Volker Hartkopf

An integrated approach to design and engineering of intelligent buildings-The Intelligent Workplace at Carnegie Mellon University

Abstract In the past few years, there have been significant advances made in the design and engineering of “intelligent” workplaces, buildings that not only accommodate major advances in office technology but provide better physical and environmental settings for the occupants. This paper will briefly present recent approaches to the creation of innovative environments for the advanced workplace. The architectural and engineering advances demonstrated in Japan, Germany, North America, the United Kingdom, and France can be summarized in four major system categories: (1) enclosure innovations including approaches to load balancing, natural ventilation and daylighting; (2) heating, ventilation and air-conditioning (HVAC) system innovations including approaches to local control and improved environmental contact; (3) data/voice/power “connectivity” innovations; and (4) interior system innovations, including approaches to workstation and workgroup design for improved spatial, thermal, acoustic, visual and air quality. In-depth international field studies of over 20 intelligent office buildings have been carried out by a multidisciplinary expert team of the Advanced Building Systems Integration Consortium (ABSIC) based at Carnegie Mellon University. ABSIC is a university-industry-government partnership focused on the definition and development of the advanced workplace. The ABSIC field team evaluated the component and integrated system innovations for their multidimensional performance qualities, through expert analysis, occupancy assessments and field diagnostics. Based on the results of the case studies and building on the most recent technological advances, the ABSIC team developed the concepts for the Intelligent Workplace, a 7000 square foot living laboratory of office environments and innovations. This project is now under construction at Carnegie Mellon University and its features are discussed in the second section of this paper.

Education and environmental performance-based design: a Carnegie Mellon perspective

There are both negative and positive drivers for curricular change in architecture and architectural engineering departments to embrace more fully systems integration for building performance. On the negative side, failures in indoor air quality, spatial flexibility, acoustics and building integrity represent increasing challenges for designers, leading to costly litigation and remediation, and undermining the reputation of professionals. Heightened performance goals, including environmental sustainability goals, as well as emerging materials, components and system innovations require a greater level of expertise and collaboration between architect, engineers, building scientists and other disciplines. Advancing building performance quality and life cycle decision-making will require more integrated design processes. Least-first-cost decision-making and highpressure value engineering lead clients to decisions that compromise the quality of building projects, and the design community often lacks the relevant information to argue for life cycle quality.

Critical Frameworks for Building Evaluation: Total Building Performance, Systems Integration, and Levels of Measurement and Assessment

Although there has been heated discussion over the past few years about the need for both objective and subjective field evaluation methods, there has been very little discussion about the need to complete those field evaluations in all performance areas simultaneously. One possible explanation of this void might be the difficulty that the design community has in defining total building performance, much less establishing limits of acceptability and testing for them. Notwithstanding, there have been some collective attempts at the definition of total building performance by the National Bureau of Standards (NBS, 1972), the International Standards Organization (ISO, 1972), and the Centre Internationale de Batiment (OB, 1982). The authors of this chapter have built on these efforts, to develop a more manageable yet comprehensive list of six performance mandates for the built environment: spatial quality, thermal quality, acoustic quality, visual quality, air quality, and long-term building integrity against degradation (figure 1) (Hartkopf, Lof tness, Mill, 1983).

Detailed Energy and Exergy Analysis for a Solar Lithium Bromide Absorption Chiller and a Conventional Electric Chiller (R134a)

The Building Energy Data Book (2009) [1] shows that commercial and residential buildings in the U.S. consume 39.9% of the primary energy and contribute 39% of the total CO2 emissions. In the operation of buildings, 41.8% of building energy consumption is provided for building cooling, heating, domestic hot water, and ventilation for commercial buildings, while in residential buildings, this percentage increases to 58%. In energy system analysis, the energy approach is the traditional method of assessing the way energy is used in an operation. However, an energy balance provides no information on the degradation of energy or resources during a process. The concept of exergy combines the first law and second law of thermodynamics. The exergy analysis clearly quantifies the energy quality match between the supply and demand sides, and also addresses the exergy destruction (entropy generation) in each component. In this paper, a solar thermal driven absorption cooling system was analyzed for providing cooling to a building, the Intelligent Workplace South Zone at Carnegie Mellon University. The system includes a 52 m2 parabolic trough solar collector, and a 16 kW (4 tons) two-stage lithium bromide absorption chiller. The energy model and newly developed two-stage lithium bromide absorption chiller are programmed and integrated in Engineering Equation Solver (EES). The temperature, enthalpy, entropy, mass flow rate, and mass fraction of lithium bromide in the solar absorption system were presented in steady state operation. The exergy destruction in each component is calculated. The exergy destructions for the solar collector, generator, absorber, and heat exchangers were significantly higher than those in evaporator, condenser and expansion valves, the overall energy and exegetic efficiency were also calculated.Copyright

Building as Power Plant—BAPP

ABSTRACT The Building as Power Plant (BAPP) initiative seeks to integrate advanced energy-effective building technologies (ascending strategies) with innovative distributed energy generation systems (cascading strategies), such that most or all of the buildings energy needs for heating, cooling, ventilating, and lighting are met on-site, under the premise of fulfilling all requirements concerning user comfort and control (visual, thermal, acoustic, spatial, and air quality). This will be pursued by integrating a “passive approach” with the use of renewable energies. In addition, the project will achieve unprecedented levels of organizational flexibility and technological adaptability. The project has progressed though preliminary architectural design and engineering and 5 workshops (Ascending Energy Strategies, Floor-by-Floor Infrastructures, Interior Systems, HVAC Systems, and Cascading Energy Strategies). BAPP is designed as a 6-story building, located in Pittsburgh (a cold climate with a moderate sola...

The GSA Adaptable Workplace Laboratory

This paper is a progress report on the Adaptable Workplace Laboratory (AWL) within the Headquarters of the General Services Administration (GSA) of the United States of America. GSA owns, operates, leases and rents real estate for major U.S. Government agencies and departments, such as the Environmental Projection Agency, the Department of Energy, and the Department of Commerce. About 1.5 million office workers are housed nationwide in GSA owned, leased or rented buildings. Consequently, GSA is one of the world’s largest landlords.

Life Cycle Energy and Exergy Analysis for Building Cooling Systems: A Comparison Between a Solar Driven Absorption Chiller and an Electric Driven Chiller

Buildings in the United States utilize 39% of the primary energy, and more than 60% of that energy consumption is provided for heating and cooling in buildings. Most of the heating and cooling systems commercially available in the market today are driven by electricity and natural gas, which are high exergy resources, while the operating temperature in the building from a year-round perspective is closer to the reference environmental temperature. Thus, from a thermodynamic point of view, there exists a gap between the high exergy resources/supply and low exergy application/demand in buildings. This paper extends the traditional means of energy comparison between solar driven absorption chillers and electric driven chillers. A life cycle energy and exergy analysis is developed with the assumption that the fossil fuel for electricity generation is a different form of storing solar energy in the long run. Thus, both the systems are driven by solar energy, and the only difference is that the solar absorption chiller is an instantaneous solar energy utilization, while the electricity chiller utilizes the stored solar energy. A simple absorption chiller model is developed, and is calibrated using a paper published by the Center for Building Performance and Diagnostics in Carnegie Mellon University, using a 4-ton 2-stage absorption chiller provided by Broad Air Conditioning. The energy and exergetic efficiencies in each process are analyzed and provided in the two systems. This paper is useful in understanding the fundamental life cycle energy and exergy in chiller applications for building cooling.Copyright

Turning light bulbs into objects

40% of the United States’ energy is used for heating, cooling, ventilating, and lighting buildings. Given the efficacy of current righting systems of about 2-6% when measured from the power plant, we are wasting a lot of energy. In this context, the goal of the OWL (Object-oriented Workplace Laboratory) system is to provide a testbed that supports the operation of buildings with more efficient lighting systems. OWL’s software architecture is based on a tiework using a combination of web and object technology. It offers location-transparent and manufacturer-independent access to a variety of lighting systems. The OWL system supports a user-driven lighting control scheme for the Intelligent Workplace at Carnegie Mellon University. Both on-line remote control and diagnosis of lighting systems are facilitated by the system. With OWL, a lighting fixture failme triggers a “push” type notification event and sends it to a process for further diagnosis and treatment, This paper describes the requirements, design decisions, and the implementation specific experience in the OWL system development. We discuss the “legacy” system interface, the extendable system design using design patterns, and a component-based multi-modal user interface with Java Beans technology.

Critical Frameworks for Building Evaluation: User Satisfaction, Environmental Measurements and the Technical Attributes of Building Systems (POE + M)

An integrated approach to building performance evaluation mandates that post-occupancy evaluation subjective tools be matched by metrics (POE + M). While leveraging occupants as sensors to quickly capture indoor environmental quality or IEQ conditions in a work environment is valuable, the addition of measured environmental conditions across all variables, and of carefully captured records of critical workplace attributes that define their physical environments, are equally critical to understanding building occupant comfort, satisfaction, health, and performance. With over 15 years of POE + M field measurements in office workplaces, the Center for Building Performance and Diagnostics (CBPD) at Carnegie Mellon University (CMU) has a database of over 1600 workstations with statistically significant findings about the measured and user-perceived quality of the indoor environment, as well as the technical attributes of building systems that contribute to successful, high performance buildings. This chapter provides an overview of the National Environmental Assessment Toolkit (NEAT) developed with the US General Services Administration (GSA), and an array of findings that will catalyze future indoor environmental standards and improve building enclosure, mechanical, lighting, and interior design.

A fog architecture for decentralized decision making in smart buildings

The integration of humans into smart buildings raises challenges between meeting individual preferences and the generic rules set to optimize energy effectiveness of interest to organizations. Merging the individual preferences of multiple occupants that share thermal zones compounds the challenge. To address related challenges, we have developed FRODO (Fog Architecture for Decision Support in Organizations), an architecture designed to establish a location- aware environment for conflict negotiation and decision support that is based on fog computing. This paper describes the model transformation from a centralized software architecture towards a decentralized Cyber-Physical System (CPS) which encompasses sensors, actuators, and the occupants of smart buildings. The transformation is implemented through MIBO, a framework that allows occupants to control their environment. MIBO has been extended to introduce a fog layer for improved negotiation and conflict resolution. This enables additional benefits to be optimized, such as increased quality of service, reduced latency, and improved security and resilience. The fog layer, introduced with FRODO, allows occupants and organizations to express and discuss conflicts in decision-making, at their point of origin.