Technical Reports, Papers, & Presentations
An Evaluation of the actual energy and indoor environmental quality performance of on-campus buildings designed in accordance with LEED V4 rating criteria for new construction, Final Report (PDF)
The research presented in this report develops a suite of guidelines for architects and engineers to ensure adequate Indoor Environmental Quality (IEQ) along with providing measures for reducing energy consumption in the operation of Green buildings. The guidelines prompt designers to account for occupant comfort via means of ensuring adequate IEQ when considering implementation of energy efficiency strategies in Green buildings. This study also establishes a hands-on experience for students of architecture and engineering in evaluating the physical performance of building systems. By establishing this experience, the study underlines the importance as well as the correlation between energy efficiency and IEQ in Green buildings.
Identifying Appropriate High-Performance Building Environmental Control Technologies for Commercial Code Enhancement in Montana (Part 1 PDF, Part 2 PDF)
This report identifies and evaluates advanced design and construction practices that have been adopted in High Performance Buildings across Montana. The intent is to evaluate the feasibility and affordability of such practices as well as to identify potential code measures appropriate to Montana. A general list has been compiled for High performance systems and equipment that were commonly found in the buildings that were surveyed. Several High Performance buildings were identified as case-studies. High performance technologies implemented in these buildings was documented and the buildings were evaluated in terms of energy performance. In addition, several emerging High performance technologies were identified from a literature review. The High performance environmental control technologies were then evaluated individually in terms of: advantages, applications, challenges of operating in a cold climate, incorporating system specifications in energy codes, and challenges associated with the O&M of the system.
REHAU MONTANA ECOSMART HOUSE PROJECT
The REHAU Montana Ecosmart House in Bozeman is a LEED®-certified house with high levels of insulation and low heat loss, resulting in a certified HERS score of just 32. Each of the following PDF files explains the various tests done on the Ecosmart House. Download the files to read more about the project!
Evaluation of Temperature Stratification in Room with Cathedral Ceiling:
Radiant Floor Heating vs. Forced Air
Peer Reviewed Papers
Using Computational Fluid Dynamics to Characterize Airflow Through an Air Handling Unit: ASHRAE Conference Proceeding OR-16-C070. Authors: Andrew E. Byl; Kevin L. Amende; Erick L. Johnson.
HVAC equipment manufacturers spend a considerable amount of time and effort updating existing product lines in order to meet ever-increasing performance standards. Traditional approaches consisting of several prototype iterations being built and experimentally tested are time consuming and costly. Through advancements in computer technologies within the last decade, computational fluid dynamics (CFD) has become an economical solution allowing HVAC equipment designers to numerically model prototypes and reduce the time required to optimize a given design and identify any potential failures points. Airflow uniformity is considered an important consideration for air handling unit (AHU) manufacturers as it affects the performance of the overall system. Plenum fans inherently produce a rotational airflow pattern, which, if not mitigated appropriately, can create a highly, non-uniform airflow that enters a heat exchanger located downstream. This can lead to lower heat transfer rates and premature heat exchanger failure. While CFD offers the ability to visualize and characterize the airflow through an AHU system, it is often used to solely model individual components such as fans or heat exchangers without analyzing it in a real world situation. This paper presents the CFD models used to characterize the airflow uniformity within an AHU in order to aid in understanding heat exchanger performance.
Reduction of Campus Greenhouse Gas Emissions through a Hybrid Centralized Energy Distribution System: ASHRAE Conference Proceeding OR-16-CO35. Authors: Chelsea L. Guenette; Joshua W. Talbert; Kevin L. Amende.
Institutional campuses often times encompass both centralized and decentralized heating and cooling systems. Each configuration inherently has advantages and challenges when trying to maintain occupant comfort while minimizing energy consumption. Recent technological advancement in computing power allows building energy modelers to quickly and efficiently develop models which can be evaluated as part of a centralized plant or as a stand-alone system. International attention to greenhouse gas (GHG) emission reduction has influenced policy in many nations around the world. According to the White House Press Secretary, the United States is targeting net GHG emissions 26-28% below 2005 levels by 2025. The attention to GHG emission reduction has brought the benefits of energy modeling to the forefront of building designers, managers and policy makers. Montana State University, located in Bozeman, Montana, has a dry, heating dominated climate. Currently the university operates a centralized steam plant serving 59 buildings totaling just over 3-million square feet. This centralized heating system distributes steam across campus using a network of utility tunnels. The cooling systems, however, are decentralized and primarily use cooling towers to reject heat. This paper details an alternative configuration the university evaluated and subsequently implemented to reduce GHG emission on campus. The university interconnected a small group of buildings to form an energy “mini-district” within the large centralized campus district. This mini-district contains eight buildings totaling just over 400,000 ft2 (37,000 m2) or 14% of the total campus building square footage. These buildings contain research laboratories with substantial internal demand loads and traditional classrooms having natural, diurnal loads. Before implementing the mini-district it was common to see some buildings rejecting heat through cooling towers while adjacent buildings were experiencing heating demands. The energy mini-district uses a centralized heat pump plant with water loops allowing energy to be shared between the buildings. This configuration also allows for future incorporation of low carbon energy sources such as solar thermal arrays and ground-source bore fields. Building energy models were created and tuned using both historical utility data and energy measurements within the mini-district. Evaluation of the energy mini-district shows a GHG emission reduction of 14.26% over the original configuration using the steam heating plant with cooling towers.
In-Situ Testing of Shallow Depth Helical Heat Exchangers for Ground Source Heat Pump Systems: ASHRAEConference Proceeding OR-16-C044. Authors: Francisco J. Alvarez-Revenga; Kevin L. Amende; Angelo Zarrella.
This paper explores the performance of shallow depth helical heat exchangers coupled with ground source heat pumps (GSHP) for residential HVAC applications. These vertical helical heat exchangers occupy considerably less land when compared to horizontal configurations, and are less influenced by outdoor temperature and weather conditions. When compared to traditional vertical deep probes, savings on drilling costs can be significant. However, performance data and design information is limited for this type of heat exchangers, which has limited their adoption amongst GSHP system designers and installers. In-situ heating and cooling tests were performed at a residence located in Bozeman, Montana, with a system containing three 12 ft (3.7 m) long helical ground heat exchangers installed to a depth of 6 to 18 ft (1.8 to 5.5 m) below the surface. The heat exchangers were coupled to a GSHP with variable capacity compressors. Moreover, a recently developed numerical model was used to compare the experimental results with the simulated performance. Heat exchanger outlet temperature as predicted by the CaRM-He model were compared with experimental data, resulting in a good agreement, especially in cooling mode. The advantages of this ground coupling method and the possibility to predict its performance make these systems an interesting option for the residential geothermal designer.
In Situ Testing of Earth-Air Heat Exchangers: Under Slab vs. Under Yard: ASHRAE Conference Proceeding DA-14-C081. Authors:Chantz M. Denowh, Student Member ASHRAE; Kevin L. Amende, PE, Associate Member ASHRAE.
Earth-air heat exchangers (EAHX) have the potential to reduce residential heating and cooling loads by pre-conditioning outside air through under soil pipes. Typical installations of EAHX occur in green space located adjacent to existing residences. However, during new construction these systems could be installed under the foundation with a minimum amount of additional excavation taking place. The following study compares the performance of both installation types located at a residence in Bozeman, Montana. The comparison indicates the soil temperature distribution and heat transfer mechanisms are different for each location. For a comprehensive comparison, the annual soil temperatures under the green space and foundation are modeled using an analytical and finite element method approach respectively. This is done for both a heating and cooling dominate climate. The results indicate the annual soil temperatures in the green space vary around the average annual surface temperature while under the foundation the temperatures are higher and relatively constant. It was concluded that for a heating dominate climate the under foundation installation results in higher annual soil temperatures, and thus greater energy savings through the heating season. Cooling dominated climates tend to benefit more from installations under the green space where soil temperatures are reduced during the winter months.