Closed-loop geothermal heat pump (GHP) systems offer a variety of possibilities that can be optimized to the needs of the building type and owner’s resources.  Distributed systems in which several ground loops serve a single building are often a good option for large footprint buildings and owners with minimal maintenance resources, such as K-12 schools. Topics for this session will include building layout, cost of headers and vertical bores, total HVAC component efficiency and demand, load diversity, flow control options, experience and quantity of maintenance personnel, and results from long term field measurements.

The design process should take into consideration several parameters when determining which is a better fit; Centralized or Distributed GHP Systems.  Centralized GHP can provide advantages such as; higher efficiency for simultaneous heating/cooling which is quite common in commercial building; ease of maintenance due to reduced number of moving parts in a central location; greater potential for reduced ground loop size; easier integration with other technology such as thermal energy storage and finally, providing a more “future proof” solution.

The design of a hydronic system with a standard two-way control valve with manual balancing valve solution.  The discussion will address the need for balancing the system and controlling the load, and address the need for measurement and verification.  The two-way control valve and balance valve solution will focus on the control valves responsibility in responding to load variations in the conditioned space as well as responding to variations within the hydronic system. Design considerations will be addressed as will advantages and disadvantages of the design in a typical hydronic system.

The pressure independent control valve will be examined as two valves within one body that separate the duties of controlling pressure variations within the hydronic system by way of a pressure controller – a form of pressure reducing valve – and a standard two-way control valve.  The advantages and disadvantages of designing with pressure independent control valves, as well as design considerations, will be addressed.  These will be highlighted utiilzing the same hydronic system from the initial presentation that addressed standard two-way control valves.

A major concern in the operation of cooling tower systems is the prevention of scale on heat transfer and evaporative surfaces. The process by which scale forms is not often clear or well explained, and the means by which scaling may be controlled is commonly not explained to any significant degree. This paper attempts to outline the mechanisms of scale formation, discuss chemically based and non-chemically based strategies for scale control, provide real-time instrumental data illustrating the effectiveness of both chemical and non-chemical control and then discuss the basic requirements for successful implementation of each strategy given the many chemical, physical and operational variables generally associated with cooling tower operation. Each strategy has its advantages and diadvantages and no one strategy is well suited under all circumstances. It is hoped that this paper will help clear up some of the misconceptions concerning chemical and non-chemical cooling water treatment and promote more meaningful and informed discussion during the treatment strategy selection process.

HVAC water systems (cooling tower/condenser water) are frequently operated without filtration—leading to reduced efficiency. Filtration selection for cooling tower water is accomplished by determining the type of solids present in the water, water quality requirements, physical space availability, weighing the pros and cons of the various filtration options and budget constraints. Selecting the wrong type of filtration is akin to taking vitamins for pain relief: good product but wrong application. This paper compares the differences between barrier and non-barrier filtration options and when to apply each option. Either type of filtration, when correctly applied, assists HVAC equipment to operate at design efficiency.

Awareness of non-chemical processes and the successes of various technological solutions to common water treatment problems are now well established. Despite detractors, non-chemical and physical water treatment products continue to make their mark by providing results that meet and exceed water treatment industry standards. Although initially propelled by the greening of the built environment, physical water treatment now stands as a viable alternative to traditional chemical programs. The debate over whether these technologies work is over, with the new discussions centered around when and how to apply them. With technological progress and continued innovation, these once-experimental technologies have given birth to experienced and proven methodologies. This paper covers the history of various technologies and examines the plusses and minuses of each class of non-chemical water treatment. It illustrates how the latest advancement improves on pulsed power and in combination with advanced suspended solids management provides unmatched savings of water and energy, while matching or exceeding the performance metrics of modern water treatment deliverables.

The debate continues between the use of non-chemical water treatment devices and chemical water treatment for treating cooling water systems. The goals of any cooling water treatment program are to protect against corrosion, deposition and microbiological fouling. This paper presents the chemical water treatment method to accomplish the best performance standards. In doing so, the authors critique both and highlight the benefits of chemical water treatment. The authors present results of trials where both technologies have been used to treat cooling water and discuss the methodologies behind each technology. Many providers promote “green,” “safe” and “economical” as the reason to use a certain technology. Many users select their appropriate method of treatment based on these same factors. What factors should determine the type of treatment? When we define success, we can determine the best method to achieve it.

Site energy is a useful metric for a variety of purposes in examining building energy performance.  It is the only metric that is measured directly at the building, and therefore provides an easy way to calculate energy consumption and evaluate the impact of changes in energy consumption associated with more efficient equipment.  This presentation will illustrate the use of the site energy metric in Standard 100-2015, and describe its value in determining building energy performance.

When trying to judge a building's energy performance considering both economic and environmental factors, one metric may no longer be sufficient.  It may be more useful to consider multiple complementary metrics, while finding a metric that provides a good compromise solution for many purposes today.  This presentation will hypothesize why the TDV and emissions metrics may be the most useful over time for societally beneficial decisions.  In the meantime, the use of a metric such as normalized modified end use loads may provide a good enough compromise to satisfy competing stakeholders in the residential marketplace.

The choice of metric is critical when evaluating and comparing a mixed fuel building's energy performance with an all-electric building's energy performance, or for comparing competing energy investment options for new buildings and replacements.  This presentation will explore the benefits and limitations of different metrics that may be useful for such comparisons and decisions, including energy cost, primary energy, and environmental emissions metrics.  It will also provide an overview of different methodologies and values to implement these metrics to ensure the most equitable treatment of different competitive design and investment options.

Automated testing is the execution of a human's test. It must include the obvious parameters that define components and thermal and fluid exchanges expected in design. Nodes of protection, assure equipment can recover from a fault, require real external actions to be detected not simulated within the BAS.  Load response can be digitally simulated and evaluated to preset acceptance criteria.  Commissioning one device with human flexibility a repetitive system is continually reviewed by occupants for comfort. Discontinuities created by energy saving modes require real events to confirm  operation within the limits of the physical world.

Many building automation systems allow for 3^rd party software to interact with them directly through published APIs (Application Programming Interfaces). Automated commissioning uses these APIs to autonomously drive passive (read-only) and active (read-write) commissioning tests of HVAC systems in existing buildings and during construction projects. This presentation will define the concepts and system architecture that support automated commissioning and explore the pros and cons of this novel approach to component and system testing. The presentation will also introduce the Structured All-Purpose Language for Testing which can be used to define tests in a formal way suitable for automation.

More stringent performance goals of energy efficiency, health and wellness are extending the conventional scope of design teams, which increases the risk of failing to deliver these needs. Work methods such as 'fat in the design' and following a silo mentality are no longer acceptable and can lead to failure in budget, operations and quality. Increasingly the engineer will lead interdisciplinary design solutions - formulating a plan for design, construction, commissioning and operation - including architecture, building operations and post-occupation. This presentation will show that planned and programmed communication with all building stakeholders can deliver successful integrated solutions.

Building projects require many parties to succeed and even then an educated building occupant may struggle to understand and use design features. Communication is increasingly important in project delivery - although if everything is done for the client's benefit why can each party appear so antagonistic? And in international projects even 'simple' industry terms can have different interpretations. Through examples of international projects (China, Middle East, Far East, USA, and Europe) communication (or the lack of communication) resulted in problems and success stories. The main case study will be a 500+ metre high Indonesian net-zero building.

Wherever in the world, built environment professionals should have a common cause – to deliver effective buildings that perform as the client expected. Buildings, whatever the use, demand enormous resources throughout their life - and, in many cases, will waste a large proportion. To maintain reputation and risk, many design for conditions that rarely occur, employing unrealistic 'safety' margins delivering compromised installations that often lack proper commissioning due to over-running programmes. Through real-world examples this will show how, by 'putting its head above the parapet' collaboratively working across the whole supply chain HVAC&R professionals can deliver truly effective buildings.

This brief presentation introduces the topic of the seminar - centralized vs decentralized heating and cooling. Major topics that will be addressed include: Background - History of centralized (district) energy systems. District Energy System Summary - Description of a district energy system along with its strengths and weaknesses. Decentralized System Summary - Description of a decentralized energy system along with its strengths and weaknesses. Current Trends - Briefly describe the current industry trends that is seeing some district energy systems being replaced with decentralized system.

Centralized energy systems supply steam, chilled water and/or hot water to multiple buildings on a campus.  Decentralized energy systems supply utilities to a smaller group of buildings.  Key factors that need to be considered when determining if a centralized or decentralized energy approach should be used for a multi building campus are: Existing Building Systems. Existing Central Plant Equipment. Existing Campus Distribution. Campus Thermal Profile. Capital, Operating and Maintenance Costs. Future Campus Building Expansion Plans. Carbon and Energy Footprint. Life Cycle Cost Analysis. The presentation will present two case studies with a comparison of a centralized vs. decentralized energy approach.

The Indiana Veterans Home is an active short-term care/independent living facility for retired veterans located in West Lafayette, IN. The site was originally constructed on 1896 and utilizes steam for heating. The current steam system age is approximately 40 years old and in need of repair. Options considered in a study for a heating replacement included a steam system replacement, conversion to centralized heating hot water, decentralized heating hot water and conversion to a geothermal heat pump. This presentation focuses on factors to consider when looking at centralized vs. decentralized solutions for a campus heating system.

This presentation provides a historical discussion of peak envelope cooling load calculation methods from the 1800s until the present. The discussion focuses primarily on U.S. analysis methods, and includes a discussion of the engineering-based methods that can be traced, either directly or indirectly to textbooks in the 1800s by Professor Eugene Peclet, at the College of Marseille in France, and Professor Hermann Rietschel, Professor of the Technical University of Berlin, Charlottenburg Germany.

This presentation will discuss the development of the Radiant Time Series (RTS) Method for performing design cooling load calculations is derived from the heat balance method. In the current ASHRAE Handbook, the RTS method has replaced all other simplified (non-heat-balance) methods such as the Cooling Load Temperature Difference/ Cooling Load Factor/Solar Cooling Load (CLTD/CLF/SCL) method, the Total Equivalent Temperature Difference/Time Averaging method (TETD/TA), and the Transfer Function Method (TFM).

This presentation addresses an architectural perspective of the design cooling load calculation methods presented in the current ASHRAE Handbook. Earlier versions of these methods allowed architects to extract desirable design moves from the data presented--leading to the potential for better initial design decisions. The current methods, although representing an advance in accuracy, are generally not usable by an architect in conceptual or schematic design decision making.

This presentation will provide a brief historical perspective of the air-conditioning industry and cooling load calculation in Australia.  It will look at the landscape of education and course work available; and will also review the basis of most popularly used cooling load calculation software used in Australia.  Finally it will address the question of “Is this where we want to be?”

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Simplified simulation models can be used for determination of effectiveness of energy-conservation measures in design stage as well as assessing performance optimization measures in retro-commissioning process. This presentation will deal with the general approaches that are followed to calibrate simplified simulations – auto and manual. The presentation will also show some examples on how the calibrated simulation can be used in practice.

Bayesian calibration is one of many methods that can be used for calibrating building energy models.   In Bayesian calibration, modelers start from an assumption that parameters to be calibrated are uncertain through assignment of probability distribution functions. The Bayesian calibration algorithm adjusts the parameter probability distribution functions by comparison of model predictions to measured data.  The posterior parameter distributions parameters are statistically more consistent with the measured data than the prior distributions with the probability distributions representing the confidence of the values of the input parameters given both the model of the buildings and the observed values from the building.

This paper summarizes a method for testing model calibration procedures. We call this a pure test method because it tests only the calibration procedure and not the correctness of the associated simulation program. This is accomplished by using the simulation program (used with a calibration method) to generate synthetic/surrogate building energy use data for a pre and post retrofit test case.  Thus the “correct” inputs are precisely known and the calibration technique can be tested for closure on the correct pre-retrofit model input values and the post retrofit energy savings along with the usual “goodness of fit” criterion.