Organizational Unit:

School of Architecture

Permanent Link

https://hdl.handle.net/1853/70770

Parent Organization

Organizational Unit

College of Design

ArchiveSpace Name Record

https://finding-aids.library.gatech.edu/agents/corporate_entities/1120

Full item page

Publication Search Results

Now showing 1 - 10 of 10

Solar shift: A perspective on building energy performance under haze pollutions in China

(Georgia Institute of Technology, 2016-05-31) Jia, Yiyuan

The severe haze pollution in China has arisen concerns among the public and government officials, due to its impacts on pubic health, visibility, climate and agriculture. To augment these findings of the negative impacts of haze pollution, this study investigates the “solar shift” effect due to haze pollutions and the potential (unreported) impacts on buildings’ energy performance in China. This study takes the aerosol optical depth (AOD) as a measure of the solar blocking effect of haze pollutions. By plugging in the measured and projected AOD data in solar models, three weather files for Beijing are developed that represent different haze pollution for the following scenarios: the 2014 situation, the optimistic projection of 2050 (2050A) and the pessimistic projection of 2050 (2050B). Together with the TMY, these weather files serve as the boundary conditions in building energy modeling practices. The results indicate the district heating energy consumption under the 2014 aerosol emission levels would increase 5 % compared to the current practice using TMY weather file. In the pessimistic scenario where we assume to keep the current pace of aerosol emissions, the district heating energy would increase 10 %. The current ASHRAE design day sizing method would assure the heating load being met under all possible scenarios investigated in this study.
Application of the functional scenarios method on alternative settings

(Georgia Institute of Technology, 2016-05-09) Bushehri, Yousef

Goals of this study are to set up the frame-work for analyzing residential buildings using the functional scenarios method and to tests the applicability of the method on large scale projects. The metrics for the analysis are based on guidelines for designing spaces that promote healthy aging. In addition, the study was providing an opportunity to developing and refined the method. The result of the analysis determines that the functional scenarios method is applicable to large scale buildings as effectively as smalls scale buildings; design configurations can be extracted from the results of the analysis to inform future designs. The limitations of the analysis are due to the available resources. Opportunities for continued work include 1) developing standard ways of representing the results of the analysis; and 2) developing a systematic approach for extracting design configurations based on the research questions asked.
Towards modeling of retrofit processes

(Georgia Institute of Technology, 2015-08-05) Szymkiewicz, Paul M.

Energy retrofits can be executed by a building owner with or without the supervision of a third-party agent. We define process models to capture third-party energy retrofit inspection activities, and refine, augment, and generalize those models to then examine the impact of third-party retrofit inspections. Buildings included in the study vary considerably in type, and so do retrofit programs applied to those buildings.
Digital representation and constructability of minimal surfaces in concrete

(Georgia Institute of Technology, 2015-07-27) Keskin, Zeynep

This thesis investigates minimal surfaces in design and researches their potential for constructability in concrete through the creation of physical prototypes with the design of two mold making processes, one being sacrificial and the other reusable. The study starts by acknowledging that minimal surfaces have been extensively explored in the field of differential geometry for decades. In spite of the availability of geometric definitions which provide the basic background for digital model generation (which in this text is assumed to be equal to design itself), minimal surfaces inspired very few people in their architectural design. This study attempts to look into the wider implications of minimal surfaces for architecture by taking up the challenge of designing and realizing various processes of mold making for the fabrication of such surfaces in concrete. Throughout this study, a gradient of complexity in the definition and digital modeling of minimal surfaces will be included as well as a variety of production methods in a research and fabrication based process, in order to investigate the correlation between what can be designed and what can be produced. I shall begin with a historical survey of the constructability of surfaces in thin shell concrete to provide background information for the reader. This chapter on the evolution of concrete structures presents a compilation of selected projects to illustrate the progress of thin shell construction throughout the history of architecture. It is here that I review what happened, why, and who made it possible. I draw heavily on published scholarly studies as most of the selected projects are cornerstones of the evolution of architecture and have been discussed by many others. Here, I simply attempt to remind the reader of the achievements of these projects in order to justify why investigation of the constructability of minimal surfaces may be the next step in the evolutionary process. After this section, the mathematics of surfaces in the complex plane is discussed based on information retrieved from many excellent resources. Here, the intention is to acquire information related to descriptions of various minimal surface types in differential geometry in order to be able to generate their representations in the digital environment. It would have been impossible to generate digital representations of minimal surfaces without the knowledge acquired through these descriptions. The last section provides a comparison of ruled surfaces and minimal surfaces meant to reveal the similarities and differences of such surfaces with regard to the principles of digital representation and fabrication. It provides insight into various fabrication techniques and materials to illuminate the design of a making process in which the goal is to know and control every parameter regarding both the design and fabrication of an object. The discussion of the design of a making process for a complexly shaped object provided in this part is followed by discussion of casting prototypes in concrete. In that section, the subject matter is the design and testing of various mold making techniques for the production of concrete prototypes of a selected minimal surface geometry. This section presents an increasing complexity of mold making from a sacrificial mold to a reusable mold.
HVAC operation uncertainty in energy performance gap

(Georgia Institute of Technology, 2015-05-19) Wang, Yijia

This study aims at a preliminary characterization of system operation uncertainty. It bases this on an analysis of the energy consumption of 6 existing buildings on the Georgia Tech campus. The analysis is speculative in nature.
Thermo-hygroscopic envelope to support alternative cooling systems: speculative feasibility study in a small office building

(Georgia Institute of Technology, 2014-09-02) Marshall, Marionyt Tyrone

The thesis explores the technical feasibility of an alternative method of decoupling air-conditioning systems function within the context of ecological issues. The system is a variant of dedicated outdoor air systems to separate dehumidification and cooling in air conditioning equipment. The project specifically investigates locating these components within the building envelope. Placement in the envelope moves the systems closer to fresh air and offers architectural expression for components that are normally out of sight. Designers, engineers, building science, mechanical, structural, biologist, and architectural engineers ideally as agents offer beneficial improvement to the system. The reduction in size of components into the building envelope offers risk. The thesis design space uses historical works, biological analogues, and past work to ground the technical understanding of the topic. Specific use of biological inspired design realizes translation from other systems to improve the alternative decoupled air conditioning system. The thesis develops prototype models for lighting analysis and for sensible and latent heat calculations. Psychrometric charts serve as tools to understand the thermodynamic air-conditioning process in conventional direct expansion vapor compression and solar liquid desiccant air conditioning systems. Data, models, and sketches provide tools for improvements to the 'thick' building envelope. Finally, the diagrams translate into functional decompositions for modifications to improve the system. The thesis probes the constraints in the areas of cost, fabrication, and technology that may not yet exist for selective improvement rather than a barrier to development of the thesis.
Characterization of HVAC operation uncertainty in EnergyPlus AHU modules

(Georgia Institute of Technology, 2014-04-21) Sui, Di

This study addresses 5 uncertainties that exist in the operation of HVAC systems, which will presumably affect the actual energy consumption of the HVAC system in comparison to the consumption under idealized bahavior. We consequently add these parameters and their uncertainty range into the source code, eventually resulting in an EnergyPlus program in which the HVAC operation uncertainty is embedded as so-called model form uncertainty. The upgraded EnergyPlus is tested for each parameter uncertainty separately, and to show the impact of each uncertainty albeit for hypothetical uncertainty ranges of the parameters.
A study on the heat transfer and energy performance implications of cool roofs

(Georgia Institute of Technology, 2013-11-26) Zhang, Tianyao

In this study, we examined the effect of cool roofs on commercial and residential buildings in each climate zone, by looking at monitored case studies and DOE-2 simulations from various sources of literature; and using an online tool - the Cool Roof Calculator and a simple COP ratio model to validate the results of the case studies. It was found that the Cool Roof Calculator does not take building form into account, hence a sensitivity analysis was first conducted to rank the importance of various building parameters against one another. The analysis was conducted on the EPC normative building energy model. Results indicated that roof absorptance coefficient, aspect ratio and number of floors were the three parameters that either ranked highest or were important parameters, and were chosen for further parametric analysis to evaluate the impact of these building parameters on total building loads. A simple COP ratio model was also developed to validate the results from the literature review and Cool Roof Calculator, and it was found that in terms of cost, for a prototype medium-sized commercial building, it is always beneficial to use a white roof, but cities in northern climates may have little advantage, and insulation may be a better choice.
Comparative analysis of the VRF system and conventional HVAC systems, focused on life-cycle cost

(Georgia Institute of Technology, 2013-11-26) Park, Jaesuk

As concern for the environment has been dramatically raised over the recent decade, all fields have increased their efforts to reduce impact on environment. The field of construction has responded and started to develop the building performance strategies as well as regulations to reduce the impact on the environment. HVAC systems are obviously one of the key factors of building energy consumption. This study investigates the system performance and economic value of variable refrigerant flow (VRF) systems relative to conventional HVAC systems by comparing life-cycle cost of VRF systems to that of conventional HVAC systems. VRF systems consist mainly of one outdoor unit and several indoor units. The outdoor unit provides all indoor units with cooled or heated refrigerant; with these refrigerants, each indoor unit serves one zone, delivering either heating or cooling. Due to its special configuration, the VRF system can cool some zones and heat other zones simultaneously. This comparative analysis covers six building types—medium office, standalone retail, primary school, hotel, hospital, and apartment—in a eleven climate zones—1A Miami, 2A Houston, 2B Phoenix, 3A Atlanta, 3B Las Vegas, 3C San Francisco, 4A Baltimore, 4B Albuquerque, 4C Seattle, 5A Chicago, and 5B Boulder. Energy simulations conducted by EnergyPlus are done for each building type in each climate zone. Base cases for each simulation are the reference models that U.S. Department of Energy has developed, whereas the alternative case is the same building in the same location with a VRF system. The life-cycle cost analysis provides Net Savings, Savingto- Investment ratio, and payback years. The major findings are that the VRF system has an average of thirty-nine percent HVAC energy consumption savings. As for the results of the life-cycle cost analysis, the average of simple payback period is twelve years.
Inverse modeling to predict effective leakage area

(Georgia Institute of Technology, 2012-11-14) Qi, Te

The purpose of this research is to develop a new approach to estimate the effective leakage area using the inverse modeling process as an alternative to the blower door test. An actual office building, which is the head quarter of Energy Efficiency Hub, was used as an example case in this study. The main principle of the inverse modeling process is comparing the real monitor boiler gas consumption with the result calculated from the EnergyPlus model with a dynamic infiltration rate input to find the best estimation of the parameter of effective leakage area (ELA). This thesis considers only the feasibility of replacing the blower door test with the calibration approach, so rather than attempting an automated calibration process based on inverse modeling we deal with generating a first estimate and consider the role of model uncertainties that would make the proposed method less feasible. There are five steps of the whole process. First, we need to customize our own actual weather data (AMY) needed by the energy model (EnergyPlus model), which can help increase our quality of the result. Second, create the building energy model in EnergyPlus. Third, create a multi-zone model using CONTAM with different ELA estimation of each facade to calculate the dynamic infiltration rate of each ELA estimate. Fourth, input the dynamic infiltration rate got from the CONTAM model to EnergyPlus model and output the boiler energy consumption. Fifth, compare the boiler gas consumption from the model and the real monitor data and find the best match between the two and the corresponding ELA, which gives the best estimate from the whole inverse modeling process. From the simulation result comparison, the best estimation of the total building ELA from the inverse modeling process is the 23437cm2 at 4pa, while the result from the blower door test is 10483cm2 at 4pa. Because of the insufficient information of the building and also the uncertainty of the input parameters, the study has not led to a definite statement whether the proposed calibration of the ELA with consumption data can replace a blower door test to get an equally valid or even better ELA estimate, but it looks feasible. As this this case study is done in a deterministic context, the full feasibility test should be conducted under uncertainty. A first step towards this will talk be discussed in chapter 4.