Graduate Students
 

Graduate Student Guide

Welcome to the Building Systems Program! The BSP Guide contains an outline of things you need to know about the program. It is by no means exhaustive, but should get you started.

Weekly Seminar Series

The Building Systems Program holds a weekly seminar series with guest speakers on current topics in sustainability and research relating to building systems engineering.  Potential students, current students, and alumni are invited to attend.  Below is a list of past and future seminars:

·         August 27            – Kickoff Meeting

·         September 3      – Introduction to Engineering Equation Solver (EES)

·         September 10   – Smart Grid Research Opportunities

·         September 17   – Getting it Right: International Development in the 21st Century

·         September 24   – Review of Building Systems Research, Part 1(Zhai and Krarti)

·         October 1            – Review of Building Systems Research, Part 2(Henze, Protzman, and Brandemuhl)

·         October 15          –  Food:  The Environmental Connections

·         October 22          – Measurement and Verification in Building Energy Efficiency Projects

·         October 29          – Energy Efficiency as a Utility Resource

·         November 5       – Flack + Kurtz Recruiting Presentation

·         November 12    – NREL Residential Buildings Research

·         November 19    – Student Research Presentation

·         December 3       – The new LEED

·         December 10     – Student Research Presentations

Selection of Current/Recently Graduated Students

Erik Greensfelder

HVAC Control Algorithms for Mixed-Mode Buildings

Funder: US Green Building Council

PI: Dr. Gregor Henze

The primary purpose of heating, ventilating, and air-conditioning systems is to provide acceptable indoor air quality and thermal comfort. Hybrid or mixed-mode ventilation systems provide good indoor air quality and thermal climate using natural ventilation whenever the outdoor weather conditions are favorable, but revert to mechanical systems for HVAC whenever external conditions are too harsh. A hybrid building should switch between these two modes of operation according to seasonal, and diurnal variations in the indoor thermal conditions and the outdoor environment. Such a hybrid building requires an intelligent control system that can switch automatically between natural and mechanical modes in such a way that minimizes energy consumption without compromising indoor air quality or the thermal omfort of its occupants.

This research seeks to develop a control algorithm for mixed-mode buildings, which

• minimizes site energy consumption by means of an optimal ventilation and HVAC strategy using both low-energy energy sources such as groundwater, ground, or cool night air as well as mechanical cooling
  
• potentially reduces investment costs by downsizing installed HVAC system capacities
• improves occupant acceptance and reduces sick building syndrome (AC mode only) and heat stress and uncomfortable room temperatures (natural ventilation mode only

William Surles

My emphasis areas are Energy Analysis and Solar & Renewable Energy. I work with the Integrated Teaching and Learning Laboratory as a GK-12 Fellow. This involves bringing engineering activities into K-12 classrooms to excite the students about engineering and to improve their interest in math and science related fields. I teach on many topics related to energy conservation and renewable energy. I am looking to begin thesis/project work next year on the potential of different energy saving techniques in buildings implemented through Boulder’s innovative and unique Smart Grid City project.

David Denkenberger

Dissertation: Novel microchannel heat exchanger that is low cost and high effectiveness with one application of solar water pasteurization for less developed countries.

Other research interests: wind turbines, geoengineering (reducing the amount of sunlight absorbed by the earth by things like mirrors in space, particles in the atmosphere, white plastic in the desert, etc), vehicle to grid, electricity storage, thermal storage in buildings, urban planning, energy efficiency policy

Chad Corbin

Design Parameter Sensitivity of a Building-Integrated Photovoltaic-Thermal Collector

This research explores the design parameters having the greatest impact on thermal and electrical efficiency of a novel, building integrated photovoltaic-thermal array constructed for the 2007 University of Colorado Solar Decathlon. A computer simulation model is constructed from first principles and calibrated using measured performance data from the physical test collector. Results indicate that significant performance improvements are possible through changes in the collector design. Overall combined efficiency of the collector is predicted to reach 67% and electrical output can be as great as 10% higher than a comparable building-integrated photovoltaic collector.

Jessica Rivas

Variable Refrigerant Flow Systems – Simulation Software Evaluation
Advisor: Prof. John Zhai
Committee: Prof. John Zhai, Prof. Moncef Krarti, Prof. Gregor Henze

Variable refrigerant flow (VRF) or variable refrigerant volume (VRV) heat pumps are multi-zone air conditioning systems that vary refrigerant flow rates in order to provide adjustable levels of cooling and/or heating. These systems have been cooling buildings in Asia and Europe for nearly twenty years and are just now making their entrance into North America markets. The major barrier is the lack of a definitive way to calculate the energy consumption, and thus the energy savings, of a VRF system. As the main focus of this research, the accuracy and usability of the few currently available software programs able to model VRF systems are compared. Ultimately, Jessica hopes to provide recommendations to help the industry determine the most convenient and accurate way to both size and estimate the energy savings associated with VRF systems.

Eric Wilson

Eric is currently working to develop a simulation tool that will be able to calculate the energy savings resulting from removing fouling from a forced-air HVAC system (e.g. dirty filter or evaporator coil). Most of the current simulation tools assume steady-state conditions for air-side energy losses, such as fan power, duct leakage, and duct conduction. This project seeks to evaluate the magnitude of these factors, by developing a simulation model that accurately represents the physics of typical residential and commercial forced air HVAC systems.

Knud Hermansen

Data center modeling
Funding: ASHRAE
Advisor: John Zhai
I am a master’s student working on data center modeling. Current models for predicting heating patterns and airflow in data centers are currently not very accurate – tending to exaggerate hot and cold spots. The question that I am looking at is to what degree we need to model – from looking at the servers as black boxes to modeling individual fans and chips. The issue becomes one of optimizing the accuracy of the model with the time (and money) requirments of each level of modeling detail.

Rois Langner

Rois Langner, RA, Managing the complexity of energy modeling with time efficiency: Guidelines for rapidly modeling large commercial office buildings in EnergyPlus

My research strives to determine best practices for conducting energy audits to expediently develop energy models for large commercial buildings. For a particular geographical location, this assumes that the energy consumption in typical office buildings is effected by a particular list of driving factors. To verify that such a list of driving factors exists, a fractional factorial analysis will be conducted to identify the effects of a large list of modeling parameters on heating and cooling loads. In order to conduct this fractional factorial analysis, 36 high-rise office buildings in downtown Chicago have been audited. Out of the 36 buildings, approximately one dozen have been modeled with the help of a custom made suite of rapid modeling tools, and lessons learned have been documented. If the same, small set of parameters emerges from this analysis as being of primary importance, it is reasonable that the presumed modeling guidelines can be developed.