Practical guide to energy efficient design
- 1. Practical Guide to Energy Efficient Design IEEE IAS San Francisco May 15, 2009 INTEGRATED DESIGN ASSOCIATES INC
- 2. Presentation Overview Sustainability Sustainability Features Case Study – Tahoe Center for Environmental Studies Case Study – 1084 Foxworthy Conclusions
- 4. Green Building Integrated Design: When designing a Swiss watch or a green building, you don’t design each piece in isolation from the others.
- 5. Sustainable Design Sustainability = No Waste
- 6. Sustainable Design The Engineering Paradox: Is it our education? How Engineers are Taught….and design Accept Givens Perform Calculations Create Details Integrate with Project A Collaborative Approach Respond to Project Goals Integrate Design with Project Create Details Perform Calculations • Linear Solutions • Solves Engineer’s Problems • Textbook Approach • Safe for Engineer • Solves Project’s Problems • Adds Value • Leads to Innovation • Riskier for Engineer • Requires Technical Expertise
- 7. Sustainable Features Reuse material where possible Use eco-friendly material Use less material Reduce Energy Usage/Maximize Efficiency
- 8. Reuse Materials Building Reuse Reuse electrical systems that have remaining life
- 9. Eco-Friendly Materials Avoid PVC Avoid Mercury Materials with lots of embedded energy Courtesy Sylvania/Osram
- 10. Use Less Material Use 480/277 volt where possible to limit wire size Think “wireless” Double usage - VOIP
- 11. Reduce Energy/Maximize Efficiency Use Energy Efficient Equipment Controls to Minimize Usage Building Orientation Thermal Envelope Courtesy Wattstopper
- 12. Case Study – Tahoe Center for Environmental Science High efficiency light sources Astronomic time clocks Task/ambient lighting Light pollution reduction Daylight switching photosensors Daylight dimming photosensors Photovoltaic systems Natural Gas Microturbine Upsized wiring High efficiency transformers Energy star equipment Plug load controls Wireless data VOIP
- 13. Case Study – Tahoe Center for Environmental Science High efficiency light sources
- 14. Case Study – Tahoe Center for Environmental Science Daylight switching photosensors Daylight dimming photosensors
- 15. Case Study – Tahoe Center for Environmental Science Upsized wiring 1. Larger wires = less resistance 2. Less resistance = less energy loss 3. Less energy loss = lower wire temperature 4. Lower wire temperature = less resistance (see #2) Payback can be as low as 2 years!! Courtesy: Copper.org conductor size length resist/lf resist (ohms) amps loss (va) conductor size length resist/lf resist (ohms) amps loss (va) Row 1 #12 80 0.00170 0.2720 12.0 39.17 #10 80 0.00105 0.1680 12.0 24.19 #12 8 0.00170 0.0272 3.2 0.28 #10 8 0.00105 0.0168 3.2 0.17 #12 8 0.00170 0.0272 2.4 0.16 #10 8 0.00105 0.0168 2.4 0.10 #12 8 0.00170 0.0272 1.6 0.07 #10 8 0.00105 0.0168 1.6 0.04 #12 8 0.00170 0.0272 0.8 0.02 #10 8 0.00105 0.0168 0.8 0.01 Row 2 #12 10 0.00170 0.0340 8.0 2.18 #10 10 0.00105 0.0210 8.0 1.34 #12 8 0.00170 0.0272 3.2 0.28 #10 8 0.00105 0.0168 3.2 0.17 #12 8 0.00170 0.0272 2.4 0.16 #10 8 0.00105 0.0168 2.4 0.10 #12 8 0.00170 0.0272 1.6 0.07 #10 8 0.00105 0.0168 1.6 0.04 #12 8 0.00170 0.0272 0.8 0.02 #10 8 0.00105 0.0168 0.8 0.01 Row 3 #12 10 0.00170 0.0340 4.0 0.54 #10 10 0.00105 0.0210 4.0 0.34 #12 8 0.00170 0.0272 3.2 0.28 #10 8 0.00105 0.0168 3.2 0.17 #12 8 0.00170 0.0272 2.4 0.16 #10 8 0.00105 0.0168 2.4 0.10 #12 8 0.00170 0.0272 1.6 0.07 #10 8 0.00105 0.0168 1.6 0.04 #12 8 0.00170 0.0272 0.8 0.02 #10 8 0.00105 0.0168 0.8 0.01 Total: 43.45 26.84 use: 12 hrs/day, 5 days/week Annual Loss 136 kwh Annual Loss 84 kwh cost of electricity: $0.12/kwh Annual Cost $16.31 Annual Cost $10.08 light fixture: 3 lamp, 32w/lamp Difference $6.24 Payback 27 months
- 16. Case Study – Tahoe Center for Environmental Science Biodeisel/Natural Gas Microturbine Grid Tied – Electricity Waste Heat – Hot Water Biodeisel avoids releasing new carbon into atmosphere Courtesy: Capstone
- 17. Case Study - 1084 Foxworthy High efficiency light sources Astronomic time clocks Task/ambient lighting Individual occupancy sensor task lighting controls Occupant sensor ambient lighting controls Mesopic lighting Light pollution reduction Daylight switching photosensors Daylight dimming photosensors Photovoltaic systems Upsized wiring Electro chromic glass High efficiency transformers Energy star equipment Plug load controls Wireless data VOIP
- 18. Case Study - 1084 Foxworthy Reuse an existing building
- 19. Case Study - 1084 Foxworthy High Efficiency Light Sources
- 20. Case Study - 1084 Foxworthy Control Solar Heat Gain
- 21. Case Study - 1084 Foxworthy 17 fc ambient light level 90% reflective paint 83% reflectance ceiling tiles Task Ambient Lighting
- 22. Case Study - 1084 Foxworthy Automatic Lighting Controls
- 23. Case Study - 1084 Foxworthy Combination Lighting Controls
- 24. Case Study - 1084 Foxworthy Maximize Daylight and Views
- 25. Case Study - 1084 Foxworthy 14 16 22 30 65 66 77 79 85 86 93 95 97 105 105 175 0 20 40 60 80 100 120 140 160 180 200 Incandescent LowVoltageHalogen LineVoltageHalogen LED StandardMetalHalide Compactfluorescent PulseStartMetalHalide StandardT-12 HighPressureSodium StandardT-8 StandardT-5 T-5HighOutput "SecondGeneration"T-8lamp LowPressureSodium Sunlight Sunlightwithhighperformance glazing lumens/watt Daylight Harvesting
- 26. Case Study - 1084 Foxworthy High efficiency equipment Software based shut off Occupancy based controls Minimize Plug Loads
- 27. Case Study - 1084 Foxworthy Security system circuit controls Night Time Plug Load Shutoff
- 28. Case Study - 1084 Foxworthy All electric building Net zero energy Zero carbon emissions Building Integrated Photovoltaics (BIPV)
- 29. Case Study - 1084 Foxworthy Building is all electric - no CO2 is generated from burning natural gas. Estimated annual energy consumption (DOE 2.1): 54,000 kWh per year 60% below ASHRAE 90.1 1999 Standards PV Capacity: 30 kW, 54,756 kWh / year PV’s sized to generate 100% of the net electrical load. Analysis: Energy Use
- 30. Case Study - 1084 Foxworthy PV Capacity 30 kW, 54,756 kWh / year Estimated PV Cost: $255,000 installed cost ($8.50/watt) -78,000 CEC rebate ($2.60/watt) 34,206 tax on CEC rebate (35% fed tax, 8.854% state tax) -76,500 30% federal tax credit -89,250 accelerated depreciation* (35% federal corp tax) $45,456 cost of system after 5 years * calculation does not include the time cost of capital the cost after rebates, tax credits and depreciation is about 20% of the installed cost. Energy savings at $ 0.16 / kWh = $8,760/year Payback is about 5.2 years Analysis: PV System Incentives
- 31. Case Study - 1084 Foxworthy $20,000 97,500 38,000 45,500 $201,000 241,000 $4,100,000 6.2% cost of upgraded glass cost of radiant mechanical system over traditional system. cost of concrete for radiant floor cost of PV systems (after rebates and tax incentives) total total with soft costs total cost of building premium to build a net zero energy building Key differences from a conventional building: Analysis: Estimated Additional Cost
- 32. Case Study - 1084 Foxworthy Previous gas use - 460 therms @ 12.27 lbs CO2 / therm (1)* Previous electricity use - 36,424 kWh @ 0.88 lbs CO2 / kWh (2)* Automobile travel - 43,775 miles / 23 mpg (4) = 1903 gals @ 19.56 lbs CO2 / gal (3)* Air travel - 35,484 miles @ 0.44 lbs CO2 / mile (5)* Total (lbs) 5,644 35,053 37,228 15,613 93,538 (1) Carbon Trust, http://www.carbontrust.co.uk/KnowledgeCentre/conversion_factors/default.htm (2) EPA's eGrid database for calendar year 2000, emissions include adjustment for 9 percent line loss. (3) Energy Information Administration, http://www.eia.doe.gov/oiaf/1605/coefficients.html (4) Weighted average of reported employee vehicle mileage. (5) Carbon Fund, http://carbonfund.org/site/pages/calculator/category/Assumptions/ *based on 2005 statistics Analysis: Estimated CO2 previous (lbs)
- 33. Case Study - 1084 Foxworthy Gas use - 0 therms @ 12.27 lbs CO2 / therm (1)* Electricity use - 0 kWh @ 0.88 lbs CO2 / kWh (2)* sub total building CO2 (lbs) Automobile travel - 43,775 miles / 23 mpg (4) = 1903 gals @ 19.56 lbs CO2 / gal (3)* Air travel - 35,484 miles @ 0.44 lbs CO2 / mile (5)* sub total travel CO2 (lbs) Carbon offsets Total 0 0 0 37,228 15,613 52,841 (52,841) 0 (1) Carbon Trust, http://www.carbontrust.co.uk/KnowledgeCentre/conversion_factors/default.htm (2) EPA's eGrid database for calendar year 2000, emissions include adjustment for 9 percent line loss. (3) Energy Information Administration, http://www.eia.doe.gov/oiaf/1605/coefficients.html (4) Weighted average of reported employee vehicle mileage. (5) Carbon Fund, http://carbonfund.org/site/pages/calculator/category/Assumptions/ *based on 2005 statistics Analysis: Estimated Final CO2 (lbs)
- 34. Lessons learned Use simple user interfaces Complex controls have complex commissioning City planning staffs are behind on the green building curve Using things for two purposes saves money Using things for two purposes can have unintended results (heat pump as water heater) drawn by Giselle, age 5.
- 35. Conclusions
- 36. Successful Green Projects Minimize energy consumption first, size PV’s second. Look for LEED points after the design is completed. (The building will probably be Gold or Silver.) Have a client who is committed to sustainability and willing to take risks. Hire a team who is experienced in sustainable design. Bring together the entire team during conceptual design.
- 37. One final thought: The scientific community has come to a consensus that Global Warming is a real phenomenon... Think about it. America is one of the leaders in development of efficient building standards and technologies... Buildings contribute nearly 50% of the CO2 generated in the US… Imagine the impact we would have if all of our buildings were Z Squared.