Loading...
HomeMy WebLinkAboutLaw and Justice Center Public Comment, Bilo 8-1-14To: The City of Bozeman Commission From: Susan Bilo, Bozeman Citizen Regarding: July 21st Law & Justice Center Presentation Date: August 1, 2014 _____________________________________________________________________ I watched the July 21st Commission meeting recording regarding the Law & Justice Center, and I’m submitting the following comments and suggestions for your consideration. 1. Appropriate building orientation elongated along the east/west axis (as acknowledged by one of the architects) would provide free heat from the sun in winter and would keep the building cooler in summer. It also optimizes daylighting opportunities. As proposed, The Law & Justice Center will not take full advantage of the sun’s skypath for free winter heat! And, it will require significant energy to keep occupants cool and comfortable from the heat-build up that will occur due to the large number of east- and west-facing windows. An architect said they will look at windows that can reduce solar heat gain, but here are several other options to consider to help reduce summer heat build-up: 1A. Move the trees from the boulevard closer to the building on the east side and add trees to shade the west-facing windows. Choose native and/or xeric trees that will grow tall enough to shade the two stories but will not shade solar panels or collectors. 1B. Ask the designers to consider integrating a night-time air flushing system. Our cool nights can provide free cooled air to flush out the day’s heat build-up. 1C. The public entrance with two stories of glass wall will overheat in the summer, increasing the cooling energy-load requirements. Tall deciduous trees, operable windows, and ceiling fans will help reduce the heat build-up. In winter, the lower-in-the- sky winter sun will help heat it, but it could get too warm. Ask the designers to model the winter heat gain for this area and if it will get too hot, ask if they can get the extra heat distributed into other parts of the building. Glare will likely be an issue – especially for occupants with offices on the east- and west- sides of the building. 2. South-Facing Exterior Walls: What south-facing exterior wall area there is should be fitted with transpired solar collectors (TSCs): dark-colored, perforated metal attached to the outside of the south wall. The sun hits and heats the metal heating the surrounding air. This heated air naturally rises and with the assistance of a fan, is drawn into a room or area, or can feed into the HVAC system to pre-heat ventilation air. These systems are very cost-effective when installed on existing buildings, but are even more efficient and cost-effective when integrated into the initial design. For example, instead of covering (more expensive) existing wall materials, the TSC becomes the exterior wall material. And, you can design for the fan installation (versus punching holes later, etc.) and efficient Heating, Ventilation, and Air Conditioning (HVAC) connections. - http://solarwall.com/posts/transpired-solar-collector-ventilation-preheating46.php - Details: http://www1.eere.energy.gov/femp/pdfs/FTA_trans_coll.pdf FYI - Another version of this basic system can be placed on (sloped in MT) rooftops. Overhangs: If not included, ask the designers to place (based on our latitude) overhangs on the south-facing windows to block the higher direct summer sun. This will reduce the summer cooling energy load. 3. Solar Hot Water: TSCs mentioned above and solar hot water systems are two of the most efficient and cost-effective (with quick paybacks) solar applications available. I did not see solar hot water collectors in the designs. Thus, if a system (and/or additional PV) will be installed at a later date, make sure they design it “solar-ready:” - http://www.nrel.gov/docs/fy10osti/46078.pdf - http://www.nrel.gov/docs/fy12osti/51296.pdf - The Resource (on the right side) Specifications and Checklists are applicable to non- residential buildings as well: https://www.energystar.gov/index.cfm?c=rerh.assessment 4. Photovoltaics (PV)/Solar Electricity: It is correct that Northwestern Energy caps net metering at 50 kilowatts, but Bozeman could install additional meters for separate 50-kW systems. The Montana Renewable Energy Association will introduce legislation next year to significantly raise or eliminate the net metering cap. Another possible option: MSU is looking into a Power Purchase Agreement (PPA) arrangement in order to install a larger- than-50-kW system. - The PV-covered parking canopy is a great idea, and I suggest at least one parking spot be wired for sun-powered electric vehicle (EV) charging. - Another reason to orient a building along the east-west axis is that it allows more panels to be placed on the roof. How? When considering the lower-in-the-sky winter sun’s long shade angles, more panels can be placed in longer rows that will not shade rows behind them. 5. Emergency Preparedness: I prefer to not encourage renewable energy systems based on fear, but you should consider that a back-up propane generator is great as long as you can get propane. A stand-alone PV system (wired to still work when the utility grid fails) with enough battery storage to run critical electrical loads in the building (and an EV) over a longer time period would be appropriate for this building. The sun-powered EV will be the only useable/refuel-able vehicle after the other vehicles run out of gas. Also, if there is a power outage over an extended period of time, a high-performance envelope (better insulation, windows, etc.) will keep its heated or cooled air longer. 6. Lighting: I was encouraged that LEDS and T-5 fluorescents will be used. I heard the term “light-harvesting” used, which I think of as the same as daylighting. Please ask about the integration of “lighting controls.” Controls will automatically dim LEDS when the sun provides the right amount of needed light whether through windows or the clerestories. LEDS will also reduce the building’s summer cooling load because properly installed LEDS do not emit the heat of incandescents or T-5s (allowing reduction of the cooling equipment size). 7. U.S. Green Building Council Leadership in Energy and Environmental Design (LEED) designation: I think you all asked very valid questions about the system and process. Until the concepts used in LEED become part of our building design and construction culture, LEED plays an important role in promoting an overall sustainable approach. I suggest using LEED + a Net Zero Energy goal because (depending on who selects the LEED points to achieve), LEED has the potential to be weak in the Energy & Atmosphere section. If it is decided to not pursue a LEED designation, the third-party certification and commissioning of equipment and systems will be very critical to make sure they work the way they are supposed to and we get what we pay for. 8. Hydroelectric dams comment. Hydroelectric dams are less polluting than fossil fuel- powered plants, but they do impact river and riparian ecosystems (natural fish movement, water flow and temperatures, etc.), and they need water! As drought becomes more of an issue, I would not want a large % of our electricity production dam-dependent. And, the most important idea here is to reduce energy use and costs regardless of where it comes from. Getting “cleaner” electricity from a dam would be an irresponsible reason to not build a resource-efficient building. 9. It was not mentioned, but a truly high-performance and resource-efficient building is inherently more durable (reducing maintenance costs) and a more comfortable place to work and do business! 10. If these suggestions are integrated, the energy modeling program will show how much the fossil-fuel powered mechanical systems can be reduced in size. Engineers typically oversize HVAC systems because traditionally built buildings leak a lot of air. An airtight building with a heat- or energy-recovery ventilation system and appropriate air exchanges does not need an oversized HVAC system. Also ask about the % efficiency levels of all equipment, fixtures, and appliances that use water as well as energy. As a taxpayer, I appreciate your consideration and concern for 1st price-tag initial capital costs as well as the 2nd price tag-related operation & maintenance costs paid over the lifetime of the building.