Retrotec USACE - Manual (Page 173)

Appendix D D43
the outer surface of the equipment or pipes and is then covered with insulation
to reduce the heat loss. This system should have a thermostat that monitors
the outdoor temperature and controls set to turn off the heat when it is warm
enough—normally, above 4.4 °C (40 °F). If the heat trace system continues to
provide heat when it is safely above freezing, energy waste occurs. Heat tracing
is often found on cooling water systems connected to cooling towers or out-
door heat exchangers that operate year-round. They are also found on above-
ground steam condensate pipes, city water lines, and fi re protection piping in
unheated spaces.
D.3.3 Water Supply to Buildings No Longer in Use (Waste)
As time passes, some buildings lose their function and no new use can be found
for them. At this time, the water supply should be turned off. If there is no one
occupying or using the building, there should be no need for city water service
to the building. However, it may be desirable to keep the fi re protection active
and thus the water supply to the sprinkler system should remain. Shutting off
the city water to unused buildings has a minimal energy impact but can help
avoid issues such as frozen pipes and leaks.
D.3.4 Use of High-Pressure Pumps to Service a Remote Location
Instead of Use of Booster Pump (Ineffi ciency)
Water distribution systems have pumps that move water throughout the entire
system. These pumps generate enough pressure so that all locations receive
the water they are scheduled to obtain. It is not uncommon for one part of
the distribution system to require a higher distribution pressure than others to
achieve the required fl ow. This may be caused by longer runs or more restric-
tive piping in specifi c zones of the system. If this is the case, it may be better to
boost the pressure to only those zones rather than operating the entire system
at the higher pressure. In this way, the main system pumps would use less
power to generate the required fl ow and some smaller booster pumps would
be used to increase the pressure to the zones needing it. This would save pump-
ing energy and reduce the stress on those locations near the main pumps that
would be exposed to the greater incoming pressures.
D.3.5 Discharging Condensate Water Rather Than Using It for
Other Purposes (Waste)
The air-conditioning process produces condensate water at the cooling coil,
which is typically discharged to the sanitary sewer. The cooling coil reduces
the temperature of the supply air as it passes though the coil. When this air is