Higher Education Energy Efficiency Partnership Program BEST PRACTICES AWARDS UC CSU Sustainability Conference June 2005 A program created by the UC CSU IOU Partnership and under the auspices of the California Public Utilities Commission UC San Diego Supercomputer Center Craig Johnson PE Rumsey Engineers Inc Peter Rumsey Cindy Regnier EHDD Architecture Richard Feldman NaturalWorks Engineering Consultants Paul F Linden Guilherme Carrilho da Gra a L B N L Commercial Building Systems Group Philip Haves Displacement Ventilation with Hot Water Radiators Engineering Creativity Science Engineering Creativity Science Every building is a new opportunity Prove it Generic design objectives First ensure that the HVAC system meets the needs of the building occupants Second deliver this environment as efficiently as possible Environmental 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 system PMV 0 303e 0 036M 0 028 M W 3 05 x 10 3 x 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 consultant San Diego Supercomputer Center Performance simulation of the indoor climate control system Optimization of the shading design NaturalWorks Engineering Consultants Paul F Linden Guilherme Carrilho da Gra a L B N L Commercial Building Systems Group Philip Haves Presentation Contents Introduction 1 Site climate analysis 2 EnergyPlus simulation of indoor conditions 3 Analysis of external shading systems Conclusions 1 Climate analysis Variation 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 1 Climate analysis where does the wind blow during warm hours Temperature in red T 70 F Wind velocity mph Wind direction Accumulated 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 1 Climate analysis night cooling what is the minimum temperature at night after each warm day 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 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 analysis There are no systematic historic weather data records for UCSD campus locations Local topography influence and proximity to the sea make Carlsbad a close representation to campus sea influenced conditions Available 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 analysis Two 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 temperature 10000 Degree hour analysis Variation of degree hours above a given base temperature for the 7 years analysed Degree Hours 1000 100 SAN 88 SAN 66 KCRQ99 KCRQ00 10 KCRQ01 KCRQ02 KCRQ03 As discussed above KCRQ03 is cooler than SAN 1988 and SAN 1966 1 68 72 75 79 82 Base Temp F Base T F SAN 88 SAN 66 KCRQ03 68 5684 4536 3442 72 2363 1898 1369 75 887 689 494 79 334 276 147 82 104 131 33 90 TMY adjustment 85 80 TMY SAN 1988 and KCRQ03 maximum and minimum daily temperatures Temperature F 75 70 65 60 55 Before adjustment KCRQ03min KCRQ03max 50 TMYmin TMYmax 45 After adjustment 40 90 J F M A M J J A S O N D O N D Days 85 80 The 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 Temperature F 75 70 65 60 55 KCRQ03min KCRQ03max TMYmin adj 50 Adjusted SAN 2 5 oF TMYmax adj 45 40 J F M A M J J Days A S 2 EnergyPlus simulation of indoor conditions 2 EnergyPlus Simulations The proposed design was modelled using EnergyPlus closely following design documentation and usage schedules The model has 77 independent thermal zones and more than 700 surfaces The geometry was zoned as shown in the next slides Two weather files were used SAN TMY 1988 and SAN TMY 1988 Adjusted to Carlsbad 2 EnergyPlus Simulations In all zones internal gains where set to approximately Occupants one occupant every 100sft 10 m2 13 W m2 Lights 10 W m2 Equipment 33 W m2 Each occupant introduces a gain of 120W and uses a PC Printer of 300W In order to test the ability to support higher gains one of the single occupant offices tested was loaded with two occupants In addition other design variations were tested Standard clear glazing SG No external insulation in the vertical envelope walls NI Optimized smaller shading devices SS Lower gains one occupant per office in all closed offices and half occupancy in the core zones LG Outside air ventilation scenarios considered free running building In order to access the importance of the ventilation strategy in the cooling period we analysed three
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