Retrotec USACE - Manual (Page 412)

L12 ENERGY & PROCESS ASSESSMENT PROTOCOL
4.3.8 Check proper size of air pressure regulators and lubricators.
4.3.9 Convert compressed air systems to distributed systems.
4.3.10 Install automatic traps/drains in larger air systems.
4.3.11 Install storage surge tanks to buffer compressed air load fl uctuations.
4.3.12 Install compressed air metering.
4.3.13 Install gas meters.
4.3.14 Optimize loading with multiple air compressors.
4.3.15 Recover waste heat from air compressor cooling system. As much as 80–93% of the
electrical energy used by industrial air compressor is converted into heat. In many cas-
es, 50–90% of the available thermal energy can be recovered for space heating, indus-
trial process heating, boiler makeup water preheating, industrial drying, and the like.
4.3.16 Reduce excessive line air pressure losses—i.e., increase pipe diameter.
4.3.17 Reduce air line pressure.
4.3.18 For individual applications that require a higher pressure, instead of raising the oper-
ating pressure of the whole system, the following equipment modifi cations should be
considered:
4.3.18.1 Use a booster.
4.3.18.2 Increase a cylinder bore.
4.3.18.3 Change gear ratio.
4.3.18.4 Change operation to off peak hours.
4.3.19 Replace existing air compressors with more effi cient units.
4.3.20 Replace oversized air compressors.
4.3.21 Use after coolers in multistage air compressors.
4.3.22 Use energy-effi cient air drying systems.
4.3.23 Use larger-area air intake fi lters.
4.3.24 Use cold outside intake air for air compressors. As a rule of thumb, each 5 °F (3 °C)
will save 1% compressor energy.
4.3.25 Equipment cooling: Use cool air compressors with a closed-loop system.
4.3.26 Turn off unnecessary compressed air. Equipment that is no longer using compressed
air should have the air turned off completely. This can be done using a simple solenoid
valve.
4.4 Thermal Storage and Heat Pumps
4.4.1 Install cool storage to save on electric bills. The concept behind cool storage systems is
to operate the system during off-peak electricity hours and use the stored coolness to
satisfy a building’s air-conditioning needs. Avoiding peak electricity hours will reduce
electric bills.
4.4.2 Install hot water storage to shave peaks of hot water usage. Hot water storage will reduce
the size or the number of boilers to be used during the peak hot water usage hours.
4.4.3 Install add-on heat pumps.
4.4.4 Install groundwater source heat pumps.