Best practices

Khansaheb’s Groves said an excellent duct cleaning practice was the use of wire hanging systems where appropriate, in addition to cleaning that required limited access doors, the use of modular units that provided better installation quality and speed, and the implementation of proper testing and acoustic design. 

Meanwhile, negative ductwork industry trends that should be changed included the use of long, flexible ductwork; lack of testing; poor acoustic design; lack of appropriate vapour barriers; part-insulation of ductwork; and delayed repair of – or failure to repair – damages to galvanised iron ductwork systems. 

Commenting on design improvements that could be implemented in the Gulf, Hameed said: “The design practices typically carried out in the GCC are the standardised model. Design teams are not catering to a project by selecting the design that the customer is looking for. They work based on experience, but that should not always be the case. Obviously the duct design has to be a prime factor; design and installation teams should use lengthy ducts, ducts that have sharp corners, and so on. 

“The second priority is installation. Ductwork professionals must select materials of the proper thickness to avoid the unwanted use of energy. Insulation must be done to avoid heat gains from the ambient environment, to avoid condensation,” Hameed said.
Groves added that the overuse of flexible ductwork was one of the malpractices he had often observed in the region: “Flexible ductwork has quite an impact on air flow efficiency, and I have seen some systems designed that are too long, and that change direction several times. 

“Flexible ductwork changing directions, is wrong, I think,” he said. 

Mishra commented on another common ducting theme that should be amended in the region: “Fabrication is one issue that actually has a big impact on the functioning of ducting systems. 

“Poor workmanship can lead to losses of up to 30%. For example, sometimes you will notice that the flanges are not insulated properly – this is not ideal. Some ductwork contractors are good, but not all of them provide the same high quality. Not all teams monitor every element of the process, and this includes consultants as well,” Mishra added.

With Expo 2020 Dubai on the horizon, all participants agreed that there was a growing demand for improved ducting and insulation systems in the region’s built environment. In addition to accountability, proper installation and testing must also be prioritised. HVAC system must be used to not only move air around, but also to condition it. To ensure both, the industry must prioritise ducting and insulation.