Duct installation in Al Sawari

Before any extension the technician checks the main duct dimensions and existing branch takeoffs, and measures air velocity at the current diffusers. If velocity is already low or the main run is narrow, he explains what must be corrected first. The site survey determines whether the extension is feasible on the existing network or whether the supply section needs to be enlarged.

Warm humid air trapped above the false ceiling meets the cold duct surface and moisture condenses on the outside of the duct wall. The most common cause is torn insulation or open joints that let warm air reach the bare metal. Armaflex or Kimmco insulation is fitted around the full perimeter and every joint is sealed with Foster sealants so no path remains for outside air to reach the duct surface.

Usually yes. The technician first identifies the cause of the sag: a failed hanger, a loose anchor point in the ceiling structure, or deformation of the duct itself. If the duct is undamaged, hangers are repositioned and spaced to prevent the sag from recurring. If the duct is deformed or the insulation has failed, the technician explains what needs replacing before re-hanging proceeds.

A damper is fitted at a branch takeoff when the cooling load differs between zones connected to the same main duct run, for example a room with a large window compared with an interior corridor. Without a damper the path of least resistance takes most of the air and the other rooms receive less. The site survey identifies which branch points require a damper and which can be balanced by adjusting the takeoff size alone.

It is usually possible by opening access panels or cutting limited sections in the false ceiling to reach the void above. The technician maps the route before starting to keep the number of openings to a minimum. Once the duct run, insulation and sealing are complete, panels are refitted or the cut sections are restored. The complexity and number of openings depend on the false ceiling type and any obstructions present, which the site survey establishes.

We calculate the airflow needed for each storey and plan the branches so each diffuser gets the same volume, using dampers in the main duct to balance the flow.

We do a site visit to the roof first to plan the best route between existing units and equipment.

We use Armaflex at sufficient thickness (usually 25 mm) to prevent heat loss in uninsulated ducts, with extra wrapping at joints.

It doesn't affect the duct itself, but we ensure the duct doesn't run directly over power cables to avoid heat transfer, keeping them separate.