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1. Provide individual electric water heating systems to each unit; or <br />2. Use a smaller scale electric central water heating system that serves up to <br />eight units. This is referred to as "mini -plants." <br />These alternative pathways are feasible for high rise residential. The operational cost <br />between a central natural gas water heating system and a smaller scale central <br />electric water heating system are similar. <br />These alternative pathways are not common practice, and require careful and <br />thoughtful design in order to achieve desired results of efficiency and cost <br />effectiveness. It is also equally important to choose the most environmentally friendly <br />electric heat pump. Heat pumps use refrigerants that have an environmental impact <br />and not all heat pumps are created equally. There are product guides available to <br />help consumers and developers make the best choices. <br />As stated previously, the proposed all -electric policy is cutting edge, and is intended <br />to drive new innovative thinking and leadership in designing hot water systems. In <br />addition, it requires consumers and developers to make smart appliance decisions <br />that will further save on costs while reducing environmental impacts. <br />There are educational forums and workshops to help support developers in <br />transitioning to all -electric buildings occurring in October. Redwood Energy has also <br />provided a Zero Emissions All -Electric Multifamily Construction Guide. Examples of <br />high-rise all -electric residential buildings include: <br />• Edwina Benner Plaza by MidPen Housing in Sunnyvale is a four story <br />residential building. Hot water is provided by two innovative central heat pump <br />water heating plants paired with large storage tanks to shift heat pump loads <br />away from peak periods. <br />• 205 Jones Street Apartments in San Francisco is a retrofit by Mercy <br />Housing (affordable home developer). This project replaced central natural <br />gas boilers with electric central heat pump domestic water heaters. <br />• St. Mark Hotel Apartments in Oakland is another retrofit that replaced 80% <br />efficient natural gas boilers with 400% efficient electric centralized heat <br />pumps. Resulted in considerable site energy savings. <br />• Coliseum Place in Oakland will be a six story high rise residential <br />development,and will be using a "mini -plant" hot water system design. Water <br />heating for the units will be provided by individual Rheem or 80 -gallon heat <br />pump water heaters (3.55 UEF) where multiple units share one tank. To <br />compensate for the length of piping to farthest resident in the "mini -plant" <br />design, 3/8 piping was used to reduce hot water wait time. This saves on <br />construction cost by not having to install recirculating piping. <br />• Hillandale Gateway, Silver Spring, MD is an 11 story tall apartment complex <br />also using a "mini -plant' hot water approach. Apartments share 80 -gallon <br />electric heat pump tanks among two to four apartments (centralized), but <br />without energy loses of a recirculation system. <br />• Casa Adelante, San Francisco will be a nine story affordable housing <br />building. Electric central colmac air source heat pumps will be used for hot <br />water heating with solar thermal power and it also provides some space <br />City of Menlo Park 701 Laurel St., Menlo Park, CA 94025 tel 650-330-6600 www.menlopark.org <br />