Experimentation is the heart of science. The knowledge and understanding gained from testing and analysis are crucial in forming theories for real-life applications. And many scientists are better able to form insights using hands-on methods, seeing and touching their ideas and creations. Such is the case in architecture as well. Technological blueprints, sketches, and systems all have their place, but being able to apply knowledge to a working building allows for testing and analysis in real time and in a real setting.
This vision became possible due to a special partnership program that allows engineers and architects to create a space to explore product testing for sustainable energy and building research. These structures are essentially living laboratories, intended to change over time and to research, develop, and test innovations in solar power, climate control, environmental barriers, and thermal insulation.
This project was created by Fraunhofer USA, a not-for-profit research organization that develops and validates scientific applications. Fraunhofer’s research centers include the Center for Sustainable Energy Systems CSE. Looking to relocate from its original location in Cambridge, MA, the company chose to renovate an old abandoned building in South Boston by upgrading it to modern sustainability standards. Leaders chose a six-story brick masonry warehouse located in Fort Point Channel in the Boston Innovation District that was designed and built in 1913 and is considered historically representative of the area.
The renovation project’s goal was to create a laboratory setting where various sustainable energy technologies, including solar panels, radiant cooling, phase change materials, and vacuum insulation panels could be implemented and carefully monitored over time for their efficacy and value. Flexibility was a key consideration, as the workflow is constantly in motion, novel equipment and materials move in and out, wall sections are replaced, and mechanical systems adapt as well. Innovations also included trying multiple HVAC systems for the best solution and researching various insulation options to enhance thermal performance while minimizing negative impacts, such as condensation, on the building.
One challenge during the renovation was to create space for two lab areas with specific dimensions required to accommodate Fraunhofer’s test labs. A floor needed to be removed to open up the space for a 20-foot high-bay lab to house tall solar manufacturing equipment, including bulky laminators. The lower floor was chosen for the high-bay lab to house equipment that was too heavy to lift to an upper level. The high bay also was needed to accommodate large climate chambers that can run 24/7 to repeatedly expose solar panels and thermal insulations to extreme conditions and simulate accelerated aging. This allows the evaluation of the impact on panel performance and the insulation’s long-term durability. Solar panel research focuses on improving performance, making the product more accessible and easy to install, and lowering costs for residents and homeowners.
The high-bay lab includes a loading dock leading directly to the outside. The lab extends up behind the reception area, allowing visitors to look down through a window to view activities without disturbing research efforts. The goal for the first-floor reception and lobby space was to highlight industry research—by Fraunhofer and others. The space includes a sustainable building technology showcase developed via a partnership program with manufacturers, giving them an opportunity to demonstrate new and emerging products. In total, nearly 50 suppliers donated products, some brand-new and not available on the market, to test and use in real-time operations and to promote to visitors.
The upper-floor layouts include enclosed lab spaces on the sides of the building; an open office with glass walls in the middle of the third floor allows more natural lighting as far into the building as possible. The sixth floor contains advance material testing laboratories for thermal and hygrothermal testing of opaque building envelope materials and fenestration components, performance analysis of heat storage materials, and development and testing of nano insulations.
In addition, the building offers the flexibility to fieldtest materials other than the masonry envelopes. For example, novel curtain wall assemblies, insulated metal panels using high-performance core insulation, dynamic fenestration technologies, and the like can be installed and tested in full-scale, instrumented, highly controlled conditions in the South Boston climate.
HVAC decisions for lobby
The first-floor reception area employs the concept of low-lift cooling, which uses a significantly higher chilled water temperature than that of traditional systems, reducing the temperature “lift” of the chiller and improving its efficiency. Humidity is a challenge in low-lift cooling systems, where radiant heating and cooling can cause condensation to form on the floor or ceiling surfaces, creating slippery conditions. A six-pipe HVAC distribution system is used throughout the building to offer flexibility. The six-pipe system includes two pipes for heating, two for low-temperature cooling loops, and two pipes for higher-temperature cooling loops. The standard cooling loop runs at 40 to 45 degrees in most buildings, and the higher-temperature cooling loops vary from 50 to 60 degrees, based on the humidity. A dual cooling loop allows facilities to use radiant cooling when they choose to or to turn it off when necessary.
The first HVAC system used for the lobby is a floor-based radiant heating and cooling system embedded in a 2" lightweight concrete topping slab that uses the fluctuating temperature cooling loop. A displacement air system is the second type used in the reception area. It delivers quiet, comfortable low-velocity air at the floor level to provide conditioned air specifically to the areas where occupants are, rather than conditioning the entire space (as a traditional air-based system does). To incorporate this design, large diffusers feature perforated metal panels below chair-rail height.
Chilled sails, the third system installed in the reception area, feature metal panels located in the ceiling, with cool water running over the back. Generally used during low-load conditions, they provide radiant cooling and perform via natural convection as cool air descends from the panels to the space below. These large panels were incorporated into the architecture by sizing them to fit within the exposed wood beams, allowing the cooling system to be an integral part of the aesthetic feel of the room.
Load-bearing masonry walls made of brick are difficult to insulate. Installing insulation on the interior wall can make bricks colder and wetter during the winter—this condition is driven by both climate and material. In addition to rain and snow passing from the outside surface of the brick to the inner wythes, moisture will pass through the brick from the inside and condense when it reaches a certain point. The point within the wall at which condensation occurs is important. The outer layer of brick can withstand freeze/thaw cycles, but when interior insulation prevents heat inside the building from warming the wall, condensation can occur in the softer, inner layers of bricks, allowing them to break down and eventually weaken the wall system.
Condensation was top of mind for project leaders as they applied advanced testing and numerical methods and strategies to assess the vulnerability of the brick to determine how best to insulate. A state-of-the-art WUFI hygrothermal analysis uses climatic data to perform dynamic simulations of flows of heat and mass (air, water, and vapor) through building assemblies. The software uses standard material properties, moisture storage, and liquid transport functions to model the performance of the brick over time and to assess its durability.
Project leaders tested all six types of brick from the building to characterize the actual material properties and used them later in hygrothermal simulations to determine how various insulation methods would perform over a long period. The structural analysis showed that the end walls of hard-fired brick were in relatively good condition, but party or long side walls were made of weak, soft brick. In theory, the party wall should have had another building against it, or it should have been an interior wall. This occurrence is common in Boston-area construction, where most older buildings feature hard face brick on the front and back walls and a softer, less-valuable, and weaker brick on the sides. If these soft brick walls are not directly attached to other structures, sealed, or covered by other, more durable materials, they may deteriorate quickly. That is why it was crucial to carefully characterize the existing wall materials and later perform a series of thermal and hygrothermal simulations with different insulation and sealing strategies for different parts of the building.
This simulation work allowed a use of several unique retrofit configurations, such as vacuum insulation panels (VIPs) on the interior wall surface of the southern elevation. VIPs are high-performing insulation panels that are R-40 per inch. The project experimented with methods of installing the VIPs to understand the strengths and limitations of the product in a real-world application.
Likewise, the findings from numerical analysis led the project team to choose blown cellulose insulation with a vapor barrier on the front and back façades, allowing some air movement on the back face of the brick. On the party wall side, architects used an experimental wall unit to test mineral fiber insulation and an internal gutter system to address condensation. The small copper gutter and drain system is flashed on the inside face of the brick at the floor line to protect the interior wood structure from potential damage.
Leave it to the professionals
Safety concerns surfaced regarding the removable wall sections on the top floor that were built to allow for testing different wall types. The project team initially thought they could replace the test wall sections themselves using moveable structural frames. However, the process was eventually considered too risky for personnel to perform in-house. It could be difficult to safely pull a test wall out and drop it 50 to 60 feet to the sidewalk below. After a thorough review, the team found the cost of the moveable structural frame was substantially more than the cost of bringing in a lift each time the panels needed to be changed. Therefore, they hired a professional rigging crew with the proper equipment and methods for walling off and putting up guardrails on the inside before removing wall sections.
The unique nature of this project-within-a-project made good communication and flexibility essential for the success of both the working laboratory and the exterior building renovation. The project team had to keep long-term goals and benefits in line while also focusing on current issues, such as the installation of solar panels, HVAC equipment, and insulation. Continued evolution is planned as well, with built-in evolving conditions that will open pathways to future knowledge and rewarding applications, all while working within the experiment.
Randy Kreie, AIA, is principal/president with DiMella Shaffer and can be reached at RKreie@dimellashaffer.com.
David A. Godfroy, AIA, is associate principal, LEED AP, with DiMella Shaffer and can be reached at DGodfroy@dimellashaffer.com.
|All images courtesy of DiMella Shaffer, Photographer: Trent Bell|