ASA Downdraft Table

The ASA Downdraft Table is a HEPA filtration system that creates a down-flow of air on a sorting surface that leads directly into two HEPA filters. Possible particulate hazards such as Chemicals or Bio-Matter are forced into the HEPA filter. Each 16" filter has 100 ft of HEPA paper and each 8" has 50 ft. of HEPA to allow maximum airflow. The clean air out can be ducted to create a negative pressure in the room (so any contaminates that do end up in the room, stay there to be drawn into the ASA Downdraft Table).

For maximum protection, items should be directed to a sealed room with an ASA Downdraft Table system in use. The operator would use latex gloves and appropriate masking. Any items would be inspected and/or opened directly on the Downdraft Table's HEPA sorting surface.

Using the Dual-HEPA design, they each employ four high-efficiency motor/fans and up to 300 sq. ft. of HEPA for 99.97% removal efficiency of particulates 0.3 microns and larger. They also employ a variety of available V.O.C. (Volatile Organic Compound) filters for removal of chemicals gases.






  • Three-Stage Filtration:
    Removes Particulates, V.O.C.s and Odors.

  • Durable Metal Cabinets
    Greater protection for filters and internal components.

  • Variable-Speed Control
    Adjust the airflow to suit your needs.

  • Highly-Efficient Motor/Fan
    Thermally protected class "B" insulated motors have low electrical consumption when continuously run over a long period of time.

  • No Harmful By-Products
    The ASA air filtration system does not produce toxins such as ozone.




Three-Stage Filtration:


Stage 1: Foam Pre-filter
Removes large particulates.
Stage 2: HEPA Filter
99.97% efficient @ 0.3 microns. Removes dust, pollen, bacteria, animal dander, attached viruses, cigaratte smoke, radon daughters and more.
Stage 3: VOC filter
Removes hazardous chemicals.

Materials: 24 gauge cold rolled steel
Control: on/off
Airflow (C.F.M.): 200-1200 cfm
Power Usage: 168 Watts
Finish: Powder coated baked enamel
Color: white, yellow
Intake: (Section): Steel enclosure surrounding a three-stage filter assembly.
Outflow: (Section):Encloses motor/fan.

Filter Life

One Incident or
Stage 1: Pre-filter as often as necessary.
Stage 2: HEPA Filter: 2-5 years
Stage 3: Carbon Filter 6 months
Filters can be changed by Haz Mat managers after an incident and saved as evidence.




Filtration System


The NPMR's downdraft environmental control system utilizes proven HEPA (High Efficiency Particulate Arresting) filtration technology for particulate control and carbon filtration technology for chemical control. Air passes through but nothing larger than 0.3m (microns) in diameter can pass through. By way of comparison, a single anthrax spore is from 1.0 and 1.5 microns in diameter. The filtration system is 99.97% efficient on airborne particles 0.3m and larger.

The NPMR will be fitted with a number of dual HEPA filtered downdraft air systems and a secondary dual HEPA filtered system outside the enclosure for added security. The total number of down draft units will vary, depending on need. Each of the HEPA filters contain a carbon filter. With 600-1200 CFM per workstation, the downdraft system can completely change the air at a minimum of once every minute. In comparison, OSHA standards for smoking lounges require only 60 CFM per person-a rate nearly ten times less than an NPMR.

The HEPA downdraft system is designed to provide a flood of clean air from the ceiling while removing potentially contaminated air by evacuating it through the air handlers below (see Figure 3). Redundant filtration is another engineered feature. In fact, the system features triple filtration. First, the air is filtered as it enters the room from the ceiling and then filtered twice more as it leaves the room. The system is deliberately redundant to provide maximum safety to the employees in the room and those outside the room. The filtered air is so clean that it has been reported by representatives at Pennzoil that since installing and using the NPMR, the company found a significant reduction in the particulate count for the entire floor of their Houston headquarters.

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