Feature
AIR GUIDANCE SYSTEMS CONNECTING FUNCTIONS
By Benjamin Brits
Ducting , and its related componentry , may be something that seems oh so simple , but this aspect of a HVAC system involves many technical elements to be revered that may never even be seen .
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Most of the time , when projects are marvelled for their great end-results , certain functional aspects are easily forgotten . Ducting , as an example , falls into that category because generally this is a component hidden away in ceiling voids , within service passages , under the floor or mounted openly or discreetly outside the facility - so well out of sight . Some projects do of course showcase ducting in the industrial or open-style spaces seen in modern architecture today .
Where all galvanised metal ducting begins – on a roll .
A stainless steel extract hood in a speciality kitchen .
Although not a particularly pleasing component to the eye for some , the critical supply and extraction of air cannot be provided without the necessary main trunk , branches , returns or vent sections that form part of a ducting system – as well as associated components such as grilles , louvres , dampers , diffusers and speciality nozzles . No matter if you are working with low , medium or high-pressures and you require channelling or guiding of air with any sort of precision , ducting will form part of your solution .
It may be interesting to know that several historical accounts point to the concept of ducting being adapted from what was then a central heating system using fire and smoke to alleviate cold conditions – the “ ducting ” was put in place to eliminate smoke filling a room . Additionally , the concept of heating reticulation progressed then to underfloor type system configurations in certain regions and only from the early 1900s did ducting evolve to the format still used today . The expansion of function was enhanced by the development of technology such as fans , filtration , air conditioning systems , and then the improvement of raw material production .
Today ducting comes in a variety of shapes and sizes , as well as materials to suit a particular application . So , from galvanised steel , to aluminium , stainless steel , plastic , and various fabrics – the ways to carry your air from one place to the next can be served simply or in style with custom designed graphics or branding .
Airflow however also involves quite a few technical engineering principles and you would encounter terminology such as velocity , friction , pressure , tumble , leakage , force , resistance , throw , roll , and capacity that are directly linked to the function of ducting collectively .
One logical thought on the subject is that no matter how much is spent on a high-spec HVAC system , the equipment installed won ’ t necessarily perform optimally without properly designed and installed ductwork . Ducts that are not well designed ultimately result in discomfort , high energy costs , possible bad air quality , and even increased levels of noise .
It then indicates that a good design and installation would tick these boxes while also taking into account other factors ,
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RACA Journal I October 2022 www . refrigerationandaircon . co . za