Laboratory And Healthcare
Ashrae 110 Fume Hood Testing
When customers ask for an ASHRAE 110 performance test, many contractors take single-point face velocity readings only. OES is certified by the National Environmental Balancing Bureau (NEBB) to conduct detailed ASHRAE 110 testing that includes the following tests:
- Velocity with additional speed of response testing for VAV hoods
- Large and localized smoke tests
- Static Mode SF6 tracer gas test
- Sash movement effect SF6 gas test
- Perimeter scan tracer gas testing
Our qualified professionals confirm that fume hoods are maintaining the best possible containment as defined by the ASHRAE 110 requirements.
Velocity Readings (VAV)
ASHRAE 110 Standards for obtaining average face velocities for VAV hoods require hood sash openings to be tested at three distinct positions (100%, 50%, and 25%). Varying of air flow through a hood can be accomplished through a variety of control strategies; however, all tests measure the system’s hoods’ ability to respond to different sash positions. While using a variable speed fan or air valves, hood control should allow minimum velocity requirements. Each velocity reading must log on 20 second intervals. Face velocities observed at the 100%, 50%, and 25% sash positions should maintain a constant velocity range in accordance with the facility SOP and ANSI Z9.5.
Air Flow Visualization Tests
Air flow visualization tests should be performed in two separate phases. The initial test is conducted with a small smoke source known as the local challenge. A small smoke source should be used to test perimeter, airfoil, inside sash, and work surface. Smoke should identify a swirling affect in the hood’s upper cavity. No visual reverse of smoke should be detected at any seam. In addition to the small local challenge, large volume tests are used to observe the hood’s ability to clear smoke when the sash is opened. In addition to hood containment, large volume smoke is also helpful in observing room HVAC effects.
Tracer Gas Tests
Tracer gas tests are conducted with a calibrated spectrophotometer detector. After the detector warm-up period, the unit should be zeroed and checked for proper calibration. The tracer gas used for most tests will be sulfur hexafluoride (SF6). Prior to testing, a background level check should be performed. Initial static mode tests begin by placing the sash position at the operating condition. The following positions are utilized for a vertical sash configuration:
- Three locations are determined within the hood for ejector system: 12” from the left wall, 12” from the right wall, and in the center. All locations are placed at a distance of 6” from the sash plane.
- A mannequin is placed directly in front of each location. An InfraRan detector sensor is placed through the mannequin’s head and out of the mouth opening at no more than ¼” distance from mouth opening. The mannequin’s position shall be confirmed to be at 3” from the sash face and 22” above the hood work surface.
SF6 gas is released at a rate of 4 l/m with frequent calibration checks to confirm gas rate. Gas is released for 30 seconds before initializing the test. The InfraRan detector is operated for a period of 5 minutes, collecting data every 1 second at each of the locations. In addition to the static test, sash movement effects are also documented by placing the diffuser in the geometric center of the workspace and releasing gas while monitoring the sash open and close positions in 60 second intervals. Fume hood certification is assigned a sash movement rating of SME-XX-XXX and a static mode performance rating of AU, AM, or AI-XXX.
With the diffuser located in the geometric center of the hood, release gas as described above in the static test and scan the perimeter of the opening 1” away from the face of the hood.
Biosafety Cabinet (BSC) Certification
OES provides NSF-49 accredited professionals for your cabinet certification needs.
Testing requirements for NSF-49 are clearly identified on each form:
- Velocity (In Flow, Down Flow, and Exhaust)
- Air Flow Smoke Pattern
- Alarm Site Assessment Test
- HEPA Filter Leak Test
Clean Room Testing
Clean rooms, like many laboratory operations, rely on continuous operations with little or no downtime associated with routine testing. OES’ qualified technicians work with the latest ISO compliant instrumentation for clean room certification that leaves the lab undisturbed by messy oil vapors and loaded filters. OES utilizes the latest in photometer and particle counter technologies for the scanning of filters with particle upstream challenge instead of loading filters with large amounts of aerosols. The particle scanner system needs very little upstream challenge. Due to high particle concentration levels from the main air handling unit, often times no additional PAO or DOP liquid vaporization is needed in the filter upstream. OES also provides the latest non-viable technologies in clean room certifications. Our particle counters are all FDA compliant. Below is a list of some of the tests performed:
- Air Flow
- Velocity Profile
- Sound and Vibration
- Non-Viable Sampling
- Viable Sampling
- Automation Commissioning