Method Statement for HVAC Duct & Accessory Install

This method description of HVAC system installation describes the different procedures for HVAC ducts. It also includes instructions for return and exhaust ducts. The installation method statement will outline the work and the requirements to be followed.

Scope of Work


All workers should attend safety induction training provided by the contractor.

Make sure that the material you are using is approved and checked.

For the design of systems, you should use accepted engineering practice and data. You must ensure that all materials necessary for work are available. If possible, signage and barriers should be installed in all working areas.

A rooftop platform enables you create safe access to pipes and other rooftop obstructions. Special support feet distribute weight so that roof membranes are not damaged.

Access and areas will need to be inspected before work can commence.

The Site Engineer/Supervisor will verify all documentation and materials applicable to a specific section of work before they begin. Each document shall be kept in a duplicate on the project (Material inspection etc.). Documents describing the fire rating of ducting for air conditioning units must be included in all ductwork. Each duct system should be constructed to the specified duct pressure classifications as per the contract drawings.

Proper storage and handling of the ducts are essential to avoid any damage to the surface. All ducts must have their open ends sealed before they can be shipped. Applying exterior duct sealant products should include those that claim to be able to create a positive, airtight, and waterproof seal, bond well with the metal involved, remain watertight with any movement, and have a temperature. All ductwork must be pre-fabricated, labeled with a number, and delivered to the site according to specifications.

General Requirements

This HVAC method statement describes how to install HVAC ducts and other accessories at the site. The majority of the HVAC duct must be prefabricated off-site, either by the contractor or from an outsourcing firm. Although minimal fabrication will be done on-site, a workshop for fabricating ducts shall be available.

For tagging, approved and coordinated drawings from the ducting shop will be sent to the fabrication workshop. The construction engineer will then review the tagging lists.

The construction program will coordinate the delivery of the fabricated ducts to the site. This will avoid the need to store ducts at site storage for extended periods. The openings of the delivered duct must be covered in polyethylene to keep dust from building up inside the ducts until they are installed on the site.

Installation of Duct Horizontal Run

Competent personnel shall assemble scaffolding according to the height at which it will be installed. All safety requirements must be met according to the HSE Department’s Risk Assessment.

The route of the duct should be marked on the soffit for slabs and walls that are not fire-rated. Make sure slabs, floors, and walls that are non-fire-rated are free of moisture and damage.

As per the specifications and approved construction drawing, prepare and attach the duct supports. Use self-drilling or a suitable masonry drill to prepare the slab for the anchors. Take into account the recommendations of anchor manufacturers for whole diameter and depth.

Make sure that the anchors are properly supported on both sides. Use lock nuts and washers for locking the threaded rod to the slab. The angles and sharp corners on the GI threaded rod should be removed. Use a locknut and the nut below to fix the angle. Before fixing, a load test must be performed.

When joining flanges together or tightening bolts, make sure you use only undamaged, rust-free bolt nuts and washers

All branches are available for tapping collar/flexible, etc. During the assembly stage, it is possible to do so.

All accessories, such as silencers and volume control dampers or balancing dampers, fire dampers and access doors, as well sensors, are to be installed according to approved shop drawings. You must ensure that your units are clean and free of damage.

Use sound attenuation equipment, suitable materials, and approved shop drawings to install the HVAC installation method statement.

Before applying thermal insulation sheets to duct joints, the complete installation of the duct with all accessories must be checked and inspected.