Green Intelligent Buildings - Literature Review - Engl202c

Wentz 1 Josh Wentz Mr. Baptista English 202C 21 July 2009 Literature Review: Green Intelligent Buildings For years, experts have had a vision of integrated systems within a building’s intelligent HVAC equipment in order to increase efficiency through creating a holistic process. Several technologies have been attempted but none have been successful in this feat. Surveys of building operators suggest that only a fraction of the implemented technology’s functionality was utilized leading to higher operating costs than would have been expected for use of these systems (Gordon and Haasl, 2006; Lowry, 2008). After many years of unfulfilled dreams, promise now seems closer to reality than ever before. This paper examines recent literature concerned with finding the solution to this central intelligent control system riddle. Current scholarship contiguous to this topic primarily focused on some of the enabling green technologies and incentives and some specific developments of intelligent servicing and control algorithms that are driving the development of embedded intelligence for connected building systems. History Before the current and future developments in this topic can be examined, it is important to understand the barriers and advancements that have taken place to shape the technology of today. The traditional building methods used through the past century are contributing to the inefficient nature of existing buildings. The ageless barrier of disconnected building systems has been the main contributor of this inefficiency. House systems relate to the systems of the human body in many ways except one. The HVAC system is the equivalent of human’s respiratory

Wentz 2 system. The structural system reflects a human’s skeletal system. Plumbing reflects digestive and electrical reflects the nervous system. The vital missing link is a human’s central ability to process information into knowledge so that it can carry out functions on its own, or in other words, automate tasks. The first advancement in connecting this missing link was started in earnest as a result of the OPEC oil embargo in 1973. The original concept of energy management and control systems (EMCS), which later became building automation, attempted to address both issue of disconnected systems and sustainability. Only about 10% of the 4,650,000 commercial buildings in the U.S. have an EMCS (EIA, 2009). Surveys of building operators suggest that only a fraction of possible EMCS functionality is utilized leading to higher operating costs than would have been expected for use of these systems (Gordon and Haasl, 2006; Lowry, 2008). Without a central control system such as this, all of the building systems are performing detached tasks rather than working together to create a holistic process. Today, in retrospect, suddenly green is the new black and the drive for new advancing technologies is even greater. Enabling Technologies A list of hopeful technologies is pushing processing closer to the sources of data and opening up many possibilities for embedded intelligence. For cost effective efficient solutions, the application of MEMS technology to HVAC&R sensors could have a dramatic effect on the costs of embedding sensors and intelligence in HVAC&R equipment (Yashar and Domanski, 2007). MEMS technologies involve manufacture of many solid-state sensors on a single semiconductor wafer, which reduces cost. MEMS sensors are low cost when manufactured in large volumes, small and lightweight, and can have good accuracy and resistance to long term drift.

Wentz 3 For small-scale retrofits, wireless can be implemented with simple point-to-point wireless schemes for wire replacement. These technologies have existed for commercial buildings for a few years (Turpin, 2007). Wireless systems compatible with BACNet (Building Automation Control Network) are also available (Wang and Nova, 2007, Kiyon, 2007). For larger scale applications, wireless mesh networks that are interconnected, self-enabling and self-healing (Kintner- Meyer and Conant, 2007) could be employed. Controls companies and wireless mesh network providers are entering into business relationships for commercial buildings (Turpin, 2007) and companies have begun to offer building-wide wireless solutions. The costs of many wireless solutions are coming down and recent studies have demonstrated that they are currently cost effective in many situations (Kintner-Meyer and Brambley,

2006; Katipamula and

Brambley, 2007) depending on the number of sensors and wireless components employed. This economic relief will result in wireless solutions undoubtedly having a major impact on building applications in the near future. Communication between systems within the home and the central control system is key to solving this interconnect ability. There are many exciting developments in communication protocols for building applications that could have even greater effects on costs and product offerings in the next few years. Several open communications protocols has recently hit the market for building controls, with BACNet and LonTalk receiving the most industry attention in the U.S. LonWorks products appear to have gained greater market share for equipment control and stand-alone controllers than BACNet (DeNamur, 2006). However, BACNet may represent the best option for system-wide monitoring and control (Kranz and Gisler, 2008) because it offers greater top-level functionality and interoperability with enterprise networks (i.e., with Ethernet and IP). But in order to keep this trend of enhancing technologies jump forward, incentives for companies and consumers must be investigated.

Wentz 4 Encouraging Incentives The use of embedded intelligence within HVAC and other equipment can lead to reduced utility costs, reduced costs for providing operations, maintenance, and service, and improved occupant comfort and satisfaction. Utility costs are a relatively small percentage of facility operating costs and have been relatively stable over the past 20 years. However, energy costs have begun to rise recently in response to dramatically increased worldwide demand. Higher energy costs provide a greater incentive for intelligent features that lead to more efficient operations. In many locations, increased electrical demand has put a strain on utilities to meet peak requirements and in response, they are experimenting with new utility rate structures that rely on electronic notification in real time to influence customers to level their electrical demand during times of peak usage. For instance, some utilities in the U.S. are offering real-time electric rates that more-or-less reflect the true cost of providing electricity at any time. The rates can increase dramatically during periods of peak demand when less efficient generating capacity is employed and when it is necessary purchase additional generating capacity from other utilities.

The real-time rates are transmitted

electronically some hours in advance. Some utilities in California are also experimenting with critical peak pricing (CPP) rate structures. With CPP, utilities can impose very high (super-peak) rates during designated times of the day (e.g., 12 – 6 pm) on a limited number of CPP days (e.g., 6) throughout each year. The utilities provide an electronic signal to the customer in advance of the CPP event. With either real-time or CPP rates, Intrachooto (2007) predicts that intelligent controls have the potential to automatically respond to these dynamic price signals and reduce overall costs. There also is a trend in the U.S. of utilities offering incentive programs to commercial customers to provide “tune-ups” for packaged HVAC equipment. Programs have been developed

Wentz 5 on both the east and west coasts that rely on diagnostic tools for diagnosing problems and evaluating performance before and after service. This is part of a growing concern about the degradation in performance of packaged equipment that occurs in the field due to inadequate service. This type of requirement would provide a tremendous boon for embedded tools that provide continuous feedback on equipment performance and developing faults. So, where do we go from here? Intelligent Controls There has been a significant amount of research and development related to intelligent control strategies that attempt to minimize utility costs for large commercial HVAC&R systems. Chapter 41 of the ASHRAE Handbook of HVAC Applications (ASHRAE, 2008) presents a number of different strategies for systems used in commercial buildings along with results that demonstrate the cost savings potential. A smart thermostat, for example, would be a replacement for existing thermostats used to control individual packaged air conditioners. A smart thermostat might also incorporate an occupancy sensor. In addition to being useful as an input to an adaptive model for building load dynamics, the smart thermostat could communicate with intelligent lighting controllers and the electrical system to reduce local lighting levels when appropriate. Although there is a significant development effort required for smart thermostats, the economic benefits are substantial (Braun , 2008b). All of these building related issues must be addressed and hopes for the future must be embraced to move towards a green and bright tomorrow. Conclusion & Outlook In summary, recent studies have shown considerable correlations between facilitating technologies and incentives along with intelligent controls servicing and implementing intelligent systems for buildings. Today, customer expectations for intelligent features are

Wentz 6 certainly increasing due to the explosion of smart consumer electronics. However, evidence through history shows that the industry has been relatively slow to adopt new technologies and the pace is unlikely to increase substantially unless driven by customer expectations or significant cost reduction opportunities. Information provided by this literature review regarding the incentives and opportunities for intelligent HVAC equipment can all be used to take a revolutionary leap in the development of intelligence within buildings systems.

Wentz 7 Resources ASHRAE, 2008, ASHRAE Handbook of HVAC Applications, “Supervisory Control Strategies and Optimization,” Chapter 41, pp. 41.1 - 41.39, ASHRAE. Braun, J.E., 2008b, “Load Control using Building Thermal Mass,” ASME Journal of Solar Energy Engineering, Vol. 125, pp. 292-301. DeNamur, M., 2006, “BAS Trends,” HPAC Engineering, June, pp. 19-22. EIA, 2009, “Commercial Buildings Energy Consumption Survey (CBECS),” U.S. Department of Energy, Energy Information Administration, http://www.eia.doe.gov/emeu/cbecs/contents.html Gordon, L.M. and T. Haasl, 2006, “Operation and Maintenance in Office Buildings: Defining Baseline,” Proc. ACEEE Summer Study on Energy Efficiency in Buildings. Pacific Grove, CA, August. Intrachooto S., Horayangkura V. “Energy efficient innovation: Overcoming financial barriers.” (2007) Building and Environment, 42 (2), pp. 599-604. Katipamula, S. and M.R. Brambley, 2007, “Wireless Condition Monitoring and Maintenance for Rooftop Packaged Heating, Ventilation and Air-Conditioning,” Proc. ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, August. Kintner-Meyer, M. and R. Conant, 2007, “Opportunities of Wireless Sensors and Controls for Building Operation,” Proc. ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, August. Kintner-Meyer, M., and M.R. Brambley, 2006, “Pros & Cons of Wireless,” ASHRAE Journal, November. Kranz, H.R. and O. Gisler, 2008, “Standardization & IT Technology Will shape the BACS Industry,” AutomatedBuildings.com, January.

Wentz 8 Lowry, G., 2008, “Factors Affecting the Success of Building Management System Installations,” Building Serv. Eng. Res. Technology, vol. 23, no. 1, pp. 57-66. Turpin, J., 2007, “The Wireless Technology Revolution: What It Means For BAS,” Engineered Systems Journal, February. Wang, W. and M. Nova, “Wireless Bridges the Technology Gap in Building Automation,” Industrial Ethernet Book, Issue 17, November. Yashar Y. and P.A. Domanski, 2007, “MEMS Sensors for HVAC&R,” ASHRAE Journal, May, pp. 69-74.