This hvac method statement covers the supply & installation of grilles, diffusers louvers & disc valves in line with project requirements as indicated in the approved shop drawings, reflected ceiling plans, specifications and manufacturer’s instructions.
Plant and equipment required
- General tool box including screwdrivers
- Electric drill with appropriate bits
- Spirit level, water level
- Measurement tape
- Marking tools
- Ladder
- Mobile scaffolds
- Lifting Equipment
On arrival at site all grilles and diffusers shall be checked for quantities, type, model no, physical damage etc. and the supplier will be notified of any discrepancies.
Upon satisfactory inspection, the grilles and diffusers shall be stored properly with protective covering.
Any items found damaged or not suitable as per the project requirements shall be quarantined, non compliant material shall be clearly marked and stored separately to prevent any inadvertent use until returned to the vendor.
Construction Supervisors to ensure that all ductwork and insulation have been inspected and signed off by the client prior to the installation of diffusers, grilles and louvres to the HVAC ducting system.
It is also responsibility of site engineer and supervisor to ensure plenum or terminal box openings are compatible for diffusers, grilles and louvres to be installed.
Roles and Responsibilities
Project manager will oversee the whole project ensuring that people have the necessary information to perform their job roles.
Construction manager will ensure that the relevant department is aware of and understands the requirements of this hvac method statement. He will ensure all relevant safety precautions in the delivery of the job are adhered to and will implement company safety standards and compliance.
Site engineer will ensure all the works are being carried out as per the latest approved drawings and specifications and co-ordinate with QA/QC department for inspection and approval and will ensure all relevant safety precautions in the execution of the job are adhered to at all times and implement company safety standards and compliance.
Quality department will be part of all quality inspections testing and control regarding installations of grilles and diffusers. Only approved sign offs from this department can allow activities to proceed.
Foreman will ensure that his crew understands this method statement and works are to be executed safely, within the time schedule and specified finishes. All foremen will provide the crew with appropriate PPE for the works and make sure it is implemented.
Installation team will execute the works safely, within time schedule and under the direct supervision of the Charge Hands and Foreman and they are also responsible for keeping the work area clean and tidy.
Health & safety HSE officer is to monitor and implement all Health, Safety and Environmental precautions and aspects of the works on site. All precautions that are put in place will be made apparent to all persons relating to this activity and situation.
HSE Health and Safety Requirements
Working at height requires edge protection (at the correct height) and in most cases harnesses with the correct length for the height of work and attached correctly.
Slab openings are to be well protected.
Prevention of falling materials from height, this would involve toe boards on scaffolding etc.
All workers to wear appropriate PPE for the task, i.e. goggles, mask, gloves etc. The foreman should provide all the necessary PPE and implement the wearing of it.
Electrical power tools will be approved, double insulated or grounded to avoid electrical shock.
Fire extinguishers are to be placed within reaching distance any works that is within risk of a fire.
Plant and equipment will have third party inspection certificates and be inspected prior to use.
All personnel entering the site will wear the appropriate PPE.
Pre Installation Checks and Requirements
- Check and ensure that the shop drawings used are the latest and approved for construction.
- Check the grille and diffuser openings and ensure they are as per approved drawings.
- Shift the grilles and diffusers to the place of installation in a safe manner using hand trolley, fork lift as applicable. Sufficient manpower will be engaged as required for safe shifting and installation.
- Ensure that the correct grille or diffuser is shifted to the place of installation.
- Volume control dampers will be installed for all inlets and outlets including concealed adjustment devices, which should be accessible without dismantling any plant, these will be shown on the contractors as built drawings and in general will be incorporated within the component that will have all internal sections painted matt-black. Prior to installation it will be ensured that Plenums are correctly acoustically lined.
- During unpacking of DGL’s care will be taken to avoid damage to the finished face of DGL’s and if any damage is noticed the supervisor will inform engineer to get the replacement.
- All diffusers, grilles and louvres will be checked against the relevant schedules by the construction supervisor prior to the commencement of installation, ensuring they are of the correct type and size as reviewed by the client/consultant. All material must be pre approved by consultant.
- Check for other services, making sure that there is no interference between each service & adequate access to work and for future maintenance can be maintained.
Installation of Diffuser, Grill & Louver (DGL)
Follow the manufacturer’s instructions while installing the grilles and diffusers.
Drawings indicate general arrangement of ducts, fittings, and accessories, air outlet and inlet locations have been indicated to achieve design requirements for air volume, noise criteria, airflow pattern, throw, and pressure drop. Make final locations where indicated, as much as practical.
For units installed in lay-in ceiling panels, locate units in the centre of panel.
Where architectural features or other items conflict with installation, notify architect and coordinate for determination of final location.
Install diffusers, registers, and grilles with airtight connections to ducts and to allow service and maintenance of dampers, air extractors, and fire dampers.
Install subframe in the duct opening as manufacturers instructions and ensure that DGL shall be installed correctly as per the direction of air flow.
Prepare DGL by installing sealing material to the internal side of the mating flange, carefully locate DGL into subframe and locate locking screws and tighten until correct level and the alignment is achieved.
Make sure that screws are fixed into a metal/ wooden frame which sits in counter sunked holes through border.
If the aperture is in masonry, the hole locations should be marked, then drilled and plugged to give more positive fixing.
Concealed rear bracket fixing is for use when a hidden fixing is required but the installation prohibits the use of clip fixing.
For fixing of Grilles, Diffusers, Louvers & Disc Valves without dampers, the grilles, perforated 4 way Diffusers, louvers & disc valves are positioned into opening with metal/ wooden frame screws are fixed through the brackets fixed into the stack of Grilles, Diffusers, Louvers & Disc Valves to the frame holes.
For Grilles, Diffusers, Louvers & Disc Valves with dampers, the dampers can be fixed with Grilles, Diffusers, Louvers & Disc Valves border by clip or rivets and damper is fixed by screwing to the duct opening. Otherwise the damper alone can be directly screwed to the duct chute.
After final alignment, carefully tighten the unit until airtightness is achieved.
Before finalizing each installation of DGL ensure it is undamaged, clean and screws are tight.
Ensure that all DGL are left in closed position and protection is provided until HVAC testing commissioning and handover.
Verify all items are furnished and installed as required, and approved also verify finishes in areas match as required i.e. RAL colors etc.
Make sure that volume control devices are provided as required and are accessible.
Verify gaskets are provided and installed as required.
The supervisor in charge and the QC Engineer will continuously monitor the activities to ensure that all diffuser, grill and louver and accessories/components indicated on the approved construction drawings have been installed and that the completed installation is in accordance with the contract requirements and manufacturers recommendations.
After all installation has been done, raise immediate inspection for approval.
Relevant documents or certificates shall be presented at the time of inspection if required by the consultant. (Coordination Drawings, Reflected Ceiling Plan, FM Listing etc.)
Attachments:
- Inspection and Test Plan ITP
- Inspection Checklist
- Risk Assessment
- Manufacturer Instructions
- Approved Drawing/RCP
- UL / FM Listing Certificates