Retrotec USACE - Manual (Page 148)

D18 ENERGY & PROCESS ASSESSMENT PROTOCOL
D.2 Heating Ventilation and Air-Conditioning (HVAC)
Systems
D.2.1 Ventilation System
D.2.1.1 Use of Excessive Dampers to Achieve Air Balance (Waste)
Air dampers are used to balance and control air fl ow to conditioned spaces
within a facility. Typically dampers are installed at strategic locations that re-
quire control of air quantities such as at outdoor ventilation intakes, mixing
boxes, branch ducts, and diffuser locations. These devices are restrictions to
air fl ow and increase the static pressure that the supply fan has to overcome.
Static pressure increases require more horsepower (hp) from the fan motor
and increase the energy consumption of the fan motor. Although air dampers
are necessary, their excessive use creates added static pressure and requires
additional fan energy to handle that added pressure.
D.2.1.2 Loose Fan Belts in Ventilation Systems (Ineffi ciency)
Figure D31. Fan belt used to turn fan by
electric motor operation
Fan belts are used to connect electric motors with fans to achieve air fl ow in an
HVAC system (Figure D31). They transfer energy from the motor to the fan
and allow the system to operate properly. When the belts become loose, there
is a loss of energy and air fl ow. In addition, loose belts can harm the motor’s
shaft or the fan wheel. An indication of loose fan belts is noise on startup and
excessive vibration of the belts during fan operation.