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Implementing
and maintaining effective facility energy management programs NOAA is committed to reducing
waste and accomplishing its mission in the most cost-effective manner. One
of the ways we can meet these commitments is by implementing and maintaining
effective facility energy management programs. Facility energy
management is one of NOAA's most important business strategies for
the reduction of total operating expenses. NOAA cannot afford
to waste energy, particularly in these days of limited funds and other
resources. The inefficient use of energy adds significantly to
operating expenses, but it also has another impact. The Air Quality Connection Energy production from fossil
fuels is the greatest source of air pollution in the United States.
Although the United States has made great strides toward reducing air
pollution over the past two decades, there are three areas of concern
connected with the 83-percent increase in electricity generated nationally
from 1970 through 1990:
- Nitrogen oxide emissions from electric utilities increased by 67
percent between 1970 and 1990. Nearly 57 percent of the nitrogen oxides
in the atmosphere are a result of combustion of fossil fuels for electricity
production. Effects on health include irritation to lungs and lowered
resistance to respiratory infection such as influenza. Nitrogen oxides
contribute to smog and the formation of acid deposition (e.g., acid
rain).
- Sulfur dioxide emissions have declined slightly since 1970, but not
nearly as much as those of particulates, lead, and carbon monoxide.
Nearly 80 percent of sulfur dioxide emissions are from fossil fuel
combustion of which nearly 85 percent is from electric power production.
Sulfur dioxide affects breathing and causes respiratory illness and
symptoms, alterations in the lungs' defenses, and aggravation of existing
respiratory and cardiovascular disease. Sulfur dioxides are also responsible
for the formation of acid deposition.
- Carbon dioxide emissions increased by 20 percent between 1970 and
1988 and the contribution of coal to total carbon dioxide emissions
increased from 22 percent to 38 percent during that period. Carbon
dioxide is the major man-made contributor to global climate change.
Worldwide increases in temperature could alter weather patterns to
a degree that would significantly affect agricultural areas and raise
the sea level by heating and expanding ocean water, melting mountain
glaciers, and partially melting the polar ice caps. A rise in sea revel
would flood coastal areas around the world which support nearly 80
percent of the world's population.
Some Ways We Can Reduce Energy
Consumption 1. Lighting (about 25
percent of all U.S. electricity is used for lighting.) To reduce energy costs from lighting:
- Reduce illumination level by
removing lamp(s).
- Ensure that wattage of each
lamp is appropriate. Evaluate whether there are too many unnecessary
lamps.
- Increase the efficiency of
existing lighting by periodically cleaning light fixtures (lenses)
or adding reflectors.
- Determine areas with special
lighting requirements. Evaluate whether current lighting arrangements
are adequate.
- Turn off lights when not needed. Check
for lights that are left on when they are not needed. Investigate
the feasibility of installing automatic sensors to control lighting
in these areas.
- Evaluate whether workstations
are organized and located to take maximum advantage of existing lighting.
- Check that the light source
is to one side of the work task area rather than directly in front
of or over it, to minimize glare and ceiling reflections.
- Evaluate whether the maintenance
of lighting systems has been effective.
- Identify large work areas that
are uniformly lit for the entire space. Investigate whether "spot" lighting
can replace unnecessary lighting of an entire work area.
- When lamp removal is appropriate,
first remove lamps over nonessential task areas.
- Consider removing the inner
two lamps in four-lamp fluorescent fixtures and/or in every other
luminary in the row.
- Disconnect non-electric ballasts
on fluorescent and HID fixtures after lamp removal.
- Find areas where more efficient
lighting components can replace original, inefficient lighting system
designs or fixtures.
- Color-code lighting fixtures
from which lamps have been removed so that maintenance crews do not
replace those removed lamps.
- Check, and if needed, install
photoelectric cells for turning outside lighting on and off.
- Make maximum use of daylight. Encourage
workers to use natural lighting by using windows and skylights. Using
daylight also helps lessen heat requirements. Natural sunlight
should cross perpendicular to the line of vision.
- Group many light replacement
projects together.
- Consider lowering light fixtures
so that they are close to task work areas in high bay areas and other
spaces. Lighting intensity at the task varies as the inverse square
of the distance between source and task.
- Remove lenses from luminaries
in corridors, storage areas, high ceiling spaces, equipment rooms,
and other spaces if the resulting glare will not be a problem. Since
lenses cut out light. removing them may allow fewer lamps to be used.
- Remove or lower room wall partitions
where they are not needed, or use low partitions with glass.
- Relocate or remove light fixtures
when the light is blocked by over stacked materials or other obstructions.
- Where possible, replace two
small wattage incandescent lamps with one large incandescent lamp
(of lower total wattage). For example, replace two 60-watt
lamps with one 100-watt lamp.
- Evaluate the use of several
types of reflective incandescent lamps to receive the light needed,
but using fewer watts (depending upon type and application). For
example, in recessed top-hat fixtures, elliptical reflector (ER)
lamps or screw-in fluorescent lamps usually can be used at a lower
wattage than regular floodlights, yet they provide equal amounts
of usable light.
- Check and, if appropriate and
practical, convert incandescent fixtures to fluorescent (by changing
fixtures or replacing lamps) or to HID (by adding ballasts plus lamps).
Mercury vapor fixtures often can be converted directly to high-pressure
sodium (HPS) or to metal halides. Note: Payback for lamp conversion
varies depending on wattage reductions, electricity rate structures,
and the number of hours electric lighting is used in a particular
location.
- Replace existing fixtures with
more efficient types. Check them, and if possible replace fluorescent
lamps with T-8 lamps and electronic ballasts.
- When replacing ballasts in
fluorescent fixtures, use 430-milliampere (mA), high-power factor,
low-wattage ballasts with appropriate lamps. Note: Reduced wattage
electronic ballasts are also available that use less electricity,
last longer, and operate at lower temperatures than standard types.
2. Steam System
- Learn how a central system
actually operates by reviewing the operations manuals.
- Check for excessive consumption
of boiler makeup water, which indicates steam leaks or bad traps.
- Check whether condensate return
systems are functional. Condensate return should be at least
85 percent.
- Check for steam leaks and condensate
leaks.
- Check all traps and tag bad
steam traps.
- Perform a flue gas analysis
to determine boiler combustion efficiency and whether a tune-up is
required. If the boilers are already tuned, have less than three
passes, and the flue gas temperature is above 400°F,
consider installing turbulators in fire-tube boilers.
- Record boiler capacity and
operating pressure.
- Determine steam requirements
to see if boilers can be staged or if one or more boilers can be
fully loaded while shutting down another.
- Determine if a blowdown systems
can the energy lost from hot boiler water and steam generation during
blowdown. NOTE: By piping the vent off a blowdown unit's recovery
unit to the deaerator, steam normally lost to the atmosphere can
be recovered. By installing heat recovery coils in the heat recovery
unit, heat from boiler blowdown to the drain can be recovered and
used to preheat boiler makeup water, combustion air, and domestic
not water.
- Study water treatment and analyze
boiler and makeup water.
- Consider installation of stack
heat recovery units such as economizers if stack gas temperatures
are high. Economizers should only be considered if all other recommendations
have failed to reduce stack gas temperatures below 420°F
for low load (200 to 600 horsepower) boilers.
Chilled Water System
- Check for chilled water leaks.
- Determine the proper chilled
water operating temperature.
- Raise the chilled water supply
temperature. Note: The temperature of leaving chilled water
in centrifugal chillers is usually maintained at 42°F
to 45°F by a chilled water thermostat. This
may be lower than required to meet the cooling demand of the building
air handling systems, particularly in moderate weather. Chilled
water supply temperatures of 50°F or higher
can be used humidity control and other comfort requirements are satisfied.
- Consider manually raising the
setpoint of the chilled water thermostat to the highest possible
temperature while still satisfying humidity control and other comfort
requirements. Install controls that reset the chilled water supply
temperature based on the return chilled water temperature. Note:
This allows the supply chilled water temperature to rise as the return
chilled water temperature drops. The chiller follows the actual building
load more efficiently rather than supplying chilled water according
to design conditions.
- Install controls that reset
the chilled water supply temperature according to the cooling coil
with the highest cooling demand. In this manner, the chiller delivers
only as much cooling as is actually required.
- Determine condenser water temperature.
Lower the entering condenser water temperature as much as possible.
- Determine the condition of
cooling towers on installations with a cooling tower bypass valve.
Ensure that the bypass valve closes completely before the cooling
tower fans operate. If chilled water is not needed during the winter
close the tower bypass valve permanently.
- Determine the condition of
forced draft cooling towers. If chilled water is not needed in the
winter, make sure the fan discharge dampers are kept completely open
or remove them, if possible.
- Determine the condition of
induced draft towers. Replace sections of fill that are damaged or
deteriorated.
- Check whether hot gas bypasses
are operating properly. Sometimes bypasses are not needed and
can be discarded.
- Check controls to ensure that
they are calibrated and functional.
- Determine whether heat transfer
surfaces on the evaporator and condenser coils are clean.
- Determine whether the refrigerant
level is too low.
- Investigate whether units can
be shut off when not needed.
- Determine whether lights in
walk-in coolers and freezers can be shut of automatically upon exit.
- Check whether time clocks are
installed on window air-conditioners. Verity usage of units with
high energy-efficiency ratios (EERs).
- Check for ways to control solar
gain to reduce the cooling load on buildings.
- Investigate whether computer
center cooling demands are the basis for setting the entire facility's
chilled water temperature. Consider using separate cooling
units for computer rooms.
Domestic Hot Water
- Measure and compare existing
water temperature versus required temperature (e.g.. 105°F
from faucets). Lower the water temperature when appropriate.
- Inspect circulating pump controls. Consider
using variable speed pumps.
- Inspect the hot water system
for any leaks. Repair them if required.
- Check for any waste heat that
can be used for water heating.
Building Envelope
- Verify that outside wall insulation
is adequate.
- Verify that ceiling and roof
insulation is adequate. About 40 percent of energy loss can occur
through poor ceiling insulation.
- Check the type of windows used.
Determine the feasibility of replacing single-pane windows with double-glazed
windows.
- Identify areas with infiltration
or wind draft problems. Seal leaking areas if possible.
- Determine if any passive measures
can be taken to reduce solar loading on buildings. The use of passive
measures depends on the orientation of the building and its surrounding
shrubs and trees.
- Check the type and number of
doors in the building. Ensure that these doors are appropriate for
their intended purpose. Consider installing revolving doors for high
traffic areas.
- Check for ways to minimize
heat loss (or heat gain) from loading dock doors or hangar doors.
Electrical Motor Checklist
- Check whether motors are property
sized for their loads. Load motors fully where possible. Replace
or switch motors as necessary. A 50 percent reduction in motor size
results in ever 80 percent reduction in energy use.
- Ensure that the highest practical
power factor is used for electric motors.
- Consider shutting down elevators
during unoccupied hours in buildings.
HVAC Systems and Controls
- Study blueprints and determine
the type of HVAC system being used.
- Determine the operations areas
being served by all fans (i.e., supply, return, exhaust).
- Study control drawings and
develop a design control strategy.
- Perform at least one inspection
of all mechanical equipment.
- Determine if the controls are
installed as shown on the original manufacturer's drawings.
- Determine if the controls are
functioning correctly.
- Determine the percentage of
outside air being used.
- Determine the actual supply
cubic feet per minute (cfm).
- Determine if there are capacity
reduction possibilities. Determine if they are not being used.
Note: often large-capacity HVAC equipment is kept running to serve
a relatively small area requiring continuous conditioning. In these
cases, separate smaller HVAC units maybe more efficient.
- Check for HVAC Systems that
draw in excessive outside air or recirculate more air than necessary.
Readjust the air mix if required.
- Check whether the central heating
and cooling plants are partially loaded most of the time because
they were originally sized according to maximum-use design conditions
that seldom occur. Large boilers and chillers operate at their
peak efficiency only at full load. Consider installing smaller boilers
or variable-speed drive motors for chillers.
- Identify any HVAC systems that
simultaneously heat and cool the same air to produce a desired temperature,
since that method of operation wastes energy.
- Reduce peak electricity demands
by installing load timers to turn off unessential loads upon reaching
a preset demand level. Load-shedding reduces the demand charge assessed
by utility companies.
- Consider using duty cycling
that turns off a compressor, pump, or air handler for a brief period
every hour or half hour, and that regulates HVAC systems by turning
of the maximum number of units that can be turned off at any given
time. Duty cycling can reduce peak energy demand without sacrificing
the comfort of the facility occupants.
- Consider installing temperature
controls that allow the HVAC system to use fresh air for ventilation.
Note: These controls monitor the outdoor temperature and signal the
HVAC system to use outdoor air depending on whether outside air temperature
is cooler or warmer than indoor air.
- Shut down AHUs or exhaust fans
during unoccupied periods.
- Minimize outdoor air intake
during unoccupied periods to eliminate the unnecessary heating and
cooling of outside air. Note: Outside air brought into, and exhausted
from, a facility uses a majority of time heating, and a significant
portion of the cooling, energy consumed by HVAC systems.
- Determine the minimum number
of outside air changes required per hour for each space served by
an air handler.
- Reduce the air moved by exhaust
fans by restricting flower changing sheaves. Adjust the minimum position
of outdoor air dampers on AHUs to meet minimum requirements.
- Install time clocks to shut
down unnecessary exhaust fans and to close ventilation air dampers
during unoccupied hours.
- Determine the present cfm being
delivered by the AHU and reduce the cfm as appropriate. Note: Many
fans circulate more air than necessary to satisfy space requirements.
Reducing airflow dramatically reduces the brake horsepower (bhp)
used by the fan motor.
- Determine the volume of each
area served by the AHUs and the cfm delivered to those areas. Using
this information. determine the total cfm required from the AHU.
Size fan motors accordingly.
- Consider installing a mixed
air controller. Most AHUs are designed to maintain a constant mixed
air temperature of 55°F. When outdoor
air has a higher heat content than return air, the economizer should
change over to minimum outside air and maximum return air. The general
practice is to approximate heat content by changing over when the
outside air temperature reaches 70°F.
- Check for any stratification
of outside and return air occurring in ducts or mixing plenums.
- Check controls on the economizer.
Find out whether the controls are based on dry-bulb temperature or
on enthalpy. Note: At low outside temperatures, the economizer should
admit only the minimum amount of outside air required. This is often
not the case with parallel-blade dampers. During cool weather, the
economizer should mix outside and return air to supply air at a temperature
no lower than needed to cool the area with the greatest cooling demand.
- Consider installing a set of
relief dampers or a gravity ventilator to vent return air to the
outdoors for fixed air handlers.
- Check humidity sensors for
damage and for sensors out of calibration. Note: In most AHUs, humidification
is accomplished by spraying steam into the supply air stream. AHUs
are usually controlled by maintaining the desired relative humidity
(RH) of supply air, by resetting supply air RH (by return air RH),
or by maintaining the desired RH in one area.
- Find out whether humidification
is required when the AHU is set in a mode other then "cooling only."
- Check the steam control valve
on the humidifier. If the valve fails to close completely, it may
leak steam through the humidifier into the airstream.
- Ensure that load optimization
with reheat systems occurs by easing at least one reheat coil off
(which minimizes the amount of reheat in the other areas). Note:
Most central HVAC systems are designed to provide sufficient cooling
and/or heating to satisfy the worst condition in any one area. By
supplying an air temperature that satisfies the area with the greatest
energy demand, energy wasted is reduced to an absolute minimum.
- Consider installing non-electric
thermostatic steam valves with wall-mounted thermostats. Sometimes
it is practical to control radiators in an area with an automatic
valve on the steam supply line.
Energy Management The Department of Energy has established
a Federal Energy Management Program (FEMP) to assist in reducing the
use and cost of energy in the Federal sector by advancing energy efficiency,
water conservation, and the use of solar and other renewable energy
sources. FEMP accomplishes its mission by leveraging both Federal and
private resources to provide technical and financial assistance to
other Federal agencies, which take actions and make investments that
increase energy efficiency and renewable energy utilization, and reduce
water consumption at their facilities. As the largest energy consumer
in the world, the U.S. government's cost- and energy-saving opportunity
is enormous. In Fiscal Year (FY) 1996, the government spent nearly
$8 billion for its 500,000 buildings, its vehicles, and process energy. Further information can be obtained
the FEMP Web Page: http://www.eren.doe.gov/femp/  For more information on the NOAA
Energy Management Program contact the Environmental Compliance and
Safety Staff. Return
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