Virtual Tour
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Introduction
Welcome to 46 Blackstone Street … Harvard University’s first LEED® Platinum-certified building!
This tour has been created to demonstrate the technologies incorporated throughout the building and to provide a better understanding of sustainable design possibilities.
History of the Site
The Blackstone Steam Plant
In 1888, the Cambridge Electric Light Company built the Blackstone Electric Station at the edge of the Charles River to power the city’s growing number of street lamps. However, due to overwhelming demand for electricity, construction of a new and larger plant began in 1901 on the corner of Western Avenue and Memorial Drive. The plant’s turbines were driven by steam which, beginning in 1930, was also used to heat many of Harvard’s buildings. Today, most of the campus is still heated by the Blackstone Steam Plant.
Other Buildings on the Site
Adjacent to the plant are several buildings along Blackstone Street. The largest is a four story brick building constructed in 1889, designed as the headquarters for the Standard Diary Company. A smaller workshop was built in 1926 and a two story warehouse was added in 1929. These three buildings — later consolidated into Harvard’s first LEED® Platinum building — were used for a variety of purposes throughout the years, even serving as a temporary studio for Julia Child who filmed several episodes of The French Chef here during the 1960s. By the 1990s, these buildings and the steam plant were all owned by a local utility company.
In 2003, Harvard purchased the Blackstone Steam Plant from the local utility, which included these adjacent buildings along Blackstone Street. While the Steam Plant was a going concern, these adjacent buildings were in a serious state of neglect. These buildings would become the focus of the Blackstone Office Renovation Project.
The Project
There were two main goals for the rehabilitation of these buildings. First, geographically consolidate significant portions of University Operations Services (UOS); an organization that provides essential services including, energy supply, facilities maintenance, transportation, and environmental health and safety. Second, create a work environment reflecting UOS’s leadership role in promoting sustainability at Harvard.
Expectations and Constraints
To help ensure these goals were realized, UOS developed a clear list of "Project Expectations" to guide the process from beginning to end. These expectations were explicitly included in contract documents for the design team and prominently displayed in project meeting rooms. The project team repeatedly referred back to these expectations which helped refocus everyone on our goals and priorities!
Cost control was also a primary consideration since all project costs would ultimately need to be fully recovered through UOS services provided to the Harvard schools and departments.
What is LEED®?
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System™ encourages and accelerates global adoption of sustainable green building and development practices through the creation and implementation of universally understood and accepted tools and performance criteria.
The Green Building Rating System ™ provides increasing levels of LEED® certification including, certified, bronze, silver, gold, and platinum. In 2006, the Blackstone Building Office Renovation Project achieved platinum level certification.
Blackstone: A building of Firsts
- First ever LEED® Platinum at Harvard
- First ever LEED® Platinum in higher education
- First ever LEED® Platinum in a pre-1900 building
- First ever LEED® Platinum renovation in New England
Courtyard
Permeable Pavers
All of the pavers in the courtyard are made from recycled materials and set on a grid of stone dust to allow maximum storm water filtration. The pavers are also light colored which reduces heat absorption during the summer, producing a cooler outdoor environment.
Exterior Lighting
All fixtures have high cut-off angles preventing light from being directed upward or outside of the property. Reducing light pollution helps to restore ecosystems and improves star viewing for city dwellers.
Bio-Retention Pond
The bio-retention pond (or bioswale) is an important part of our strategy to eliminate reliance on the municipal storm water system while managing storm water runoff from the site's 25,000 square foot parking lot. The pond is constructed in three distinct layers: a 12 inch mix of crushed stone and gravel, followed by a 4 foot layer of engineered soil (a mix of sand and soil), and topped with 6 inches of loam. All of the surrounding slopes are planted with No Mow grass and shrubs which serve as a pre-filter for the storm water runoff. When the runoff reaches the bio-retention pond, microorganisms in the soil trap the Volatile Organic Compounds (VOCs) and other suspended solids including salts, oils, and greases left behind by cars and trucks. These materials are broken down through the process of phyto-remediation and prevented from entering nearby water bodies. Also, the plants absorb phosphorous, preventing eutrophication, or the over-enrichment of water bodies, which results in excessive algal growth, reduced oxygen levels, and animal death. Water not absorbed back into the ground is captured by a drainage pipe which returns the filtered water directly to the nearby Charles River. The bio-retention pond also creates a suitable habitat for urban animal species.
Grass & Ground Cover
From April to September in Massachusetts, the average acre of maintained green space is watered at a rate of 15,000 gallons per week. As part of our water management strategy, open spaces are landscaped with native, drought-tolerant species that require no irrigation.
The grass is a fescue mix (Sheep’s, Red, and Hard), commonly referred to as “No Mow” for its minimal maintenance requirements. Highly resistant to drought, it will grow to approximately 14 inches and produce lush greenery. The groundcover, Lotus Corniculatus, commonly referred to as “Bird’s Foot Trefoil” produces a lovely yellow flower, is also drought-resistant, and does not require any regular maintenance.
The Light Slot
One of the more visually dramatic features of the building, the light slot connects two buildings that were once separated by an unattractive alley. In addition to providing architectural vitality, the glass canopy floods the interior of the building with natural light.
Bicycle Racks
To promote bicycling, several bike racks have been installed in convenient locations around the Blackstone site.
The Building Envelope
All of the windows are double-insulated glass with a U-value of 0.25%. (U-value measures the rate of heat transfer through a building element over a given area, under standardized conditions. A smaller U-value is better).
The windows were specially designed to maintain the historic look of double-hung units but instead open with an awning. Nearly all of the windows are operable, a feature integral to the design and operation of the HVAC (heating, ventilation and air conditioning) system. The Building Automation System is programmed to notify occupants by e-mail whenever outdoor conditions (temperature and humidity) are appropriate for windows to be opened.
The decision to install high quality windows, as well as upgraded wall and roof insulation, resulted in a tight building envelope. These investments allowed us to design smaller, more efficient mechanical systems for heating and cooling.
A recycled foam insulation product (Icynene®) was applied directly to the surface of the brick on all exterior facing walls. This product provides a permeable vapor barrier resulting in a continuous R value of 12, more than 50% better than code requirements. The R value is a measure of thermal resistance used in the building and construction industry. A bigger number means a better insulated building.
Kitchen
Bamboo Flooring
Bamboo is one of the fastest growing plants in the world making it a rapidly renewal resource. The species used at Blackstone grows at a rate of one foot per month!
Concrete Countertops
The large kitchen countertop is made from concrete. Concrete contains abundantly available resources such as ash, gravel, limestone, and sand making it more sustainable than products like granite. In addition to being a highly durable material, concrete can also be recycled over and over.
Heating & Cooling
Heating & Cooling – More than 160 ceiling-mounted valences are located throughout the building. These non-motorized units work silently by relying on natural airflow cycles to warm or cool most interior spaces. As a result, there are no noisy or energy robbing fans forcing air from the valance units. Furthermore, with almost no moving parts, maintenance requirements are minimal.
Here’s How They Work:
In the heating mode, hot water (converted from steam generated at the Blackstone Plant) is pumped through the fin-tube coil located inside the valance warming the surrounding air. The warm air then rises and radiates heat off the ceiling and wall surfaces increasing the space temperature.
In cooling mode, chilled water circulates through the valance units. The colder air falling along the wall surfaces forces the heat from the space to rise where it transfers to the chilled water passing through the valance, creating a natural cycle of convection. The circulating chilled water is generated from ground source heat pumps linked to geothermal wells which serve as a heat sink for the building. Rather than using a conventional cooling tower, the heat transferred from these interior spaces is rejected from the building and deposited into our geothermal wells, (See also Geothermal System)
Since heating and cooling needs within the building vary based on solar orientation, a two-pipe riser configuration is fed by a four-pipe distribution network to enable simultaneous heating and cooling across different zones. Eliminating the four pipe configuration above the basement level resulted in significant savings on pipe and installation labor.
Ventilation System & Controls
The ventilation system uses 100% outside air with no recirculation, providing a healthier environment by exhausting airborne contamination more frequently. Unlike most conventional designs, the ventilation system at Blackstone is entirely separate from the heating and cooling system (see heating & cooling). Decoupling these systems allows the equipment used for ventilation (air handler and ductwork) to be smaller and more efficient, since it only needs to move only relatively small volumes of air.
Demand control is also used to adjust the volume of fresh air brought into the primary meeting spaces (lunch room and large conference room). Sensors in these large gathering spaces measure the amount of carbon dioxide (CO²) present — created whenever people exhale — and ramp the ventilation system up or down accordingly. The "demand control" system greatly reduces energy costs and makes for a more comfortable working environment.
Forest Stewardship Council (FSC) Certified Wood
All of the wood used in the project is FSC certified. In many forests around the world, logging still contributes to habitat destruction, water pollution, displacement of indigenous peoples, and mistreatment of wildlife. FSC certification is one way to ensure that the wood has been harvested in a responsible manner.
1st Floor Offices
Natural Light
An important part of our energy conservation strategy involves the use of daylight. Large windows and skylights flood much of the interior space with natural light significantly reducing energy consumption. In fact, approximately 90% of occupants have an outside view.
Artificial Light / Interior Lighting
High efficiency lighting is used throughout the building. Most of these fixtures also have built-in occupancy and daylight sensors. When natural light fills the interior spaces, the fixtures dim to maintain a constant lighting level. Each fixture will also turn off when a space is not occupied.
Low VOC materials
All carpeting, paints and office system coverings, were selected for their low content of Volatile Organic Compounds (VOCs). VOCs, which frequently result from the manufacturing process, oxidize and emit a potentially irritating vapor that has shown to be a contributing factor in “sick building syndrome.” By using low VOC materials the indoor air quality is measurably improved.
Also, rather than using traditional rolled carpeting, the floor covering is divided into small sections, commonly referred to as “carpet squares.” This increasingly popular approach minimizes waste during installation and allows for easy and economical replacement of damaged or heavily worn areas over time.
4th Floor
Skylight
The large skylight on the fourth floor, directly above the communicating staircase, allows large amounts of natural light to flood the interior of the building. An insulating film was also applied to the glass to further improve efficiency.
Communicating Staircase
The central communicating staircase and skylight allow natural light to cascade into the core of the building. The open staircase also encourages employee interaction and communication.
Eco-Space Elevator
Our Eco-Space elevator utilizes a gearless traction system which is 60% more energy efficient than a conventional elevator. The gearless technology also eliminates the need for oil and hydraulic fluid which are potential groundwater contaminates.
Recycled Wood Beams
Carpenters cut through the old-growth timber beams and original tongue-and-groove floorboards. They then re-used the beams to support the opening for the communicating staircase. There were more than 170 rings on the beams. Given that the Diary building was built in 1887, these trees were saplings around the year 1700 - when Harvard was only about 60 years old.
Additional Features
The Enthalpy Wheel
(click on the diagram above for a full PDF version of the energy recovery wheel)
Blackstone is also equipped with an Enthalpy Wheel (see illustration) which transfers energy between the incoming and exhaust air streams. In the summer season, the excess heat contained in the incoming ventilation air is transferred to the cooler exhaust air exiting the building. In winter, the heat contained in the warmer exhaust air is transferred to the cooler ventilation air. In both cases, this reduces the amount of additional energy required to condition the ventilation air. Transferring energy (as opposed to re-circulating the exhaust air back into the building) saves money, improves indoor air quality, and helps meet modern ventilation standards while reducing total HVAC equipment requirements.
How it Works:
The Enthalpy Wheel is an air-to-air heat exchanger designed as a rotating corrugated aluminum cylinder filled with an air permeable material. This enlarged surface area provides the medium for the transfer of sensible heat (thermal energy). The energy transfer occurs as the wheel slowly rotates between the opposing ventilation and exhaust air streams, picking up heat energy and releasing it into the colder air stream. The difference in temperature between the opposing air streams, known as the thermal gradient, is the driving force behind the exchange. The humidity exchange
(latent energy) is accomplished using a silica gel desiccant. This transfer of moisture occurs through the process of adsorption, predominately driven by the difference in the partial pressure of vapor within the opposing air-streams.
The Blackstone Unit is designed to provide as much as 81% of the energy needed to condition outside air for building ventilation. The example at right is a snapshot of the energy recovery performance on a cold day in January. In the summer months, the wheel transfers both the sensible and latent heat energy from the incoming ventilation air to the exhaust air stream, effectively pre-cooling the incoming air before it reaches the cooling coil.
Geothermal System
(click on the diagram above for a full PDF version of the geothermal system)
Here’s how it works:
Located in the parking lot behind the building are two, 1,500-foot wells each 4 inches in diameter. Groundwater is drawn from the bottom of each well and pumped to the heat pumps located in the basement mechanical room at the rate of 90 gallons per minute. This water is used on the condensing side of the refrigeration cycle within the heat pump.
Chilled water circulated through the building at ~ 42° F, returns to the heat pump at ~ 52° F. This excess heat is then transferred through an internal heat exchanger to the returning well water loop. (see illustration)
The Green Cleaning Program
Blackstone is home to the Facilities Maintenance Operations; the group that pioneered Harvard’s Green Cleaning Program. The program features 100% recycled paper products, Green Seal® certified cleaning solutions, environmentally sensitive cleaning procedures, high filtration vacuums, and environmentally friendly hand soaps.
Water Use / Plumbing
Water use in the building is designed to be 43% below Energy Policy Act (EPACT) standards. All of the toilets are dual flush (.8 gallons / for liquids and 1.6 gallons / for solids). Low flow sinks (.5 gallons / minute) operate with infrared sensors further reducing water use.
