Higher Education Energy Efficiency Partnership Program BEST PRACTICES AWARDS UC / CSU Sustainability Conference, June 2005UC San Diego Supercomputer Center Craig Johnson, PEEngineeringEngineeringGeneric design objectivesEnvironmental IssuesSupercomputer design objectivesSignificant design factors Building featuresBuilding features (cont.)Why did this happenRisks to the design approachHigher Education Energy Efficiency Partnership ProgramBEST PRACTICES AWARDSUC / CSU Sustainability Conference, June 2005A program created by the UC/CSU/IOU Partnership and under the auspices of the California Public Utilities CommissionUC San DiegoSupercomputer CenterCraig Johnson, PERumsey Engineers IncPeter Rumsey, Cindy RegnierEHDD ArchitectureRichard FeldmanNaturalWorks Engineering ConsultantsPaul F. Linden, Guilherme Carrilho da Graça.L B N L - Commercial Building Systems GroupPhilip HavesDisplacement Ventilation with Hot Water RadiatorsEngineering• Creativity • ScienceEngineering• Creativity• Every building is a new opportunity• Science• Prove itGeneric design objectives• First, ensure that the HVAC system meets the needs of the building occupants• Second, deliver this environment as efficiently as possibleEnvironmental Issues•Fog• Airborne salt• Airborne particles• Santa Ana conditions• Solar loads (esp. in winter)Supercomputer design objectives• Create an acceptable indoor environment throughout the year• Construction cost to be equal to, or below, what a conventional system would cost (VAV – terminal reheat)• HVAC system that is more efficient than a conventional systemPMV = (0.303e–0.036M + 0.028) {(M – W) – 3.05 x 10–3x [5733 – 6.99(M – W) – pa] – 0.42 x [(M – W) – 58.15] – 1.7 x 10-5 M(5867 – pa) – 0.0014M(34 – ta) – 3.96x10-8fcl x [(tcl+ 273)4] – (tr+ 273)4] – fclhc(tcl–ta)}Significant design factors • To produce simple and efficient designs we need to hire wiser designers (wisdom is more critical than knowledge)• The mechanical engineering firm is accountable for indoor comfort levels• The University needs to play a role in the selection of the mechanical consultantSan Diego Supercomputer CenterPerformance simulation of the indoor climate control systemOptimization of the shading designNaturalWorks Engineering ConsultantsPaul F. Linden, Guilherme Carrilho da Graça.L B N L - Commercial Building Systems GroupPhilip HavesIntroduction1- Site climate analysis2- EnergyPlus simulation of indoor conditions3- Analysis of external shading systemsConclusionsPresentation Contents1 - Climate analysisVariation of maximum and minimum temperature (degrees F) in San Diego for the two typical weather years, measured at San Diego airport, used in the analysis (1966 and a composition of 1988 and other years).Temperature(in red, T-70, F)Wind velocity (mph)Wind directionAccumulated “warm”hours1 - Climate analysis: ….where does the wind blow during warm hours?Daytime analysis only considered hours in “warm” days where wind is significant i.e when the wind velocity is above 3mph.A day is considered warm if the maximum outside dry bulb temperature is higher than 26oC (79oF).Daily variation of maximum(red) and minimum (black) temperature for “warm” and mildly warm days (max. Tout>70oF). The data consist of selected days for the second weather year shown in figure 1.1 - Climate analysis - night cooling: ….what is the minimum temperature at night after each warm day?Potential for night cooling in San Diego is moderate. Still, since the climate is generally mild during the day, the small amount of night cooling that can be achieved in most days may be sufficient. Post processing of the data in the previous slide shows that the wind blows from an angle (A): 340>A>160 (i.e from northwest to south) for 72% of the time.1 - ”Onsite” climate analysisThere are no systematic historic weather data records for UCSD campus locationsLocal topography influence and proximity to the sea make Carlsbad a close representation to campus, sea influenced conditionsAvailable typical weather files use data measured at SAN As expected San Diego Airport temperature measurements are higher than Carlsbad, how much…?Data and method used in the analysisTwo typical weather data years, using data measured at the San Diego Airport (SAN): 1966 and a composition of1988 and other years (the year used changes on a monthly basis)Five years of temperature and wind data measured in the Carlsbad weather station (1999, 2000, 2001, 2002 and 2003)Steps taken:1- A representative year for the Carlsbad (KCRQ) weather data was selected (conservatively we used one of the warmer years)2- The two SAN and the representative KCRQ year where compared (analysis of maximum and minimum daily temperatures, running averages and degree hours above different temperatures)3- A matching of degree hours above relevant cooling analysis temperatures (Tout above 26oC, 79oF) was obtained by decreasing the SAN 1988 dry bulb temperatureDegree-hour analysisVariation of degree hours above a given base temperature for the 7 years analysedAs discussed above, KCRQ03 is cooler than SAN (1988) and SAN (1966).11010010001000068 72 75 79 82Base Temp (ºF)Degree HoursSAN 88SAN 66KCRQ99KCRQ00KCRQ01KCRQ02KCRQ03Base T (ºF) SAN 88 SAN 66 KCRQ0368 5684 4536 344272 2363 1898 136975 887 689 49479 334 276 14782 104 131 33TMY adjustmentTMY (SAN 1988) and KCRQ03 maximum and minimum daily temperatures Before adjustmentAfter adjustmentThe typical colder climate of the site is approximately represented by the SAN 1988 data by using a negative offset in the air temperature, obtaining an adjust weather year:Adjusted = SAN – 2.5 oF4045505560657075808590JFMAMJJASONDDaysTemperature (ºF)KCRQ03minKCRQ03maxTMYminTMYmax4045505560657075808590JFMAMJJASONDDaysTemperature (ºF)KCRQ03minKCRQ03maxTMYmin adjTMYmax adj2- EnergyPlus simulation of indoor conditions2- EnergyPlus SimulationsThe proposed design was modelled using EnergyPlus (closely following design documentation and usage schedules)The model has 77 independent thermal zones, and more than 700 surfacesThe geometry was “zoned” as shown in the next slidesTwo weather files were used: SAN TMY 1988 and SAN TMY 1988 Adjusted to Carlsbad2- EnergyPlus SimulationsIn all zones, internal gains where set to approximately: Occupants: one occupant every 100sft/10 m2=>13 W/ m2Lights: 10 W/ m2Equipment: 33 W/ m2Each occupant introduces a gain of 120W and uses a
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