By Thomas E. Watson, P.E.
Published in the January/February 2013 issue of Today’s Facility Manager
Conversations about sustainable facilities typically focus on water conservation, energy efficiency, and building materials. Also important in this discussion is the need to reduce the impact of refrigerants on the environment. Emitted chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants have been directly linked to the destruction of stratospheric ozone, which in the upper atmosphere shields the earth from harmful ultraviolet B radiation. These and hydrofluorocarbon (HFC) refrigerants also act as greenhouse gases with potential consequences for global warming and other climate change effects.
As industries transition away from ozone depleting and high global warming potential (GWP) substances, members of the facilities industry must turn to a more holistic analysis in their selection and regulation of refrigerants and the systems that use these chemicals.
Certainly, much progress has been made concerning the use of refrigerants to heat and cool indoor environments. At a recent conference on this topic hosted by ASHRAE and the National Institute of Standards and Technology (NIST), keynote speaker James M. Calm, P.E. shared his thoughts on refrigerant transitions and categorized the transition of refrigerants into four generations.
The first generation spanned from the 1830s to 1930s and could be characterized by “using whatever worked.” The second generation (1931 to 1990s) focused on safety and durability, which included introduction of CFCs and HCFCs as well as continued use of ammonia and, to a lesser extent, hydrocarbons. More recently was the third generation (1990 to 2010s) when industry concern turned to ozone protection and began the phaseout of CFCs and later HCFCs.
Now, the industry has entered the fourth generation of refrigerants with a focus on low GWP options. In his presentation, Calm emphasized the need to address the several application requirements and looming environmental concerns together. Piecemeal approaches will not meet the eventual targets. The industry must be forward-looking and make selections beyond minimum mandates. Otherwise, stakeholders will be forced to face still another generation of refrigerant transitions.
While traveling during 2012 for both my ASHRAE service and my work, I heard much conversation about the need for holistic analysis and an increasing focus on using low GWP refrigerants in high efficiency HVAC/R systems. Improving efficiency in air conditioners, heat pumps, and refrigeration will remain critical as the energy used and resulting combustion emissions has more significant impact on climate change than the refrigerants themselves. So it is critical that facility managers (fms) carefully address not only refrigerant selection and leak minimization, but system efficiency.
Information Please…? Cloud Technology Turns Questions Into Answers
By Mark Hendrickson
Today’s building automation systems (BAS) collect vast oceans of data. So the problem for facility managers (fms) is no longer, “I don’t have the facts.” Rather, the problem is, “I have gazillions of facts. I just don’t have the time, expertise, or resources to sift through them and turn them into something useful.” Wouldn’t it be helpful if there were a tool available to translate all those pieces of data into useful information? It would be like a guide to help fms make better decisions about cost avoidance, manpower prioritization, budgets, equipment repairs or replacement, etc.
Facilities management (FM) can be a tough job filled with challenging questions. How can I make timely, critical decisions if I don’t have reliable information? How can I decide whether to keep work in-house or farm it out if I don’t have reliable information? How can I meet the growing need to do more with less if I don’t have reliable information? How can I find creative ways to extend the life of aging equipment if I don’t have reliable information? How can I achieve cost savings if I don’t have reliable information?
Without reliable information, fms can’t achieve any of these things. The good news is they now can have that information through access to new tools that can translate BAS data into a useful form, called fault detection and diagnostics (FDD). FDD isn’t a new concept. Engineers and fms have been trying to glean predictive information from BAS data for years. But storing and sorting that data had been very costly.
What is new is “the cloud.” The cloud is a technological breakthrough that allows users to gather, store, and analyze data with more ease and less cost than ever before. And the technology makes FDD possible and goals achievable. Each element of FDD plays a crucial part in how the practice can benefit fms.
Fault: A fault is not an alarm. A BAS alarm is a simple notification that a problem has occurred. For example: The president’s office should be 72°F, and an fm instructs the BAS to notify them if the temperature drifts +4°. This is useful, but it is based on just one data point.
Meanwhile, a fault is information that results from analyzing multiple data points and systems over time, providing insight that could prevent the alarm from ever occurring.
For example: The variable air volume (VAV) box in the president’s office has been operating 10% over the calculated flow set point for more than 10% of the occupied time. Six to eight data points are analyzed over a period of three days and then compared to the performance of other VAV boxes to reveal a fault. From this, the fm learns which box is operating inefficiently, consuming more resources than it should, and, because of its inefficiency, will probably break down sooner than it should. This cost-effective storage and access to data is made possible by cloud technology.
Detection: This is the power behind FDD. If fms have enough HVAC systems data available over a long enough period of time, they can analyze patterns in the systems’ operation using standard (rules) for every system in a facility. Examples of typical FDD rules for an air-handling unit (AHU) include:
- Discharge temperature error
- Duct static pressure error
- Insufficient fan capacity
- Insufficient cooling capacity
- Insufficient heating capacity
- Insufficient preheating capacity
- Minimum outside airflow rate error
Some key things to remember about detection: All the data needed for FDD already exists in a BAS. The trick is to collect and store it in a format that can be analyzed effectively. Using cloud technology does the trick.
An average sized facility consisting of three or four air handling units, 200 to 300 VAV boxes, and cooling/heating sources will generate over two gigabytes of FDD data daily. Fms should consider if their organizations have the IT infrastructure to manage the terabytes of data that are typically stored for an average building. Better stated, does the fm want to manage the hardware and software systems, as well as the IT resources required to keep and maintain this data? Using cloud technology, fms don’t have to.
Diagnostics: Once FDD has diagnosed a fault in the data, it can offer a prognosis. That prognosis typically comes with recommendations that will help in making critical decisions about manpower, budgeting, and cost avoidance. Going back to the example of the president’s office where the VAV box has been operating so inefficiently… the diagnosis comes with a recommendation to: calibrate or replace the VAV box flow sensor; check the operation and positioning of the damper actuator; and inspect the connection between the damper actuator and the damper shaft. Taking steps to fix the flow error will make this VAV box run more efficiently, run less, and last longer.
FDD can help fms overcome challenges in several ways:
- By detecting performance issues with equipment it helps FM staff find creative ways to extend the life of aging equipment.
- By identifying the causes for increased energy spending it helps achieve cost savings.
- By offering recommendations for resolving problems it helps fms do more with less.
- By identifying performance problems before they become customer satisfaction problems it helps in making timely, critical decisions.
- By ranking faults based on severity, equipment type, and impact to the entire HVAC system it helps fms make decisions about whether to keep the work in-house or employ a vendor.
Fms have all the data they need in a BAS to aid critical thinking. Now, the cloud provides FDD capabilities to bring facility efficiency to a higher level.
Hendrickson is the director of Panoptix Operations, a suite of web based applications provided by Johnson Controls. He is responsible for the successful implementation and commissioning of Panoptix projects around the world.
Programs And Initiatives
Currently, there are several programs and initiatives underway that focus on the technologies, methods, and means needed to accommodate the imminent phase-down of high GWP refrigerants.
One such measure is the cooperative Low GWP Alternative Refrigerants Evaluation Program (AREP) by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI). Launched in March 2011, the program aims to identify and evaluate alternatives to high GWP refrigerants for major product categories, and to provide common sets of quality data. The products covered include air conditioners, heat pumps, chillers, water heaters, ice makers, and refrigeration equipment.
The AREP program seeks to help the industry select the most promising refrigerants, avoid duplicative work, understand technical challenges, and identify the research needed to use these new refrigerants. The program will not prioritize these alternatives; rather, it will identify potential replacements for high GWP refrigerants and present the performance of these replacements in a consistent, standard manner. There are currently 38 alternatives being evaluated.
Results of the AREP program so far were summarized at the ASHRAE/NIST conference, with the program expected to be complete by the end of the first quarter 2013. (Five completed reports can be downloaded on the AHRI website.)
Many of the new low GWP refrigerants are classified as mildly flammable under ANSI/ASHRAE Standard 34-2010, Designation and Safety Classification of Refrigerants, new 2L safety classification. In addition, ASHRAE Standard 15-2010, Safety Standard for Refrigeration System, is undergoing revisions to address the 2L classification.
Another project in development is the Guide for Sustainable Refrigerated Facilities and Systems by ASHRAE and the United Nations Environment Programme. This resource, slated for release in early 2014, addresses the entire range of facility and equipment design and efficiency alternatives for refrigerated processing, storage, and distribution (the cold chain) in both developed and developing countries.
The guide is also important as parties to the Montreal Protocol face upcoming compliance deadlines. For developing countries, that meant a freeze in HCFC consumption and production by January 1, 2013, followed by a 10% reduction in 2015 and a 97.5% reduction by 2030.
Currently, HCFC-22 is the preferred refrigerant for many facilities and systems, particularly for small and medium sized conditioners; this ozone depleting gas is being phased out under the Montreal Protocol. In the U.S., a ban on the sale and distribution of pre-charged new equipment containing HCFC-22 has been effective since January 1, 2010.
Meanwhile, ASHRAE is creating a voluntary refrigerant management plan, with initial publication planned in the U.S. In addition to proper cradle to grave management, the document will provide guidance on suitable refrigerants to be used to meet growing demand. The goals for this project include tracking and reporting refrigerant use and life cycle, minimizing environmental impact of refrigerant use, and raising public awareness of the environmental issues and the economic impact of refrigerant use.
So what can we as an industry do to reduce refrigerant impact on the environment? We need to focus on our efforts where they will have greatest impact.
We need to match the technology to the need. The contributions of fms, and all stakeholders, are needed to identify not just new options but those that will provide maximum benefit.
Watson, P.E., Fellow ASHRAE, Life Member is the 2012-13 ASHRAE president. He is chief engineer at Daikin McQuay located in Staunton, VA, where he oversees new product development for centrifugal compressor technology and is primarily involved in technical areas related to refrigerant applications, aerodynamics, bearing design, and motor applications. He holds five patents related to refrigerant, gas, and chiller compressors.