RACA Journal August 2020 | Page 19

INSIGHT COMBATING THE SPREAD OF COVID-19 WITH TROX By Michael Young, sales engineer, Trox The spread of COVID-19 is on the front page of every newspaper around the world. It is the main headline in every news bulletin and is the most discussed topic at the moment. This virus has managed to bring economies to a standstill and caused millions around to world to go into self-isolation. The fight against COVID-19 needs to be performed under a controlled environment as specified by the World Health Organisation (WHO). Specimens from patients need to be obtained in a facility that conforms to a biosafety level of 2. Once the specimen is collected, it is packaged and shipped to a laboratory where the specimen undergoes a nucleic acid amplification test also termed an NAAT test. These tests also to be performed in a laboratory that is rated at biosafety level 2. Biosafety level 2 states that provision of a mechanical ventilation system that provides an inward flow of air without recirculation is desirable but not compulsory. High-efficiency particulate air (HEPA) filtration for exhausted air is also not compulsory. The main fight against the virus occurs not in the testing but in specialised laboratories where the virus is cultivated and studied. The goal is to understand the behaviour of the virus and then develop a possible vaccine. These specialised laboratories require inward directional flow and need to comply with a biosafety standard level 3. The ventilation system for this laboratory must be constructed so that the air is all contained within this area. Air from the laboratory may not be allowed to migrate to other areas of the building. The ventilation system serving this laboratory must be of a high efficiency particulate grade (HEPA) and must recondition the air to the desired temperature. Any exhaust air from the laboratory (other than from biological safety cabinets) can be discharged to the outside of the building and must be dispersed away from occupied buildings and air intakes. Depending on the agents in use, this air may be discharged through HEPA filters. The HVAC system should also prevent sustained positive pressurisation of the laboratory and must be constructed complete with audible or clearly visible alarms to notify personnel of any HVAC system failure. Consulting-Specifying Engineer The HVAC system for a laboratory that combats COVID-19 needs to fulfil the following functions: • The system needs to filtrate the air to requirements as specified by WHO. • It needs to condition the air as per the specified requirements. • It needs to control the exhaust airflow from fume hoods. • It needs to control the room supply and exhaust air flowrates. • It needs to maintain the correct room air pressure. • It needs to be mobile so help can be transported to infected areas. • It needs to have audible and visual alarms, so personnel are notified of HVAC system failure. Such an HVAC system is more than just the installation of a hybrid VRF AHU. Such a system requires an EASYLAB control system that modulates airflow according to testing procedures, room pressurisation and sound attenuation management. So, if you design HVAC systems for the laboratory sector of the industry, we strongly recommend that you attend our free 1-hour laboratory airflow management course. Seats will be limited to 20 people so call 073 17 123 11 now to reserve your spot. Since this is training is a webinar, there is no chance of contracting COVID-19. RACA The HVAC system for a laboratory that combats COVID-19 needs to fulfil certain functions. www.hvacronline.co.za RACA Journal I August 2020 17