Feature
FANS AND VENTILATION :
THE MIDDLE-POINTS IN AIR QUALITY AND DISTRIBUTION
By Benjamin Brits
No matter if you ’ re bringing fresh air into a space or extracting it from a contaminated area , ventilation plays a critical role in meeting various application needs and standards .
definition of ventilation is the movement of outdoor air into
A a building or a room , and distribution of that air within that space with the purpose of providing ‘ healthy air ’ for occupants . Air quality is affected by both diluting any pollutants originating inside the space and , in certain cases , removing or cleaning out any pollutants by means of extraction or a circular process . This function is completed through the incorporation of fans , ducting and diffusion products .
Ventilation is achieved through three possible methods used in commercial and retail applications : natural , mechanical , and hybrid ( a mixed-method solution ). Building ventilation has further elements to consider :
• Ventilation rate – the amount of outdoor air that is provided into the space ( outdoor air quality is of course also an important factor ).
• Airflow direction – the overall airflow direction in a building , which should be from ‘ clean zones ’ to ‘ dirty zones ’.
• Air distribution or airflow pattern – the external air should be delivered to each part of the space in an efficient manner and any pollutants or concentrations generated in each part of the space should also be removed in an efficient manner .
© RACA Journal | Benjamin Brits
A fabric duct installation catering to the ventilation and conditioning required in a gymnasium .
From a design aspect , above what has been stated already , other elements of consideration on this topic related to buildings include indoor air quality and air changes – per hour . Ventilation in buildings may also include a series of ducting ( standard steel , fabric type and flexible option ), and conditioned air ( heating and cooling ) through an air handling unit . Ventilation will also usually include various means of air filtration .
“ The quality of air supplied into a building is obviously very important . All outdoor air supplied into the space must be filtered and must be drawn from a clean zone as mentioned before . Extracted air , from kitchens and toilets for example , must be discharged in a manner that doesn ’ t cause annoyance in the environment for people around the area . Further , extracted
© RACA Journal | Benjamin Brits
A common building extract fan installed at a rooftop plant .
air from spaces like a TB department in hospitals must be filtered before it gets discharged to the environment . Filtration systems can be installed in mechanical ventilation systems to eliminate harmful microorganisms , particulates , gases , odours
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