“The Energy Reduction Continuum”
A Process of Incremental Improvements
Rock Morille, P.E., M.B.A.
Vice President - Facilities
Baylor College of Medicine
Houston, Texas
Steam
Install Efficient Boilers to
Reduce Natural Gas Usage
Replaced 3 Cleaver-Brooks fire tube
boilers in the central plant. These
boilers were rated at a total natural
gas input of 58.5 million BTUH and an
overall efficiency of 80%. They were
replaced with seven Miura low-NOx
series high pressure steam boilers,
having a total natural gas input 82.4
MMBTUH with an overall efficiency of
85%, yielding an immediate 5%
efficiency improvement. The Miura
boilers contain only one-tenth of the
water of an equivalent sized fire tube
boiler, and thus have the ability to
ramp up to full steam production in
only 5 minutes . This complete system
upgrade yielded an overall 10%
reduction in natural gas usage, and
reduced NOx production by over 77%.
The savings associated with this
project continue to be over 17,500
MMBTU annually, or $140,000 per
year.
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Boiler Blow down - Water
Heat Recovery
High temperature (300 deg F) boiler
blow down water is run through a heat
exchanger to transfer the sensible heat
stored in the 300 deg. F liquid water to
the cold (70 deg. F) makeup water to
the same boiler. The amount of water
released (blow down) from the boiler
is controlled automatically by the
boiler water chemistry computer to
maintain the proper amount of
dissolved solids in the water inside the
boiler. Solids remain in the water
inside the boiler as a natural function
of the evaporation process. This
program works well because the ratio
of make-up water to blow down
(waste) water is relatively constant at
100:1.
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Steam Boiler Efficiency (20) Cycles-of-Concentration
with RO Water
To reduce boiler blow down
requirements and related chemical
usage, we first soften the water using
a traditional sodium ion exchange
process followed by Reverse Osmosis
(RO) Water treatment to remove all
impurities and suspended solids. This
allows us to run a higher cycles of
concentration (CoC) in the boiler,
reducing blow down requirements and
permitting the use of fewer scale and
corrosion inhibitor chemicals. By using
RO water we achieve 20 cycles of
concentration vs. 8-10 cycles with
only soft water.
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Water
Water Reuse– Clg Twr
Blow down
The local utility company requires that
any water introduced into the sanitary
sewer be cooled to less than 140 deg.
F. We use the cooling tower blow
down water (75 deg. F) to cool boiler
blow down water (300 deg. F) and high
temperature cage washer (180 deg.
F) water discharge. In the case of both
the cooling tower and boilers the
evaporation of water as a natural part
of the process causes the amount of
solids to build up in the system and a
portion of this high solid water must
be drained from the system to keep
the chemical / solid ratio in balance.
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Water Recycling – AHU
Condensate Recovery
This initiative began as a project to
collect reject water from Reverse
Osmosis water purifying systems and
pump it to the cooling tower for
evaporation as part of the air
conditioning system. Started in 1989
the system has been expanded (over
the years) throughout the campus to
collect drain water from ice machines,
scientific lasers, air handling units, rain
water / roof drains, and drinking
fountains. We are currently processing
/ recycling over 30,000,000 gallons of
water a year using this system for a
savings of over $140,000 per year.
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Reuse Back flush Water
from RO System
The college produced high purity
water for use by our researchers. The
process of producing this water
involves separating the impurities
from the water and flushing them from
the purification system. This flushing
provides a continual stream of reject
water which was historically routed to
drain. We installed a system that
would collect the water and pump it
into the cooling towers for use as
makeup for evaporation losses. These
cooling towers supply water to
support our air conditioning systems.
In the beginning we were collecting 2
million gallons a year for a savings of
$15 K per year.
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Restroom Water Usage
Reduction
In addition to the 3.5 Gallons per Flush
(GPF) we were using on our toilets,
they were now offering a new product
which regulated flow to 2.4 GPF. A
savings of 1.1 gallons of water every
time a toilet is flushed. A similar
product was offered for urinal flush
volume control which reduced the
water per flush from our 1.5 GPF to
just 1.0 GPF. A savings of 0.5 gallons
each time a urinal is flushed. We
replaced over 500 of these diaphragms
during January and February of 2005.
Our year over year water usage for the
month of April, and every month going
forward, was reduced by an average of
3.2 million gallons or $23,000 per
month as a result of this project. The
payback was just 1 month.
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Electrical
High Efficiency Motors
Motor efficiency technology (IEEE-841)
has been evolving over the last 20
years. In 2001 we stepped up our
efforts to inventory every pump, air
handler, and cooling tower fan motor
(size, efficiency, and power factor) and
evaluate opportunities to change out
existing motors for the higher
efficiency motors. In many cases we
found that although an old motor was
functioning fine, there was a huge
opportunity for energy savings by
replacing the old motor with a high
efficiency, high power factor motor.
During the years 2002 and 2003 we
replaced more than 30 large (greater
than 25 HP) motors with high
efficiency motors. Each of these
replacements had a payback of less
than 18 months and a life expectancy
of 7 to 10 years. Shown here is a 125Hp exhaust fan motor.
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Use VFD’s to Match Fume
Air Demand; Eliminate
Bypass Air Dampers
Added VFD drives to control central
vacuum system TSP, allowing the
exhaust fans to match varying fume
hood demands. Coupled with variable
air volume fume hoods vs. older
constant volume type, this upgrade
saves energy by eliminating the need
to use outside air bypass dampers to
control system static pressure
(vacuum). A total of 500-Hp of fans
that support various exhaust systems
throughout the college have been
converted to VFD control.
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Electrical Savings - Variable
Frequency Drive Motor
Controllers (VFD)
We began using variable speed drives
to control the speed of motors driving
pumps, cooling tower fans and air
conditioning fans in 1989. Since that
time we have installed these drives on
over 200 pieces of equipment. These
controllers allow us to match the
water or air moved through the system
to the demand in a much more
accurate way. The savings derived
from these units is the cubed of the
speed reduction. So a speed reduction
from 100% to 80% results in an energy
/ cost savings of 49%. We save over
$250,000 per year using these variable
speed motor controllers.
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Capacitors to Improve
Electrical Power Factor
In large scale operations it is important
that all energy delivered to a site be
used efficiently as possible. The
measure of power conversion
efficiency within a facility is described
or defined by the “Power Factor” (PF).
This increases costs for power
generation and infrastructure capacity
(larger distribution wiring) and these
costs are passed on to the customer.
Low power factor facilities are also
responsible for increased green house
gas production when compared to
facilities with higher power factors. A
facility should strive to have a power
factor between 0.96 and 0.99. At
Baylor College of Medicine we have
continually upgraded our capacitor
systems to maintain a power factor of
.97 or higher as our electrical load has
changed over the years.
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Lighting Technology – T5
Fluorescent; Motion Sensors
Replace lighting systems - In 1992 and in
2004 we changed out all the lighting
system ballasts and lamps to improve the
efficiency of the lighting system at
BCM. Each time the project resulted in a
savings of over 1.5 million KWH per
year. Our current lighting system is more
than 50% more efficient than and saves
more than 3 million KWH when
compared to the lighting system we had
in 1990. The savings have been over
$140,000 per year.
Replace Incandescent lights with
fluorescent lamps - The newest florescent
lamp technology is available with dimmer
switch compatibility.
Replace standard light switches with
motion detector switches - . Using the
motion detector switches saves BCM over
195,000 KWH ($18,500) per year.
Spec: Cooper Corelite T5, 2-bulb, shallow
2x4 fixture. P/n R1-WL-2N5-1-xxx
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Optimize Airflow to Maintain
Pressure Differentials
Three exhaust fans serve the
underground Vivarium area, in
conjunction with three air handling
units. While the AHU’s were on
variable frequency drives, the exhaust
fans ran at 100% speed. Their suction
was regulated by dampers that
bypassed outside air that caused the
exhaust fans to run at a constant load.
Added VFD’s to these three 125-Hp
exhaust fans in order to be able to
control their speed, and to match the
ACH (air changes per hour)
requirement of that space. With this
upgrade we were able to reduce ACH
from 18 to 15, yielding an immediate
70-kW power reduction, or 600,000kWh/yr for this 24/7/365 operation.
The energy savings alone was
$50,000/yr (at $0.08/kWh). The
capital cost of this program was 80%
offset by a rebate incentive program
from Centerpoint Energy.
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Mechanical
Replace AHU’s with Newer
Units to Improve
Efficiency and Reliability
The new air handling units we are
installing are constructed to provide the
highest energy efficiency combined with
the longest life of any of the equipment
we have ever installed. We are using all
the technologies mentioned above to
minimize the energy consumption and
carbon footprint of our facility. The air
handling units are designed with direct
drive fans which eliminates any
inefficiency associated with belt slippage,
variable speed drive units which match
the fan speed exactly to meet the air
demand at any time, and UV lights in
front of the cooling coils to minimize the
pressure drop across the chilled water
coil, kill all organic or bacterial life forms
thus improving the indoor air quality. We
also utilize double wall construction to
keep the air stream free of any insulation
contaminates.
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Power Transmission
Efficiency - Replace V-Belts
with Timing Belts
V belt drive systems work on the
principle of tangential friction allowing
the energy produced by a motor to be
transferred to a fan by using belts and
pulleys. In this system there is always
some amount of energy lost as the
belts slip as a result of the loss of
tension as the belt stretches with
age. The timing belts have teeth on
the inside of the belt which are used
to create a positive lock between the
motor pulley and the fan pulley. The
design eliminates the possibility of belt
slippage. An additional benefit is long
life (4-5 years) vs. less than 6-12
months for V-belts. Makes sense in
larger Hp applications (>25 Hp).
Replacing the V-belt with a timing belt
results in an energy savings of 4% to
6% with a payback of 8 to 14 months.
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AHU Hp Reduction – Install
UV Lights to Keep Coils Clean;
Destroy Organic Mat’l
In 2001, in response to the indoor air
quality issues we were having just after
Tropical Storm Alison, we installed UV
lights in every air handling unit on the
campus. The lights kill the bacteria and
mold growing in the moist cool
environment inside the air handling
units. A side benefit was the UV lamps
also killed the bacteria growing on the
cooling coils. Recently we have started
testing a new technology (Ion Bar) made
by GPS Technologies. Over the past 18months this technology has met or
exceeded the UV light performance, with
lower operating costs and longer life. The
unit generates Hydrogen Ions that
interfere with a viruses ability to
reproduce. VOC reduction is also
claimed, but we have not measured. The
energy savings resulting from the
installation of the UV lamps was roughly
5% per unit or 475,000 KWH per year
($45,125 per year).
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Airflow Reduction - Lab
Fume Hood Exhausts
In 1994 we implemented a program to
measure and adjust the air flow through
our laboratory fume hoods to meet the
National Institute of Health standards for
the work taking place in the specific
laboratory. Prior to this time, the
philosophy had been to set up each hood
to support the most aggressive chemicals
that would potentially ever be used or
simply put, to run the exhaust at the
designated CFM for the highest category
of activity (most dangerous work).
Through this effort and working with the
BCM Office of Environmental Health and
the individual investigators we were able
to reduce the amount of air we were
exhausting by 25% over all. The
beginning effort was the start of the
annual lab hood exhaust testing program
we now have at Baylor College of
Medicine. We manage this testing (and
flow adjustment) program through our
Energy Management group.
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Water Recycle - Kitchen
Exhaust Air Scrubbers
This program recycles water that was
previously being disposed of after just
one use. Our cafeteria uses water
injected exhaust fans to minimize the
amount of particulate (grease particles)
and odor that is discharged from our
cafeteria grilling operations. The
operational process is such that the water
is injected as a mist into the exhaust
stream. The injected water then
“captures” any particles and removes
them from the air stream. This water and
particle mixture then drains from the
system before the air is exhausted to the
outside air. The installation had the
water / particle mixture routed
immediately to the floor drain in the
mechanical room. We installed a tank
with a float controlled make up water line
to create a recalculating water system.
We drain this system once a week to
minimize any grease buildup. This project
saves over 1500 gallons of water each day
or 375,000 gallons of water ($3,000) each
year.
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Pumping Hp Reduction Water Pressure Control
As variable speed drive units became
more reliable in the early 1990’s, we
began replacing the older on/off style
pump control strategies with variablespeed pressure control strategies. We
soon found that the technology for
pressure tanks had changed to where
now large rubber “bladders” maintained
a separation between the air and water
thus reducing the corrosive qualities of
the water. These technology advances
allow us to run a much smaller pump at a
slower speed to maintain water pressure
in the system. The result was that
beginning in 1994 we started changing all
our domestic water pressure control
systems (pumps, pressure tanks and
motor controls) to variable speed drive
controlled, multi stage centrifugal pumps
coupled with bladder tanks to reduce
energy used to boost water pressure.
Payback on these system replacements
averaged 18 to 24 months including
energy and labor savings.
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Chilled Water
Electrical Savings - Replaced
Inefficient Chiller Units
In 1992 we started a program to
replace the two least efficient chillers
(.95 KW / Ton) with state of the art
chillers (.62 KW / Ton). Each of the
chillers we replaced was 800 tons in
size. The energy savings associated
with replacing these two chillers
amounts to 528 KW per hour or 1.5
million KWH per year (calculated
running 33% of the time). This
equates to a savings of $145,000 per
year.
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Water Savings - Cooling
Tower Filtration
As part of the HVAC process, the
cooling towers evaporate water to
provide cooling for the air conditioning
of the campus. The cooling tower
system is uses direct contact between
air and water to facilitate the
evaporation process. As a result of the
evaporation process the pure water is
removed from the system and all the
water and airborne solids and
impurities remain in the cooling water
system. This dirt accumulation in the
system remains in suspension and
precipitates out in the basin of the
cooling towers. The cooling tower
water filters save water by making sure
that the cooling tower blow down
water is very high in solids and it
minimizes the amount of the water
treatment chemicals discarded to the
environment. These systems have a
pay back on investment of 1 to 2 years
and have a life of 10 to 15 years.
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Reduced Pump and Fan Hp Reset Condenser Water Temp
based upon OAT
Using variable speed drives on the
cooling tower fans allows us to control
the condenser water temperature to
within a half of a degree F. This
accuracy allows us to reduce the
condenser water supply temperature
to 70 deg. F when the outside air
temperature is below 60 deg. F. The
air conditioning system is designed for
the condenser water supply
temperature to be 85 degrees. The
savings associated with reducing the
condenser water temperature is 1.5%
per degree reduction. So a 15 degree
reduction equates to a 22.5%
reduction in air conditioning system
energy consumption. Using this
process we have reduced our energy
consumption by over 2.8 million KWH
per year ($270,000 annually).
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Replace Cooling Tower
Media to Maintain Heat
Exchange Efficiency
Replaced the internal labyrinth media
of four (4) Marley cooling towers with
new factory-provided hanging media
and mist eliminators. The original
media was twelve years old and
beginning to show deterioration at the
edges due to UV weathering and
normal aging. The internals of the
media was found to be clean,
indicating an effective chemical
treatment program.
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Chiller Tonnage Reduction
- Reset Chilled Water
Temp based upon OAT
We adjust the chilled water
temperature based on the outside air
temperature. When the outside air
temperature is below 50 deg. F we set
the chilled water temperature at 49
deg. F. When the outside air
temperature is above 75 deg. F we set
the heating hot water temperature
at 44 deg. F.
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Spot Cooling - Computer
Room Dedicated
In 2007 we recognized that we had
one data center (650 SFT) heat load
which was forcing us to maintain a
lower chilled water temperature in the
winter than was required to satisfy the
cooling requirements for all the
activities taking place in the other 1.4
million SFT of the campus. The heat
load from this data center was forcing
us to keep the chilled water for the
whole campus 2 degrees colder in the
winter than would otherwise be
required. The solution to this problem
was to add a 7.5-ton DX, R-22, split
system air conditioning system. We
installed the fan coil (evaporator) in
the data center and the air-cooled
condenser on the Alkek Building roof.
This allowed us to raise winter-month
chilled water temperature for the
entire campus.. The payback on this
project ($20,000) was less than one
winter season (4 months).
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Controls
Efficiency Monitoring Energy Dashboard for
Central Plant
Created an “Energy Dashboard”
software program to monitor real-time
CHW tonnage versus energy usage
compared against year-ago data. Also
displayed for reference is current
outdoor air data (dry bulb, wet bulb,
and enthalpy). This provides the
operators with some guidance on how
the plant is running from an efficiency
standpoint versus load. Data flows
from NAE server that pulls PowerLogix
data for central plant, and includes
Metasys data for other parameters.
Information resides in a SQL Server
database.
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Upgrade Chiller Controls
for Efficiency / Reliability
Upgraded the controls on two Trane
chillers from the original “Classic
Black” relay logic to the newest CH530
“AdaptiView” controls to provide more
accurate process temperature control,
improved chiller monitoring, and more
accurate field instrumentation. This
also provides continuity with controls
upgrades that are offered by Trane for
all new equipment.
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Electrical Savings - Lights
Off at Night/Weekends
We utilize our energy management
system to schedule hallway lighting to
match occupancy. In this program, our
emergency lighting systems remain on
at all times to provide the life safety
illumination required by NFPA, but we
turn on and off our normal power light
fixtures (approximately 2/3 of the total
# of light fixtures) to match the hours
of occupancy of the facility. In most
cases this enables us to reduce lighting
energy consumption between the
hours of 10:00 PM and 7:30 AM
weekdays (M-F and on weekends) by
2/3 of what is consumed during the
occupied times.
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Steam Usage Reduction Reset Heating Hot Water
Temps based upon OAT
We adjust the heating hot water
temperature based on the
outside air temperature. When
the outside air temperature is
below 38 deg. F we set the
heating hot water temperature
at 180 deg. F. When the outside
air temperature is above 85 deg.
F we set the heating hot water
temperature at 105 deg. F. We
use a linear formula to adjust the
heating hot water temperature
when the outside air
temperature is between these
two values. By doing this we
minimize our natural gas
consumption and meet the
needs of the building
occupants. This energy
management program saves
BCM over 5,000 MMBTU of
natural gas consumption
annually ($35,000 annually).
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Other
Control Valves to Balance
Clg Twr Levels; Reduce
Operator Fatigue
Automate the 10” butterfly isolation
valves below cooling towers 9 and 10
to permit automatic level control
rather than labor-intensive manual
control. These towers do not share a
common basin with the other eight
cells and their flow rate varies as
condenser water manifold pressure
fluctuates during heavy summer
month usage. Provide 4-20mA BAS
control. Reduces overflow risk and
allows operators to focus on more
value-added activities such as energy
management.
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Hurricane Rated Window
Protection Film
In 2004 we began the installation of
“hurricane rated” window film as part of
the hazard mitigation program
recommended by the State of Texas’
Division of Emergency Management and
the Federal Emergency Management
Agency (FEMA). We selected an 8 mm
thick window film with a 50% shading
factor. This product is rated for sustained
impacts of objects moving at 120-mph.
Additionally, it provides energy savings
without being so dark as to create a
“cave-like” environment inside the facility.
We installed over 150,000 square feet of
this window film throughout the campus.
The project saves a total of 7.5 million
BTU’s (625 Tons) of air conditioning
during the peak of summer. This equates
to an electrical generation avoidance of
over 413,000 kWh per year. The
environmental impact of this generation
avoidance is a CO2 emission reduction of
over 568,000 pounds per year.
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Recycling & Resource
Stewardship
BCM has a robust recycling program
that is an integral part of the Texas
Medical Center’s community-wide
initiative to reduce waste and promote
sustainability.
2012 Recycling Highlights
Water Conserved - 27,800,00 gallons
Metal Recycled - 152,878 lbs. or 76.44
tons
Plastic Recycled - 14,352 lbs. or 7.18
tons
Paper/Cardboard Recycled - 922,888
lbs. or 461.44 tons
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Demand Response –
Electrical Energy Load
Shed Rebates
We have elected to participate in a
Centerpoint power company initiative
whereby we agree to load shed our
power usage during periods of peak
power demand in order to allow the
power company to meet all critical
loads without interruption. For 2013
we have elected to put 3.8-MW of
power on this program. (summer) We
are able to take advantage of this
program by using our diesel powered
backup systems to drive our largest
2,500-ton chillers. This saves BCM
over $225,000 per year. Shown here is
one of two 2.5-MW Cummins diesel
generators.
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Q&A