The key objective of this study was to gain a deeper understanding of the benefits of GPS Air’s NPBI™ technology within grow facilities. The data collected can then be a key resource in the decision to implement NPBI into grow facility systems. To collect this data, the teams got together to set up and run the tests detailed below.
The test set up comprised of the following instrumentation (reference Figure 1):
1. Coriolis: Viable Mold and Bacteria
2. Incubator: Viable Bacteria
3. BAMS: Bioaerosols
4. APS: Fine Particulate
5. NanoScan: Ultrafine Particulate
6. COM-3800: +/- Ion Density
7. Control Center Panel: Network via Wi-Fi, Live Data Streaming, Data Logging, Remote Access/Monitoring
As shown in Figure 2, three destratification fans were employed with four FC-48 ionizers per fan.
The ion output at the fans was above 10 million ions, driving the average ion density within the space to be above 50 thousand ions/cc.
The fans were spaced to maximize air mixing, and ion levels were continuously monitored while ionization was applied during daily activity for a duration of three days.
The space in which the test occurred included the following HVAC/Air system configuration (reference Figure 3):
Five Ton DX Split Systems
22 AHU’s serving the space
MERV 10 filters installed on each AHU
50/50 ducted/non-ducted supply air
Anden De-humidifiers
12 total installed above canopy
MERV filters on return
Propane CO2 Burners in Space
2 burners installed above canopy
Air Circulating Fans (Perimeter)
10 total on each side
Figure 5
Prior to ionization, the team collected samples directly from the coil surface using sterile swabs. Two separate units were sampled.
Each unit had been in operation for only 2 years and housed UVC bulbs (shown in Figures 4 and 5) to prevent microbial colonization and biofilm growth.
Below is a chart that reports the viable concentration of bacteria and mold on the coils.
The Swab samples were analyzed and reported by an AIHA accredited environmental microbiology laboratory.
| HVAC Coil on Unit 3 | HVAC Coil on Unit 8 | |||
| Bacteria CFU/in2 | Mold-Fungi CFU/in2 | Bacteria CFU/in2 | Mold-Fungi CFU/in2 | |
| Swab 1 | 30,000,000 | 650,000 | 900,000 | 3,400,000 |
| Swab 2 | 20,000,000 | 500,000 | 20,000,000 | 2,800,000 |
| Swab 3 | 3,100,000 | 3,500,000 | 40,000,000 | 30,000,000 |
| Average | 17,700,000 | 1,550,000 | 20,300,000 | 12,066,667 |
Control Sample (4-25)
24 hrs: Fans ON / Ions OFF
153 CFU/m3
Ionized Sample (4-26)
24 hrs: Fans ON / Ions ON
33 CFU/m3
Control Sample
24 hrs: Fans ON / Ions OFF
306 CFU/m3
Ionized Sample
24 hrs: Fans ON / Ions ON
120 CFU/m3
Ionized Sample
48 hrs: Fans ON / Ions ON
13 CFU/m3
