Testing, adjusting, and balancing of HVAC systems

All test and inspection reports and the following should be completed before starting the distributed control system (DCS) field test.

• Testing, adjusting, and balancing should be performed by an independent firm
using certified technicians under the direct supervision of a registered engineer.
—Technicians should be certified by the National Environmental Balancing

Bureau (NEBB) or by the Associated Air Balance Council (AABC). —The firm should select AABC MN-1, or NEBB-01 as the standard for testing, adjusting, and balancing the mechanical systems.

• Air-handling unit filters should be artificially loaded during testing and balanc­
ing operations. Air-handling unit airflow should be set for maximum with the fil­
ters fully loaded.

VENTILATION ADEQUACY

Ventilation systems are designed to protect the health of individuals by removing physical and chemical stresses from the workplace. To ensure that these ventilation systems are operating effectively, ventilation flow rates may require periodic checking. Manufacturer's specifications and applicable guidelines for specific types of equip­ment and applications are utilized to ensure the proper operation of local exhaust ventilation.

Capture velocities may vary depending on contaminant size, generation rate, air cur­rents, and other variables. Each local exhaust ventilation system must be independently evaluated to determine adequate operating parameters.

• Local exhaust ventilation systems without a static pressure manometer should
have performance evaluations conducted annually.

• Local exhaust ventilation systems with a static pressure manometer must have
performance evaluations every 3 years.

LABORATORY FUME HOOD PERFORMANCE CRITERIA

Face velocity measurements must be 90-150 fpm with the fume hood sash fully opened, unless superseded by manufacturer's specifications or other applicable guide­lines. Readings should be obtained and recorded every 3 months for fume hoods both with and without a static pressure manometer. If the static pressure deviates ±10%, the fume hood will be inspected and reevaluated. Inspections need to be documented.

FLOW HOODS

Flow hoods measure air velocities at air supply or exhaust outlets.

Calibration

No field calibration is available for flow hoods. Periodic calibration by a laboratory is essential.

Maintenance

Flow hoods typically require little field maintenance other than battery-pack servicing and zero balancing of analog scales. (Check the applicable manufacturer's manual.)

Дата добавления: 2015-11-16