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Energy Efficient Buildings at Dartmouth College
Thayer EngineeringMay 22, 2017
Dartmouth College Facility Summary
• 200 + Buildings• 250 Acre Core Campus• 5.0+ Million Square Feet• Central Heat Since 1898 w/ Co-generation since 1911• 5 miles of underground steam piping• District Chilled Water. Four plants. • Centralized Digital Building Controls• Second College Grant• Dartmouth Skiway• Mt. Moosilauke
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Dartmouth College Energy Efficiency History
– 1911 Cogen steam plant– 1961 thru 2005 Absorption chillers (good then, not so much today)– 1990 Burke (design awards)– 1997 Moore (baby steps with small heat recovery)– 1999 Webster (now we are getting somewhere)– 2000 McCulloch dorm (thinking outside the box)– 2000 Whittemore (became a mile stone)– 2006 Maynard dorms, Tuck Mall dorms, Kemeny (bold steps)– 2008-2010 Tuck Living and Learning, Floren, Sudikoff addition
(applying what we have learned)– 2011 Class of 1978 Life Sciences (the best yet)– 2012 Visual arts (it’s ok but…)– 2013 Class of 1953 Dining, Hanover Inn (vision not so clear
anymore)– 2014 Burke Renovation (Fantastic results)– 2014 Baker Berry Library (Aircuity for demand controlled ventilation)– 2014 Moore Hall (Aircuity for demand controlled ventilation)– 2017 Steele Hall and Wilder (Konvekta Heat Recovery)
Historical Oil Cost and Usage – Last 20 Years
Rising Energy Use – Oil
‐
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
GALLONS PER
YEA
R
YEAR
Dartmouth Oil Consumption
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Historical Electrical Cost and Usage – Last 20 Years
And Rising Energy Use – Electricity
‐
10,000,000
20,000,000
30,000,000
40,000,000
50,000,000
60,000,000
70,000,000
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
KWH PER
YEA
R
YEAR
Dartmouth Electrical Use
Gross Square Feet14% Growth
Air Conditioned GSF 41% Growth
Air Conditioned Growth from 33% to 50% of Campus GSF
Dartmouth’s Growth 2005-2012
Expanding Conditioned Area
‐
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
SQUARE FEET
YEAR
Dartmouth Total Building Area
‐
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
SQUARE FEET
YEAR
Dartmouth Air Conditioned Building Area
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• Increasing building area and conditioned space requires additional campus utility capacity
• Boiler Plant expansion
• Chiller Plant(s) construction
• Long term energy planning is showing results.
• “Business as Usual” will not achieve goals for reduction in energy use / cost and emissions
• Decisions based on short term energy cost / payback will not provide long term value to institution
• Need a total cost accounting approach to energy investments
Dartmouth Energy Picture
Good Buildings come from good processes
• Team effort
• All disciplines work together
• Trust each other
• Open and frank discussions
• Active and educated owner and occupants
• Stated common goals
• Holistic view
• Prompt decisions
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Building Performance Practice - Process
How DC used to do it How DC does it today*
• Hire traditional design firms• Focus mainly on program and
appearance• Did not challenge the design
approach• Installed traditional big HVAC
systems• Go with what worked in the past
• Hire progressive design firms
• Focus on program, appearance, reduce loads and recover energy
• Minimize systems, sometimes even eliminate systems
• Right size equipment
• Open to try new approaches
• Recover as much energy as possible.
• Smart lighting systems and design
• Pump energy instead of blowing
• Integrated Design
• Performance Goals
* Most of the time
Rauner Library at Webster Hall, 1999 Setting a Baseline for Efficiency in Design
• Reuse of Existing Building
• Structure Within Structure
• Desiccant Wheel Reduces Cooling Latent Load
• Variable Air Volume Ventilation with Variable Frequency Drives on Fans
• Variable Frequency Drives on Chilled Water Pumps
• Centralized Direct Digital Controls on Mechanical & Lighting Systems
• Energy Efficient Lighting & Motors
• Fully Commissioned Systems
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Whittemore Hall, 2000 Amos Tuck School of Business AdministrationBeginning the Integrated Design Process on Campus
• Enthalpy Energy Recovery Wheel
• Variable Air Volume Ventilation with Variable Frequency Drives on Fans
• High Performance Envelope with Triple Glazed Windows
• Energy Efficient Lighting & Motors
• Fully Commissioned Systems
• High Performance Building Envelope Combined with Ventilation Air Heating and Cooling Allowed for the Elimination of Perimeter Radiation = $ saved in construction and operation.
McLaughlin Cluster, 2006Developing Integrated Design, Implementing LEED™
• High Performance Envelope, R-25 Walls, R-40 Ceilings, High Performance Windows – Triple Glazed Fixed Lights
• Radiant Heating and Cooling• Enthalpy Energy Recovery on
Ventilation System• Variable Frequency Drives on
Pumps and Fans• Direct Digital Mechanical
Controls Linked to Central Plant • Energy Efficient Lighting &
Motors• Heat Recovery on Bathroom
Wastewater• Wood from College Property• Fully Commissioned Systems
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Radiant heating and cooling eliminates need for perimeter heating, eliminates need for fan driven air cooling systems and delivers optimal environmental comfort with minimal expenditure of energy
Embedded PEX Tubing and Control Manifold
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Tuck Mall Residence Hall
• High Performance Envelope, R-25 Walls, R-40 Ceilings, High Performance Windows
• Radiant Heating and Cooling• Enthalpy Energy Recovery on
Ventilation System• Variable Frequency Drives on
Pumps and Fans• Direct Digital Mechanical Controls
Linked to Central Plant • Energy Efficient Lighting & Motors• Heat Recovery on Bathroom
Wastewater• Wood from College Property• Fully Commissioned Systems• Ground Source Heat Pump
Tuck Mall Residence Hall
• High Performance Envelope, R-25 Walls, R-40 Ceilings, High Performance Windows
• Radiant Heating and Cooling• Enthalpy Energy Recovery on
Ventilation System• Variable Frequency Drives on
Heating/Cooling Pumps• Direct Digital Mechanical Controls
Linked to Central Plant • Energy Efficient Lighting & Motors• Heat Recovery on Bathroom
Wastewater• Wood from College Property• Ground Source Heat Pump• Fully Commissioned Systems
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Kemeny Hall / Haldeman Center
• High Performance Envelope, R-25 Walls, R-40 Ceilings, High Performance Windows
• Valence, Chilled Beam and Air Delivered Heating and Cooling
• Enthalpy Energy Recovery• VFD’s on Heating/Cooling
Pumps• DDC Mechanical Controls• Energy Efficient Lighting &
Motors• Fully Commissioned Systems
Valance unit creates convection heating and cooling without forced air
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New Life Science Center
New Life Science Center
• Exhaust air heat recovery. Oversized wheels.• Lighting at less than 1W/sqft• Refrigeration heat recovery• Chilled beams in laboratories• Demand controlled exhaust system – IAQ control and
record• Medium temperature chilled water system• Natural ventilation in certain areas• Green roof• Storm water collection• Platinum LEED
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New Life Science Center- Results
• Actual steam load 800 lb/hr in -14F (initially estimated to be 18,000 lb/hr)
• Chilled water plant load 400 tons (initially estimated to be 900 tons)
• Computer modeling indicates energy use almost down to 100,000btuh/sqft-yr (comparable to a traditional office building)
• Actual energy consumption meets the energy model (this is unusual)
• One of the most energy efficient lab building in North America.
First Year of Operation
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
kBT
U/s
f
Projected vs. Actual Monthly Energy Consumption (kBTU/sf)
Actual TotalEnergy
Projected TotalEnergy
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AHUPreheat
Coils
ChillerPlate HxMTCH
W
Chiller Mode > 55°F OA
Condenser Water Free Cooling / Preheat System
Heat Recovery
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Condenser Water Free Cooling / Preheat System
AHUPreheat
Coils
Chiller MTCHW
Free Cooling Mode: 25 - 55° F OA
Plate Hx
Heat Recovery
Condenser Water Free Cooling / Preheat System
Preheat Mode: < 25° F OA
Heat Recovery
AHUPreheat
Coils
Chiller MTCHW
Plate Hx
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Gilman Laboratory
Class of 1978 LSC RATIO
Gross Square Footage 62,770 174,500 1 : 2.8
Avg. Mo. Steam Usage (100's of lbs) 14,684 1,358 10.8 : 1
Avg. Lbs Steam per Sq. Foot 23.4 0.8 30 : 1
Gilman Laboratory vs. Class of 1978 LSC Steam Usage
Bottom Line
Visual Arts Center
• Challenging Design• Enthalpy Recovery• Chilled Beams• Valance Units• Displacement Ventilation• Storm water collection
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Class of 1953 Dining
• Challenging Schedule and Construction Circumstances• Ultraviolet filtering that will allow kitchen exhaust recovery.• Demand control ventilation• Demand control kitchen exhaust
Burke Upgrades
• 70,000 sqft• Completed in 1989• Each lab exhaust and fume hood had an individual exhaust fan• State of the art for that period. Won design awards• No energy recovery• Energy use well over 500,000 btu/sqft-year
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Burke Upgrades
• Lab control upgrades
• Lab exhaust redesigned into manifolded ducts to EAHUs
• High efficiency glycol run-around system
• Heat energy recovers ~70%
• Cooling energy recovery ~50%
• Changed two steam absorption chillers to high efficiency electric chillers with higher capacity.
Burke Upgrades
Benefits
• Energy usage cut in half
• Better control
• Reduced maintenance
• Noticeably reduced energy usage on
entire campus (Oil consumption reduced by 13% for a
building that represents 1.5% of campus building area)
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Other Projects
• Steele and Wilder Hall (Konvekta heat recovery and controls upgrade)
• Baker Berry Library (Aircuity DCV)
• Moore Hall (Aircuity DCV and Controls)
• Hood Museum
Time for a Net Zero?