Feature reducing noise levels . These include , the physical blade shape , thickness and tapering , inclusion of additional blade fins or ‘ winglets ’, and symmetry .
Permanent magnet motors have also gained traction due to their further increased efficiency and are used in several fan models today . Fan speed ranges also continue to be developed to produce varying outputs .
“ Looking forward , ebm-papst has in fact moved their focus away from the development of AC products . Within the next 5 to 10 years , AC products will no longer be manufactured in the European market at all as technology aligns to the ERP regulations . A manufacturer ’ s biggest job now will be to educate the end users to the benefits of new technology and the results they bring . This will be a challenge for all manufacturers who unfortunately sit in the middle of the supply chain . Users persist to select products as cheap as possible , but when cheap products are put forward against a comparative quality overall solution the benefits are seemingly insignificant for the client and they don ’ t yet realise the long-term results ,” notes Schoombie .
“ Today smart diffusers coupled with various sensors in a building offer an array of options to continually monitor and control air quality , air flow as well as space conditioning .”
AIR DISTRIBUTION AND DIFFUSION Generally , grilles , and more so , diffusers , are perceived as the horizontal or vertical split sections in walls , ceilings or bulkheads that are seen around any commercial , retail or hotel room settings , to distribute the air flow in a particular direction .
Today smart diffusers coupled with various sensors in a building offer an array of options to continually monitor and control air quality , air flow as well as space conditioning , and can further be connected wirelessly . Remote connection and control has seen great drive over recent years .
“ Diffuser technology , like other elements of a building ’ s ventilation has also seen large developments in recent years . It is a product that has seen incorporation of intelligent mechanical devices and now offers users variability – essentially meaning control or modulating of any environment ’ s airflow and temperature to their requirement . Further , through a buildings management system ( BMS ), the occupancy , temperature conditioning demand and ventilation demand in a space can be determined offering better
Rickard Air Diffusion management and thus operational efficiency ,” says Mark Rickard , director at Rickard Air Diffusion .
This VAV or Variable Air Volume diffuser technology contains an actuator and damper that modulates the space requirements through the various add-on sensors by opening or closing to allow more or less air into the space , thus providing more accurate room conditioning . Through the BMS , groups of diffusers can be connected offering building-section information . With this data , it is possible to identify areas , that for example need to be flushed with more fresh air where higher concentrations of ‘ stale air ’ sits , or open and close diffusers in emergency situations where smoke or hazardous air is present .
There are different styles of diffusers available for different applications . These include drop-in ceiling or tile type , wall mounted or bulkhead , floor type and linear options . Shapes and styles have also seen development with improved aesthetics to make the product more appealing for the client . Style and design can also be custom engineered . “ Starting off with just a grille or diffuser as has been mentioned , you can see how suddenly this seemingly simple product can become quite complex and intelligent . Intelligent control solutions are going to continue to come into focus as users seek out more and more optimal ways to manage buildings and facilities . Many spaces also require very different conditions , even if they are in adjacent rooms . Look at how cell phone technology has developed – starting out as a simple device , they now have light and motion sensors , face and fingerprint recognition and GPS . Now , combining all that technology allows you to do much more . Better control also leads to better occupant productivity as Siphiwi mentioned earlier – better air supply monitoring and control avoids all the symptoms of unhealthy air . Further , in future we may be able to control or mitigate things like the spread of airborne pathogens like the Coronavirus by being able to quickly action isolation , space flushing or extraction of air through smart ventilation systems and inclusion of other technologies such as UV sterilisation ,” says Rickard . RACA
An example of a large cone-screw adjustable-face diffuser .
www . hvacronline . co . za RACA Journal I June 2021 17