Projects return air and fresh air to the gymnasium are sterilised through the use of UV-C lights mounted within the packaged unit .
All ventilation systems for the ducted units and toilet extraction was completed according to the requirements of ASHRAE airflow guidelenes . The ducting was manufactured strictly in accordance with SMACNA guidelines for the flow and distribution of conditioned air within the occupied spaces . ( SMACNA is the Sheet Metal and Air Conditioning Contractors ' National Association that is an international association of union contractors . SMACNA standards and manuals address all facets of the sheet metal and HVAC industry , from duct construction and installation to indoor air quality , from energy recovery to roofing , from solar energy to welding .)
© RACA Journal | Benjamin Brits
PROJECT CHALLENGES As you may have experienced , picking up the pieces of a stop-start project is not an easy feat as there are many loose ends to be identified and managed – not to mention a limited budget . One such element that TCE had to navigate was the appointment of the prior HVAC contractor . This original HVAC sub-contractor was appointed by the first main contractor and assumed that their engagement would be automatically validated by GVK Siya Zama when they were appointed as the final main contractor .
“ You cant handle something like the Coronavirus without understanding it and how it spreads .”
© RACA Journal | Benjamin Brits
The gymnasium was the most challenging aspect of the HVAC system purely because of the massive void and continuously changing occupancy .
Three fans located in the gymnasium are smoke exhaust fans that only operate in the event of a fire . They are interlocked with the fire alarm system and will activate when the fire is contained and the alarm is cleared .
To TCE ’ s disappointment , this prior contractor could not provide current gas handling and recovery certification . Nor could they demonstrate a professional knowledge of the differences between various refrigerant gases and the protocols applied to their application . When it comes down to these important fundamental elements , TCE has very specific requirements for the contractors they appoint ( as should all consulting engineers ) and thus had to seek out a more competent HVAC contractor .
Worth including here , TCE notes that the Montreal Protocol on Substances that Deplete the Ozone Layer was developed and adopted to establish a worldwide awareness of the fragile state of our environment . The terms of this protocol state that , “ Parties shall take appropriate measures in accordance with the provisions of this convention and of those protocols in force to which they are party to protect human health and the environment against adverse effects resulting or likely to
© RACA Journal | Benjamin Brits
The return air inlet for the central Packaged VRF system . A sensor noted on this terminal is the control sensor for the packaged unit . The UV-C sterilisation unit is mounted in the return air / fresh air plenum at the unit located on the external plant deck . This gives the benefit of sanitising both return and fresh air before processing and discharging to the occupied space .
www . hvacronline . co . za RACA Journal I March 2021 33