etc.
The final location should be suitable for optimum performance of the outlets.
Transfer the Grilles & Diffusers from the stores to the working area, taking into account the make, model, capacity, and tag number, this will ensure the correct material is installed at the correct location.
After completion and clearance of the false ceiling work mark the location of grill/diffuser as per approved false ceiling drawing.
Cut the opening using the suitable electric cutter/grinder.
Check the level of ceiling board surface while installing grilles & diffusers.
Grilles & Diffusers should not be directly supported on gypsum surfaces, provide proper frame at the back of the false ceiling to support the grill/diffuser.
All Supply and Return air diffusers / grilles shall be supported independent of the ceiling suspension system.
Supply diffusers shall have drop rods fixed to the concrete and attached to the plenum boxes.
Diffusers shall be fitted to plenum boxes with concealed fixing.
Where grilles are not fixed with plenum boxes it shall be fixed to rigid duct work with concealed fixing.
Check grilles/diffusers collars are securely fixed to the inside frame.
Ensure that the damper blades of supply grilles and diffusers are properly secured in nylon bushes for rattle free operation.
After installation, adjust diffusers, registers, and grilles to air patterns indicated or as directed, before starting air balancing.
Wall Mounted Installation of Grills/Diffusers
Grille should not be fixed directly on the wall.
Frame works for all grilles to be provided by the main contractor.
Check horizontal & vertical vanes of grilles and register, there should not be any bend and adequate support should be provided by manufacturer if grille is long.
Ensure the installation of grilles / diffusers are carried out in accordance with manufacturer installation recommendations.
Ensure that all grilles / diffusers are covered and protected from damage till the completion of construction works.
Check grilles / diffusers flexible connections are properly connected with duct and plenum and both side are clamped with jubilee clamp.
Where linear grille is used, plenum box shall be used as final connection of the duct branch to the grille.
Gaps in between the connection shall be sealed using approved sealing materials / sealants.
Install diffusers, registers, and grilles with airtight connections to ducts and to allow service and maintenance of damper, air extractors, and fire dampers etc.
On satisfactory completion of the installation works, an internal inspection will be carried out to ensure correct installation as per approved drawing, project specifications and method statement.
Notify the main contractor / consultant in advance at least 24 hours prior to offering for consultant’s inspection.