This workshop discusses the results of 1627-RP, completed in 2016. This research investigated the effectiveness of 30% Advanced Energy Design Guidelines (AEDGs) for K-12 schools and small office buildings, determined the factors common to well and poorly performing buildings and provided recommendations for how future AEDGs could be made more effective.

Using the recent success of 1627-RP as a template, this workshop discusses the potential for additional research projects that identify statistically-significant samples of real buildings built using Std 90.1-2010. Can this type of research be replicated to provide real-world input to future ASHRAE Standards and publications? What guidance can the actual performance of these buildings provide?

This paper examines developing air conditioning systems in the playground zone of a stadium by employing several kinds of technologies to cool the outdoor spaces. The most serious challenge of air conditioning in a playground zone in stadium is controlling the temperature and humidity in the outdoor area and also the enormous energy needed by the cooling system to maintain thermal comfort conditions within the football playground area. The main task for the analyzed model was to ensure the better method to distribute air to achieve the human comfort level for players and reducing the cooling capacity of playground zone by using a large sunshade to reduce the sun's rays and maintain the stadium's temperature.

This paper describes the chiller selection design and procurement process for a building thermal management system. The design procedures described in this paper are based on those carried out during an energy efficiency engineering internship in a local Los Angeles company and thus serving as an example of real world training. This paper presents the results of a case study to replace chillers that are approaching the end of their useful life. This case study is an example of how engineering interns are exposed to the various ASHRAE Standards. The retrofit project was carried out according to specifications and drawing of the existing obsolete equipment and adhering to Standard 90.1 “Minimum Requirements for Chillers” and the ASHRAE “Chiller Life Expectancy” guidelines used to govern chiller selection and installation. Results for COP lift versus load and chiller load versus system load are presented in the paper.

Louvers (or vents) are primarily used in air conditioners, fans and air-coolers for directional circulation of air in a confinement. Hence, it is of interest to determine the downstream flow field characteristics of air passing through these louvers for cooling and ventilating the confinement. A detailed Computational Fluid Dynamics analysis can be done by resolving all the geometrical features of the louver and setting the appropriate boundary conditions. However, this involves high computational effort, especially, in case of physical movement of the louvers for time-varying directional delivery of the air. The central aim of this research is to develop a rapid airflow model which can replicate similar downstream flow characteristics while obviating the necessity to geometrically resolve the louver. This paper examines the results of this research.

Air finned-tube evaporators and/or condensers, are the predominant type of heat exchangers used in building air conditioning applications. The compact V-shaped, or sometimes called A–shaped, finned-tube heat exchanger installation considerably enhance the capacity of heat transfer by allowing the maximum number of coils installed in a given space and increasing the total surface area of heat transfer. On the other hand, this design configuration creates noticeable problems of uneven distribution of air flow velocity over the heat exchanger surfaces, which decreases the energy efficiency of the air conditioning system. This paper uses computational methods to investigate the problems of mismatch between the air and refrigerant flow distributions and propose different engineering solutions at air flow side as well as refrigerant flow side to remedy the problems.

Streamwise longitudinal vortex generation is a promising method for enhancing air-side heat transfer performance of heat exchangers in a range of applications. In this paper, the vortex-enhanced air-side flow and heat transfer for offset strip-fin array is studied with an emphasis on understanding the relation between flow structure and heat transfer. The flow and heat transfer behavior of the baseline offset strip-fin geometry has been thoroughly investigated both experimentally and numerically in the literature. However, numerical modelling of vortex generator (VG) enhanced offset-strip fin array has not been reported. The predictive capability of the model in terms of the local flow and heat transfer characteristics is evaluated in such geometry for both baseline and enhanced cases.

Currently, the taxonomy of HVAC system and components has various basis, which can get quite complex because of the various components and system configurations. In addition, some of the system names might be commonly used in a confusing manner, such as “unitary system” vs. “packaged system.” Without a systematic classification, these components and system terminology can be confusing to understand or differentiate from each other, and it creates ambiguity in communication, interpretation, and documentation. It is valuable to organize and classify HVAC systems and components so that they can be easily understood and used in a consistent manner. This paper aims to develop a systematic classification of HVAC systems and components.

Within the last decades, needs for building control systems that reduce cost, energy, peak demand and that facilitate building-grid integration, district-energy system optimization and occupant interaction have come about. Model Predictive Control (MPC) is a control technique that utilizes system models and forecasts to predict performance and optimize control inputs in real-time. This presentation discusses in detail the ways occupant interaction with MPC-controlled building systems can occur, particularly as related to the control of HVAC systems, including benefits, drawbacks and challenges. This presentation discusses progress on current work that is exploring and implementing these interactions in demonstration buildings.

This presentation reviews current occupancy behavior (OB) based MPC control projects for smart building at the University of Texas at San Antonio. Challenges and opportunities of OB-MPC for smart buildings are presented and discussed, particularly on models to use, occupancy data and optimization algorithms. Simulation results show that OB-MPC can achieve up to 24% energy cost reduction in residential buildings and 17% in commercial buildings.

This presentation covers the collaborative research work from cross-functional team effort behind the journal paper that was recently honored with ASHRAE Research Journal Best Paper of the Year Award. The development and application of a fault and occupant tolerant control technology, its online implementation, and results from several tests conducted for a large-sized HVAC system are discussed. The performance and limitations of the fault detection and diagnosis, model predictive control as well as the fault and occupant tolerant control algorithms are illustrated and discussed using measurement data recorded from multiple field tests.

MPC is a new approach to controlling building systems to optimize equipment operation. Meanwhile, occupant behavior is a key contributor to the uncertainty of energy consumption. The combination of MPC and OB would foster great building energy saving potential. The integrated network to measure occupancy and behavior related with environmental parameters is introduced. With the measured data, the occupant behavior predicting models will be built and integrated with the building system model to improve the control logic. A demonstration of the predictive model application is presented to see the effect of occupant behavior based model predictive control.

This presentation introduces exotic applications of absorption heat pumps that have been actually implemented. These can serve to provide new creative solutions to modern challenges in industrial thermal management. After a quick introduction into absorption process, the examples are explained in their economic context, the technical solution is explained in brief and the results are explained in their economic and environmental context.

This presentation introduces numerous case studies from the US and beyond for successful applications of absorption heat pumps. A diverse set of examples is presented, and all are demonstrating real world savings of energy and water.

This presentation provides an overview of which mass markets have potential for large-scale adoption of packaged absorption machines. Whereas small scale cooling applications often struggle to compete on energy savings with electric-driven cooling, heating applications often have compelling energy and economic attributes. Small packaged units are beginning to be available to serve these applications.

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Presentation content includes items that engineers need to be aware of so that obstacles to a successfully operating system can be avoided. UFAD systems are highly integrated with other services and more closely couple with the building structure than compared to traditional overhead mixing systems. This inherent characteristic of UFAD systems demands an integrated and collaborative approach when working on these types of projects. This seminar addresses issues that need attention and sometimes get overlooked when designers treat UFAD projects similar to overhead mixing system during design.

The major challenge for design of underfloor air distribution systems is the reconciliation of comfort requirements between the interior and perimeter zones served by the system. For a variety of reasons, the past UFAD design strategy has proved less effective. Newer strategies have been proposed and applied to overcome this issue. Each of these strategies has implications for the building architecture, first cost and performance for specific weather conditions. Some strategies may even be used together. This presentation reviews each of these strategies, discusses their benefits and limitations and presents energy modeling results for the strategies for a large office project.

Automated tools facilitate an ongoing commissioning process to improve occupant comfort, ensure the persistence of correct system operation and reduce energy consumption. These tools decrease the time and the skill level required to carry out necessary quality assurance measures, and as a result they enable more thorough testing of building heating, ventilating and air-conditioning (HVAC) systems. This paper describes the algorithm developed by the U.S. National Institute of Standards and Technology (NIST) to analyze chiller loops and presents the results of a passive monitoring investigation using field data obtained from BACnet controllers and field validation of the findings. The tool was successful in detecting faults in system operation in its first field implementation for performance monitoring.

Design of chilled water plants has a very large impact on building energy uses and energy operating costs. This paper proposes a design tool for optimal design of chilled water plants. The tool that integrates system models with a genetic algorithm optimization solver minimizes the life cycle cost by finding the design variables such as chilled water and condenser piping diameters, chilled and condenser water temperature differences and chilled water supply temperature. The proposed modeling methods depend on detailed cooling load analysis and head and energy calculations. The pump head calculations including piping, all fittings, valves, and devices are achieved by using the Darcy-Weisbach equation with given flow parameters. The energy calculations are done by using generic chiller, fan, and pump models. The hourly cooling loads need to be obtained from any energy simulation software. The method is tested on an existing three-story, eighty-eight thousand square foot building.

A preliminary evaluation of the performance of a consumer-based control system was conducted by the Oak Ridge National Laboratory (ORNL) and Southwest Gas as part of a cooperative research and development agreement (CRADA) authorized by the Department of Energy (DOE) (Mahderekal et al. (2013). The goal of the research was to evaluate the low-cost approach as a solution for implementing a supervisory control system for a residential gas-operated heat pump. This technical paper explains the research process. A robust data set was produced that allowed detailed assessment of the reliability and the operational performance of the newly developed control system. Experiences gained from the test provided important points of improvement for subsequent evolution of the heat pump technology.

While the design and installation of Variable Refrigerant Flow systems is not inherently difficult, there are nuances and details specific to these systems that if overlooked can lead to costly repairs, poor comfort control and improper system operation. This seminar discusses methods of mitigating potential issues before they occur and reviews best practices and considerations for equipment design and selection, contract documents, functional testing and installation quality control.

This seminar reviews lessons learned from projects utilizing VRF systems from the perspective of the commissioning agent. The importance of properly commissioning these sophisticated systems, means of identifying and addressing common oversights found in various project stages and developing realistic plans for incorporating commissioning into a projects scope are discussed. Additionally, examples and lessons learned from projects the speaker has personally been involved with are reviewed to further improve the confidence among industry professionals responsible with commissioning these systems.

Thermodynamically, the application of heat recovery to kitchen exhaust air is very attractive to design engineers and foodservice facility managers. Exhaust air temperatures are significantly higher than space conditions (due to heat load from the cooking equipment) and the makeup air heating loads are recognized as a major energy end use within foodservice facilities. Because of the recent advances in commercial kitchen ventilation, the potential for heat recovery is more viable than ever before. This seminar presents the potential for energy recovery and the technologies that have recently taken advantage of the opportunities for heat recovery in commercial kitchens.

This seminar discusses the results of the application of commercial kitchen hood grease filters with integral air to water heat exchangers. Topics in this seminar include a system overview, recommended applications, energy advantages and grease extraction and hood system cleaning advantages.

Utilizing various technologies, today’s Clean In Place hoods reduce water consumption while providing labor savings and increased employee safety but at what cost? With rising minimum wages, increasing labor and utility costs, does a compelling business model exist to offset the initial capital and long term investment? This presentation focuses on validating the variable costs.

DCKV systems are becoming more popular as food service designers strive to achieve higher energy savings. However, DCKV systems can be a challenge for energy modelers due to unknowns with expected system operation and lack of features in modeling software. For example, varying the rate of exhaust and makeup air in relation to cooking process heat, smoke, or vapor load is not explicitly modeled in available software. This presentation highlights modeling methodology for three popular energy modeling software packages and provide tips for work-arounds.

Thermal response tests (TRTs) are often conducted to inversely estimate the design parameters of borehole heat exchangers (BHEs); those are the effective thermal conductivity of ground and borehole thermal resistance. TRT can only provide the design parameters of a borehole heat exchanger, but it cannot provide the transient heat exchange rate of installed BHE which represents the actual performance of installed BHE. This paper proposes an estimation method of TPT that can provide both the thermal performance of BHEs and design parameters that usually obtained from TRT. Results showed that the performances of BHEs strongly depend on the inlet temperature. Additionally, transient heat exchange rates obtained from TPRTs provide valuable information on BHE performances that can be used for the design of BHEs.

The heat recovery ground source heat pump (HR-GSHP) system that has several types of GSHPs for different uses connected in the ground heat exchangers yields two types of heat recovery effects. The first one is the direct heat recovery effect obtained by operating the several types of GSHPs. The second one is the indirect heat recovery effect that utilizes the underground thermal storage effects and is brought by alternately operating the several types of GSHPs in the short term. By utilizing these two effects, the HR-GSHP can yield both energy saving effect and drastic reduction of the ground heat exchanger’s total length. This paper investigates the design and operation method of the HR-GSHP system.

In office buildings, the use of a Gas Heat Pump air-conditioning systems may be able to meet thermal demands with the same efficacy as a conventional electrical system while reducing energy demand of the whole building. This paper investigates technically, ambient and economically the substitution of a conventional air-conditioning system of an existing office building by a Gas Heat Pump air-conditioning system. The analysis was conducted through a data assembling of the potential of retrofit of operating office buildings in the city of Sao Paulo; through interviews with mechanical engineers and consultants; and through a case study developed in an existent office building, using computer simulation to evaluate energy performance of different air-conditioning scenarios.

Pollution Control Units have been used in the marketplace for several years. However, with increasing pollution control regulation, and the boom of mixed-use (residential / commercial) complexes, there has been a significant increase in the use of these products. This led to a stronger demand for standardized safety requirements. This session focuses on the timely development and publication of UL8782, Outline of Investigation for Pollution Control Units for Commercial Cooking Operations released January 30, 2017. This session also reveals plans for inclusion of these requirements into the appropriate ASHRAE Standards and installation Codes.

Pollution control units (PCUs) utilized for commercial kitchen exhaust is increasingly more common due to tighter environmental regulation, as well as a greater propensity to install foodservice establishments in population-dense and mixed-use areas. This presentation explains the process of selecting and applying the scrubbing device for commercial kitchen exhaust air.

Balancing performance, capital costs and cost of operations; Electrostatic Precipitator based pollution control units have been providing reliable cost effective smoke and odor abatement for nearly four decades. This presentation focuses on the performance deliverables of these units and where the application of this technology makes great sense.

The use of ozone generators in CKV exhaust treatment is a new technology recently introduced to North America, yet one that has been in widespread use throughout Europe for about a decade. Although ozone is already applied in many areas of science and industry, this presentation focuses upon its use in CKV. Topics covered include methods of production, benefits realized, limitations and code-compliance requirements for grease applications.

Thermal load management studies have been carried out at small and large scale, covering all the range from a single building to the country level, although prior research provides valuable information on the possible energy management schemes and gains, the large scale studies typically suffer shortcomings. This paper addresses those shortcomings focusing on the existing building stock. It describes a comprehensive tool to estimate the potential for thermal load management at large scale accounting for the buildings passive storage potential. The paper also describes the application to a 10 buildings case-study in Geneva (Switzerland) and quantifies the associated gains.

Energy efficiency in buildings is one of the key measures to tackle global energy and emission concerns. The large share of air conditioning in commercial buildings makes air conditioning systems as primary targets for retrofitting. This paper studies 50 commercial buildings in Singapore that have undergone chiller plant retrofitting. The energy audit reports from these buildings are studied in detail to gather data related to building energy consumption and chiller plant efficiency (measured in kW/RT). The energy utilization index (EUI) which is measured as the total energy per square meter is analyzed for these buildings before and after retrofitting.

Commercial buildings alone are responsible for 36% of the total United States electricity consumption, and on average 30% of this electricity consumption is wasted. One of the greatest challenges in improving building energy efficiency lies in the ability to do simple and non-intrusive disaggregation. Building energy disaggregation extracts system and equipment level energy signals from a whole building’s energy consumption data. This paper proposes a novel unsupervised non-intrusive building energy disaggregation technique using 15-minute interval whole-building energy consumption and weather data. The proposed disaggregation technique consists of an analysis loop with three steps.

Benchmarking energy use can help building owners and managers to assess building energy performance and to identify energy efficiency opportunities. Energy consumption data makes it easy to understand the energy use characteristics of each building, and can promote occupants’ awareness of building energy efficiency when providing an energy performance index developed from this data. As a way of improving energy efficiency in the building sector, the Korean government has developed a nation-wide integrated energy consumption database with more than six million building records. This paper introduces the framework of the national building energy consumption database and to analyze energy use characteristics of office buildings across the country.

Knowledge of occupants' interactions with building components and systems and how indoor environments are influenced in response to occupant behaviors is highly beneficial to operate and maintain existing building more efficiently and to design new buildings to be more comfortable and energy-conscious. This paper provides insight in this regard. To this end, occupant behaviors and energy flows are being monitored in an academic building in Ottawa, Canada. The paper presents results of this monitoring campaign on occupants' presence and behaviors, indoor environmental conditions, and energy demands in various offices.

The experimental performances of a dual-mode CO₂ heat pump system coupled with hot and cold thermal storage is investigated in this paper. This combined system was tested by controlling compressor frequency, expansion valve opening and hot and cold circulation water flow rates. Experimental results show that high compressor frequency benefits the combined system performances. Expansion valve opening affects the thermal stratification of thermal storage tanks very slightly. Low hot and cold water flow rates are good for the thermal stratification of thermal storage tanks although high water flow rates can enhance the COP of heat pump system; and thermal stratification in thermal storage tanks is one of the most important impact factors on the COP of heat pump.

Growing concerns about climate change, new decarbonization agenda, research for energy independence and geopolitical evolutions have led countries and industries to rethink their energy consumption. In this research for sustainability, major stakeholders in the UK food retail market are investigating pathways to reduce their carbon footprint. Low-carbon energy production technologies such as photovoltaic systems coupled with battery storage constitute potential solutions, also driven by rising electricity bills. The purpose of this paper is to develop an end-user optimization model assessing potential benefits of photovoltaic systems associated with battery storage for commercial buildings integration.

This paper discusses new methods for the operation of interacting simulating models. These methods provide tools to step into optimization of combinations of integrated energy systems. The main design issues that are addressed are hydronic flow system and the sizing of storage systems. The hydronic layout is important with respect to utilization of exergy i.e. water temperature, but the research also shows the importance of control strategies on energy savings. A proposed new hydronic layout and control design are described in this paper, as applied to heating, cooling and storage systems.

When modeling an HVAC system using fan powered terminal units with EnergyPlus, the user must enter values for fan total pressure rise and fan/motor efficiency. A recent study found that for an 8 inch inlet (203 mm) series fan powered terminal unit, the fan total pressure was considerably lower than values commonly recommended in online training sources. Values in that study were on the order of 0.25 in. w.g. (63 Pa) and not 1.5 or even as much as 3 in. w.g. (374 – 747 Pa). Manufacturer’s performance data were used to verify and extend VAV fan powered terminal unit total pressure rise measurements as determined in a previous study.

The current version of ASHRAE Standard 170 procludes natural ventilation in all spaces in healthcare facilities. This work-group suggests it should be allowed in most healthcare spaces, except for Operating Rooms, Procedure Suites, Sterile Core areas, Interventional Radiology or Cardiology Spaces, Airborne Isolation Areas, and Protective Environments. Natural or mixed-mode ventilation designs may offer some benefits. Among the most likely are energy reduction and enhanced occupant satisfaction. Less likely benefits may include enhanced indoor air quality and a more beneficial microbiome. When considering natural ventilation in health care, designers must fully address the fundamental challenges of space appropriateness, climate appropriateness, acoustics, security, and outdoor air quality. Projects implementing natural ventilation should anticipate commissioning challenges.

The energy consumption of the heating and cooling coils of the air handling units of an educational building with multiple laboratories has been evaluated and suitable energy recovery methods were assessed in an attempt to reuse the energy lost in the exhaust air stream and promote energy conservation while complying with the current building codes. The HVAC system of Life Sciences II (LS II) building of Southern Illinois University Carbondale, is a constant air volume (CAV), 100% outside air (OA) system due to the many laboratories in the building. It is one of the most energy intensive buildings on campus.

The adoption of energy efficient standards significantly cut the energy consumption in buildings by reducing envelope heat transfer and internal heat gain. These energy efficiency measures reduce not only the electrical load but also the cooling load as well as the supply airflow rate. As a result, additional reheat is typically required to maintain the minimum airflow setpoint under partial space cooling loads for conventional air handling units (AHUs) and may degrade the effectiveness of energy efficient measures. The AHUs with return air bypass (RAB) provides an alternative to reduce additional reheating and overcooling at the minimum airflow rate with good space humidity control. The purpose of this paper is to investigate the energy and control performance of the AHUs with RAB under different operating conditions through simulations.

In most HVAC systems, water is usually delivered by several centralized pumps, which may reduce the pumping system’s energy efficiency because of unnecessary pressure loss. A decentralized pumping system is an alternative system that only circulates the minimum water required by the respective terminal unit and can reduce the excess pressure loss. This paper verifies the performance of the decentralized pumping system by conducting an experiment comparing centralized and decentralized pump systems under various water flow conditions in terms of their energy consumption in water delivery and their energy saving potential.

District cooling means producing cooled water in a centralized plant and distributing it in pipelines to a number of buildings to cool the air in each building’s air conditioning system. This paper investigates the effect of the wind speed and direction on cooling towers' thermal performance. Moreover, the distance between stacks, cooling tower fan speed, and effect of wind barriers were also simulated. A three-dimensional Computational Fluid Dynamics (CFD) model of a power plant cooling towers is utilized to assess the effect of flow circulation air on entering air wet bulb temperature under different ambient conditions and orientations.

Texas A&M University’s Main campus has its heating and cooling district to provide needs of both heating hot water (HHW) and chilled water (CHW) to over 230 buildings. Commonly, buildings exceeding the plant static pressure level experience negative pressure in their tallest parts, allowing air into the system that reduces heat transfer efficiency, causes noise, and increases corrosion. The negative pressure also results in consuming much more pumping power due to the requirement of lifting water above plant static pressure to above top building coil. This paper identifies the reason for the negative pressure, and a pressure distribution analysis was performed on the campus thermal loop.

Chiller plants are commonly used to provide cooling water to data centers. While chiller plants are designed for the maximum projected heat load, majority of data centers produce a fraction of the design load. Chiller plants that operate at partial load may not perform efficiently. Evaluating the performance of a working chiller plant is challenging because of the limited data available at the site. Moreover, it is not possible to know how the system will perform after making an adjustment to improve the efficiency. This paper illustrates the use of a scientific approach based on the Flow Network Modeling (FNM) technique for improving the operating efficiency of a real-life data center in Rochester, NY.