Feature where the air is coming from to ensure that they ’ re treating air that won ’ t be contaminated with return air after it is supplied . In an office environment you want to install products that treat the room air in high circulation areas like boardrooms and mixed office spaces first and then rooms with lower occupancies .
“ Our UV Air Purifier doesn ’ t use much energy and it wouldn ’ t make much impact on your electricity bill , but the lamps need to be replaced annually , and the units have a finite life span . To stay effective , the lamps need to be cleaned when dust builds up .” Most bulb manufacturers such as Philips , GE and Sylvania state that their UV C lamps have a life cycle of 9 000 hours and need to be changed every 12 months .
“ The installation of UV-C lamps in units has been found to damage filters , filter frames and non-metallic components . Depending on the cleanliness of the building , filters need to be periodically cleaned and replaced based on the pressure differential across the filter and the pressure drop across them – or they may use a lot of energy or just poorly circulate the building ,” says Rickard .
SFI Group
“ Our UV Air Purifier doesn ’ t use much energy and it wouldn ’ t make much impact on your electricity bill , but the lamps need to be replaced annually , and the units have a finite life span . To stay effective , the lamps need to be cleaned when dust builds up .”
DO I NEED AIR PURIFICATION ? Clive Donnelly of BD & O Group says : “ The simple answer is that every enclosed occupied space should have air purification . It augments traditional ventilation and air cleaning systems that come standard in offices , shopping centres and hospitals .
“ As most people spend about 90 % of their time indoors , IAQ matters to all of us for the reason that providing a good indoor environment is the main reason why we erect buildings . A bad indoor climate can have a negative impact on issues such as your family ’ s health , work productivity , study performance and human comfort . Loss of work performance caused by poor air quality due to increased pollution load / decreased ventilation is experimentally estimated to be 5 %, while the cost of providing a good indoor air quality in office buildings is less than 1 % of the labour cost .
Edward Hector , MD of the SFI Group
“ Recovering that lost 5 % work performance equates to an additional 25 minutes per person per day ; reduced number of breaks in work ; 10 fewer sick leave days per person per year – suggesting that an investment in air quality is highly profitable ,” suggests Donnelly . This is because labour cost is :
• 25 to 100 times higher than energy cost
• 25 to 100 times higher than maintenance cost
• Roughly 4 to 15 times higher than renting cost
• Roughly 4 to 40 times higher than construction costs
AIR QUALITY AND COVID Donnelly explains that the Covid-19 pandemic highlighted how infections with respiratory viruses are principally transmitted through three modes :
• Contact transmission is infection spread through direct contact with an infectious person
• Droplet transmission is infection spread through exposure to virus-containing respiratory droplets
• Airborne transmission is infection spread through exposure to those virus-containing respiratory droplets comprised of smaller droplets and particles that can remain suspended in the air .
He lists the health benefits when air purification improves indoor air quality and occupant well-being :
www . refrigerationandaircon . co . za RACA Journal I February 2023 33