Chilled beams ... Self-cleaning cement ... Preferred permitting ... Mini-wind turbines ... Air-filter skyscrapers ... Form-based codes ... Online processing for LEED projects ...
Think you've seen it all when it comes to sustainability? BD&C dug deep to uncover groundbreaking products and ideas that take green building to a whole new level.
U.S. designers are constantly scouring Europe, Asia, and Australia in search of new energy saving technologies—from double-wall façades in the 1980s to under-floor air distribution in the 1990s to digital lighting control schemes more recently.
The "chilled beam" system is one the latest innovations to make its way to the U.S. market. Popular in Europe and Australia for more than a decade, the system involves placing cooling coils at the ceiling level to cool the rising warm air. The cooled air then gently descends to occupant level, providing a pleasant cooling effect with minimal air movement.
"Designers in Europe start with chilled beams as the baseline system, much like we start with VAV systems as the baseline here in the U.S.," says Mike Walters, LEED, sustainable systems and energy analyst with Affiliated Engineers Inc., Madison, Wis. Walters says the technology has a lot of promise for offices, labs, healthcare environments, and even data centers.
Engineers like Walters are hot on the technology because of potential energy reductions of anywhere from 20–50%, depending on the type of system, climate, and building. Laboratories that are heavily equipped are the most ideal application, says Walters, because they often require many more air changes per hour than is required by code to offset the heat gain from the lab equipment.
"By cooling and recirculating the air, we can reduce the amount of air changes in a lab from 12 to 18 per hour to six to eight per hour," says Walters. "That results in up to 50% energy efficiency."
With less air changes needed, Building Teams can downsize ductwork, air-handling units, exhaust fans, chillers, and boilers to help offset the cost of the chilled beam units and infrastructure, which can cost anywhere from $24–36 per sf for a typical lab facility, according to Walters. In fact, Walters says the savings as a result of the smaller HVAC components often exceeds the first costs of the chilled beam system (see chart page 26).
Other benefits include:
High indoor air quality—air is reused locally, so there's no contaminant mixing
Space savings—no high-volume ductwork
Increased comfort—no drafts, even cooling, and more pleasant cooling temperatures
Low maintenance/high life expectancy—no moving parts
Low risk of mold growth—computerized building automation control system carefully controls humidity levels.
There are two basic types of chilled beams: active and passive. Active systems tie into the room's primary air supply ducts, mixing supply air with existing air that is cooled by the coils, which is then distributed through diffusers in the ceiling.
Passive technology relies entirely on the natural convection process, whereby warm air rises to the coils, is cooled, and then lowers back down freely without the assistance of fans. In both cases, water cooled to 59–65 degrees F is pumped from a chilled water system to each of the coil units.
Greg Mella, LEED, principal with Detroit-based SmithGroup, expects to achieve 50% energy savings with the help of a passive chilled beam system at Clemson University's new $8.5 million, 25,000-sf Sandhill Research and Education Center. The system will incorporate geothermal technology, whereby water from a nearby campus lake will cool the coils.
"The lake water is 66 degrees Fahrenheit pretty much year-round, so we won't need to chill the water too often," says Mella. "The system will provide the bulk of the cooling for the building."
Mella says the most common misconception about chilled beam technology is that the indoor humidity will condensate on the beams, especially in warm, humid climates like South Carolina. "Humidity control is key," he says. "To make it work, you have to control the humidity internally so it's always under the dew point."
Walters says building controls have advanced to the point where condensation is a non-issue. "People think of the radiant panel technology of 20 years ago," says Walters. "I have toured dozens of installations and there's no condensation with these systems."
One drawback to the technology is the size of the units, says Robert Bucci, PE, LEED, principal with Affiliated Engineers. Bucci says the system components are bulky (about the size of a standard fluorescent light fixture) and can impede aesthetics of the interior spaces.
"Even when the systems are installed flush to the ceiling, you'll still have perforated metal ceiling tiles that the architect may not desire," says Bucci. He says certain manufacturers will work with the design team to create custom designs that better adapt to the architecture of the facility and that incorporate key infrastructure components, such as lights, sprinkler heads, speakers, sensors, air nozzles, smoke detectors, and voice/data cables.
Finding reasonably priced contractors to install the systems is another major concern. Most mechanical contractors are not familiar with the technology, and, therefore, will charge a premium or won't take on the project at all. Bucci says it will most likely require a specialty contractor to complete the work.
For Mella, these concerns are minor drawbacks compared to the potential energy savings chilled beams can offer.
"It's a great concept, and I think it has tremendous potential in the U.S.," says Mella.
More than two years after the grand opening of the Richard Meier-designed Jubilee Church in Rome, the structure's triple-shell concrete façade appears as gleamingly white as the day the church opened its doors.
How does the Jubilee maintain its pearly white sheen? The secret is in the cement.
The New York-based architect specified an experimental white-cement mix from Italian cement supplier Italcementi that is self-cleaning. Italcementi is among several cement companies marketing so-called "photo-active" cement, which uses daylight to breakdown harmful pollutants, such as nitrogen dioxide, carbon monoxide, VOCs, and formaldehyde, that stem from vehicle exhaust, industrial emissions, and other sources.
The special cement is formulated with selective amounts of titanium dioxide that, when exposed to ultraviolet rays, triggers a catalytic reaction that oxidizes organic and inorganic substances deposited on the surface. The by-products of this photocatalytic reaction—carbon dioxide and harmless inorganic salts, such as calcium nitrate, sulfate, and carbonate—are then washed away by rainwater, thereby cleaning the concrete surface. By eliminating the organic molecules, the reaction also indirectly prevents bacteria, dust, and dirt from sticking to the surface.
The technology has been applied to other building materials, including glass, but cement has significant promise from an environmental standpoint because of the vast amount of concrete structures and surfaces that cover the planet.
An added benefit to self-cleaning cement is its potential to help clean the surrounding air. A test in Milan in 2003 by Italcementi, for example, showed that nitrogen oxide levels were reduced by up to 60% on and around 75,000 sf of road surface that was paved with photocatalytic cement. But other than a few isolated experiments, very little data exists on the "depollutioning" performance of self-cleaning cement.
Also, Building Teams can expect to pay a premium for self-cleaning cement, according to Italcementi. The company suggests, however, that owners will make up the up-front expenditures with reduced maintenance costs.
Anyone who's built anything in the Windy City—or in another city, for that matter—knows how painfully arduous the permitting process can be. Even the most carefully planned submittals can take months to review by permit inspectors and code officials. Each day means a dollar lost in the minds of developers.
As part of Mayor Daley's ongoing green crusade, the city has transformed the permitting process into an incentive for developers to go green. Projects that are designed to EnergyStar or LEED standards or better (and also meet certain city requirements) will get permitted in just six weeks. That's two months faster than the average permit process, says Erik Olsen, green projects administrator, Department of Construction and Permits, who personally processes all green permitting.
"The department averages 90–100 calendar days for permits, but it's not unusual for permits to take four months," says Olsen.
Olsen says he is able to expedite the process for projects participating in the city's Green Permit Program by only taking on 10–20 projects at a time, compared to the 50–60 permit requests handled at any given time by other employees in the department.
"I spend a lot more time with the projects and am able to be very responsive to help them get their permits faster," says Olsen. "For instance, when projects go to other city departments for review, they'll jump to the front of the line."
To qualify for the Green Permit Program, the building must meet specific requirements, based on the size, type, and location of the structure (see table opposite page). Market-rate multifamily developments, for instance, must be designed to achieve a LEED Certified rating. In comparison, multifamily developments that include at least 20% affordable housing only have to meet EnergyStar Design standards, as well as incorporate one additional feature from a green "wish list" created by the department. The list includes everything from green roofs to renewable energy to developing in blighted areas of the city.
The city provides additional financial incentive for developers that go beyond the minimum green requirements by waiving all independent code consultant fees associated with the permit (the city requires developers of medium- and large-sized projects to pay for an independent code review). Olsen says these fees can range from $5,000 to $50,000, depending on the size, type, and complexity of the project. "It's incentive to go a little bit greener," he says.
Speedy permitting has become popular among jurisdictions nationwide for residential construction, but Chicago is one of the first to include nonresidential construction projects.
Olsen says of the 10 projects that have gone through the program thus far, at least one developer is considering going green on another project based, in part, on the benefits of the program.
"They were so pleased with how well everything went, the owner's rep. said the existence of the Green Permit Program will weigh heavily into their decision to go green again," says Olsen. "Which is the whole purpose of the program."
Until recently, the only viable option for harvesting wind for power was to erect one of those colossal propellers commonly found on rural wind farms.
Several building owners have successfully integrated industrial-sized wind propellers to help power their facilities. In early 2005, St. Louis-based general contractor Alberici installed a 125-foot-tall, 65kW wind turbine at its new headquarters to provide about 20% of the 100,000-sf building's energy. Similarly, a 120-foot-tall, 250kW wind turbine installed in late 2002 at Harbec Plastics' factory in Ontario, N.Y., provides about a quarter of the electricity needed to operate the building and the equipment it houses (BD&C March 2005, p. 7).
But these cases are few and far between. Besides the shockingly high upfront costs and ongoing maintenance expenses associated with owning one of these monstrous propeller systems, the shear size of the units limits the applications for on-site building power generation, especially in urban environments. Even small propeller systems cannot be placed on rooftops (the vibration and turbulence inherent with propellers can disturb building operations and occupants), and they require open expanses and extreme heights for optimum performance. Norman, Okla.-based Bergey WindPower, for instance, recommends an acre of open space and at least a 60-foot-tall tower for its 10kW propeller system—hardly ideal for a tight, urban site.
A Building Team in Chicago is experimenting with a new type of wind turbine specifically designed for dense urban and suburban environments. The cylindrically shaped units, each weighing less than 250 pounds and just 5×10 feet in size, will be mounted on the roof of the Ford Calumet Environmental Center, planned along Lake Calumet on Chicago's Southeast side.
Developed by University of Illinois-Chicago professor William Becker and marketed by his company, Aerotecture Ltd., Park Forest, Ill., the 1.5kW turbines produce energy at wind speeds as low as 6 mph and continue generating in winds exceeding 70 mph. The innovative helical-blade design minimizes noise and vibration and harnesses the "chaotic, turbulent winds" common in dense urban environments, says Becker.
"Wind power applications for buildings require that because winds tend to whip around buildings," says Becker. "These machines really 'enjoy' variable, gusting winds."
Because the units are small and virtually silent, they can be placed almost anywhere atop or within a building, at heights as low as 20 feet. The steel frame permits the units to be situated in any direction—horizontally, upright, and diagonally—and they can even be stacked.
At the Ford Calumet Environmental Center, which is set to break ground in November 2006, 12 units will be placed vertically atop cone-shaped ventilation stacks on the rooftop, according to Jeanne Gang, AIA, principal and founder of Studio/Gang Architects, Chicago, design architect on the project.
Gang says the unit's low profile and inherent safety features make the technology ideal for the building, which is being designed to achieve a LEED Platinum rating.
"We needed something that was bird-safe, because the building is located in a migratory bird path, and the site is habitat for all types of wildlife," says Gang. Each unit will be wrapped with a metal mesh screen to prevent birds and other wildlife from coming into contact with the blades. Even if the screen is breached, the blades rotate at a much slower rate than traditional propeller systems, minimizing harm to animals.
Sachin Anand, PE, LEED, lead engineer on the project with Chicago-based consulting engineer CCJM Engineers, says the wind turbines will be tied directly to ventilation fans inside each stack. In the warm months, the heated air will collect in the 12 "chimneys" and will be extracted out of the building by the ventilation fans. In the winter, the ventilation stacks will be closed and the fans reversed to direct the warm air back down into the interior spaces.
"Instead of using an intermediate mechanism to convert wind into energy to power the ventilation fans, the turbines will be coupled directly to the fan," says Anand. He says this approach will greatly reduce electrical demands for air circulation for the building.
The Building Team is considering using the wind turbines to generate power for the building at times when the ventilation fans are not needed, but Anand says this "integrated" approach may prove too costly. "My gut feeling is that we probably won't use the systems for power generation," he says.
Regardless, Anand sees much potential in the technology for building-integrated applications. "These turbines are not as expensive as wind-farm propeller systems, and they're much more quiet," says Anand.
As for the cost, Becker says individual units go for $5,000–$10,000, depending on the features, but he expects the costs to dip much lower as production ramps up.
It's safe to say that when the 4,300 employees of Bank of America's New York operations move into their new home at One Bryant Park in 2008, they will be breathing some of the cleanest air in any office environment.
Developed jointly by BOA and The Durst Organization, the 55-story Bank of America Tower at One Bryant Park will be fitted with high-efficiency air-filtration systems commonly found in clean-room environments that will extract 95% of particulate matter, as well as ozone and volatile organic compounds, from the outside air. In comparison, typical building mechanical systems filter about 35–50% of particulates and extract very few VOCs or ozone matter.
The robust air-delivery system will not only maintain a "near clean-room" environment inside the 2.2 million-sf structure, but it will also help clean the atmosphere immediately around the skyscraper, according to Robert Fox, Jr., partner with local design architect Cook + Fox Architects.
"The air that is eventually exhausted from the building will be much cleaner than the air that came in," says Fox. As a result, the building will effectively function as a "giant air filter" for the city. It's a novel concept that, if applied to a great number of buildings within a city or region, could make a noticeable difference in the fight against pollution.
Outdoor air will enter the building at two locations—at the upper level of the podium (about 150 feet above grade) and at roof level (about 850 feet)—and will be filtered through MERV 15-rated air filters to remove particulate matter as small as 2.5 microns in diameter. (MERV, or minimum efficiency reporting value, measures the efficiency of air filters on a scale of 1 to 16, with 16 being the most efficient.) A second filter, called an "activated carbon" filter, will remove VOCs, ozone, and other pollutants, according to Scott Frank, partner with Jaros Baum & Bolles, New York, mechanical engineer on the project.
"This is not done in a typical class A office building," says Frank. MERV 10 filters are the industry standard for buildings like Bank of America Tower, and air intakes are commonly placed near grade level. "With the air intakes located high up in the building, they'll be removed from major sources of air pollution, like vehicle exhaust."
"My hope is that building systems like this will become the norm," says Fox. "And that it will become common for potential tenants and brokers to ask building owners about the type of filters they have on their air-delivery systems."
Can the design of buildings actually improve the atmosphere?
"Certainly," says Fox. "But there's other factors at work here, namely vehicles and power plants." Once those are under control, then buildings like Bank of America Tower can truly make an impact.
From Arlington, Va., to Ventura, Calif., cities across the nation are replacing conventional zoning regulations with a streamlined, "form-based" approach that, experts say, will help set the stage for community-wide sustainable development.
Cities are realizing that the tried and true method of zoning—where jurisdictions place strict controls on land use and density, but offer little guidance on the physical form of buildings and overall districts—often leads to poorly designed, sprawling communities.
Form-based codes, on the other hand, employ a more holistic and prescriptive approach to town/regional planning based on a city's long-term conceptual master plan. Emphasis is placed on the physical form of the built environment, rather than the land use, with the goal of producing a specific type of "place."
"Form-based codes are very direct in asking for what the community wants," says Geoffrey Ferrell, partner with Ferrell Madden Associates, Washington, D.C. Through the use of simple, straight-forward graphical diagrams and photos, the codes dictate everything from the size and scale of the streets to how buildings are situated on a site to the placement of doors and windows. A typical form-based ordinance may be just several pages, compared to hundreds or even thousands of pages of zoning regulation language with conventional codes.
"With a form-based approach, a picture is quite literally worth a thousand words, or at least a few hundred words," says Steve Coyle, principal with LCA + Sargent Town Planning, Oakland, Calif., a division of HDR, Omaha, Neb. Coyle says by simplify the code language with very specific visuals and language, jurisdictions can take much of the "guess work" out of the design review process, making life easier for both the Building Team and the planning review commission.
How do form-based codes promote sustainable design?
At the very basic level, form-based codes promote the development of more efficient, dense communities, says Ferrell. "It's common-sense urbanism, where towns, cities, and villages are consuming less land," he says. With a smaller ecological footprint, less energy is consumed on transportation and power and water infrastructure. In addition, districts are much more pedestrian-friendly.
Form-based codes also allow cities to handle important environmental issues like parking and storm-water runoff from a holistic approach.
"With conventional codes, every developer must provide their own parking and water detention/retention on site," says Mary E. Madden, partner with Ferrell Madden Associates. "That's why every property has a huge parking lot and ponds on site."
With form-based codes, jurisdictions can establish shared parking venues or an integrated storm-water runoff solution. This approach not only minimizes land use and upfront costs for the developer, but it also results in a more efficient system.
Form-based codes can also encourage or mandate green design, such as the inclusion of vegetated roofs, and can work hand-in-hand with green building programs, like LEED. In fact, the U.S. Green Building Council is working with the urban planning industry to create LEED for Neighborhood Development, which would incorporate the principals of form-based codes.
"There are a lot of buildings that meet the technical green standards, but, by their placement and location, are actually sprawl development," says Madden. "LEED-ND will look at green design more broadly."
A common criticism of the U.S. Green Building Council's LEED rating program is the time and costs involved with certifying buildings. The application process alone for a typical project involves assembling thousand of pages of documentation. In addition, Building Teams often spend thousands of dollars on third-party consultants to help evaluate and interpret the LEED credits, manage the project, and generate a final submittal.
To help ease the LEED process, Milwaukee-based Johnson Controls has launched a suite of online software tools, called LEEDSpeed, that streamline everything from assessing LEED credits to generating the final application documentation. The company developed the software four years ago to manage its in-house LEED projects, including the LEED-Silver Brengel Technology Center in Milwaukee. "We found that software dramatically reduced the time and cost to go through the process," says Paul von Paumgartten, director of energy and environmental affairs with Johnson Controls.
LEEDSpeed is composed of four distinct tools:
The Building Assessment tool presents users with 100–150 questions to help assess which LEED credits have been met and which are reasonably attainable. "It identifies the 'low-hanging fruit,' as well as features that would require a bit more investment," says von Paumgartten.
The Financial Evaluator details the up-front and ongoing costs and operational savings as a result of each LEED credit.
The Project Management tool allows users to assign specific tasks to different members of the Building Team. "It breaks down what is required for the implementation and documentation for each credit," says von Paumgartten.
The Certification Application Generator automatically organizes and formats the project data into the submission forms required by USGBC.
So, how much can Building Teams expect to save using LEEDSpeed?
It's too early to tell, but von Paumgartten says no project that was managed using the software has exceeded $50,000 in LEED processing costs. "We often hear of certification costs of $50,000 to $150,000," says von Paumgartten.
For more, visit www.leedspeed.com .
Financial analysis of a chilled beam installation vs. standard VAV in a laboratory (14,100 sf lab)
|Active chilled beam||Active chilled beam w/built-in light||Passive beam|
Source: Affiliated Engineers
Analysis of chilled beam mockups and installations in lab facilities shows that the technology is financially competitive with standard variable air volume systems. The potential savings in downsized mechanical components as a result of installing a chilled beam system often outweighs the first cost of the units and infrastructure.
|Cost of beam units||$350,300||$455,900||$397,260|
|Reduction in costs for downsized HVAC components (fans, ductwork, chiller, etc.)||-$525,900||-$497,000||-$527,000|
|Net first cost||-$175,600||-$41,100||-$129,740|
|Percent cost of standard VAV||84%||96%||88%|
Requirements for Chicago Green Permit Program
|Benefit tier I||Benefit tier II||Benefit tier III|
|Expedited permit (goal: &30 business days)||Consultant review fee 100% waived1; Expedited permit (goal: &30 business days)||Consultant review fee 100% waived1; Expedited permit (goal: &15 business days)3|
|1 Fee waivers in 2005 are for first 15 residential projects (&4 units) and the first 15 projects of any other type.
2 EnergyStar will be replaced with the Chicago Residential Green Standard, when available.
3 Appropriate coordination with city infrastructure prior to permit submission is required to meet 15-day goal.
4 Green Permit menu items include: Green roofs, on-site renewable energy, affordable housing, exceed accessibility code requirements, transit-oriented development, building in under-developed areas, on-site power generation, natural ventilation, and exceptional water management.
Source: City of Chicago, Department of Construction and Permits
|Market-rate, single building (&4 units)||Not applicable||EnergyStar2 + one menu item4||EnergyStar2 + three menu items4|
|Market-Rate, multiple buildings (&4 units/building)||Not applicable||EnergyStar2 + two menu items4||EnergyStar2 + three menu items4|
|20%-affordable, multiple buildings (&4 units/building)||Not applicable||EnergyStar2 + one menu item4||EnergyStar2 + three menu items4|
|Market-rate, multifamily||LEED Certified||LEED Certified + one menu item4||LEED Gold + two menu items4|
|20%-affordable, multifamily||EnergyStar Design2 + one menu item4||EnergyStar Design2 + two menu items4||LEED Certified + two menu items4|
|Hospitals||LEED Certified + one menu item4||LEED Silver + one menu item4||LEED Platinum or LEED Gold + two menu items4|
|Community centers, schools||Not applicable||LEED Certified + one menu item4||LEED Gold + one menu item4|
|Industrial||Not applicable||LEED Certified + EnergyStar Roof||LEED Gold or LEED Silver + two menu items4|
|Retail (&10,000 sf)||LEED Certified + one menu item4||LEED Silver + one menu item4||LEED Platinum or LEED Gold + two menu items4|
|Retail (>10,000 sf)||LEED Certified + EnergyStar roof + one menu item4||LEED Silver + 25% green roof + one menu item4||LEED Gold + 50% green roof + one menu item4|
|Office (under 80 feet tall)||LEED Certified + one menu item4||LEED Silver + one menu item4||LEED Platinum or LEED Gold + two menu items4|
|Office (over 80 feet tall)||LEED Certified + 50% green roof + one menu item4||LEED Silver + 75% green roof + one menu item4||LEED Platinum or LEED Gold + 75% green roof + two menu items4|
Comparison of wind-power technologies
Source: Aerotecture Ltd.
|Ideal in rural settings with steady, unidirectional winds||Ideal in urban settings with variable direction and gusting winds|
|Must be mounted on towers that extend above trees and buildings||Can have low-visible profiles on rooftops or within structures|
|Require special zoning, code exemptions, and insurance||No special code, zoning, or insurance issues|
|Operate best in rural settings where noise, visibility, and vibration are less problematic||Operate well in suburbs/cities where low noise, low visibility, and low vibration are mandatory|
|Require major investments for large structural towers and open space for the towers||Require minimum structural tower investments|
|At high speeds, can become "invisible" to birds||Low speed, caged system that is easily spotted by wildlife|
|Cannot be mounted on rooftops without special noise and vibration provisions||Can be mounted on roofs without special provisions|
|Start generating power at 9 mph; max out at 45 mph||Start generating power at 6 mph; max out at 70+ mph|
|Limited integration with building architecture||Fits within a variety of architectural schemes and within cages and towers|