AAF Helps Convert Standard Laboratory into Corona Testing Lab

LOCATION: Bengaluru, India

• Founded in 1987, one of the leading diagnostic labs in South India
• First diagnostic laboratory in South India to gain NABL accreditation

Filtration Situation

As per the health ministry’s latest data, Corona Virus cases in India is crossing the 4 lakh mark. WHO has provided the checklist to the testing laboratories that are receiving and processing suspected or confirmed cases infected with novel corona virus. WHO recommended that all diagnostic laboratory work and PCR analysis on clinical specimens taken from suspected corona virus patients should be conducted according to practices and procedures described as per WHO laboratory biosafety manual.

As per the manual, the laboratories must adopt a controlled ventilation system to maintain directional airflow into the laboratory room. Exhaust air from the laboratory room should not be recirculated to other areas within the building. Air should be HEPA filtered if reconditioned and recirculated within the laboratory. When exhaust air from the laboratory is discharged to the outdoors, it must be dispersed away from occupied buildings and air intakes. This air may be discharged through HEPA filters.

The laboratory consulted their solution provider to upgrade its air filtration system to handle suspected or confirmed corona virus cases.

The AAF International Solution

The solution provider consulted the world’s largest air filtration expert, AAF for the optimum solution for this emergency issue. AAF recommended the newly launched three-stage high-performance filter equipment with UV light – PurAir 350C ceiling-mounted unit.

PurAir 350C is compact design ceiling mounted unit integrated with three-stage of high-performance filters which can efficiently remove indoor fine particles, harmful gases, bacteria and virus.
Stage- 1: Coarse panel filter (AmAir) to effectively remove indoor large particles, dust and hair.
Stage- 2: Gas-phase filter (VariCel RFC) to effectively remove indoor TVOC, odor and harmful gases such as formaldehyde.
Stage – 3: H14 HEPA filter (AstroCel – II) to remove indoor fine particles such as PM2.5, PM1 and bacteria and virus.
Stage – 4: UV light

The machine adopts EC fan and a three-speed switch function. The optimized sealing structure can effectively control noise. A quick ceiling mounted structure design is suitable for ducts and surface mounted environments. Its easy-to-access design helps maintenance activity. It also comes with a humanized automatic stop function adopted to open the cover to protect operator safety.

Real-Time Installation Picture


Since there was no past reference for the design calculation, AAF designed and developed the estimates, which was approved by both the design consultant and the customer.

Field conditions are within AAF’s stated application guidelines in terms of humidity and temperature. However, we wanted to rest assured about our carbon performance in-field removal efficiency and lifetime which are the major factors in deciding media selection. The selected media was for the target gases, the media performance was tested based on lab-scale testing and industry experience. Using this data, engineers at AAF calculated the performance of the media and the overall effect of this continual operation. AAF does not expect site conditions to significantly impact the performance related to the primarily chemisorbed contaminants (hydrogen sulfide, ammonia) nor the contaminant that is both adsorbed and chemisorbed (acetic acid).


The PurAir 350C is performing as expected and as a supplement to safe exhaust air, it can be connected to an existing fresh air system or mixed (fresh & recirculating) air system. The addition of filters to the existing HVAC system as per ISHRAE / ASHRAE guidelines would have a significant variation in the pressure drop which, the current fan may not be designed to take care of. So, this equipment itself has a fan that will take care of the additional pressure drop due to several filtration stages. The user and the solution provider were highly impressed with the functioning of PurAir 350C as it was a perfect retrofit solution to upgrade the current lab to handle the corona virus tests without impacting the existing HVAC system.