Four Embarcadero Center
Four Embarcadero Center Lobby Level Suite One
San Francisco, CA 94111
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Energy management at Four Embarcadero Center begins with proper preventive maintenance and repair of the installed systems. The building's systems were also designed under the earlier Title 24 building code requirements, which included energy performance measures available at that time. The building is equipped with a full OSA/economizer on the central variable air volume (VAV) fan systems and air distribution systems conditioned by central plant chillers and boilers. A perimeter HVAC curtain wall tempering system is also installed and designed to supplement space conditioning by elevation exposures. Because it was designed and installed under early Title 24 requirements, the original lighting had large fixture spacing, which has since been retrofit using T8 lamps, electronic ballasts, and optical lighting reflectors.
After completing retrofits of the installed systems, the team introduced an energy management control system (EMCS) and hybrid direct digital control (DDC) interfaces, as well as variable frequency drive (VFD) technologies and strategies to both the water and air sides of the existing HVAC systems to further enhance the building's comfort and their control of the large, energy-consuming systems.
Through the 1990's, occupancy sensors and timed and staged controllability of the lighting systems were added to enhance building performance. The team also completed lighting retrofits to T-8 lamp and electronic ballast technology and added more efficient optical reflectors to increase energy savings and improve the quality of lighting. Along the way, the building specification for lighting installations required the use of energy-efficient fixtures, sensors, and technologies as a standard for all tenant improvement work. The replacement of an older, less-efficient chiller with a new (non-CFC) variable speed drive chiller to more efficiently handle low load periods was done mid-decade. The evolution of building codes, such as Title 24 in California, was key to supporting these moves, as was the availability of state and utility rebate programs to incentivize and improve ROI calculations.
From 2000 to present, additional lighting retrofits using technologies such as T1 systems, LED, and cold cathode lamps were performed. Expanded use of occupancy sensors and sentry switching were explored and deployed where suitable to increase the OFF time during both peak and non-peak operating hours.
In 2002 and 2003, the application of new ABB VFDs on the central variable air volume (VAV) fans, which replaced older mechanical linkage fan applications, improved the overall efficiency and effectiveness of the main air delivery systems throughout the building.
In 2004, VFDs were installed on the building's chiller pumping plant to improve system performance and delivery. Also in 2004, the installation of 3M-NV25 solar reflective window film was performed on the elevations of the building affected by the sun to contain the heat gain that impacted the building's HVAC system and operation, reducing loads during those high solar days.
In 2007, the energy management team installed a new DDC BACnet compatible energy management front end and backbone infrastructure to begin phasing out the older EMCS system and technologies from pneumatic-DDC to direct DDC technology. This work is on-going and will transition over time (through the tenant improvement process as well as intentional owner capital projects) to a full DDC system.
In 2008, the building's four main HVAC systems and cooling towers were completely overhauled and outfitted with new motors and VFDs to improve operating efficiency and performance. Particulate media filtration was also installed to improve water quality and treatment performance of the system.
Also in 2008, numerous improvements further enhanced the energy performance of the building, including the launch of additional de-lamping strategies, cold cathode lamps in retail common areas, as well as changes in the building's holiday lighting schemes and the installation of occupancy sensors in stairwells as well as on all parking garage light fixtures. In 2008, the building earned the ENERGY STAR for superior energy performance for the first time with a score of 81.
In 2008-09, the team implemented policies for lighting efficiency to encourage staff to turn off lights after hours and to purchase low mercury fluorescent lamps when replacing lamps that have that option.
In 2010, the building again qualified for the ENERGY STAR for the third consecutive year, earning it with a score of 81. The same year, we also converted the constant volume garage ventilation system to variable volume with the installation of new VFDs, new carbon monoxide sensing technology and integration into the building management system (BMS). We expect to see substantial demand and consumption savings from this retrofit in 2011 and moving forward.
Also, and in the near future, the team has and will be looking at projects such as: 1) installation of VFDs on additional air handling units to take advantage of the new DDC system's capability as well as VAV strategies that occur during tenant improvement projects; and 2) continued lighting technology shifts from conventional lamps to emerging lamps, such as the LED offerings as they are appropriate. We also continue to explore and deploy new lighting technologies in our building specifications and have adopted some LED technologies in the last year. We are now installing LED down lighting fixtures in common areas and restrooms with good success and impact.
With regards to water consumption, in San Francisco, we have adjusted our building specifications to require that all new toilets and urinals be high efficiency or ultra low flush technology and are replacing some of the older units throughout the building in 2011.
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Testimonial:
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Please note: Narrative information in this profile has been provided by Boston Properties or a representative of this facility. Other building information was verified and submitted to EPA at the time of application. Building energy performance, operating characteristics, and ownership/management may be subject to change over time.
Building Owner:*
Boston Properties
Property Manager:*
N/A
Year(s) Labeled (Rating):
2008 (83)
2009 (81)
2010 (81)
2011 (76)
2012 (79)
2013 (82)
2014 (86)
2015 (85)
2016 (87)
Facility Type: Office
Total Floorspace: 942573 sf
Year Constructed: 1979
Contract Type: None
Financing Type: Internal Capital
Technologies Used:
| Stage 1-Recommissioning |
| Stage 2-Lighting |
| Stage 3-Load Reductions |
| Stage 4-Fan Systems |
| Stage 5-Heating and Cooling Plant |
| Other Technologies/Strategies |