Browsing by Subject "energy efficiency"

Now showing 1 - 4 of 4
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    Challenges of Creating a Verifiable Building Energy Model
    (ASHRAE, 2019) Ligade, J.; Sebastian, D.; Razban, A.; Mechanical and Energy Engineering, School of Engineering and Technology
    Conducting an energy model simulation for building systems design is indispensable when designing for optimal energy efficiency. Without a critical understanding of the potential energy limitations and waste that a building might exhibit, the substantial financial increase of a project might inhibit the growth of environmental conservancy and progress in business. Computational software operated by professionals helps to sustain that growth. The Science Engineering & Technology (ET) building on the Indiana University - Purdue University Indianapolis campus provided the model for this study and allowed observation of the usability of three distinct software packages - eQUEST v3.65, Trace 700 v6.3.2, and EnergyPlus paired with OpenStudio V8.7.0 - and a comparison of the end results with actual utility data provided by Campus Facility Services. This was an attempt to identify the main challenges that building energy modeling software has yet to overcome and to evaluate the merits of the software packages regarding ease-of-use, detail, accuracy, and modeling options. It is shown that the two biggest challenges are 1) creating a model that accurately represents the physical building and its internal systems, and 2) accurate representation of usage and conditions to which the building will be subjected. The former can be mitigated by creating more user-friendly programs with a better system of checks and balances to identify errors in the physical model. The latter is highly complex, often due to the lack of data acquisition to represent the past and the absence of exacting foresight into the uses and conditions of the building. The results show that energy consumption can be calculated with error ranging of 11%-21% with eQUEST, between 18%-90% with Trane Trace 700 and between 5%-20% with EnergyPlus.
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    Design and Configuration of a 5 hp Microprocessor Controller Inverter
    (Office of the Vice Chancellor for Research, 2014-04-11) Seck, Ndeye Bitylokho
    The purpose of this project is to design a 5hp variable electric drive that converts an AC input signal to DC then to a variable AC output signal voltage that would vary the speed of an AC induction motor. To achieve the goals of this project, two three phase rectifiers are used to convert the AC input voltage to a DC voltage which in turn is inverted and its output amplitude and frequency varied using a pulse width modulation microcontroller. The inverter consists of six Insulated Gate Bipolar Transistors with gate drivers and a digital signal processor to generate the switching signals. The variation in AC output voltage allows the speed of the AC induction motor to be varied from zero to 1700 rpm. Although the load in this application is a 2 hp induction motor, the power system has been designed for a 5 hp unit. The main advantage of this system is its affordability and energy-efficiency. The cost of all components except that the motor has been estimated to be less than $500, while similar products in the market cost at least ten times more. Low cost and energy efficient variable speed drives have numerous applications including appliances (fans, vacuums, etc.), industrial drives (robotics, centrifugal pumps, etc.) and automotive control (hybrid electric vehicles, electric trains, etc.)
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    Does Renewable Energy Renew the Endeavor in Energy Efficiency?
    (2022-03-29) Awaysheh, Amrou; Chen, Christopher; Wu, Owen Q.
    Improvement in energy efficiency (EE) has slowed globally since 2015 and is now falling short of the 2.6% per year target recommended by the United Nations Sustainable Development Goals, despite an abundance of EE opportunities. Barriers to EE have existed long before the rise in renewable energy (RE) investment. However, increased RE adoption may have unintended consequences for improving EE as adoption may raise or lower the barriers to EE. In this paper, we examine whether and how RE adoption can increase or decrease EE improvement. On the one hand, RE represent a competitor to EE for managerial attention and budget. On the other, the adoption of RE may increase the overall awareness of energy usage and drive EE improvement. Using site-level data from an industrial conglomerate, we estimate the impact of changes in RE usage and in the acquisition approach on the EE of 183 manufacturing sites across the globe from 2015 to 2020. On average, we find that using RE to meet 10% more of a site’s energy demand led to an additional 2.0% improvement in EE. However, there is significant heterogeneity in the effects depending on the acquisition approach. We find that while purchasing RE credits or entering into power purchase agreements led to gains in EE, installing on-site RE generators had no effect. To understand these gains, we surveyed site managers regarding their attitudes and intentions. The results suggest that there was a greater focus on EE by both managers and workers after increasing their RE usage. We also find quantitative evidence of managers submitting more budget requests for EE improvements in the twelve months following increases in RE. For corporations looking to use more RE, we offer evidence of additional returns in the form of energy savings, but realizing them requires careful consideration of the acquisition approach of RE.
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    Spatial Effects in Energy-Efficient Residential HVAC Technology Adoption
    (2013-05) Noonan, Douglas S.; Hsieh, Lin-Han Chiang; Matisoff, Daniel C.
    If your neighborhood adopts greener, energy-efficient residential heating, ventilating, and air conditioning (HVAC) systems, will your proenvironmental behavior become contagious, spilling over into adjacent neighborhoods’ HVAC adoptions? Objective data on more than 300,000 detailed single-family house sale records in the Greater Chicago area from 1992 to 2004 are aggregated to census block-group neighborhoods to answer that question. Spatial lag regression models show that spatial dependence or “contagion” exists for neighborhood adoption of energy-efficient HVACs. Specifically, if 625 of 726 homes in a demonstration neighborhood upgraded to green HVAC, data of this study predict that at least 98 upgrades would occur in adjacent neighborhoods, more than doubling their baseline adoption rates. This spatial multiplier substantially magnifies the effects of factors affecting adoption rates. These results have important policy implications, especially in the context of new standards for neighborhood development, such as Leadership in Energy and Environmental Design (LEED) or Low-Impact Development standards.