Commercial Buildings In The 21st Century: Prototypes And Personnel
In short, while technology often steals the spotlight when discussing the future, the change likely to mark the next decades is a philosophical one - spending less time focusing on how buildings work and more time on how people work inside those buildings. The technology will follow suit.
A Million Reasons To ResearchIndeed, there will be plenty of new technology in the years to come, but you might have to wait a little longer than you'd expect to use it. Why? Because innovation is a double-edged sword: everyone wants to have the latest equipment, but only after it's been tested by somebody else. Given the potential expense and headaches surrounding retrofit and replacement, it's no wonder people are reluctant to let their buildings serve as "guinea pigs" for innovation. Likewise, companies aren't eager to take blind leaps of faith and capital on technologies that might fizzle out, either.
The Air-Conditioning and Refrigeration Institute (ARI) and the U.S. Department of Energy (DOE) have acknowledged this hesitance and tackled it head on. ARI has formed the Air-Conditioning & Refrigeration Technology Institute to take on this challenge, under the heading, "HVAC&R Research for the 21st Century" (21-CR). With an opening DOE contribution topping $1 million, ARTI is launching its first 11 projects designed to eventually achieve marked energy-efficiency gains while addressing indoor environmental quality needs.
"We're looking at the high-risk, long-term research," says ARTI's vice president, Glenn Hourahan. He says the group is "examining what we can do over the next five years so that manufacturers a decade from now can make better products."
ARTI has identified five areas of strategic focus:
- Alternative equipment (hvacr cycles other than today's fluorocarbon vapor compression cycles);
- High-efficiency equipment (improved heat exchangers, motor systems, compressors, controls and sensors, air handlers, testing, diagnostics, pumps, etc.);
- System integration (improved distribution, zone control, waste heat recovery, integration of building envelope and lighting with mechanical systems, etc.);
- IAQ (enhanced control of temperature, moisture, contaminants, and ventilation); and
- Environmentally friendly working fluids (refrigerants, lubricants, secondary heat transfer fluids, eutectics, etc.).
Toward those ends, the first 11 projects received 21-CR approval in late April. Hourahan is unwilling to pick favorites, as far as which of these projects could have the largest long-term payoff.
"Any one of them, if it worked out to be extraordinarily worthwhile, could have a profound impact," he says. He sees benefits coming both from improved equipment and from integrating improved refrigeration processes into various building applications.
The ARTI AgendaLet's take a quick tour around a few topics in this initial batch of projects that are especially pertinent to commercial buildings of the future.
"The Efficiency Limits of Water Vapor Compressors Suitable for Air Conditioning Applications." Advancements in testing methods may make as big a difference as anything in this realm.
"Just now, we're in a position, with computers getting smaller, more efficient, and less expensive, that we can do some of these applications that took great computers before," Hourahan explains. "Carbon dioxide and water technologies haven't gotten too much attention in the past," but this research might help uncover whatever possibilities exist, he says.
The project aims to provide an optimum design concept and efficiency limits for a family of water vapor
"Microchannel Heat Exchangers with Carbon Dioxide." ARTI hopes newer testing methods will help here, too, developing more accurate and realistic computer models to assess the possible benefit of the transcritical carbon dioxide cycle. This will hopefully yield heat exchanger capacity and pressure drop data correlations as a function of specified operating conditions and flow rates of refrigerant and air. Hourahan suspects translating these findings to products might be "a little easier to do. It can fit into more existing systems. Plus, it's already being done in some automotive systems, and is moving into the residential sector."
"High Performance Heat Exchangers for Air Conditioning & Refrigeration Applications." On the other hand, Hourahan sees any progress on this front coming in small steps. "In this case, the challenge is identifying the attributes of the compressor that need attention in order to improve the design." In particular, the focus will be on "the air-side characteristics of several styles of serpentine fins used in conjunction with flat tubes in a fluid-to-air heat exchanger."
When asked for a timeline on seeing improved flat-tube exchangers as a result, Hourahan does see a ray of light. Maybe. "That can be done somewhat quickly if positive results come out. Another year or two (for manufacturers) to test on top of that, so maybe three to five years (to market). But if you hurry, you get into problems," he warns.
"Flexible and Adaptive Hvac Distribution Systems." This project is especially prone to, and designed toward eliminating, the "guinea pig" syndrome among so many building owners. The study will measure effective innovations by preparing case studies that identify salient and comparative features on multiple buildings.
The goal is to document the progress new distribution systems are making in terms of IAQ, occupant comfort and productivity, cooling and lighting energy savings, and reduced solid waste generation. As Hourahan says, "Instead of installing ductwork in your ceiling - and once you're done, you're done - there are other ways to do it. Beyond just the zoning of ductwork," he also sees possibilities for powergrids and telephone lines as well.
Still, Hourahan sees a likely delay for implementation in new buildings. "It'll probably be 10 years or so," he predicts. "It takes some to convince people that (a new distribution method) is a safe enough method to use."
"State of the Art Review of Whole-Building and Building Envelope Simulation and Design Tools" and "State-of-the-Art Review of HVAC Component and System Simulation, and Design Tools." Hourahan explains the goals of these projects include helping to silence some time-honored gripes. "We'd like to have some tools out there for a designer to design and lay it out, regardless of geography, and be able to do load analysis, weigh all the factors, and find out the net efficiency per dollar. We need to look at the tools for whole-building or component design that exist today, see what the shortcomings are, and go from there.
"By giving them better tools, architects can make better tradeoffs. Hvac has always complained about small mechanical rooms, so here's an application to help avoid that kind of problem in the first place."
While Hourahan admits that the time-to-market for these projects may vary widely, he's much more confident about the timeframe for the research itself. The winning bids on all 11 projects will be selected this fall. After a few weeks to get all the paperwork done, the projects themselves will each last 12 to 18 months.
As for the second batch, Hourahan could not disclose what the next topics might be. However, he did confirm that ARTI will be reviewing the candidates in September, releasing the final decisions by January. "We'll have a constant overlapping cycle," says Hourahan. "The authorization of new projects would be done in batches two to three years apart."
Triple-effect: A Chilling ProspectBeyond its contribution to the 21-CR program, DOE is propelling research of its own, attempting to multiply the efficiency of popular equipment and methods. For example, DOE is looking for better variations on established themes behind chillers performance and desiccant dehumidification processes.
It's been 40 years since the double-effect cycle changed the way a chiller works. DOE thinks the time is right for a similar step forward. It has initiated research, aided by The Trane Company (La Crosse, WI) and York International (York, PA), to bring triple-effect chillers to the market in hopes of helping the U.S. industry regain market share in large commercial chillers.
The program's objective is to achieve 30% to 50% efficiency improvement over double-chillers by employing a triple-effect chiller. Such a chiller would use lithium bromide-water fluids and boast a COP of 1.4.
York's portion of the program, done in conjunction with Oak Ridge National Laboratory, is in the testing phase. It is pursuing a double-condenser coupling concept, patented by ORNL for DOE, as its base cycle. As a result, York's prototype 400-ton chiller is currently undergoing laboratory testing, to be followed by more testing in the field.
Meanwhile, DOE reports that Trane has an operational triple-effect prototype that is based on another ORNL-patented innovation, a dual-loop cycle, that was subsequently licensed to Trane in 1989. This prototype, which is the result of a cost-shared program with the Gas Research Institute, is undergoing optimization and characterization testing.
The eventual success of either triple-effect chiller would have a host of positive effects. Utilities could improve offers to reduce peak usage through demand-side management, according to DOE. In addition to increased energy efficiency and economic payback, the United States would also enjoy job creation and a competitive boost in global markets.
Complaining vs. MaintainingWhen all that next-generation equipment is introduced, it will be doubly efficient. The improved technology will boost performance, of course, but we will also be employing the equipment more efficiently as we keep learning how to let hvac system design reflect the way people use those systems on an everyday basis.
"I think the commercial building will be much more intelligent. And hvac will make some pretty substantial leaps," says Kevin Powell, the administrator of the Center for the Built Environment (CBE, Berkeley, CA). CBE is supported by the University of California - Berkeley and the National Science Foundation, with contributing partners that include manufacturers, building owners, facility managers, contractors, architects, and engineers. CBE's staff of faculty, research specialists, graduate student engineers, and partners work to provide unbiased information on promising new building technologies and design techniques.
Powell also helps provide a different perspective on costs incurred in a building. "Over a thirty-year period, occupant salaries represent 92% of total expenditures associated with a commercial building," he says. Thus, the largest financial investment inside a building is not its construction cost or computer system, but its people. Corporations will use hvac technology in the coming years to maximize that investment.
In addition to underfloor air supply, CBE is conducting a variety of research toward this end, including a study on the impact of team space on productivity. Knowledge-based work is a rapidly growing sector of employment, and the term "alternative office" represents a package of technologies and design strategies to support this environment. A frequent element of this strategy is team workspace. In this arrangement, a "team" has both individual workspaces as well as meeting areas for group activities. The increased prominence of this design option will influence hvac design accordingly, Powell believes.
Along the same lines, learning how to collect, analyze, and act on occupant feedback will become even more critical. CBE is currently working to develop Internet-based software to achieve these goals. Ideally, an occupant could use a feedback form on the computer to document specific complaints and the current conditions when those complaints are submitted. CBE believes that up to $2 billion could be saved annually by the resulting improvement in information given to facility personnel and the automation of many feedback functions now handled manually, not to mention the improved productivity spurred by faster reaction time.
A companion CBE project also focuses on a web-based occupant survey to combine subjective occupant perceptions about the environment with objective measurements of indoor environmental quality. Such a survey would allow the creation of a benchmark database which could then be used for seasonal analysis, refining a system's use, and comparing a building's performance to that of similar buildings elsewhere.
Occupant feedback may be valuable, but it is still no substitute for an accurate sensor system. CBE sees the digitalization of all forms of communications as pointing toward the next generation of sensors. Just as the emergence of radio- and infrared-based data networks for use inside buildings may free employees from the invisible "tether" to desks and telephones, wireless may also revolutionize building sensors.
One CBE project investigates how the wireless phenomenon might improve security and environmental control systems' flexibility and service. CBE envisions a scenario in which enhanced occupant tracking provides densely populated parts of a building with more telecommunications availability, as well as appropriate hvac adjustments to compensate for high and low occupancy in different areas as needed.
Intelligent Buildings By 2030?Elsewhere in Berkeley, the DOE is conducting its own related research with its Building Performance Assurance (BPA) program. This research is conducted at the Lawrence Berkeley National Laboratory by the Building Technologies Department of the lab's Environmental Energy Technologies Division. They theorize that fully half of all energy consumption in commercial buildings is wasted, compared to what is cost-effectively achievable. The BPA program focuses on the following three areas.
Diagnostics & Commissioning. A primary part of this area is the Whole Building Diagnostician, a modular diagnostic software system that provides detection and diagnosis of common hvac problems. The development team consists of government researchers as well as the Honeywell Technology Center and the University of Colorado, in hopes of speeding the transfer of this technology into practice. The Pacific Northwest Laboratory is also contributing to whole-building design and diagnostics progress.
The second prototype is currently being worked on; this two-part version includes the Whole-Building Energy (WBE) model and the Outdoor Air / Economizer (OAE) diagnostic module. The WBE tracks overall building energy use, alerting the operator when unexpected changes in consumption occur. The OAE segment monitors the performance of AHUs and control of outside air; it can currently detect approximately 20 different basic operation problems. Color coding helps the operator recognize and address the variety of potential problems.
DOE sees a number of potential uses for this technology. The OAE could be used during commissioning to verify proper performance and improve the quality of the commissioning process. The OAE could also be integrated into the controls systems of packaged hvac units, providing and/or storing diagnostic results for periodic review. The WBD could also be deployed by manufacturers as an embedded part of a control system, bas, or supervisory software. The WBD would also allow campus facility staff to process data from several different buildings, saving time and money.
Performance Metrics & Benchmarking. The chief product of this research is the Metracker. It is intended to document building performance across the life of a facility. Moreover, it can help establish performance objectives during predesign planning and update those objectives through the design process. Said objectives can then be used as benchmarks during commissioning and again later for O&M diagnostics. Having such a complete record of a building's design and performance would prove helpful not only in maintaining conditions in that building but in planning future buildings as well.
Life Cycle Tools. At the moment, this area's key product is the Building Life-Cycle Information Support System (BLISS). Similar to the Metracker, BLISS is designed to provide a distributed computing environment for managing the wide variety of data provided across the life of a building. Therefore, it would require standardization in both a common building database model and in the mechanisms for transferring this information between tools.
Judging from the DOE website, it is even willing to look further into the future of its research efforts. It predicts the following fruits of its labors by 2010.
- Energy design tools will save designers time by instantly providing hypertext guides and hints. Their analytic capabilities will also allow modeling of real building operation, taking factors like control system dysfunction and equipment degradation into account as well.
- Building operators will have better individual diagnostic tools for detecting and diagnosing operation problems and troubleshooting. They will work with monitoring systems and data display, along with efficient reporting tools that forward information to on-site and remote managers.
By 2020, progress will supposedly gain even more ground.
- Design tools and environments will be fully integrated with CAD systems, and will possess analytic capabilities that thermal performance, mechanical systems, illumination, safety, and security.
- Buildings will be based on intelligent building systems (IBS) that will include controls, sensors, and diagnosticians that automate parts of both commissioning and operation. IBS will include some adaptive, self-correcting, and self-calibrating capabilities.
Finally, the DOE crystal ball apparently gets fuzzy around 2030, but not before another round of improvements. According to DOE, research will have provided design environments with seamlessly integrated building design tools with advantages ranging from design suggestions and rapid data analysis to automatic generation of all design documents. The building's electronic data structure will support start-up, operation, maintenance, and renovation of the building by its IBS.
Energy Options iInclude Earth, Wind, And FireSo if the experts are to be believed, the way people work in buildings will continue to evolve, and the hvac industry will adapt to those usage patterns. Furthermore, the industry will produce equipment unprecedented in its energy efficiency. It might seem certain that we'll use less energy in the future, but one other question remains: where will that energy come from?
Dan Reicher, the EPA's Assistant Secretary for Energy Efficiency & Renewable Energy, seems certain that buildings will be fueled by a sense of urgency if nothing else.
"Let me put it this way," Reicher explained during the 10th Annual Energy Efficiency Forum, sponsored by the DOE and Johnson Controls (Milwaukee) and held in Washington last June. "With oil imports at record levels and rising, with world electricity needs growing at an absolutely phenomenal rate, with the seven hottest years on record happening in the last decade, with an unprecedented tightening of air pollution requirements, and with competition and choice coming to the electricity industry, the 'clean energy decade' has truly arrived."
Reicher also believes the answer will be a breeze (literally). Of the alternative energy sources, he firmly believes wind power will rise in prominence over the first part of the next century. Wind energy, which he says cost $0.40/kWh in 1980 and had only 10 MW installed worldwide, today costs about $0.10/kWh. Availability is also on the rise.
"Texas recently adopted electricity restructuring legislation that will add another 2,000 MW of wind energy in that state alone," by 2009, he points out.
Elsewhere in the alternative universe, solar energy hangs on, if still not reaching the potential that seemed to be bursting in the 1970s. Whether incorporated into initial design or used in a retrofit, the installation cost of solar projects is still relatively high. On the other hand, low maintenance requirements, no emissions, and the fact that no fuel is needed do reward those willing to pay the up-front costs.
High energy usage during peak cooling load hours is an increasing no-no in the dawning era of deregulation, and photovoltaics do represent some respite from the cost of midday usage, since their power output reaches its own peak at midday. To that end, better rates and possible utility credits or rebates should be considered by installers considering photovoltaic, in addition to the general cost benefits of solar energy.
(Source of energy aside, ARI also expects that thermal storage will be another popular strategy for owners trying to avoid the most expensive rates. Thermal storage systems can be charged to capacity during off-peak hours at lower costs. The lower head pressures would allow the chillers to operate more efficiently, says ARI, and the owner could shift power consumption to times with more favorable rates. Such maneuvers may help make the adjustment to deregulation a little less painful for owners, especially those in states that now enjoy generally inexpensive energy costs.)
Solar thermal heating also continues to be used for more specific purposes such as domestic hot water, low-temperature industrial processes, and swimming pools. Likewise, swimming pools were the first commercial installations to receive the benefit of geothermal power. Dozens of communities in the West have been identified as prime candidates for such systems, and over 200 resorts reported using geothermal hot water at the beginning of the decade, but geo-thermal's use in general commercial design is far from certain.
On the other hand, fuel cell technology - which was invented by NASA - may be a space-age technology that is finally coming down to earth. The fuel cell is a cogeneration system, efficiently producing electricity and heat (as steam or hot water). Better, the DOE says they produce fewer emissions and make less noise than other cogeneration options. DOE's Fuel Cells for Buildings Program is just one exploration into fuel cell technology, with which it is hoping to continue advancements toward mainstream commercial applications. Carbon dioxide reductions, less need for electric utility infrastructure and delivery, and domestic job growth are some of the enticements to help such projects succeed.
Today, several different kinds of fuel cells are being examined for their potential. The cells that are already commercially available have been observed to perform at 50% to 60% efficiency, but laboratory settings have seen efficiencies as high as 70%. A recent $15 million DOE grant program has been launched to expedite fuel cell installation in government facilities in general, and Dept. of Defense facilities in particular. Based on this kind of initiative and optimistic remarks from legislators involved in energy management, it is not unrealistic to expect fuel cells to enter the residential and subsequent commercial markets within the next decade. ES
More To The StoryAs always, there's more to the story:
improved lighting technology and modeling software will play a role in better buildings, too. Read online sidebars about them at ES Online, http://www.esmagazine.com.
Also, visit the following websites for more information on the projects mentioned here:
Air-Conditioning & Refrigeration Technology Institute - http://www.arti-21cr.org.
Center for the Built Environment - http://www.ced.berkeley.edu/cedr/cbe.
U.S. Department of Energy - http://www.eren.doe.gov/buildings.