ASHRAE Journal - February 2012 - 80

EMERGING TECHNOLOGIES
evolving faults before they become severe, allowing the owner to schedule service calls at typical nonemergency rates. At an estimated additional cost of $80 to $500 per integrated unit, the savings ﬁgures are promising for market adoption, and policy-making bodies have taken notice. The California Energy Commission’s Title 24 now provides credits for the use of FDD in packaged rooftop units. Other regulations will likely include FDD as well as it becomes more widely studied and recognized. Many owners purchase their HVAC systems based on performance ratings achievable when the systems are ﬁrst installed and commissioned, not for the long-term efﬁciency in the presence of fault conditions. This has resulted in manufacturers targeting best-case performance numbers while keeping costs down relating to other systems, such as FDD. Some high-end units have basic, yet important, FDD capabilities, but these have not been sold in signiﬁcant enough numbers for large-scale impact, continuing to make underperforming HVAC units a common occurrence and a major source of wasted energy. The FDD subcommittee of ASHRAE TC 7.5 and NIST have been working toward integration standards, protocols to verify system beneﬁts, system ratings, and labeling conventions. Education of the consumer about the long-term beneﬁts of FDD systems will be important for their long-term success.

References
1. Roth, K.W., et al, 2005. “Energy Impact of Commercial Building Controls and Performance Diagnostics: Market Characterization, Energy Impact of Building Faults and Energy Savings Potential.” TIAX. http://tinyurl.com/TIAX2005. 2. Siegel, J. and C. Wray. 2001. “An Evaluation of Superheat-Base Refrigerant Charge Diagnostics for Residential Cooling Systems.” Lawrence Berkeley National Laboratory. LBNL-47476. http://tinyurl. com/LBNL2001. 3. Kim, W. and J. Braun. 2010. “Impacts of Refrigerant Charge on Air Conditioner and Heat Pump Performance.” International Refrigeration and Air Conditioning Conference. http://tinyurl.com/KimBraun2010. 4. Schein, J., S. Bushby, and J. House. 2003. “Results From Laboratory Testing of Embedded Air-Handling Unit and Variable Air Volume Box Diagnostic Tools.” National Institute of Standards and Technology. http://tinyurl.com/NIST2003. 5. Braun, J., and H. Li. 2003. “Automated Fault Detection and Diagnostics of Rooftop Air Conditioners for California.” Purdue University. http://tinyurl.com/Purdue2003. 6. Feng, M., et al. 2005. “Packaged rooftop units: Automated fault detection and diagnostics.” ASHRAE Journal 47(4):68 – 72.

Matthew Wiggins, Ph.D. is an associate principal with TIAX LLC, Lexington, Mass. James Brodrick, Ph.D., is a project manager with the Building Technologies Program, U.S. Department of Energy, Washington, D.C.

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ASHRAE Journal

February 2012

ASHRAE Journal - February 2012

Table of Contents for the Digital Edition of ASHRAE Journal - February 2012