Optimizing Energy Cost Performance for Schools

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Optimizing Energy Cost Performance for Schools

• Dennis Jones, PE, CEM, LEED AP
• E M C Engineers, Inc.

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Poudre School District

• PSD is committed to building and operating
  high-performance schools in terms of student
  performance, energy efficiency, and environmental
  sustainability.

• Fossil Ridge High School
• Energy Consultant
• Kinard Junior High School
• Energy Consultant, Mechanical Design

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RBB Architecture
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Fossil Ridge High School
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Kinard Junior High School
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Poudre School District Goals

• High-performance learning environment for
  students
• Daylighting for most classrooms
• Minimize energy costs
• Minimize maintenance costs
• Environmentally Sensitive design

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Energy Atmosphere - Credit 1

• Optimize Energy Cost Performanceup to 10 LEED
  points
• Should it be based on cost?

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Assumes Energy Costs reflect the Strategic or
Environmental Value of Energy

• Energy costs reflect the market value of natural
  gas versus coal-generated electricity
• The electric demand cost reflects the cost of
  building a new power plant

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Energy Costs in Fort Collins
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Coincident Peak Demand

• Demand charge occurs when Rawhide Power Plant
  peaks each month
• Statistically occurs in late afternoon to evening
  in Spring, Fall, and Winter
• School lets out at 2 p.m.

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Energy Costs for Schools
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Computer Energy Simulation is the Key to Energy
Optimization
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Fossil Ridge High School
39 of the energy cost of the ASHRAE 90 baseline
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Start with the Building Form and Orientation

• Use multi levels to minimize surface area
• Low albedo roofing

• Use North South orientation
• Locate classrooms to the North for optimal
  daylighting
• Upgrade insulation on envelope

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Fossil Ridge High School Window
Orientation Shading
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Daylighting Section
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Daylighting Plan
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Daylighting
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Daylighting Simulation
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HVAC System Efficiency
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Heat Recovery Ventilators
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Condensing Boiler
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Ice Storage
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Kinard Design ElementsSite Plan
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North Daylighting
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North Elevation
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Unit Energy Cost

• Energy Component Fossil Ridge HS Kinard JHS
• Electric Energy 0.0185/kWh 0.0185/kWh
• Facility Demand 4.87/kW 4.87/kW
• Coincident Demand 13.12/kW N/A
• Natural Gas 4.08/MBtu 6.57/MBtu

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Energy Costs are Major Factor in Optimizing HVAC
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Building Energy Simulation
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Geothermal Heat Pumps

• GeoExchange Systems
• How do they work

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Geothermal Heat Pumps
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Operations Maintenance
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Service Water Heating
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CO2 Demand Ventilation Control
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Thermal Mass

• Adding 8 inches of solid concrete to interior of
  exterior walls reduced overall energy costs by 3
  according to an eQUEST simulation

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Conclusion

• Optimizing energy cost performance requires
  careful consideration of local energy rates,
  evaluation of design options, life cycle cost
  analysis, and attention to detail