Duct installation in Petromin

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.

If existing ductwork is there, we clean it before inspection and assessment. If it is not fit for purpose, we replace it with new insulated ductwork to specification.

Yes, we design the new run to integrate with the existing system and calculate the branch count and diffuser size to match the addition's area and cooling load.

Long runs reduce velocity, so we verify branch and diffuser sizing and test air pressure and flow after installation to ensure adequate delivery to distant zones.

We measure the ceiling cavity and design the duct diameter and route to fit. We use flexible duct where needed to work within architectural constraints.