Air conditioning is essential to keep glass-clad high rises habitable, but there is also growing awareness of the value of clean air and energy efficiency in all buildings – two things often at odds if buildings aren’t properly designed. Air filtration, dust extraction and climate control would be impossible without a surprisingly simple invention – spiral ducts.
Ducts channel fresh or filtered air, and warmed or cooled air, to where it is needed, and enable the extraction of dust, fumes and bacteria. In some systems, recovered heat energy helps to run the system making them extremely cheap to operate. In glass and steel constructions, ducts allow heat accumulating on the sunny side to be used to heat the chilly side – with almost no additional energy input.
New regulations regarding CO2 emissions and building energy efficiency came into force in April 2018. The sections of this document (L1A, L1B, L2B etc.) tighten requirements on both domestic and public buildings, both new builds and pre-existing.
Why spiral duct?
Spiral duct is assembled from bands of lightweight material woven spirally into tubing, with minimal wastage. They are relatively easy to fabricate, and then position, cut and join on site. Steel ducting can be spun in diameters exceeding 10’ if needed, and lengths are limited only by the logistics of moving it into position. The greater the strength to weight ratio, the fewer hangers required, and the quicker installation becomes.
Air conditioning often uses 24 gauge light galvanised steel , but alternative materials include vinyl-coated steel, stainless steel, brass, , copper, aluminium, rubber and plastics.
How it’s made
It begins as coiled bands that are first passed through an uncoiler and flattened by rollers. Lengths are then fabricated by passing through a succession of tooling surfaces combined in a “tubeformer”.
There may be cases where extra resources are needed electrical connectors, gaskets or pipe seals which can all be made with Rubber Injection Moulding and links including https://www.meadex.co.uk/ could take you to businesses that provide these. The edges are then trimmed and profiled, ready for joining. Its path through the tubeformer moulds it precisely to form the tube as it emerges. Rollers press the edges firmly together, and then both inner and outer surfaces are usually welded closed as the tubing rotates beneath tooling heads.
Some tubeformers can profile edges for simple click-locking into shape, while with plastic materials, adhesives and heat treatments provide alternative sealing methods.
The spiral appearance of these ducts appeals to many people, to the extent that they’ve become a fashion statement in many clubs and restaurants.