HIGH POINT NEIGHBORHOOD CENTER ENERGY MODELING REPORT CONTENTS. Goals 2. Method 2. Acknowledgements 3. Challenges and Standards 3. equest Results 4-13

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2 Community Design Center HIGH POINT NEIGHBORHOOD CENTER ENERGY MODELING REPORT CONTENTS Goals 2 Method 2 Acknowledgements 3 Challenges and Standards 3 equest Results 4-13 Summary Table 14 Comments 15 Going Forward 16

3 Goals The primary goal of this exercise was to use an energy modeling program (equest) early in the design of the High Point Neighborhood Center in order to determine the most effective means of conserving energy in the building. Special attention was paid to the 2030 Challenge, which calls for a 60% reduction in building energy use by Methods 1. Established a baseline building against which subsequent Energy Conservation Measures were tested. This baseline building incorporated the requirements of the proposed 2006 Seattle Energy Code: web_informational/dpdp_ pdf The above is recommended code, and has not yet been adopted, but was judged suitable for the purposes of this early modeling exercise. The baseline building contained 30% glazing area (as a percentage of the gross wall area), with most windows 4-feet wide by 5- feet high. Energy loads in the building were estimated by the Mechanical Engineer (Sider + Byers Associates) with input from the Electrical Engineer (Glumac International, Inc.). 2. Established seven Energy Conservation Measures to test. These measures were agreed upon in a meeting with the Mechanical Engineer, the City of Seattle Green Building official, and the Architect. The seven Energy Conservation Measures were: Building Orientation Rotated the building so that it lay roughly east-west on the site in order to increase access to north and south light Shading Devices for Glazing Applied shading devices in three different ways to decrease heat gain: 4-foot deep horizontal shading at all southeast and southwest-facing windows Above, plus 4-foot deep horizontal shading at all northwest- and northeast-facing windows Above two, plus 4-foot deep vertical fin at the south side of all southwest, southeast-, northwest-, and northeast-facing windows Skylights Provided skylights at 3% of the roof area to increase daylighting. Glazing Upgrade Improved all windows to a U-value of.15 and a SHGC of.37. Ground Source Heat Pump Changed the HVAC system from a Split-System Single Zone Heat Pump to Ground Source Heat Pump. 2

4 3. Compared the hypothetical energy use of the building with each of the above Conservation Measures to the energy use of the baseline building. 4. Created a Modeling Results table summarizing the above results, their approximate initial capital cost, a comparison with the 2030 Challenge Target Energy Use, and the amount of solar power required to achieve an Energy Neutral Building. Acknowledgements This energy modeling exercise was completed by Environmental Works Community Design Center (Architect) with the assistance of Sider & Byers Associates (Mechanical Engineer) and Peter Dobrovolny (City of Seattle). Challenges and Standards ASHRAE/IESNA Standard Proposed 2006 Seattle Energy Code: LEED This standard provides methods for energy efficient building design (lighting, HVAC, etc.) and for comparing a baseline design to an improved design. It does not provide a straightforward, persquare-foot standard for different building types. Aims for 20% improvement in energy savings over ASHRAE/IESNA Standard In theory, by meeting the 2006 Seattle Energy Code, the Neighborhood Center would be 20% above ASHRAE. LEED is a rating system intended to measure the overall sustainability of a building. Up to 10 points out of a possible 69 can be achieved based on energy efficiency compared to ASHRAE/IESNA Standard Meeting Seattle Energy code would in theory automatically give us 3 points Challenge Sets targets based on a 2003 statistical sampling of existing United States non-residential buildings. Achieving the 2030 challenge means meeting a 60% reduction in annual energy use compared to a similar building type measured nationally. The building cannot use fossil fuels but can use up to 20% on-site renewable or off-site renewable energy (Seattle s hydroelectric power would probably be eligible for this). Net Zero Site Energy Building Living Building Building that consumes only as much energy as it produces on-site. This could be considered the strictest form of a Zero Energy Building. Building that produces all of its own energy and collects/treats all of its own water on-site. 3

5 equest Results The following pages show screen captures of the equest modeling results, including: 1. The Energy Modeling results for the baseline building. 2. The Energy Modeling results for the building with each of the seven Energy Conservation Measures employed. 3. The ninth page of results contains the results of a test that used both a Ground Source Heat Pump as well as Better Glazing, which were judged to be the most effective Energy Conservation Measures. Each page contains highlighted text near the top of the page which describes its contents (for instance, the baseline building, which was based on Code Minimum requirements, is called Code Min ). 4

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15 High Point Neighborhood Center Energy Modeling Modeling Results Summary June 26, 2007 Modeling Method After the baseline was established, each of the Energy Conservation Measures below was tested INDIVIDUALLY against the baseline building. Code Minimum Baseline: Based on the proposed 2006 Seattle Amendments to the Washington State Energy Code. Uses split-system single-zone heat pump. Orientation: Rotated the building so that its primary orientation was east-west (I.e. its long façade faced south). Shading: S Windows (Horizontal Shade) Added 4-foot deep awnings immediately above all southeast- and southwest-facing windows. S, W, and E Windows (Horiz. Shade) Above, plus 4-foot deep awnings immediately above all northeast- and northwest-facing windows. S, W, and E Windows (Horiz. Shade + Vert. Fin) Above two, plus 4-foot deep vertical fin at the south side of all southwest-, southeast-, northwest-, and northeast-facing windows. Skylights: Provided skylights at regular intervals for 3% of the roof area. Glazing Upgrade: Improved all windows to a U-value of.15 and a SHGC of.37. Ground Source Heat Pump: Changed the HVAC system from a split-system single-zone heat pump to a Ground Source Heat Pump. Table #1: Energy in kw-hrs (x000)/yr Ground Source Heat Pump Better Glazing + GSHP Component Baseline Orientation Shading Shading Shading Skylights Better Glazing (Code Minimum) (S) (S-W-E) (S-W-E + Fin) Space Cool Space Heat HP Support Hot Water Ventilation Fans Pumps and Auxiliary Misc. Equip Task Lights Area Lights Total Energy Percent Energy Saved % 0.19% -0.71% -1.63% -4.69% 6.81% 9.86% 11.41% Annual Cost (1) $ 11, $ 11, $ 11, $ 11, $ 11, $ 11, $ 10, $ 10, $ 9, Annual Cost Savings - $ 4.50 $ $ (80.25) $ (183.00) $ (527.25) $ $ 1, $ 1, Estimated Additional Initial Capital Cost $ - $ - $ 16, $ 28, $ 64, $ 20, $ 112, $ 60, $ 172, Monetary Payback Period (years) n/a n/a n/a Environmental Cost/Savings (lbs of CO2 saved per yr) (2) (1,605) (3,660) (10,545) 15,300 22,155 25,575 Table #2: 2030 Challenge 2030 Target Energy Use- (kw-hr/sq. ft./year) 40% of "similar" building Modeled Energy Use (kw-hr/sq. ft./year): calculated with Total Energy from above Table #3: Energy Neutral Building (3, 4) Average Instantaneous Demand in Building (kw) PV required (sq. ft.) Cost of PV required $ 235, $ 235, $ 235, $ 237, $ 239, $ 246, $ 219, $ 212, $ 208, (1) 7.5 cents per kw-hr assumed for 2010 (in order to more closely match equest estimates) (2) Based on avg. 1.5 pounds of CO2 produced by Coal, Oil, or Natural Gas fired Power Plants. We have primarily hydroelectric in Seattle. (3) Square feet of PV Panels determined roughly by: Total kw-hrs divided by 265 days divided by 12 hours equals Instantaneous Demand divided by 7 watts equals sq. ft. of PV req'd year year day sq. ft. (4) From Glumac: PV typically costs $4-$5/watt or $35/sq. ft. Other Notes Shading Devices: $15/sq. ft. (based on 50% escalation on Neighborhood House Rainier Vista Community Center sun screen cost estimate). 160 windows (total) at 4-feet wide by 5-feet tall each. S=70 horiz shades. S-W-E=120 horiz. shades. S-W-E + Fin=120 horiz. shades vert. fins. Skylights: $225 for 2'0 x4'0 skylight (Milgard). For 3% coverage of roof, need 40 skylights. Estimate $275 for additional installation cost per skylight (or $500 per skylight total) Better Glazing: Visionwall 4 element VE12M, U-value=.13, SHGC=.35, VT=50%, clear. Roughly $60/sq. ft., not including installation. Should we run simulation with Milgard Cascade WindPro Series Vinyl Double Pane at $25/sq. ft? (U-value=.26, SHGC=.25) From equest, 30% Glazing yields roughly 160 windows at 20 sq. ft. each or 3200 sq. ft. of glazing $25/sq. ft. x 3200 sq. ft. = $80,000 total for Milgard windows (materials only, and these are probably better than "code min.") $60/sq. ft. x 3200 sq. ft. = $192,000 total for Visionwall windows (which are slightly better than those used in the "Better Glazing" equest simulation) Additional cost for Better Glazing = $192,000 - $80,000 = $112, Challenge: Average of EnergyStar Target Finder for General Office building (with 130 occupants at 60 hours a week with 20 computers) AND Preschool/Daycare Target from 2030 list = 8.5 kw-hrs/sq.ft./yr. Roughly 3000 kw-hr/year improvement if you eliminate East and West windows after rotating the building (Orientation + Window Modification)

16 Comments The results of this exercise helped determine some of the major energy conservation strategies for use in the building. The team found that the two most effective measures were the implementation of a Ground Source Heat Pump, and the upgrade to better glazing. (Note that there did not seem to be an explanation for the slight increase in cooling load when using better windows.) Surprisingly, changing the building s orientation did not reduce the building s energy use, which may be due to Seattle s climate. Skylights also did not reduce energy use, due to an increased cooling load even with a very slightly reduced lighting load. Shading devices at windows increased energy use in the building, due to an increased lighting load and only very little reduction in cooling load. In addition to Seattle s overcast skies and temperate weather, the strictness of the Seattle Energy Code may also mitigate the effects of certain commonly applied Energy Conservation Measures. However, it should also be noted that certain Measures could not be fully modeled. For example, while equest provides for Shading Devices, there is no clear way to model a light shelf, which would not only shade the space in the summer, but also reflect light into the space, thus reducing lighting loads and potentially reducing energy usage below the baseline. Furthermore, it was surprising to find that even with a code minimum building, energy use met the 60% threshold of the 2030 Challenge, which may mean that designing energy neutral buildings of this type becomes the true challenge. It must be mentioned, however, that all numbers for energy use in the building are still hypothetical and actual energy use can only accurately be measured when the building is operational. Finally, because of some of the discrepancies and inadequacies mentioned above, the modeling team still has questions about the accuracy of the modeling results. If the cooling load increases with better windows, which seems highly unlikely in reality, how can we be sure that other test runs related to the windows are accurate? If we test a building based on code minimum inputs for Seattle and we end up with a baseline building that already meets the 2030 Challenge, how can we convince the owner to implement any Energy Conservation Measures? And is it possible to use a program designed for California office towers to test a two-story Seattle building? As mentioned above, it is possible that Seattle s weather and strict codes explain some of the counterintuitive results. If so, it would be extremely 15

17 informative to have a sampling of a variety of local equest modeling results to determine whether it is the challenge of sustainable design in the Pacific Northwest or the questionable functionality of equest that draws out these questions. Going Forward The team plans to use the results of this modeling to help guide schematic design decisions. Specifically, the owners of the building (Neighborhood House) now have a clearer idea about the costs and benefits of different energy saving strategies, which will only become more clear as more cost information is developed during the Schematic Design and Design Development Cost Estimates. 16