A Demonstration Model and Living Laboratory

 

 

Location	Building Size	Building Owner
4960 S. 12th Street, Philadelphia, PA 19112	38,000 square feet	The Pennsylvania State University
Building Usage	Year Constructed	Project Budget
Small Commercial	1942	$33 Million
Energy Star Rating	Expected Energy Savings	Expected Cost Savings
Expected between 90-95	42.9% compared to baseline model	32.6% compared to baseline model

General Info

The Center for Building Energy Science, located in building 661 at The Navy Yard in Philadelphia, is the headquarters of the Consortium for Building Energy Innovation (CBEI).CBEI completed a comprehensive Advanced Energy Retrofit (AER) of this 38,000 square foot building to repair damage from long neglect, to showcase energy efficiency technologies, and to demonstrate the design process and technologies used to retrofit a historic building into a highly energy efficient commercial office space. As part of the AER, CBEI designed Energy Conservation Measures (ECMs) for all building systems: enclosure; lighting; heating, ventilation, and air conditioning (HVAC); and sensors and controls. The AER design phase was completed in 2012, construction began in 2013, and was completed in late-2014.

Existing Building Systems Overview

The Building

The Philadelphia Industrial Development Corporation (PIDC) owns much of The Navy Yard’s decommissioned land, although it sold Building 661 to the EEB Hub for a nominal sum. Designed in 1942 by Henry D. Dagit & Sons Architecture firm, the structure was the 661st building site at the Navy Yard and served as a recreation facility. The two-story brick building, which is in the form of a head house with an adjoining pool and gym building, has an articulated roof and large front setback. While its basic composition remained the same – housing a swimming pool, basketball courts, and a multipurpose room – Building 661 underwent three major renovations before it was taken out of commission in 1996. Several window openings were filled in with brick in 1978 and a second-level bowling alley was removed in 1980.

Building 661 was designated a historic structure in 1999, and while its style does not represent the majority of the region’s building stock, it does exemplify an important architectural style in a region with many historical buildings. The structure helps anchor the Philadelphia Naval Shipyard Historic District as it shares an architectural style and exterior materials with neighboring buildings, which together create a campus-like atmosphere in this area of The Navy Yard. The retrofit will restore many of the architectural features lost during renovations in the 1970s and 1980s while at the same time employing energy efficient strategies that complement the original design.

The building is composed of two main parts: the “head house” and two high bays. The head house is a two-story brick structure with a gable at the front of the building. Two high bays , distinguished by arched roof trusses and fully glazed gable roofs, run perpendicular to the head house. The new design for the building takes advantage of the natural lighting throughout the space and builds upon the structural “bones” of the building.

The structure, which had been out of active service for over fifteen years, was in a state of moderate disrepair. Cracking from natural expansion and contraction of brick was an ongoing concern and the roof needed to be replaced as open patches allowed water infiltration. Structurally, the concrete frame of the head house and the wooden arches that support the high bay pool and gym sections were generally in good condition. Likewise, the exterior walls were in good condition, although the wood gutters, cornices, and fascia all needed repair. The cupola required substantial restoration, as well. Building 661 certainly provided ample challenges for the architecture, engineering, and construction (AEC) team and an opportunity to inform other projects in the region

Design Phase Details

Design Process

Presently, a major challenge for successfully executing an AER is in upending existing practices among the various service providers in the building renovation process. To begin with, the AEC fields all tend to work independently of one another, rather than collaboratively. While they do interact over the details, especially during the construction phase, having everyone at the table starting with the design phase is uncommon. Integrated Design and Integrated Project Delivery (ID+IPD) incorporate all players – building owner, architects, engineers, construction management, building suppliers, and building trades – from the get-go.

One of the first steps in the ID+IPD process is to set project values that will guide the project development and decision-making. Significant effort was made in the preliminary phase to create a sense of collective vision and shared values for the CBES project. Even before the design team was selected, CBEI held a daylong workshop where CBEI experts set goals and intentions for the project, such as ‘serving as a regional resource that attractively highlights energy efficient building techniques to a wide audience and demonstrates effectiveness (comfort, function, appeal) as well as efficiency.’ Once the design team was in place, they created a set of project values, specific to the process of retrofitting Building 661: influence, repeatable demonstration, learning, collaborative environments, systems integration, cost certainty, and time reliability. When issues arose during project design, the project values were used to resolve them. The ID+IPD process facilitates a collective approach to managing design documents and construction plans between architects and construction teams. This approach  can eliminate “blame games” and “covering of tracks,” as all parties assume responsibility for design documents and planned construction processes. CBES followed this approach through a Collaboration Addendum, a non-binding agreement defining the collaborative practices to be followed between the design and construction firms. The addendum was necessary, because the Pennsylvania Separations Act (described in the next section) required that a traditional design-bid-build contract – which defines discreet divisions of risk between parties – be applied [1].

Following the protocols laid out in the addendum, the project team set up a management process for collaborative budget and schedule planning, as well as design. Every two weeks the project manager and construction management estimator hosted a budgeting call with the design team that ensured a rapid response to budgeting concerns. This process generated extremely positive feedback from the design team and is expected to lead to smaller overruns and underruns, a major plus when trying to stay within budget.

When the project transitioned to the construction phase, collaboration focused on the construction work by the four prime contractors. Balfour Beatty is hosting weekly on-site meetings with the aim of boosting construction reliability and reducing construction time.

Compensation was also based on collaborative work and tied to specific deliverables.

The design team produced a Building Information Modeling (BIM) execution plan at the EEB Hub’s Immersive Construction (ICon) Lab, following a model used by Penn State on its projects [2]. The use of BIM, an increasingly common practice in integrated design building projects, involves developing a detailed 3D model that can be used to make precise predictions about energy efficiency and as an information exchange medium between the various companies and disciplines working on the design. The BIM execution plan for Building 661’s retrofit provided the design and construction teams with specific implementation details on topics such as process flow, information exchange, and infrastructure. During the course of the retrofit design process, the project architect, construction manager, and facility manager met regularly to review the BIM and identify any potential clashes among the building’s mechanical, electrical, and plumbing systems. The BIM was also integral to accurate cost estimating, used as a communication medium between the design team and construction cost estimator.

Setting energy performance metrics, though not unique to ID+IPD, was of critical importance to the project team and reflected a number of project values: influence, repeatable demonstration, learning, system integration, and cost certainty. The team faced the challenge of creating an influential energy efficient building retrofit, while balancing repeatability and cost certainty. Energy performance metrics were based on audits and modeling, rather than on speculative predictions by building equipment manufacturers and suppliers.

Design Performance

The performance of the retrofitted building, as reflected in a computer model of the new design, was measured against the performance of an alternate “baseline” building model using the ASHRAE 90.1-2007 building code, which is considered the norm for the retrofit of vacant buildings like Building 661. The baseline building model was created by Atelier Ten. The comparison revealed that the proposed retrofit design described in this digest will perform 42.9% better in terms of annual energy consumption and 32.6% better in terms of annual energy cost relative to the baseline model. The building will use much less natural gas because less heating energy is needed, and less electricity primarily because less cooling and lighting is required. The total cost savings (32.6%) will be less than the total energy savings (42.9%) since most of the energy savings comes from lower-cost natural gas.

The proposed design will use significantly less energy to heat the building due to the additional wall and roof insulation, heat recovery chiller, energy recovery wheel, high efficiency condensing boilers, and demand controlled ventilation. Less energy will be needed to cool spaces, too, due to improved glazing, improved envelope insulation, a high efficiency chiller, and displacement ventilation. The chilled beam system will further reduce the energy needed for cooling by supplementing conditioned air with chilled water supplied to the beams at higher temperatures than other systems that rely on chilled water for cooling. The fans, too, will require less energy because the fans in the chilled beam system and several other technologies consume less power than those specified in ASHRAE 90.1-2007. Finally, daylight dimming contributes to the energy savings in lighting as well as cooling (due to reduced internal heat gains).

The proposed design is expected to earn 13 of 19 possible LEED Energy and Atmosphere (EA) credit 1 points, which are allocated to buildings that have optimized energy performance. According to Atelier Ten, the project may be able to earn an additional 3 points if the infiltration reduction credit is approved by the U.S. Green Building Council. The project is expected to earn between 60 and 70 LEED points out of a possible 110 points, which would earn LEED Gold certification.

The preliminary Energy Star rating for the proposed design is likely between 90 and 95, which exceeds the target rating of 75 and the median rating of 50. The current projected rating is excellent, but should be viewed with the understanding that it is built upon the current project data and could change based on the actual building energy use.

Building Envelope

Strategies that impacted the building envelope include replacing existing windows with double glazed, low-emissivity (low-e), argon- and aerogel-filled units with thermally broken frames and adding insulation to existing walls and roof. Low-e windows reflect radiant infrared energy while letting visible light pass; as a result, radiant heat originating indoors in winter will be reflected back inside while infrared heat radiation from the sun in summer will be reflected away. The argon and aerogel fillings act as additional thermal insulation, further limiting the building’s thermal losses.

A model used to determine and test the proposed technologies for Building 661 showed that a building’s overall energy use is strongly affected by the building envelope’s air infiltration rate. According to this model, cutting the infiltration rate of a typical building (0.8 air changes per hour) in half reduces building energy use by 20%.

To reduce the air infiltration rate in Building 661, the design team specified the use of spray foam insulation on the building interior; they chose this method of insulation because it serves as a continuous air barrier, performs well under diverse weather and usage conditions, and because the building’s status as a historic structure prohibits any insulation from being affixed to the building’s exterior. Additionally, the high bay roofs were replaced with Structurally Insulated Panels with R-30 insulation values.

Lighting

Lighting ECMs focus on bringing in as much natural light as possible, a strategy known as daylighting, and supplementing that with artificial lighting as necessary. For this project, the design team established the goal of daylighting 90% of all active office spaces. The lighting system includes daylight dimming controls in perimeter spaces and occupancy sensors in most spaces. All rooms are divided into multiple zones, each with sensor-controlled lighting. These controls ensure that lighting is in use only when a room is occupied and allows occupants more control over lighting than is typical.

The lighting in the head house builds upon the existing windows, while the high bay space has undergone a dramatic transformation. Many of the openings in the building that were closed during previous remodels were retrofitted with windows. Furthermore, the design team worked with the natural lighting distribution within the building to place the programs strategically, as discussed above.

The design team brought light into the darkest part of the building – the second level mezzanine space – with a new clerestory window. The labs and offices all have sufficient access to natural lighting to eliminate the need for artificial lighting, although dimmable ballasts were installed for supplemental light as well. The dimmable ballasts adjust light output accordingly to the amount of daylight in the room. Occupants are also be able to adjust light levels manually, via roller shades for each window and light switches. Of the two existing skylights, one was replaced and one remained as is; both were fitted with mechanical shades.

Newly planted trees on the south and east sides of the building shade the windows and further prevent glare and heat gain from sunlight. Combined, these strategies are expected to reduce lighting power densities (energy use for lighting per building floor area) by 8.5%.

Heating, Cooling, and Air-Conditioning System

The HVAC systems employed in Building 661 were designed to demonstrate three distinct approaches to conditioning spaces applicable in the Philadelphia region. Each approach offers important benefits. Employing all three in this AER will clearly demonstrate their different strengths.

The first approach uses radiant heating and cooling along with a dedicated outdoor air system for distribution, humidity control, and maintaining indoor air quality in the conditioned space; the second involves energy recovery Variable Air Volume (VAV) rooftop units providing air through displacement ventilation; and the third uses two variable refrigerant volume heat-pump systems coupled with operable windows providing natural ventilation.

Mechanical Zone 1

Mechanical Zone 1 is comprised of the first and second level of the high bay space, and the lobby (1st floor) and mezzanine (2nd floor) areas of the head house, which are large open spaces. It employs both active and passive chilled beam systems, using convection to maximize energy efficiency while ensuring occupant comfort. Slot diffusers supplement air delivery for the chilled beams in the first floor of the head house, a large open-plan area, and an under floor air delivery system with swirl diffusers complements the chilled beams in the mezzanine. A dedicated outdoor air unit with desiccant dehumidification and enthalpy wheels ventilates these spaces and handle latent loads. The waste heat from the air-cooled chiller regenerates the desiccant wheel, increasing the overall system efficiency.

Mechanical Zone 2

The second zone, covering high-occupancy spaces, includes a few rooms on the first level and all of the enclosed spaces on second level  of the head house space – the lobby and mezzanine spaces of the head house are part of Zone 1. Zone 2 uses three packaged energy recovery variable air volume (VAV) rooftop units with direct expansion (DX) cooling and gas furnace heating. In addition, hot water radiator heating is used in spaces along the building perimeter. Displacement ventilation in the meeting spaces minimizes air requirements and consequently increase energy efficiency.

VAV systems have two primary advantages over constant-volume systems. The fan capacity control, especially with modern electronic variable-speed drives, reduces the energy consumed by fans, which can be a substantial part of a building’s total cooling energy requirements. Further, dehumidification is greater with VAV systems than it is with constant-volume system.

Mechanical Zone 3

The third zone, aimed at multiple small spaces with varying occupancy, encompasses small office spaces on the first level of the head house. This zone uses two variable refrigerant volume heat-pump systems coupled with operable windows. The variable refrigerant volume system only operates as needed, based on individual unit settings, even allowing for simultaneously heating and cooling different spaces within the same system. This flexibility allows for substantial energy savings under part-load conditions, such as during the night and on weekends, and increased occupant comfort during fall and spring when solar radiation creates cooling needs in some portions of a building while ambient temperatures are still cool enough to require heating in other portions.

Sensors and Controls

All sensors and controls in Building 661 adhere to CBEI’s building-wide requirement that all technologies be scalable, “state-of-the-shelf” interventions that can be implemented at a reasonable cost. The CBEI team selected technologies that strike a balance between occupant control and automation in order to maximize comfort as well as energy efficiency. For example, the fluorescent and LED lights will have ballasts that are capable of being individually controlled, allowing each unit to respond to occupancy, lighting levels, and load shed commands. In fact, most spaces in the building have vacancy sensors, so lighting in vacant areas powers off automatically.

In each of the three mechanical zones, heating, cooling, and ventilation are customized to the needs of the occupants and the facility programming. The building also provides a wealth of data for CBEI researchers via sub-meters for each zone that includes data on the light levels, CO2, CO, relative humidity, and indoor environmental quality.

Eco-Friendly Furniture

Herman Miller tries to make sure their furniture is environmentally friendly without sacrificing style. They make sure at least some part of the furniture is recyclable both pre and post-consumer. Most of the seating and lounge furniture in building 661 is GREENGUARD certified meaning it has passed 3^rd party testing proving that it complies with environmental and air quality requirements. The Sayl task chairs in the work rooms are also Cradle to Cradle certified Silver. This means that it follows the Cradle to Cradle guild lines and most parts of the chair can be recycled for new uses after the chair is done being used.

Green Transportation

The Navy Yard has 2 different shuttle types for employees and visitors. The Center City Express hits a few central stops in The Navy Yard and then goes straight to Jefferson Station from there many employees take a train or bus home. The other shuttle is the Loop which hits more stops in the navy yard and goes to the AT&T Subway Station on the Broad Street Line. According to a survey about 10% of Navy Yard employees commute to work using the free shuttle.

Others live close enough that they can ride their bikes to work, here at 661 we have a bike rack and showers so that employees can ride to the navy yard and still feel fresh before starting the work day.

Taking public transit as a commuter instead of a vehicle has many benefits not just for the environment but also for you and your health. For one it is usually less money than paying for gas and parking especially with the free shuttle The Navy Yard offers. People who use public transportation often get more exercise because they walk to and from stops and stations. Public transportation commuters walk up to almost 68% more than those who drive to work, this extra walking helps improve your health and wellbeing. During the longer time walking you would be breathing fresher air because public transit uses cleaner fuel than cars and bikes don’t emit any carbon expect for the CO₂ the rider breaths out.

Other Green Features

Dual Flush Toilets

A dual flush toilet is different from a standard toilet because it flushes differently for solid and liquid waste. Most toilets you see are the old standard toilets that use about 5 gallons of water per flush, nowadays most new toilets are either low flow or dual flush.

A standard low flow toilet uses no more than 1.6 gallons per flush while a dual flush toilet will use less than a gallon for liquid waste. The toilet uses a different system which allows it to use less water without clogging. Most old toilets use a siphoning action to pull the waste and water away where as a dual flush toilet uses a larger trap way at the bottom of the toilet and pushed the water and waste away. This method allows less water to be used and because of the larger trap, clogging happens much less often.

Because a low flow toilet still uses the same amount of water for every flush switching to a dual flush toilet can save you 68% more water than a low flow toilet and almost 80% from an old standard toilet.

Water Bottle Refill Station

Plastic water bottles get used and thrown out every day, only a small percent are even recycled. The water bottle refill station allows people to use reusable water bottles and fill them with filtered water. This means people are less likely to keep buying plastic water bottles and throwing them out. People can reuse the same bottle over and over again.

Lessons Learned

Changing the way of doing business in the building renovation field is no simple task. For example, because the retrofit of Building 661 is funded with public money, it is subject to the Pennsylvania Separations Act (also known as the multiple prime delivery system), a century-old law designed to promote fair competition and protect worker rights and safety. The legislation mandates that the recipient of public funds contract four separate firms for general, mechanical, electrical, and plumbing construction and that these contractors cannot have been involved in the design phase [3]. However, such involvement is essential to the success of integrated design for CBES, in which early participation from contractors in the design phase is critical to delivering an integrated product.

Complying with the Separations Act, CBEI contracted “design assist” consultants for the project’s design phase: commissioning; mechanical, electrical, and plumbing (MEP); and integrated electrical. These contractors worked with the project architect to consult on constructability, function, and pricing. Identifying this compliance need meant that this challenge did not impact the project schedule. Many potential energy retrofits will also need to work through this legislation, given widespread reliance on public subsidy and loan programs to help fund such projects.

Another initial challenge for CBEI’s hiring committee was identifying project management firms with extensive experience both with projects implemented using the ID+IPD contract structure and with the use of BIM from design through commissioning of a building. Ultimately, Hill International was selected as project manager. On the architecture and engineering side, many qualified firms entered bids, with the contract finally going to Kieran Timberlake of Philadelphia. Balfour Beatty, now a CBEI partner, won the construction contract. Design-assist consultants for mechanical, electrical, and plumbing were subject to the Separations Act and thus were unable to bid for the construction phase, even though as initial team members they were familiar with the integrated design process.

Despite these challenges, the retrofit design moved forward successfully and ground was broken on April 24th. The design team has gleaned valuable lessons about integrated design and project delivery from this AER design experience.

References

1. The Pennsylvania State University, Office of Physical Plant. (n.d.). Collaboration Addendum (Version 6.0)
2. The Pennsylvania State University, Office of Physical Plant. (2012). Building Information Modeling (BIM) Contract Addendum (Version 2.0)
3. Leavitt, Josh, McIlwee, John, and K&L Gates. “Navigating State Design Build Statutes in the Wake of a ‘Turned Federal Battleship.’”  Building Better Construction Contracts: Tailoring Incentives, Creating Collaboration and Developing Effective Risk Allocation. New York City: Practicing Law Institute Symposium, 2011.