Energy Efficient Buildings at Dartmouth College

Thayer Engineering May 12, 2015

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

Dartmouth College Energy Efficiency History – – – – – – – – – – – – – – – –

1911 Cogen steam plant since 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 DMV) 2014 Moore Hall (Aircuity for DMV) 2015 Steele Hall and Wilder (Konvekta Heat Recovery)

Rising Energy Use – Oil Historical Oil Cost and Usage – Last 20 Years

6,000,000

12,000,000

5,000,000

10,000,000

4,000,000

8,000,000

3,000,000

6,000,000

2,000,000

4,000,000

1,000,000

2,000,000 0

0 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Oil Consumption (gals)

Oil Cost (S)

Oil Cost ($)

Gallons

Oil Consumption and Cost

And Rising Energy Use – Electricity Historical Electrical Cost and Usage – Last 20 Years Electric Consumption and Cost 80,000,000

6,000,000

70,000,000

5,000,000 4,000,000

kWH

50,000,000 40,000,000

3,000,000

30,000,000

2,000,000

20,000,000 1,000,000

10,000,000

0

0 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Total Electric Consumption (kWH)

Purchased Electric Cost ($)

Electric Cost ($)

60,000,000

Expanding Conditioned Area Dartmouth’s Growth 2005-2012 6,000,000

Total GSF

5,000,000

• Gross Square Feet 14% Growth

4,000,000 3,000,000 2,000,000 1,000,000 0 2005

2006

2007

2008

2009

2010

2011

2012

• Air Conditioned GSF 41% Growth

Air Conditioned GSF

3,000,000 2,500,000 2,000,000 1,500,000

• Air Conditioned Growth from 33% to 50% of Campus GSF

1,000,000 500,000 0 2005

2006

2007

2008

2009

2010

2011

2012

Dartmouth Energy Picture • Increasing building area and conditioned space requires additional campus utility capacity • Boiler Plant expansion • Chiller Plant(s) construction • Long term energy planning has started to show 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

Good Buildings come from good design 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

Building Performance Practice - Process How DC used to do it • • • • •

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

How DC does it today* • • • • • • • • • •

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

Whittemore Hall, 2000 Amos Tuck School of Business Administration Beginning 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, 2006 Developing Integrated Design, Implementing LEED™ • High Performance Envelope, R25 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

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

All new technologies require understanding and experience

Wastewater Heat Recovery

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

Well Drilling Standing column Well

Ground Source Heat Pump

Ground Source Heat Pump

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

Active Chilled Beams

Enthalpy Heat Recovery

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

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 Projected vs. Actual Monthly Energy Consumption (kBTU/sf) 18.00 16.00 14.00

kBTU/sf

12.00 10.00 8.00 6.00 4.00 2.00 0.00

Actual Total Energy Projected Total Energy

Heat Recovery Condenser Water Free Cooling / Preheat System Chiller Mode > 55°F OA

AHU Preheat Coils

Chiller

MTCH W

Plat e Hx

Heat Recovery Condenser Water Free Cooling / Preheat System Free Cooling Mode: 25 - 55° F OA

AHU Preheat Coils

Chiller

MTCH W

Plat e Hx

Heat Recovery Condenser Water Free Cooling / Preheat System Preheat Mode: < 25° F OA

AHU Preheat Coils

Chiller

MTCH W

Plat e Hx

Bottom Line Gilman Laboratory vs. Class of 1978 LSC Steam Usage

Gilman Laboratory Gross Square Footage Avg. Mo. Steam Usage (100's of lbs) Avg. Lbs Steam per Sq. Foot

62,770

Class of 1978 LSC 174,500

RATIO 1 : 2.8

14,684

1,358

10.8 : 1

23.4

0.8

30 : 1

Visual Arts Center

• • • • • •

Challenging Design Enthalpy Recovery Chilled Beams Valance Units Displacement Ventilation Storm water collection

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

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 abuilding that represents 1.5% of campus building area)

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?

Questions?

Thank you for your attention