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HIGH PERFORMANCE DESIGN Kristine Chalifoux, SEDAC Trade Ally Rally │Illinois │December 2014 WHAT IS HIGH PERFORMANCE DESIGN? What will it take to achieve high performance? A. Goal Setting: design & performance energy goals Know where you are and where you want to go. B. Pick the right team: identify an energy champion C. Focus on energy: in design & construction Know the most effective strategies D. Verify energy goals: model & measure E. Plan to maintain: training & ongoing verification 2 BENCHMARKING 3 ENERGY USAGE ANALYSIS Obtain at least one year’s worth of energy data on the building (two years or more is better). Plot the energy consumption for each month versus heating degree days and cooling degree days. Review the graphs for anomalies. Here is a bank… CDD 25,000 400 20,000 KWH 0 10,000 CDD 200 15,000 Therms 5,000 HDD 1400 4,000 1200 1000 3,000 HDD kWh 800 2,000 600 400 1,000 5,000 200 June May Apr Mar Feb Jan Dec Nov Oct June May Apr Mar Feb Jan Dec Nov Oct Sep Aug July 0 Sep 0 - Aug July THERMS TWO TYPES OF BUILDINGS Envelope Dominated: energy usage pattern tied to the climate, generally with some base load electrical and natural gas usage. Internal Gain Dominated: energy usage pattern only slightly or not linked to the climate. Cooling load year-round. Typically, small buildings are envelope dominated and large buildings are internal gain dominated – although this is not cast in concrete. UTILITY BILL ANALYSIS/BENCHMARKING Electricity Natural Gas Total Facilities Area Electricity Use Intensity Energy Use Intensity Annual Consumption 504,000 kWh 8,551 therms Total: 2 15,753 ft 2 32 kWh/ft /yr 163 kBtu/ft /yr Target Finder Results Energy Performance Energy Use Intensity Annual Costs $ 50,249 87% $ 7,236 13% $ 57,485 2 Bank 31 Percentile 163 kBtu/ft2/yr Average Unit Cost $ 0.10 $/kWh $ 0.85 $/therm Gas Use Intensity Energy Cost Intensity Average 50 Percentile 104 kBtu/ft2/yr 0.54 $ 3.65 2 Therms/ft /yr 2 $/ft /yr ENERGY STAR Certified 70 Percentile 82 kBtu/ft2/yr ENERGY STAR® Target Finder was consulted for a comparison with similar buildings. Target Finder uses a large collection of building energy data to provide an estimate of an average building’s energy consumption, taking into account its location, size and use. Energy Star Target Finder Score 1-100 www.Energystar.gov TYPICAL DATA ANALYSIS – A SCHOOL… We know… A school Oct-11 Degree Days kWh (3,753,262) CDD (1,237) REMEMBER When you shift a secondary axis you are changing the story you tell. Sep-11 Aug-11 Jul-11 Jun-11 May-11 Apr-11 Mar-11 Feb-11 Nov-10 Comfortable kWh Cooled 500 450 400 350 300 250 200 150 100 50 0 Jan-11 Heated 400,000 350,000 300,000 250,000 200,000 150,000 100,000 50,000 0 Dec-10 No summer school Base Load is typically lights, fans, pumps, plug loads, etc. 400 200 Oct-11 Sep-11 Aug-11 Jul-11 Jun-11 May-11 Apr-11 Mar-11 Feb-11 Jan-11 Degree Days 0 Dec-10 April is a reasonable “guess” for baseline monthly usage 500,000 450,000 400,000 350,000 300,000 250,000 200,000 150,000 100,000 50,000 0 Nov-10 kWh OR is the baseline electric use closer to ~275,000 kWh? High electric use in air conditioned schools - late spring/ early fall is not unusual as students return to classes and cooling demand can be high. kWh (3,753,262) CDD (1,237) REMEMBER The graph tells only part of the story! A school with minimal summer occupancy… 500,000 450,000 400,000 350,000 300,000 250,000 200,000 150,000 100,000 50,000 0 2,000 1,000 kWh (3,753,262) HDD REMEMBER Remember to look for the unexpected! Oct-11 Sep-11 Aug-11 Jul-11 Jun-11 May-11 Apr-11 Mar-11 Feb-11 Jan-11 Dec-10 Degree Days 0 Nov-10 kWh Correlation with heating degree days likely means electric resistance heating somewhere in the building (i.e. teachers bringing in small space heaters) Consider whether or not it is likely the baseline (base utility) natural gas use is ~2,500 Therms/month? Base Load is typically DHW, pilot lights, etc. 6,000 2,000 Monthly Therms 1,000 4,000 500 3,000 0 Heatng Degree Days 1,500 5,000 2,000 1,000 0 Jun-10 Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Nat'l Gas Usage (Therms) HDD REMEMBER When you shift a secondary axis you are changing the story you tell. Or is it more likely that high natural gas use in summer indicates excessive use of ventilation system reheat – and the baseline (base utility) use is closer to 300 Therms/month. 6,000 1,500 Monthly Therms 1,100 4,000 900 3,000 700 Heatng Degree Days 1,300 5,000 500 2,000 300 1,000 100 0 Jun-10 Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Nat'l Gas Usage (Therms) HDD REMEMBER When you shift a secondary axis you are changing the story you tell. Election Day, school is closed. But some portions are open for polling. 160 ) W k ( 140 d n a m e 120 D y g r e n 100 E c ir t c le 80 E d e r e t 60 e M l a v r 40 e t n I r u o 20 H /2 1 November 2010 Monday November 1, 2010 Tuesday November 2, 2010 0 12:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11: 00 AM to AM to AM to AM to AM to AM to AM to AM to AM to AM to AM to AM to PM to PM to PM to PM to PM to PM to PM to PM to PM to PM to PM to PM to 12:30 1:30 2:30 3:30 4:30 5:30 6:30 7:30 8:30 9:30 10:30 11:30 12:30 1:30 2:30 3:30 4:30 5:30 6:30 7:30 8:30 9:30 10:30 11:30 AM AM AM AM AM AM AM AM AM AM AM AM PM PM PM PM PM PM PM PM PM PM PM PM Figure 1: 1/2-Hour Interval Metered Electric Energy Demand – November 2010 Don’t forget the power of interval data analysis when available! Mo Tu We Th Fri Sa Su Mo Tu We Th Fri Sa Su Mo Tu We Th Fri Sa Su Mo Tu We Th Fri Sa Su Mo Tu TOP 10 STRATEGIES NEW AND EXISTING BUILDINGS 13 TOP TEN ENERGY STRATEGIES Form & Environment 1. Orientation & Form 2. Insulation 3. Air Sealing Loads 4. Lighting 5. Loads Heating, Ventilating, & Air Conditioning 6. Heating 7. Cooling 8. Motors & Pumps 9. Building Automation 10. Commissioning EXTRA CREDIT: After implementing all of these, consider renewables such as solar and wind. Science & Technology magnet school Replaces existing building CASE STUDY Base Case Annual Proposed Annual kWh kWh Savings Annual % Saved % Total kWh Heating 437,167 25,197 411,970 94% 45% Cooling 74,963 31,606 43,357 58% 5% Pumps/Fans 72,140 166,560 -94,420 -131% -10% Interior Lighting 123,298 104,357 18,941 15% 2% Exterior Lighting 18,505 18,505 0 0% 0% Plug Loads 200,509 200,509 0 0% 0% Total 926,582 546,734 379,848 41% 41% Proposed Annual kWh Plug Loads Interior Lighting Baseline Annual kWh Pumps/Fans Cooling Heating KWH 500,000 450,000 400,000 350,000 300,000 250,000 200,000 150,000 100,000 50,000 0 ORIENTATION & ENVIRONMENT Orient buildings on the eastwest axis (+/- 10°) Reduce west facing glass Shade south glazing Take advantage of, or block, prevailing winds Orientation makes a difference in energy use! CASE STUDY ORIENTATION East West Axis South overhangs Northern and southern windows $82,000 $80,000 $78,000 $76,000 $74,000 $72,000 $70,000 0° 90° 180° 270° ORIENTATION “DON’TS” Curtain wall… ORIENTATION “DON’TS” Curtain wall… JUST SAY NO! ORIENTATION “DON’TS” …faces west Beware of value engineering! Shading devices compensate for the heat gain from large banks of windows, only to be eliminated later in order to cut up-front costs. If the windows themselves are not redesigned, the result is visual discomfort from glare and higher energy costs. ENVELOPE Exceed code Wall and roof insulation levels Continuous insulation Windows Percent of wall area Low-e coating Reduced infiltration Air sealing Air barrier Vestibules Envelope commissioning AIR SEALING Air infiltration is unwanted air flow into and out of the building caused by leakage paths and pressure differences between inside and outside of the building. Openings at the top and bottom of the building are the most important to seal. plumbing chases wiring recessed lights chimney enclosures sill plate look above a recessed ceiling ducts in unconditioned areas surprises that you will find SEALING THE ENVELOPE Wall to Roof Junction Air Sealing Pre-Retrofit Post Air Sealing Current condition From SEDAC report STACK EFFECT Don’t let this happen to your building! Positive pressure (with reference to outside) Neutral pressure plane Negative pressure (with reference to outside) Photo Credit: David Keefe, Vermont Energy Investment Corporation CASE STUDY ENVELOPE R-18 to R-24 walls 3” continuous insulation (polyiso) R-37 roof insulation 6” continuous insulation (polyiso) 3” minimum at drains Windows U-0.27, SHGC-0.31 Vestibules Designed with heat exchanger to make up for reduced air infiltration ENVELOPE “DON’TS” Building in southern Illinois Built in 2005 Designed to code ENVELOPE “DON’TS” Occupants were cold No continuous insulation Don’t underestimate the impact of thermal bridging MORE ENVELOPE “DON’TS” Avoid these common pitfalls • Assemblies with significant thermal bridging 28 MORE ENVELOPE “DON’TS” Avoid these common pitfalls • Assemblies with significant thermal bridging 29