Environmental Design Commons^™

Sensible Air To Air Heat Recovery Strategies In A Passive House, Santiago Martin Rodriguez-Anderson

Dissertations and Theses

Due to rising energy costs and concerns about global climate change, high performance buildings are more in demand than ever before. With roughly 20% of the total energy consumption in the United States being devoted to residential use, this sector represents a significant opportunity for future savings. There are many guidelines and standards for reducing building energy consumption. One of the most stringent is the Passive House Standard. The standard requires that that air infiltration is less than or equal to 0.6 air changes per hour at a 50 Pascal pressure difference (ACH 50), annual heating energy is less than …

Air Change Rate Vs Airflow Pathway: Bioaerosol Containment And Removal In Patient Rooms, Kevin R. Grosskopf

Durham School of Architectural Engineering and Construction: Faculty Publications

Recent studies have shown that higher air change rates may have the unintended consequence of creating turbulent airflows that entrain high concentrations of infectious particles within the breathing zone, and possibly, breakdown pressure relationships necessary to contain the spread of infectious particles to other clinical spaces.

Adaptive Predictive Functional Controller, Fadi Alsaleem, Arvind Rao

Durham School of Architectural Engineering and Construction: Faculty Publications

A controller device and a method for controlling a system that utilizes an adaptive mechanism to self-learn the system char acteristics and incorporates this adaptive self-learning ability to predict a control parameter correctly to provide precise control of a system component.

An Adaptive Photovoltaic Topology To Overcome Shading Effect In Pv Systems, Mohamed Amer Chaaban, Lana El Chaar, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

Shading in photovoltaic systems can cause many undesired effects.When shading occurs, the power generated from the PV system is much less than nominal power, increasing the electrical mismatching losses between PV system components. Active research to address this power loss focuses on static and adaptive systems.This paper addresses an adaptive system solution and proposes a new method to adaptively overcome losses due to shading during low radiation conditions. In addition, a statistical analysis for choosing the most feasible and efficient configuration for the system size is presented. The proposed system has been validated under shade conditions in a simulation and …

Building Envelope And Interior Grading Systems And Methods, Fadi Mohammad Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

A difference module determines differences between an out door ambient temperature and an indoor temperature, deter mines a first average of the differences, and determines a second average of the differences. A storing module stores a first data point, the first data point including the first average and a first total run time of a heating, ventilation, and/or air conditioning (HVAC) system, and stores a second data point, the second data point including the second average and a second total run time of the HVAC system. A fitting module fits a line to the first and second data points. An …

A Review Of Approaches For Sensing, Understanding, And Improving Occupancy-Related Energy-Use Behaviors In Commercial Buildings, Hamed Nabizadeh Rafsanjani, Changbum R. Ahn, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

Buildings currently account for 30–40 percent of total global energy consumption. In particular, commercial buildings are responsible for about 12 percent of global energy use and 21 percent of the United States’ energy use, and the energy demand of this sector continues to grow faster than other sectors. This increasing rate therefore raises a critical concern about improving the energy performance of commercial buildings. Recently, researchers have investigated ways in which understanding and improving occupants’ energy-consuming behaviors could function as a cost-effective approach to decreasing commercial buildings’ energy demands. The objective of this paper is to present a detailed, up-to-date …

Use Of Fiber-Reinforced Cements In Masonry Construction And Structural Rehabilitation, Ece Erdogmus

Durham School of Architectural Engineering and Construction: Faculty Publications

The use of fiber reinforcement in traditional concrete mixes has been extensively studied and has been slowly finding its regular use in practice. In contrast, opportunities for the use of fibers in masonry applications and structural rehabilitation projects (masonry and concrete structures) have not been as deeply investigated, where the base matrix may be a weaker cementitious mixture. This paper will summarize the findings of the author’s research over the past 10 years in these particular applications of fiber reinforced cements (FRC). For masonry, considering both mortar and mortar-unit bond characteristics, a 0.5% volume fraction of micro fibers in type …

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …

Volunteered Geographical Information: An Alternative Solution For Overcoming The Chasm Between Stormwater Management And Community Participation, Yanfu Zhou

Community and Regional Planning Program: Theses

It is a dramatic challenge to promote public engagement in stormwater management and green infrastructure initiatives. When traditional outreach approaches made important influence on public engagement, their limitations are also obvious. With the development of Web 2.0 technology, Volunteered Geographic Information (VGI) has been emerging as one of the most important user-generated geographic contents. The crowdsourcing data that generated by volunteers through geo-web, smartphones, and other geo-devices provides invaluable mass data for decision-making. VGI can provide a better understanding of planning issues and other challenges. The research aims to develop a mobile information platform to allow citizens to report the …

Quantifying And Modeling Stream–Aquifer Interactions In The Elkhorn River Basin, Nebraska, Can Liu

School of Natural Resources: Dissertations, Theses, and Student Research

This study combined statistical analyses, field investigations and numerical groundwater flow modeling to quantify the connectivity between the Elkhorn River and its adjacent aquifers in Nebraska. The Mann-Kendall trend tests were conducted to detect increasing or decreasing tendencies on the time series data of streamflow, which were collected from eighteen gauging stations in the Elkhorn River and its tributaries. Decreasing trends were not found in the annual streamflow data.

Field investigation of streambed hydraulic properties was performed in the Elkhorn River near Winslow and Norfolk. Vertical hydraulic conductivities (K_v) of the shallow streambed sediments were obtained by …

Method And System For Optimal Coordination Control And Soft Repair Of Multiple Rooftop Heating And Cooling Units, Haorong Li

Durham School of Architectural Engineering and Construction: Faculty Publications

Techniques are described that may be implemented in an adaptive control device to regulate multiple zone environmental units based upon multiple temperature values and multiple airflow values, where each temperature value and each airflow value is related to the temperature and the airflow in a specific zone. In an implementation, the input interface of the adaptive control device is configured to receive multiple temperature values and multiple air flow values from multiple zone sensors. The adaptive control device may calculate multiple operational values based on the multiple temperature values and the multiple air flow values. An operational value indicates a …

The Influence Of National Culture On Effectiveness Of Safety Trainings During Postdisaster Reconstruction, Behzad Esmaeili, Kevin Grosskopf, Amy Javernick-Will

Durham School of Architectural Engineering and Construction: Faculty Publications

Non-English speaking workers constitute a disproportionately high number of workers involved in postdisaster reconstruction. Additionally, the rate of fatality among these workers is higher than the industry average. Research shows this population is more prone to unsafe behaviors in the working environment, conceivably because many of these workers are sent into the field prior to any formalized training. Recent studies show that the native culture of construction workers can impact risk-taking behavior. While numerous researchers have attempted to develop training materials for Hispanic workers, the number of studies that consider the impact of native culture on safety behavior is minimal. …

Virtual Surface Temperature Sensor For Multi-Zone Commercial Buildings, Yuebin Yu, Denchai Woradechjumroen, Daihong Yu

Durham School of Architectural Engineering and Construction: Faculty Publications

Multi-zone structure is commonly used in small commercial office buildings, retail stores and supermarket. While there is no adjacent wall between the zones, the impact of a neighbor zone on the current zone can be approximated and analyzed through the application of virtual walls. It is critical to accurately estimate the virtual wall surface temperature in order to evaluate the model uncertainty and apply improved supervisory control on multiple rooftop air-conditioning units (RTUs). We propose an innovative virtual surface temperature sensor based on system-identification to solve this challenge. The validation of the virtual temperature model is processed by the three …

Shallow Flat Soffit Precast Concrete Floor System, George Morcous, Maher Tadros

Durham School of Architectural Engineering and Construction: Faculty Publications

A precast concrete floor system that eliminates the need for column corbels and beam ledges while being very shallow. The main advantages of the present system include a span to-depth ratio of 30, a flat soffit, economy, consistency with prevailing erection techniques, and fire and corrosion protection. The present system consists of continuous precast columns, prestressed rectangular beams, hollow-core planks, and cast-in-place composite topping. Testing results have indicated that a 12 inch deep flat soffit precast floor system has adequate capacity to carry gravity loads (including 100 psf live load) in a 30 ft x 30 ft bay size. Testing …

Hybrid Of Natural Element Method (Nem) With Genetic Algorithm (Ga) To Find Critical Slip Surface, Shahriar Shahrokhabadi, Vahid Khoshfahm, Hamed Nabizadeh Rafsanjani

Durham School of Architectural Engineering and Construction: Faculty Publications

One of the most important issues in geotechnical engineering is the slope stability analysis for determination of the factor of safety and the probable slip surface. Finite Element Method (FEM) is well suited for numerical study of advanced geotechnical problems. However, mesh requirements of FEM creates some difficulties for solution processing in certain problems. Recently, motivated by these limitations, several new Meshfree methods such as Natural Element Method (NEM) have been used to analyze engineering problems. This paper presents advantages of using NEM in 2D slope stability analysis and Genetic Algorithm (GA) optimization to determine the probable slip surface and …

A Case Study Of Zero Energy Home Built For Solar Decathlon Competition 2013, Sanjib Mulepati

UNLV Theses, Dissertations, Professional Papers, and Capstones

Energy consumption in residential homes has been a subject of research related to sustainability. Reduction in the consumption of energy is a goal of sustainable construction. The Department of Energy (DOE) started a Solar Decathlon competition in 2002 in which the students from different universities around the globe build an energy efficient and affordable home suitable for their climate and location. The main goal of this competition is to select the best home that is designed and built in a sustainable way. In this study, the home designed and constructed for participation in the competition by the students at University …

The Cost Of Green Infrastructure: Worth The Investment?, Martha Sheils

Green Infrastructure

Is GI worth the investment?

• LID techniques often lead to cost savings when we look at WHOLE PROJECT COSTS

• Natural Infrastructure investments for flood control, drinking water protection and wildlife habitat can yield SIGNIFICANT AVOIDED COSTS and additional co-benefits to communitites

Compression Testing And Failure Modes Of Steel-Concrete Composite (Sc) Structures For Nuclear Containment, Patrick Michael Wanamaker, Amit H. Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

Although being able to provide much cleaner power than burning coal and other fossil fuels, nuclear power plants are still a tough sell to the general public due to their history of being spontaneously dangerous. The containment structures surrounding these nuclear plants, however, can play a huge role in reducing the risks associated with them. Relatively new designs for these containment assemblies, known as SC (steel-concrete composite) structures, aim to increase the strength and durability of the containment facilities while keeping costs down. By varying the spacing between shear studs, the ratio of concrete to steel, and the ratio of …

Environmental Monitoring In Preparation For The Installation Of A Green Roof, Andrew N. Martin, Ming Qu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Green roofs are becoming an increasingly popular way to improve the environmental, economic, and aesthetic performance of both new and existing buildings. Along with the green roofs themselves, it is also common to install sensors to measure various environmental parameters that are affected by or important to the operation of the roof such as precipitation, temperature, and runoff. However, for most of these systems, the sensors are installed at the same time or even after the green roof. Therefore, no before-and-after comparisons can be made for those roofs. To account for this missing data, monitoring equipment was installed on a …

Evaluation Of Phase Change Materials For Cooling In A Super-Insulated Passive House, Jeffrey Stephen Lauck

Dissertations and Theses

Due to factors such as rising energy costs, diminishing resources, and climate change, the demand for high performance buildings is on the rise. As a result, several new building standards have emerged including the Passive House Standard, a rigorous energy-use standard based on a super-insulated and very tightly sealed building envelope. The standard requires that that air infiltration is less than or equal to 0.6 air changes per hour at a 50 Pascal pressure difference, annual heating energy is less than or equal to 15kWh/m2, and total annual source energy is less than or equal to 120 kWh/m2. A common …

Sustainable Design Education Through A Self-Directed Online System, Jeremy Faludi, Adam Menter

Dartmouth Scholarship

Sustainable design and engineering is an important topic, yet it is under-represented in educational institutions; moreover, it must be taught to practicing professionals, not just students. A free online system has been created to address both problems at once, providing educational materials for educators and also providing a self-paced program for professionals or students to earn a certificate in sustainable design. Called the Autodesk Sustainability Workshop, it is a collection of video tutorials and supporting materials (PDF reference guides, slide decks, quizzes, and other resources) that can be used either by individuals themselves or by educators (either in schools or …

Sustainable Urban Rail Trails: Designing The Cross Kirkland Corridor, Mia Cooledge

Scripps Senior Theses

This thesis is a guide to building a sustainable rail-trail, wherein I focus on invasive species removal, green pavement, and creating an inviting space with the inclusion of integrated art. When the City of Kirkland, WA purchased the 5.75 mile long section of railroad going through the city, I approached city manager Kurt Triplett to ask about his plans for the corridor. He liked the idea of aiming for a sustainable trail, so I wrote a guide to building an environmentally friendly trail based on a number of prominent readings on sustainable design.

Managing Moisture - The Key To Healthy Internal Wall Insulation Retrofits Of Solid Walls, Joseph Little, Benat Arregi

Conference papers

This study investigates the appropriateness of internally insulating solid walls to the Passivhaus standard. A number of variables are assessed using numerical hygrothermal simulation (under EN 15026) to check (1) associated risk of mould growth on original substrate and (2) if they result in a greater likelihood of timber decay at built-in joist ends. While air and vapour control layers (AVCLs) perform well regarding mould risk in low absorption walls, the results question their appropriateness where joist ends are built-in: when AVCLs are used, moisture levels at joist ends can potentially rise above critical thresholds, even in low absorption walls. …

Multi-Objective Time-Cost Optimization Using Cobb-Douglas Production Function And Hybrid Genetic Algorithm, Zhigang Shen, Ashkan Hassani, Qian Shi

Durham School of Architectural Engineering and Construction: Faculty Publications

Existing research on construction time-cost tradeoff issues rarely explore the origin of the crashing cost. Crashing cost function was either assumed without much justification, or came from historical data of some real projects. As a result the conclusions of the papers can hardly be used to guide allocations of labor and equipment resources respectively. The authors believe Cobb-Douglas function provides a much-needed piece to modeling the cost functions in the construction time-cost tradeoff problem during the crashing process. We believe this new perspective fills a gap of existing time-cost tradeoff research by considering project duration, labor and equipment cost as …

Effects Of Reverberation And Noise On Speech Comprehension By Native And Non-Native English-Speaking Listeners, Z. Ellen Peng, Lily M. Wang, Siu-Kit Lau, Adam M. Steinbach

Durham School of Architectural Engineering and Construction: Faculty Publications

Previous studies have demonstrated the negative impact of adverse signal-to-noise-ratios on non-native English-speaking listeners' performance on speech recognition using recall tasks, as well as implied that comprehension skills were more impaired than recognition skills under reverberation and noise. The authors have themselves previously conducted a pilot study on three native and three non-native Englishspeaking listeners to examine the effects of reverberation and noise using speech comprehension tasks. Those results suggested that speech comprehension performance is worse under longer reverberation times (RT), and that a longer RT is more detrimental to speech comprehension by non-native listeners than native listeners. This paper …

Acoustic Tweets And Blogs: Using Social Media In An Undergraduate Acoustics Course, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Each fall, the author teaches an undergraduate architectural acoustics course to around 40 third-year architectural engineering students at the University of Nebraska. Beginning in 2011, a social media component was introduced to explore the use of this technology and how it may supplement the students' learning experience. Students were given an opportunity to receive extra credit by using Twitter and/or blogging about course material using a set hashtag (#AE3300) or through the course website. Results were positive, and the author will discuss pros and cons that she has experienced in adding this social media component. Suggestions for future implementations and …

Development Of Dynamic Thermal Performance Metrics For Eco-Roof Systems, Seth Sinclair Moody

Dissertations and Theses

In order to obtain credit for an eco-roof in building energy load calculations the steady state and time-varying thermal properties (thermal mass with evapotranspiration) must be fully understood. The following study presents results of experimentation and modeling in an effort to develop dynamic thermal mass performance metrics for eco-roof systems. The work is focused on understanding the thermal parameters (foliage & soil) of an eco-roof, further validation of the EnergyPlus Green Roof Module and development of a standardized metric for assessing the time-varying thermal benefits of eco-roof systems that can be applied across building types and climate zones. Eco-roof foliage, …

Mixed Method Collaboration In The Built Environment, Dermot Kehily

Conference papers

The built environment discipline or inter-discipline is a relatively new field in academic research. Its subject matter however is based on the traditional disciplines of the construction and property industries. Determining your ontological position and epistemological approach based on the researchparadigm of one of these fields’ may not provide an adequate solution to your research objectives.This paper outlines that framing your research within the broader confines of the built environment; drawing from related fields in an integrated manner may provide a more successful outcome.Arguments whether the built environment is an academic discipline or even the range of subjects thatmake up …

Lifecycle Energy Consumption Prediction Of Residential Buildings By Incorporating Longitudinal Uncertainties, Endong Wang, Zhigang Shen

Durham School of Architectural Engineering and Construction: Faculty Publications

Accurate prediction of buildings’ lifecycle energy consumption is a critical part in lifecycle assessment of residential buildings. Longitudinal variations in building conditions, weather conditions and building’s service life can cause significant deviation of the prediction from the real lifecycle energy consumption. The objective is to improve the accuracy of lifecycle energy consumption prediction by properly modelling the longitudinal variations in residential energy consumption model using Markov chain based stochastic approach. A stochastic Markov model considering longitudinal uncertainties in building condition, degree days, and service life is developed: 1) Building’s service life is estimated through Markov deterioration curve derived from actual …

Implementing Building Information Modeling In Public Works Projects In Ireland, Barry Mcauley, Alan V. Hore, Roger West

Conference papers

The Irish State in recent years has suffered huge financial losses in the public works sector, which has now pushed the Irish Government to explore new ways of controlling cost. This background lead to the introduction of the Capital Works Management Framework in 2007 which aimed to support the certainty of outcome in terms of cost and quality, as well as improved risk management, through the implementation of fixed price contracts. In order to successfully compete within this framework it is recommended by the authors, that Irish Government moves towards the legal mandating of BIM. This can ensure a greater …