Basic Documentation

Table Of Contents
Laboratory Ventilation Codes and Standards
Siemens Industry, Inc. 56
Topic Requirement(s) Commentary
Evaluating
VAV (Variable
Air Volume)
Systems
American National Standard for Laboratory Ventilation ANSI/AIHA Z9.5-2003
6.5.3 VAV hood systems shall be commissioned prior to use by laboratory personnel
to ensure that all system components function properly and the system operates as
designed under all anticipated operating modes. The commissioning procedure for
VAV systems shall include:
Verification of VAV sensor calibration;
VAV Hood performance Tests;
VAV Laboratory and Ventilation System Tests; and
Verification of System Diversity (See VAV Diversity on the next page.)
6.5.3.1 VAV sensors shall be capable of accurate measurements and control within
10% of actual at the design maximum and minimum flow conditions.
6.5.3.2 In addition to hood performance tests described for evaluation of CAV hood
systems, commissioning tests on VAV hood systems shall include measurement of
flow or
face velocities at different sash configurations and VAV Response and Stability
tests. Flow or face velocity tests shall be conducted at a minimum of two separate
sash configurations. VAV Response and Stability tests shall include continuous
measurements and recording of flow while opening and closing the sashes for each
hood (calibrated flow sensors or measurements of slot velocity within the hood can be
used as an indicator of flow. VAV Response shall be sufficient to increase or decrease
flow within 90% of the target flow or face velocity in a manner that does not increase
potential for escape. VAV stability shall be sufficient to prevent flow variations in
excess of 10% from design at each sash configuration or operating mode.
6.5.3.3 The VAV hood controls shall provide stable control of flow in the exhaust and
supply ducts and variation of flow must not exceed 10% from design at each sash
configuration or operating mode.
VAV ventilation systems need to be properly
tested, adjusted and balanced initially and
thereafter closely monitored to ensure proper
functionality and attainment of the potential
energy savings.
Also see Appendix 4 - Audit Form in
ANSI/AIHA Z9.5-2003, which provides a
comprehensive checklist for the Laboratory
Ventilation Management Program including
Commissioning Tests.