The Energy Audit 183result is approximate, due to the diffi culty in determining the average
air speed and the free vent area. Regular calibrations are necessary to
assure the accuracy of the instrument. The anemometer can also be used
to optimize the face velocity of exhaust hoods by adjusting the door
opening until the anemometer indicates the desired airspeed.
Airfl ow hoods also measure airfl ow. They contain an airspeed in-
tegrating manifold, which averages the velocity across the opening and
reads out the airfl ow volume. The hoods are typically made of nylon
fabric supported by an aluminum frame. The instrument is lightweight
and easy to hold up against an air vent. The lip of the hood must fi t
snugly around the opening to assure that all the air volume is measured.
Both supply and exhaust airfl ow can be measured. The result must be
adjusted if test conditions fall outside the design range.
INDUSTRIAL AUDITS
Introduction
Industrial audits are some of the most complex and most interest-
ing audits because of the tremendous variety of equipment found in
these facilities. Much of the industrial equipment can be found during
commercial audits too. Large chillers, boilers, ventilating fans, water
heaters, coolers and freezers, and extensive lighting systems are often
the same in most industrial operations as those found in large offi ce
buildings or shopping centers. Small cogeneration systems are often
found in both commercial and industrial facilities.
The highly specialized equipment that is used in industrial pro-
cesses is what differentiates these facilities from large commercial oper-
ations. The challenge for the auditor and energy management specialist
is to learn how this complex—and often unique—industrial equipment
operates and to come up with improvements to the processes and the
equipment that can save energy and money. The sheer scope of the
problem is so great that industrial fi rms often hire specialized consult-
ing engineers to examine their processes and recommend operational
and equipment changes that result in greater energy productivity.
Audit Services
A few electric and gas utilities are suffi ciently large, and well
staffed to offer industrial audits to their customers. These utilities have