What made this project an award winner? “This is an
adaptive reuse project and lab building that found a way to get really
outstanding metrics and performance and this was a low-bid public
project with no extra money for green strategies,” the jury remarked.
“They did some simple, clever things: the tapered ceiling, putting all
the mechanical systems in the middle of the building. This was one of
the best building sections we saw, and we loved the hand-drawn quality
of it.”
Located in an underserved neighborhood of north Philadelphia with high
crime rates, low income levels and few services, since its renovation
the Forensic Science Center has helped to breathe new life and a better
sense of security into the entire neighborhood. A noticeable upgrade to
the entire area has taken place since this building opened; many
Philadelphians now see this neighborhood as the next wave of urban
improvement.
Project Funding Challenges
The city of Philadelphia mandated that the project improve management,
reduce energy use, reduce impact on the region's air and watershed, slow
the depletion of natural resources, improve the work environment of
30,000 employees, develop local business opportunities, and save
taxpayer dollars.
The project faced a number of major challenges including limited
financial resources, a multiple prime construction contract, low-bid
awards and difficult communication among the many involved parties.
Project partners included the city of Philadelphia and its Capital
Program Office, Municipal Energy Office, Recycling Office, Water
Department, and Office of Risk Management; the U.S. Department of
Energy; Oak Ridge National Laboratory; and the Non-Profits Energy
Savings Investment Program.
The major economic problem with the project was the city’s delay in the
receipt of significant federal funding; this delayed the project for two
years and ultimately required the project to be rebid. However, the
additional time allowed the Growing Greener grant from the Pennsylvania
Department of Environmental Protection to come through with a grant that
provided $225,000 for greening the asphalt parking lot.
The $11.45 million project was completed in 2003. The project's
energy-efficiency strategies are projected to save 67 percent in utility
costs, paying for themselves in about 2.2 years.
Renovating to Save
Prior to the renovation, the site was entirely impervious, contributing
to the 42 annual discharge events carrying stormwater and sewage into
the Delaware River rather than onward for treatment at the Southeast
Water Pollution Control Plant. The Pennsylvania Department of
Environmental Protection's Growing Greener grant was a key funding
source for sitework, including a system of vegetated swales, “rain
gardens” and stone-reinforced water pathways.
 The site now includes large areas of
vegetated swales and buffer vegetation, improving water catchment by
roughly 33 percent, while still meeting the center’s demanding parking
and servicing requirements. Linear vegetated swales paralleling the
parking rows filter stormwater and allow it to evaporate or infiltrate
the ground before it enters storm drains.
Indigenous trees, shrubs, and grasses were selected for plantings. The
site plantings are drought-resistant, requiring less watering and
maintenance than conventional landscaping.
Further, waterless urinals reduce water consumption by approximately
176,000 gallons per year (one urinal is included in each of the four
bathrooms). Low-flow fixtures were used for all plumbing fixtures.
Utilizing Light
One of the strongest assets of the existing school structure was its
large windows. The windows were 9 feet, 6 inches high and 3 feet, 2
inches wide and organized in groups of three; they comprised more than
30 percent of the exterior walls.
The building is oriented along a north-south axis, with the long facades
facing east and west. As a result, the windows receive low-level sun at
sunrise and sunset. Both sides of the building typically receive direct
sun for half of the day and ideal, glare-free shade for the other half
of the day.
The design team used the design of the windows and shading devices and
the placement of circulation areas and work stations to mitigate glare
and heat gain. The high-performance glass reduces visible transmittance,
and the addition of white thin-line blinds allows for either a
self-diffusing light source at the window or a bounce of light toward
the sloping ceiling.
Optimizing Energy
Even though the laboratories in the center have energy-intensive
requirements, the building is projected to achieve the following
improvements over a comparable building designed in minimal compliance
with ASHRAE 90.1—1989:
--A 69 percent reduction in 25-year carbon dioxide emissions
--A 65 percent reduction in 25-year sulfur dioxide and nitrous oxide
emissions
--A 61 percent reduction in annual peak electrical demand
--A 72 percent reduction in total annual source energy use and
--A 67 percent reduction in the total annual energy bill
 The laboratory spaces require 100
percent outside air. On the other hand, office spaces do not. Four-pipe
fan coil units are used in the office areas to minimize the central
plant load, and the central plant provides fresh air and ventilation
only to offices. The pressurization system requires only minor
modifications in order to maintain separation of airflow to offices and
labs.
On a room-by-room basis, air systems go into setback mode when there is
no occupancy. The entire facility can remain operational even in the
event of a failure of one air handler or exhaust.
Rooftop exhaust-air heat recovery is used to precondition outside supply
air. Water-side economizers are used in office fan coil units. In
addition, heat exchangers utilize cooling-tower water in lieu of
chillers during shoulder seasons. Air-side economizers in central supply
outside supply for free cooling. A gas chiller heat exchanger recovers
heat to generate hot water for heating and domestic hot water. Domestic
hot water is provided through heat-recovery systems and high-efficiency
boilers.
Fume hoods were designed with limited sash openings in order to reduce
air volumes. The setback mode saves energy while maintaining pressure
differentials.
Also, provisions were made for the roof to accept a horizontal roof-tile
photovoltaic system of approximately 15 kilowatts, and the roof
equipment was configured to accommodate such a system.
In addition, the electric lighting system features T-8 lamps and
electronic ballasts and separate task and ambient lighting, even in
laboratory space. Lighting is controlled by occupancy sensors and
daylight-dimming sensors.
Material Considerations
This project was a restoration of a physically intact but derelict
building. The existing stairs were reused, and existing ventilation
shafts were used for vertical air and plumbing infrastructure. The
existing subgrade space is utilized for firearms testing.
 Polyvinyl chloride (PVC) was avoided
for all uses for which there was a reasonable alternative. For example,
all piping is stainless steel, glass, cast-iron, or copper; and rubber
flooring and base and stainless steel corner guards were used in place
of PVC materials. Also, no CFCs or HCFCs are used in any of the
equipment in the building, including the water fountains, refrigerators,
and mechanical systems.
Rapidly renewable products (including linoleum and agrifiber board) and
products including recycled content (such as cellulose insulation,
carpeting, tile, steel and gypsum board) were used whenever possible.
All glues and adhesives were selected for their low emissions of
volatile organic compounds (VOCs) in order to protect indoor air
quality.
Ductwork is made of galvanized sheet metal, due to the low volume and
high dilution. Stainless steel ductwork was used only at the acid fume
hood.
Fresh and exhaust airstreams are separated and located at remote points:
exhaust is located at the north end of the roof (and directed straight
up), and supply is located at the south wall (the vertical face of the
grill). All duct insulation is external rather than internal.
The AIA Committee on the
Environment (COTE) works to advance, disseminate, and advocate—to
the profession, the building industry, the academy, and the
public—design practices that integrate built and natural systems and
enhance both the design quality and environmental performance of the
built environment.
Published 07/07/2006
 ©
2005 Greenmedia Publishing Ltd. |
