Edgerly School Case Study

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Edgerly School Case Study What Utility
Companies Could Do Today Doug Sacra HMFH
Architects, Inc. P 617.492.2200 Sacra_at_HMFH.com
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Edgerly Early Childhood Development
Center Somerville, MA

• Grades Pre-K to 1
• 80,000 square feet, 2 story
• 500 students
• Fully air conditioned
• NSTAR Gas Electric
• MTC Green School Pilot Program
• Currently under construction

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Design Process - in the beginning

• Green for non-green clients
• Improve the learning environment
• Decrease maintenance
• Decrease energy usage
• Shhhh - Dont use the word Green

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Design Process - after wearing them down

• Educated Client to Green Opportunities
• Researched broad array of green issues
• Completed CDA Energy Analysis
• Receiving Utility Incentive Funding
• Accepted to MTC Green Schools Pilot Program
• Now everyone is talking Green!

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Design Process

• Edgerly original client H. P. goals
• Maximize daylighting in teaching spaces
• Reduce energy usage if payback reasonable
• Deliver fully functioning HVAC system
• Use materials systems that reduce maintenance /
  replacement

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Improve Thermal Building Envelope

• Add batt insulation to exterior wall,
• R12 upgraded to R20
• Increase roof rigid insulation from 4 to 5 1/2
  R20 upgraded to R27.5
• Provide R5 rigid insulation under entire slab on
  grade

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Improve Thermal Building Envelope

• Upgrade window glazing to 1 1/2 heat mirror R2.5
  upgraded to R4.5
• Glazing tuned to different exposures
• West South - reduced solar heat gain
• East North - higher light transmittance

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Improving the Learning Environment

• Daylighting
• Changes to typical HMFH classroom
• Changed classroom shape
• Skylights at all second floor classrooms
• Translucent glazing at skylights
• Clerestory windows at classrooms
• Light shelves where performance enhanced
• Used daylight consultant
• Physically modeled classroom daylighting

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Daylighting - Classroom Layout
Edgerly School Classroom Plan
Healey School Classroom Plan
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Daylighting
--------
Edgerly School Classroom Section
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Daylighting - Physical Model
Up on the roof - testing the model
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Daylighting - skylights
2nd floor - with skylights Equinox at noon -
south side
2nd floor - without skylights Equinox at noon -
south side
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Daylighting - Analysis Graphs
Exterior Wall
Interior Wall
Exterior Wall
Interior Wall

• 2nd floor - with skylights
• south side

2nd floor - without skylights south side
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Daylighting - light shelf (why no incentive?)
1st floor - with light shelf south side
1st floor - without light shelf south side
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Daylighting - Analysis Graphs
Exterior Wall
Interior Wall
Exterior Wall
Interior Wall
1st floor south side
1st floor north side
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High Performance Electric Lighting Goals

• Provide high quality, high efficiency artificial
  lighting
• Shut off or dim the lights when

• People arent there
• People dont want them
• People dont need them - sufficient daylight
• (daylight harvesting)

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High Performance Electric Lighting

• 100 indirect linear fluorescent fixtures
• Multi-circuit switching for 1, 2, or 3 lamps
• Occupancy sensors control lights
• Lights laid out in relation to daylight
• Photosensors in occupancy sensors dim / shut off
  lights as daylight sufficient
• Dimming ballasts in fluorescent fixtures near
  windows or under skylights
• Apply for utility company rebates to increase
  funding

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Energy Analysis for Daylight Harvesting
Edgerly School - Somerville, MA Lighting
Efficiency Measures (kWh/yr)
Cost Lighting base case electrical
usage 169,325 27,092 Lighting reduced
electrical usage 114,655 18,344 El
ectrical Gas Usage Usage Utility
Utility Final Simple Reductions Reductions Sa
vings Construction Incentive Owner Payback Effici
ency Measures (kWh/yr) (MMBTU) per
year Cost Amount Cost Years Lighting Occupancy
Sensors 16,706 -69 1,638 4,168 2,131 2,037 1.2
Lighting daylight dimming 38,740 -113 4,503 19,
000 14,250 4,750 1.1 Multi-Circuit
Switching 13,166 -47 1,402 5,104 3,498 1,606 1
.1 Total Energy Use Reduction 68,612 -229 7,543
28,272 19,879 8,393 Lighting Usage
Reduction () 33 Notes 1.
Electricity cost based on .16/kWh. 2.
Natural Gas cost based on 7.50/million Btu
3. Payback does not take 90 state
reimbursement on initial construction cost into
account. 4. Projected lighting energy reduction
eliminates production of 78,116 lbs CO2/year

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Daylighting improvements not incentivised by the
Utility Company

• Architect Education
• Daylight modeling
• Clerestory windows
• Skylights (or improved higher VLiT, lower SHG
• skylights)
• Angled light wells at skylights
• Light shelves
• Vertical blinds
• Higher reflectance ceiling tiles

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Why are any of those important to Utility
Companies?

• Daylight harvesting can only occur with adequate
  daylight that leads to lights being dimmed or
  shut off.
• The lights cannot be shut off if
• there is not adequate daylight
• the daylight is not well diffused around the
• room

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Why are any of those important to Utility
Companies?

• Design strategies will be modified to defeat
  daylight harvesting if
• Daylighting is poorly designed decreases
• student staff performance comfort
• Strategies are distracting to occupants
• It does not allow staff flexibility like room
• darkening

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Additional Classroom Daylighting Options
Option 2 - improved VLIT/U-Value/SHG Multiple
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Additional Classroom Daylighting Options
Option 3 - Polycarbonate Skylight
Built-in photosensor controlled shading
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Additional Classroom Daylighting Options
Option 4 - South facing monitor
480 - equinox
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Additional Classroom Daylighting Options
Option 5 - Photovoltaic sun shade - 2nd fl - south
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High Performance HVAC - we did not do

• Central HVAC with Enthalpic heat recovery in
• classroom wing
• Cooling tower
• Evaporative Chiller

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High Performance HVAC - we did do

• Variable Frequency Drives - pumps, fans
• CO2 monitors in return air ductwork
• Occupancy sensor control of unit vent
• fresh air dampers
• Expanded DDC Controls
• Condensing lead boiler
• Applied for utility company rebates to increase
• funding

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Energy Efficiency Measures Chart

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How Much Energy Do We Save?
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How Much Energy Do We Save?
Edgerly School - Energy
Performance of total
Base Case energy (ASHRAE
90.1-99) Projected cost Reduction Lights 169,3
25 kWh/yr 114,655 kWh/yr 17.04 32.3 Plug
Loads 57,497 kWh/yr 57,497 kWh/yr 8.54 0.0 Coo
ling/Heat Rejn 144,607 kWh/yr 113,433
kWh/yr 16.91 21.3 Pumps 188,754
kWh/yr 161,254 kWh/yr 23.96 14.6 Fans 260,08
0 kWh/yr 101,127 kWh/yr 15.03 61.1 Elec.
Heat 1,413 kWh/yr 1,470 kWh/yr 0.22 -4.0 Total
Electricity 821,676 kWh/yr 549,849
kWh/yr 81.7 33.1 Gas Heat 3,626
MMBtu/yr 2,407 MMBtu/yr 16.73 33.8 Dom. Hot
Water 260 MMBtu/yr 227 MMBtu/yr 1.58 12.8 Total
Gas 3,886 MMBtu/yr 2,634 MMBtu/yr 18.3 32.4

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Data that could be provided by the utility from
past projects

• Typical breakdown of energy spent for each
• major type of use in regions schools
• Case studies of improvements possible with
• associated improvements, costs, incentives
• Typical incentives actually received
• Payback for various typical improvements

• This type of data could get an owner and design
  team excited on Day 1

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How Much Money Do We Save?
Energy Cost Base
Case (ASHRAE 90.1-99) Projected
Reduction Electricity
131,468 87,976 33.1 Natural Gas
29,148 19,712 32.4 Total
160,616 107,688 33.0
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HVAC related improvements not incentivised by the
Utility Company

• Reducing heat island effect by breaking up
• parking lots, adding trees for shading
• Shading building with trees
• High reflectance roof membrane
• Shading at skylights
• Shades or blinds at windows

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Renewable Energy, environmental education

• 30 kWp Photovoltaic System on roof
• Photovoltaic sun shades over classroom windows
• Mini-wind turbine for demonstration
• Submetering energy systems
• Web based data acquisition system
• Environmental Curriculum

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Influence of Submetering on occupants (not
incentivised by the utility)

• Measures each systems typical commissioned
  performance
• Allows regular affirmation that efficiency
  measures are working
• Educates maintenance staff to implications of
  changes made
• Educates students and staff
• Allows competitive energy conservation
• (do it in the dark contest)
• Provides input to environmental curriculum

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H.P. Incremental Construction Costs
Edgerly Base Construction Cost
14,220,000 Base Incremental H.P. Constr. Cost
420,000 Green Schools - Submetering
20,000 Renewable Energy Systems
356,000 Subtotal Incremental Costs 796,00
0 Total Construction Cost 15,016,000
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H. P. Incremental Funding
Massachusetts Technology Collaborative Renewabl
e Energy Construction 320,000 Energy
Efficiency Construction 150,000 Green
Consulting Fees 130,000 Green
Curriculum Development
30,000 Subtotal 630,000 N
STAR Gas and Electric (estimated) Electrical
Efficiency Construction Incentives
72,300 Natural Gas Efficiency Construction
Incentives 43,300 Commissioning
28,700 Design and Analysis Fees
35,000 Subtotal
179,300 Total from Utility and
MTC 809,300
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What more should the utilities be doing?

• Be proactive and responsive
• Be realistic, have historical data on hand
• Provide data - You are the keepers of energy
  efficiency archives - open it up (owners with
  information will make intelligent decisions)
• For review with the Owner - use their costs, not
  utility company avoided costs, these are the
  costs they need to base decisions on

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What more should the utilities be doing?

• Think outside the box, Broaden your horizons -
  lots of non-electrical stuff leads to electricity
  efficiency (or failure)
• Educate Architects to nitty-gritty efficiency
  issues, Engineers arent that motivated
  Architects are interacting with Owners
• Incentivise facilities that teach energy
  conservation (educated occupants make buildings
  more energy efficient)

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