Diagnostic Advances that Support Commissioning
IDENTIFYING THE CAUSE of equipment problems can be particularly challenging when symptoms are difficult to detect. New developments in diagnostic equipment have the potential to be extremely useful for maintenance and engineering technicians.
“We’re developing software systems that can archive data and then act on it, both through developing interactive graphics and applying rules and models to evaluate whether systems are working correctly,” says Mary Ann Piette, staff scientist at Lawrence Berkeley National Laboratory.
While more such applications are becoming available for chillers, developers are just beginning to create tools to enable overall energy analysis, she says.
“At the system level for air handlers, for example, we’re not so far along, because airflow measurements are much more difficult,” she says.
These software developments could help technicians identify equipment problems, such as a stuck economizer damper. It could also identify other energy-saving opportunities, such as filters that need changeout and building balance problems.
“These are the kinds of day-to-day problems that these tools can help maintenance staff see from the EMCS (energy monitoring and control system) data,” Piette says.
Large organizations with energy managers, such as large office buildings and college and university campuses, are the likely early adopters of these technologies, she says.
“It is very important to understand the link between these new tools and commissioning practices,” Piette adds. “These tools are going to help the commissioning process and even help define and develop what people are starting to call continuous commissioning.”
These tools will be helpful in determining retrocommissioning measures and, once a problem is fixed, ensuring savings.
The biggest hurdle in implementing these tools in existing facilities is retrieving data from an organization’s EMCS. The ability of these systems to trend and archive data historically has been a weak leak, Piette says. But companies are starting to improve the data-management features of new control systems. These improvements will help in overcoming this challenge.
For more information on these developments, individuals can download the Comparative Guide to Emerging Diagnostic Tools for Large Commercial HVAC Systems at http://buildings.lbl.gov/hpcbs/ pubs.html
Technology developers also are focusing their efforts on remote diagnostic tools, says James E. Braun, a professor at Purdue University’s school of mechanical engineering.
While maintenance managers can expect to see improvements in hand-held diagnostic tools, the next big advance will give maintenance and engineering managers at remote locations, as well as on-site technicians, information on equipment conditions.
“I think (managers) can expect to see several companies providing online diagnostics,” he says.
While some tools currently available imply diagnostic capabilities, their abilities tend to be limited, Braun says. Managers soon can expect to see tools that go beyond simply enabling equipment monitoring. Instead, he says, they will provide real energy savings for organizations needing such benefits.
Green Growth in Schools, Hospitals
Two recent reports give strong indications that ‘green’ concepts and practices are taking deeper root in facilities nationwide.
The first report offers encouraging news on efforts to minimize the environmental impact of health care facilities. A national survey by Hospitals for a Health Environment (H2E) reports that hospitals nationwide have greatly reduced the amount of mercury found in their facilities. Among the survey’s findings are these:
- 97 percent of hospital respondents nationwide say they had taken steps to address the issue, including labeling mercury-containing devices.
- 80 percent of respondents had eliminated the use of mercury fever thermometers.
- 73 percent had removed all mercury sphygmomanometers from facilities, more than 81 percent now buy mercury-free cleaning chemicals, and 64 percent buy mercury-free pharmaceuticals.
- 60 percent had implemented a mercury-management policy, and more than 54 percent had established a policy to eliminate mercury facility-wide.
The second report, based on a survey of 665 U.S. building owners, engineers, architects, and corporate-owner clients, outlines their opinions of the benefits of green facilities, especially education facilities.
According to the report from the Turner Construction Co., one of United States’ largest building consortiums, organizations involved with green facilities rated them more highly than traditional facilities on a range of benefits, namely:
- the ability to attract and retain teachers, 74 percent
- reduced student absenteeism, 72 percent
- improved student performance, 71 percent.
When asked which green features were most beneficial, 49 percent of respondents cited improved indoor air quality as most important.
But respondents remain concerned about the higher construction costs of green schools, according to the report. The survey revealed that officials in most education institutions either don’t consider total long-term costs at all or are much more heavily focused on initial construction costs.
Additive Promises Cooling-load Savings
A researcher at the National Institute of Standards and Technology (NIST) has developed a refrigerant additive that could improve the energy efficiency of chillers in large buildings.
If experiments with full-scale chiller systems confirm the performance of the additive, the method could save up to 1 percent of the 320 million kWh of electricity used annually by the chillers, roughly the equivalent of 5.5 million barrels of oil per year, according to Mark Kedzierski, the NIST mechanical engineer who developed the technique.
The research focuses on mixtures of refrigerants and lubricants. Researchers discovered that some lubricants, when injected in small amounts, can significantly enhance evaporator heat transfer, increasing the efficiency of chillers.
Manual Focuses on IAQ Standard
A new user’s manual provides facilities professionals with guidance on the installation and operation requirements of the ventilation standard from the American Society of Heating, Refrigeration and Air Conditioning Engineering (ASHRAE). The Standard 62.1 User’s Manual explains the requirements of ANSI/ASHRAE Standard 62.1-2004, Ventilation for Acceptable Indoor Air Quality. It also contains numerous application examples . The manual includes a CD with a spreadsheet to assist in calculating the standard’s new ventilation rate procedure.
For more information, visit www.ashrae.org