Ventilation and ductwork will often be manufactured in a
sheet metal factory. Ducting for air conditioning varies from very narrow ducts
to huge rectangular ducts which you can practically walk through. A number of
machines are used in the production of ventilation ducting. Ductwork is
typically made in lengths that are suitable for transport. Then they’re driven
out on site where they are installed by professional ductwork installers.
Ductwork is often hidden above ceilings in commercial and
office buildings, however you’ll often see it exposed in underground carparks
and loading docks. Ductwork can form part of contemporary design, where the
ceiling lining is deliberately left out for aesthetic purposes. The dimensions
of the air conditioning duct are directly related to the amount of air flow
which is required to service the building and which will travel through the
ductwork.
Optimising Air Flow
in a Square Duct
Have you ever wondered how the air travels around a right angle
in a duct system? In a square duct system, a basic square elbow would disrupt
the air flow significantly, so to ensure that the disruption to the air flow is
minimal within the elbow joint, turning vanes are inserted at the bend. These turning
vanes are manufactured within the warehouse by rolling them on a three-part
roller which can be set to bend a flat piece of metal to the required curve.
This is then inserted into place at the top and bottom of the elbow. Air
travelling through the system will then be deflected around the bend, rather
than rebounding off the back wall.
Use Hearing
Protection in a Ductwork Manufacturing Plant
Ductwork manufacturing factories are extremely noisy places
to work. The walls and floor are often made of concrete and the noise from
production is exacerbated by these hard surfaces. Hearing protection is recommended and, in most cases, mandatory. Steel capped
boots are absolutely mandatory in these factories. Machines that are used to
press and bend the various components of the ductwork can cause significant
injury. Care must be taken when using them and a first aid kit should always be
on site.
Insulating
Ventilation Systems to Dampen Noise
Large ventilation and ductwork can be very noisy when in
use, so to counter this, these ducts will often be insulated on the inside. The
only problem is that there is nothing to hold the insulation in place inside
the duct. So, a metal channel is first inserted at either end and screwed into
place. This lines four insides of the square ducts, leaving a small calculated
gap between itself and the actual duct. Now you can crawl into the duct with
your 40mm piece of insulation and tuck the ends into the channels that you’ve installed
at either end. The insulation that lines the top of the duct will most likely
sag, so a perforated piece of sheet metal, goes in and also tucks itself into
the channel at either end, which is then screwed down. That is how a large duct
is insulated for sound. Insulation also serves to minimise heat transfer as the
air moves through the duct, which is particularly relevant since these ducts
are often located in a very hot ceiling spaces.
