This presentation summarizes the ASHRAE sponsored research used to develop the new duct calculator tool. This includes a brief description of the experiments that were carried out and the results of those experiments.

This presentation covers a brief history of flex duct research at LBNL and TAMU. Data is presented illustrating flex duct performance measurements at various compression levels followed by the averaged data that was used for the duct design tool. Illustrations from ducts installed in residential attics is also presented.

Heat networks can be an effective way of supplying low carbon heat to buildings. Current UK systems are largely based on fossil fuel Combined Heat and Power (CHP). Such systems may likely be unacceptable in the long term, if the levels of decarbonization visualized in the UK are to be attained. Heat networks are best suited to areas with high heat demand density such as big cities. This paper demonstrates that Underground Railways (UR) could be an attractive year round heat source and presents numerical investigations into the interactions between these systems.

Ground source heat pump system can reduce energy consumption and CO2 emission of heating, cooling and hot water supply system in buildings. The capacity of ground heat exchanger is subjected to the restriction of the building or site area and this leads frequently to the situation where the amount of heat supply from ground heat source does not balance the heat demand by whole the building. A heat source water supply network was designed and installed between two actual buildings in Japan.

Ground Source Heat Pumps (GSHP) have significant potential to reduce carbon emissions. The performance of heat pumps is highly dependent on their interaction with the ground and specifically the extraction and injection of the heat. A number of literature reviews has shown how the performance of GSHP systems vary in practice when compared to the theoretical aspects. This paper provides detailed investigative work on heat metering installation difficulties and associated errors which affect the long term practical performance of GSHP systems and identifies a range of installation errors.

This presentation explains why Variable Speed Drives (VSDs) are used in many HVAC applications and how they operate. Explains variable torque vs constant torque loads. Describes the different Variable Speed Drive (VSD) terms commonly used in HVAC applications and defines the acronyms and names commonly used: 
Variable Speed Drive (VSD), Variable Frequency Drive (VFD), Adjustable Frequency Drive (AFD), Adjustable Speed Drive (ASD), Freq Drive Inverter.

Positive displacement chillers, more commonly known as Screw chillers, offer significant energy savings when applied as variable speed chillers. Screw chillers are offered around 550 nominal tons and can be easily incorporated into multiple chiller designs. This seminar segment describes the differences between how variable speed screw chillers and centrifugal chillers operate. An energy analysis demonstrates efficiencies reflecting true building and chiller operating conditions.

Centrifugal chillers are very dependent on operating speed in order to achieve maximum efficiency. Advances in Variable Speed Drive (VSD) technology are enabling optimized operating speeds that improve system efficiency over a broad range of centrifugal chiller applications and operating conditions. This presentation provides technical understanding of how VSD’s work within a chiller system as well as application examples of how that chiller system can be optimized within an HVAC system.

This seminar presentation defines Galvanic Corrosion and what causes this form of corrosion. It also offers insight into distinguishing the modes of degradation in All-Aluminum micro channel heat exchangers.

Condensation and corrosion can be major problems when surfaces are exposed to environmental conditions. Because of geometry it may be difficult to drain condensate, leading to increased corrosion or frosting at lower temperatures. Superhydrophobic (SH) materials can minimize anti-condensation and corrosion. SH coatings can be tailored for micro-channel heat exchangers, fin tube coils, and internally enhanced shell-tube heat exchangers. The impact of SH coatings on heat transfer performance needs to be considered along with the overall energy efficiency improvement resulting from SH coatings. SH coatings can help reduce performance degradation from corrosion by 50% and therefore improve the operational efficiency.

Round tubing is used in non-brazed, mechanically assembled in form of U-Bend hairpins. Aluminum hairpins provide requisite formicary corrosion protection and have the majority market share for indoor application. Outdoor application requires more stringent corrosion protection, smaller diameter tubing and larger coils. This makes applying this tubing in outdoor environment an engineering challenge. Developments in long life 3000 series alloys, hairpin lubrication, processing and coil fabrication may open up a limited outdoor market, and make the indoor market more attractive. Alloy development has focused on refinements/composition that alter failure mode from pitting to general lateral corrosion, increasing tubing’s corrosion performance.

After this presentation, attendees will understand and distinguish the three inter-related design factors that influence corrosion durability of an aluminum heat exchanger. They will also be able to apply fundamental learnings to future HEX designs.

Two types of gas absorption units have been installed in field tests in Germany. A larger capacity unit (140 kBtu/h or 41 kW heating) with 50-100% modulation was installed with an auxiliary boiler in a school building to replace a 150 kW boiler. In addition, smaller (61 kBtu/h or 18 kW heating) units were installed for residential applications, without auxiliary boilers. The measured savings over the baseline boiler systems have been up to 40%. This seminar describes the system layouts and how the savings were achieved.

Several prototype ammonia/water absorption water heating units, aimed at the residential water heating market, have been recently evaluated. Field tests as well as laboratory reliability evaluations were conducted. Energy factors significantly higher than 1 were observed in a variety of installations. Analysis of these results and lessons learned are discussed in this seminar.

Proper equipment testing standards give consumers confidence, reduce uncertainty for manufacturers, and enable utilities to offer incentives for more efficient products. Besides these goals, a standard should not be too burdensome to conduct. This seminar describes the unique characteristics of gas heat pumps and how those relate to standards. Attendees will gain a better understanding of how gas heat pumps operate and can be applied.

For the first time, sorption heat pump units were subjected to round-robin testing at two different laboratories. Testing was conducted according to existing European standard EN12309 and German standard VDI 4650. In order to inform ongoing standards development, the team identified recommendation to address challenges with measurement of low part loads, as well as how to minimize testing burden while achieving a seasonal efficiency rating.

The air cooled packaged chiller is a very popular choice for HVAC designers in capacities up to and slightly above 1,900 kW (550 tons). Until recently, the only compressor types commonly available in air cooled packaged chillers across that entire range were of the positive displacement type. By contrast, for nearly 100 years, the efficiency and other inherent advantages of centrifugal compressors have made them a popular compressor choice in water cooled packaged chillers with capacities as low as 350 kW (100 tons). This article explores the history of centrifugal compressors when applied in air cooled chiller systems.

Although counter intuitive, using a heat pipe air-to-air heat exchanger in summer for both sensible cooling (Indirect) and adiabatic cooling and humidification (Direct) of the outdoor air in an arid climate can reduce peak refrigeration tonnage while exceeding Standard 62.1 outdoor air ventilation for a Natatorium. Heat recovery in cold ambient conditions allows the system to exceed minimum code outdoor air flow requirements into the Natatorium to dilute and remove Chloramines and maintain a better Indoor Air Quality ( IAQ) in the pool enclosure without additional heating costs. This case study analyzes the Aquatic Center project installed in Dublin, California.

This conference paper explores the ever-changing dynamic of air-cooled versus water-cooled systems. While water-cooled systems still often reduce the building energy use, there have been dramatic improvements in air-cooled chiller performance. There is increasing concern with fresh water scarcity as we acknowledge the cost and energy consumption required at desalination and water treatment plants. And there’s major growth of renewable power generation in the grid energy mix which affects both the process water use and greenhouse gas emissions. The market’s demand for sustainability, energy efficiency, and water efficiency must be weighed carefully as competing interests continue to evolve over the next decade.

Roof top equipment is often concealed for aesthetics reasons, by a solid or louvered parapet walls aka “Architectural Screens”. This results in inefficient dispersion of exhaust air and reduces the thermal efficiency of the equipment inside the screens. This work estimates excess energy used at an 8000 tons district cooling plants when cooling tower fan operates at higher speeds to compensate for the entrainment and recirculation of exhaust air caused by architectural walls around a cooling tower. Air properties for two locations: 1) inside the walls near the cooling tower and 2) away from it, outside the walls were monitored and analyzed.

There are nearly 60 thousand Mosques spread across the Kingdom of Saudi Arabia, consuming nearly 3 Terawatt-Hour of site electrical energy, 70% of which is due to the use of mostly inefficient HVAC systems. It is estimated that 20 million M³ of expensively treated water used annually for ablution, 50% of which flows directly to the drain without any contamination. This paper evaluates the potential savings in water and energy of reusing ablution water to run mosque Air-Conditioning systems using high efficiency IDEC technology.

Fan systems can be configured with a wide variety of options. The number of combinations and the lack of scaling laws makes testing and rating of fan system energy performance an impractical task. While estimates can be made using component peak efficiencies, these calculations are often applied inconsistently or without part load performance. Method to standardize the calculations under general operating conditions is presented which applies to fan systems containing any combination of regulated poly-phase induction motors, v-belt transmissions, and pulse-width modulated variable frequency drives. This presentation provides detailed review of the underlying assumptions, the calculation procedure, and examples of those calculations. 

Wire-to-air fan efficiency depends on individual component efficiencies of the fan, motor, V-belt drive, and VFD. The efficiency of each of these components can be evaluated at full rated load as well as at part loads encountered in VAV systems. Tests were conducted and results will be presented for these components including multiple sizes at various loads. These component efficiencies are also compared with the measured overall fan efficiency.

This presentation examines the scope of Guideline 36 and the research agenda that will fuel its content over the near term. He will also address the integration of Guidline 36 with Guideline 13..

Discuss aspects of Fault Detection and Diagnostics and how SGPC 13 is moving towards providing guidance and references for the specifier to adopt the technology in their automation projects.

Discuss views on how buildings can, should, and will be more secure and where the convergence of access and risk align for Cyber Security and how SGPC 13 is moving towards providing guidance and references for the specifier to adopt the technologies in their automation projects.

High solar reflectivity roof membranes have been a focal point of energy saving efforts in building design. These efforts have been codified in the International Code Council (ICC) International Energy Conservation Code (IECC) and the American Society of Heating and Air-Conditioning Engineers (ASHAE) Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings. In both of these texts prescriptive aged and or initial roof membrane solar reflectivity is specified. This paper reports the numerical findings of this study, examines causation for the differential levels solar reflectivity values discovered and proposes guidelines for roof membrane solar reflectivity used for design and modeling.

As HVAC systems advance to meet the energy savings goals, their control system becomes increasingly complicated. In order to optimize the operation of a control system, the ideal combination of its parameters need to be realized, aiming at providing an acceptable indoor environment as defined by the standards and at the same time reducing the energy use as much as possible. In this simulation study, the coupling of solar panels with Phase Change Material (PCM) ceiling panels for cooling an office room was examined during the cooling season of Copenhagen (Denmark) by means of dynamic simulations.

Building integrated photovoltaic/thermal (BIPV/T) system provides sustainable solution in design structure as part of the building envelop. A mathematical model was developed for transparent and opaque BIPV/T collector, (TBIPV/T) and (BIPV/T). Both models were implemented in TRNSYS to conduct comparative study. A single zone house was modeled in TRNSYS to conduct a case study to evaluate the performance of each collectors. Comparative studies were performed between both systems, each integrated into the façade and roof of the house for two locations in Canada.

This article proves that the use of Fan Law Equations to calculate changes in air flow and pressure lead to significant errors in cases where air handling units have considerable internal resistance. It also demonstrates methodologies for a more accurate calculation of fan system parameters.

The work was completed under ASHRAE Research Project 1467-RP Balancing Latent Heat Load between Display Cases and Store Comfort Cooling. The overall objective is to provide a comprehensive assessment of the potential for energy savings in supermarkets by optimized design and operation of the combined HVAC and refrigeration systems. The research addresses the impact of supermarket design, HVAC and refrigeration system design, temperature and humidity setpoints, and store location. The study uses EnergyPlus as the simulation tool for modeling supermarkets, and generally found good agreement with both measured results and expected outcomes on an individual variable level.

The primary objective of the 1609 research project was to formally specify information exchange use cases for O&M work processes based on existing ASHRAE publications. Four use cases were developed from Guideline 4, Standard 180, Service Life and Maintenance Cost database, and Standard 105. A fifth combined use case, focused on asset management. A User Guide was written to help practitioners implement a practical asset management program. These products can be adopted by O&M professionals to bring Building Information Modeling (BIM) techniques into their practice and increase ASHRAE involvement in adopting BIM technologies to support its members’ work processes.

One of the critical tasks of the International Energy Agency’s Energy Conservation in Buildings and Communities (IEC ECBC) Program’s Annex 61 “Business and Technical Concepts for Deep Energy Retrofit (DER) of Public Buildings” is to develop bundles of core technologies (measures), which, when applied in major renovation projects to older (pre-1980) buildings, allow site energy reduction by 50% or better compared to the pre-renovation baseline. This paper shows that application of a core technologies bundle to dining facilities, which have high process loads and ventilation requirements, significantly improves energy use in the building compared to the typical renovation scenario.

Presidio of Monterey, host to the military’s premier language training institute, faces the same challenges as other Army bases in managing its aging building stock. This paper demonstrates the acquisitions strategies employed and field lessons learned in an attempt to better guide prospective DER project stakeholders. This project employed a regimented process to its various contracting phases with some strategic augmentation to support the DER method that are transferrable to similar retrofit efforts. There have also been many process-based and technical takeaways that can be used to bolster future DER work at Presidio, in the Army, and throughout the sustainability industry.

Deep energy retrofits can supercharge our transition to a clean energy future without relying on radical technologies or untested methods. Buildings are the largest energy-consuming sector in the United States and 80% of existing buildings today will likely remain in operation by 2030, making existing building retrofits essential to national and global energy and carbon reduction strategies. There are three main funding mechanisms to deliver deep energy retrofits to federal facilities: congressionally appropriated funding, performance contracting, including commonly used energy savings performance contracts (ESPCs) and a combined funding model blending appropriations with ESPC. This paper focuses on ESPCs and the emerging combined funding model.

In this study, heat transfer coefficients for radiant floor heating systems were investigated in a special test chamber that is one of the very first implementation of the ANSI/ASHRAE Standard 138 in the world. Radiant systems offer high energy and exergy efficient sensible heating and cooling potential. These systems can be directly coupled with low enthalpy, renewable or waste heat resources. Heat transfer coefficients are important design parameters for radiant systems that effects the heat transfer capacity of the heated/cooled surface to indoor. In this study, radiant, convective and total heat transfer coefficients for radiant floor heating are investigated experimentally.

As Semi-Transparent Photovoltaic (STPV) windows are advancing within the building and window industry, the need for deeper understanding and quantification of key performance parameters such as the solar heat gain coefficient (SHGC), operating temperature profile and electrical power output is required. This study proposes an experimental methodology suited to the determination of the SHGC of STPV windows. The methodology presented utilizes an indoor solar simulator and calorimeter facility. A SHGC reduction from 2% to 20% was estimated, when the STPV windows were tested with no-load and with load applied at maximum power point.

The study describes an experimental and simulation study to estimate load handling capacity and thermal performance of radiant cooling system installed in existing building in India. To evaluate thermal performance and capacity, experiments are conducted and simulations were carried out using EnergyPlus tool. Building model was calibrated using the experimental results and a parametric analysis at different operating condition has been done on calibrated model. The results are validated by evaluating the characteristic performance exponent (nco’’) given in ASHRAE Standard 138.

A solar collector cum regenerator (C/R) is a key component of a liquid desiccant air cooling system that concentrates liquid desiccant flowing over its absorber surface. Simultaneous collection of solar energy and evaporation of water occurs as the solution flows over the absorber surface of the solar C/R being exposed to the ambient air throughout sunshine period. This paper discusses the use of a single solution tank for regeneration of liquid desiccants (LiCl and CaCl2 solutions) using a solar C/R of absorber area 4.0 m2 using experimentally collected data sets in a day (9am up to 4 pm) across seasons.

The present study focused on the effect of supply air temperature on air distribution in a room with floor heating (FH) or ceiling heating (CH) and mixing ventilation (MV) or displacement ventilation (DV). The vertical distribution of air temperature and velocity in the occupied zone and the horizontal distribution of containment concentration in the breathing zone were measured as the supply air temperature ranged from 15.0℃ to 19.0℃. The results showed that the vertical air temperature differences were less than 0.3℃ with FH+MV or CH+MV and between 1.9℃ and 4.2℃ with FH+DV or CH+DV. The turbulence intensity varied from 12.5% to 15.5% with FH+MV or CH+MV, and from 6.0% to 10.8% with FH+DV or CH+DV. The air distribution effectiveness was close to 1.0 with FH+MV or CH+MV, and between 1.06 and 1.16 with FH+DV or CH+DV. The results in this paper are relevant to the design and control of the hybrid systems with radiant heating systems and mechanical ventilation systems.

Many organizations take pride in improving the energy efficiency of their buildings through certifications such as Leadership in Energy and Environmental Design (LEED). However, due to limited accountability for energy consumption on a building level, particularly after some period of operation, LEED certification may not necessarily translate into efficient building operation in the long run. This paper details an energy analysis and a building energy simulation of a LEED Silver dining hall which was diagnosed with poor energy efficiency performance and appeared among Facilities Management list of buildings that needed prompt attention on the University of Maryland’s (UMD) campus.

Laboratory facilities remain expensive to operate because of the extraordinary volume of once-through exhaust air required by chemical fume hoods. Traditionally, laboratory fume hood operation is perceived as a laminar flow process to capture and contain contaminants inside the hood, and relies on face velocity to establish the volume of air required when the hood is in use. Conversely, vortex fume hood operation is understood as a dilution process that utilizes turbulence to dissolve and contain contaminants in the air stream and employs air changes per minute to establish the volume of air that passes through the hood.

The phase-out of hydrochlorofluorocarbon (HCFC) refrigerants in developing countries is currently under way according to the Montreal Protocol. R-22 is one of the most commonly used HCFCs in the developing nations. It is extremely well suited for air conditioning and refrigeration (AC&R) in high ambient temperature environments. Non-Article 5 countries have already gone through the phase-out of HCFCs and settled on using R-410A as the refrigerant of choice for AC applications. Previous studies have shown that R-410A results in significant capacity and performance degradation at higher ambient temperature conditions. There is a growing concern about finding alternative refrigerants to R-22 that would have zero ozone depletion potential (ODP), lower global warming potential (GWP), and at the same time maintain acceptable performance at higher ambient temperatures. Furthermore, the developed world’s transition through higher GWP refrigerants such as hydrofluorocarbons (HFCs) and HFC blends resulted in significant direct CO2 equivalent emissions. It is imperative to develop a bridge for developing nations to avoid the transition from HCFC to HFC and then from HFC to alternative lower GWP refrigerants. This paper summarizes data from an experimental campaign on alternative refrigerant evaluation for R-22 and R-410A substitutes for mini-split air conditioners designed for high ambient temperature environments. The experimental evaluation was performed according to ANSI/ASHRAE Standard 37, and the performance was rated at test conditions specified by ANSI/AHRI 210-240 and ISO 5151.

Variable speed heat pump systems offer capabilities for advanced control strategies that coordinate the operation of compressor, valve and fans to maximize efficiency while tracking changing heating and cooling loads. However, advanced multivariable controllers can be more complex to design, implement and troubleshoot. This paper presents energy optimal coordinated control strategies, with varying levels of complexity, ranging from decoupled PID control to Linear Quadratic Gaussian (LQG) multivariable control. The advantages and disadvantages of the three strategies are analyzed and compared in simulation and experiment.

Frosting in air-to-air energy exchangers is a common problem when the outdoor air temperature is very low. Membrane-based air-to-air energy exchangers which are capable of moisture transfer as well as sensible heat transfer may assist in overcoming frosting. To understand the effect of water vapor transfer on frosting, laboratory experiments are conducted to investigate the frosting conditions for two geometrically identical air-to-air cross-flow plate exchangers. One exchanger is made with a water vapor permeable membrane (energy exchanger), while the other exchanger is made with an impermeable polymer film with similar thickness (heat exchanger).

This paper discusses strategies to improve the cost efficiency of DER. In most cases a DER is started with a general refurbishment which covers all major non energy related investments and the investments to accomplish the minimum energy requirement for the building stock. The cost efficiency for any measure beyond the minimum energy requirements will be accomplished by accounting the energy savings in pay back periods of less of half of the average life cycle of the building; this might be acceptable for the public sector but will find no large acceptance in the commercial sector.

Fossil fuels including petroleum, coal and natural gas are being currently used as energy sources resulting in global warming. Energy consumed by buildings accounts for about 40% of the total energy consumption. Further, heat losses through windows inside buildings account for 20-40% of cooling and heating loads. In addition, various studies on energy saving are being carried out. In the present study, tightness of windows has been analyzed according to KS F 2292 by using sliding and high-performing lift sliding windows. Further, TRNSYS17 has been used to analyze infiltration and heating load with respect to lock operation and location.

Due to high installation costs and space limitations, airflow measurements with physical meters in air handling units are not adequate or/and accurate for energy efficient operations. Virtual airflow sensors that calculate airflow rate based on measurable operational data using fan curves provide a promising alternative. However, in-situ fan curves, rather than the manufacturer’s fan curves, are needed for accurate airflow calculations. This paper explores a comprehensive procedure for accurate in-situ fan curve calibration in variable air volume (VAV) systems by addressing three technical challenges.

As the energy efficiency industry evolves more complex efficiency projects, such as chilled water system upgrades, are being implemented. This is due to both the completion of simpler efficiency projects on many sites and the large room for efficiency improvements in chilled water systems that are custom designed for each application and site. In most cases owners prefer third-party measurement and verification (M&V) of the efficiency projects. Additionally, electrical utilities see benefits in incentivizing and claiming energy efficiency projects. This paper discusses the different available methodologies and their limitations.

Energy models are commonly used to examine the multitude of pathways to achieve high-performance buildings. As presently practiced, a deterministic approach is used to evaluate incremental design improvements to achieve performance targets. However, significant insight can be gained by examining the implications of modelling assumptions using a probabilistic approach. This paper describes a reproducible methodology which aids modelers in identifying energy and economic uncertainties due to variabilities in solar exposure. This approach improves modelling outcomes by factoring in the effect of variability in assumptions and improves confidence in simulation results.

Due to the rapid development of the engineering technology and the improvement of the living environment, the application scope of the fluid machines are becoming more various. In this study a comparative study on some representative anemometers and flow meters, which are used at the local sites, is conducted. It is intended to suggest a new kind of portable flow meter that supplements the existing restriction. Also in this study, an experiment comparing a mass flow meter is conducted in order to confirm the accuracy of the performance of the multi-nozzle testing apparatus conforming to ANSI/ASHRAE 51-1999.

Air conditioning in buildings that house moisture sensitive products like libraries, museums, and supermarkets etc. needs strict control of humidity. The sensible heat ratio in many such applications tend to be low and energy intensive conventional means of humidity control using electrical/gas fired heaters is not finding favor with designers and ASHRAE. Various alternative ways to avoid reheating include Desiccant Rotor System, Plate to Plate Heat Exchanger, Glycol based run around coil, Heat Pipe based Heat Exchanger (HPHE) etc. This paper presents the development of a U- shaped HPHE starting from fabrication of heat pipes to their assembly in tube fin type heat exchanger.

Increasing residential air-conditioning demand and the growing number of solar photovoltaic (PV) systems installed in the residential sector have increased electrical net energy demand fluctuation. These severe fluctuations lead to a need for flexible generation capacities that can rapidly meet the fluctuating demands. To combat these fluctuations, utility companies have introduced different price plans to financially incentivize customers to reduce their demand during certain hours of the day, making residential electricity demand constant (or “flat”) for the daytime hours. This paper explores the feasibility of coupling precooling with PV to achieve “flat” residential net demand in three Phoenix, Arizona homes.

Motor-driven pumps recirculate chilled water and hot water in heating, ventilation and air conditioning systems. The purpose of this paper is to develop an optimal pump sequencing control with improved water-wire efficiency model. First, the wire-to-water efficiency of VFD-motor-pump systems is improved by applying a motor equivalent circuit method to calculate the motor efficiency at variable frequency, and then the wire-to-water efficiency is simulated and applied to develop the optimal operating regions for a secondary chilled water system with three parallel pumps.

This paper investigates the impacts of a wireless heating management system for electrical baseboard heaters in two bulk-metered apartment buildings located in Ottawa, Ontario, Canada. A tenant survey was conducted one year after the initial installation to study the thermal comfort impact of this system. Overall this system has produced promising energy and cost reductions as much as 33% with little negative impact in tenants’ overall thermal comfort during the heating seasons. However, the authors still caution the installation of similar systems and feasibility studies should be performed to determine the suitability of such systems.

Recently the majority of multi-family residential buildings have satisfied the ventilation requirements of the dwelling units via natural ventilation and have not provided an additional means of mechanical ventilation. Changes to ASHRAE Standard 62.1 and the adoption of those changes into local codes require multi-family dwelling units to be mechanically ventilated. This paper evaluates systems and equipment available to meet the code mandated mechanical ventilation requirements and discusses the impacts of the selection on the building. Areas of impact evaluated are building aesthetics, capital cost, annual energy cost, utility billing structure, building space requirements, systems and equipment maintenance and green construction rating impact.

The optimization of energy efficient housing is a highly complex problem involving hundreds of parameters due to the many options that exist at the time that a building is being designed. To perform the optimization in an acceptable time frame, singular value decomposition is used to reduce the number of design variables by identifying those that contribute most strongly to the optimization problem. A case study of residential buildings in six separate locations across the U.S. is performed and the results are discussed.

Recent official statistics have shown that Saudi Arabia electricity consumption growth rate at 7%. Buildings primary energy consumption and electricity consumption are 23% and 80%, respectively. This trend of high energy consumption is expected to rise in the upcoming few years. According to governmental statistics, 70% of the buildings in Saudi are not insulated. Furthermore, most of the air-conditioners in existing buildings were installed before enforcing minimum performance standards on air-conditioners. In this paper, an uninsulated existing residential building model was developed and validated against utility data.

Variable capacity technology is a core feature in high efficiency air conditioners available in the residential, ducted market. Residential variable capacity air conditioners are available in a range of Seasonal Energy Efficiency Ratios (SEER), exceeding the federal minimum levels. Energy efficiency program implementers seek to understand the efficiency impact of variable capacity systems for their climates and applications. Program implementers seek guidance on structuring their programs based on available industry ratings. This report examines the performance of three variable capacity systems of varying SEER over a range of real-world operating conditions, away from the current standard testing conditions for SEER.

Annual energy consumption of a 1200 square foot residential home was modeled using four energy modeling programs: CBECC-Res, BEopt, EnergyPro, and REM/Rate. A baseline house was developed that met California Title 24 Standards, and both slab and crawlspace foundations were considered. The baseline house was additionally modified to have non-compliant (lower-efficiency) inputs, as well as advanced-efficiency inputs, for parameters including insulation, window properties, HVAC system efficiencies and air infiltration. For given set of inputs, the four models produced significant variations in calculated annual electricity and natural gas consumption with differences as high as +/- 50%.

Vapor and combustion by-products combine to create highly acidic condensate. This restricts the types of metal used in condensing appliances for hydronic heating. Prior practice was to use building location, lighting design and other factors and 20°F ΔT calculations for designing hydronic heating systems. This led to systems designed for worst case scenarios, resulting in overcapacity and wasted energy. With the emphasis on Green design, systems should and can be designed to building load. New technology in controls, segmented systems and lead lag capability allow systems to only use the energy needed, to provide the appropriate amount of heat.

The more industrial boilers are used, the more potential for corrosion exists, resulting in shortened appliance life. An extremely effective method for reducing corrosion is water treatment. This presentation covers the typical metals found in boiler systems, system operation, corrosion causes and effects, focusing on the effects of corrosion on hydronic heating systems. Systems with and without water treatment through conventional and green corrosion inhibitors are examined along with options for maintaining system efficiency.

This presentation covers venting requirements for high efficiency hydronic heating systems, including venting basics as well as special gas venting systems for Category II, III & IV. Appliance manufacturer’s requirements and proper system design will be discussed along with Code Compliance with National Fuel Gas Code and design Criteria for NFGC Compliance. Proper system design is examined with pressure drop and draft calculations as well as the results of inadequate draft and over draft control. Finally, proper application of design is reviewed as it pertains to high efficiency, condensing hydronic heating systems.

The commissioning process for a central chiller plant includes full analysis of the plant's chilled water and condenser water pumps. This includes a verification of pump capacities and proper installation, plus confirming they are started, tested, and balanced for design operating condition. This presentation includes the steps needed to ensure the pumps are fully commissioned to meet the Owner's Project Requirements and perform as designed.

The commissioning process for a central chiller plant includes full analysis of the plant's condensing water cooling tower. This includes a verification of unit capacity and proper installation, plus confirming it is started, tested, and balanced for design operating condition. This presentation includes the steps needed to ensure the cooling tower is fully commissioned to meet the Owner's Project Requirements and perform as designed.

The commissioning process for a central chiller plant includes full analysis of the plant's fluid chilling unit. This includes a verification of unit capacity and proper installation, plus confirming it is started, tested, and balanced for design operating condition. This presentation includes the steps needed to ensure the fluid chiller is fully commissioned to meet the Owner's Project Requirements and perform as designed.

This Project is a wooden office building in the forest at the foot of Yatsugatake. The client spent over a decade selecting this suitable site to ensure symbiosis with nature. An “energy-saving system” using passive methods (natural ventilation, direct solar gain, natural lighting), an “energy-making system” comprising a heat and power generator using renewable energy (solar power, wooden biomass resources) and a micro-grid system with a lithium-ion rechargeable battery are adopted to achieve ZEB. This building has been properly operated by environmentally conscious staff and has achieved a year-round PEB (Positive Energy Building).

VRF systems are touted for their superior part-load performance compared to conventional HVAC systems. This study compares both the full and part-load performance of a VRF system with a conventional RTU VAV (rooftop variable air volume) system in a multi-zone office building with emulated occupancy. During the study period starting July 2015 through February 2016, each system was operated alternately under each of the three load conditions for 2-3 days, and the system parameters, indoor and outdoor conditions, loads, and energy use were monitored. The performance of the two systems is compared in terms of weather-normalized HVAC energy consumption.

Water-based air conditioning system has attracted increasing attention because of their smaller charge amount of refrigerant which is supposed to cause global warming. It is widely used for such as chiller, and there are more requirements for higher efficiency and improvements in workability in building use. This paper discusses the outline of HVRF and explains the refrigerant and water flow. HVRF enables free selection of a cooling mode or a heating mode in each indoor unit. It also discusses the coupled simulation of refrigerant circuit and water circuit.

Europe, with a building stock responsible for about 40% of the total energy use, needs to reduce the primary energy consumption in buildings in order to meet the 2020 energy targets of the European Union. High temperature cooling and low temperature heating systems, and as an example, Thermally Activated Building Systems (TABS), have proven to be an energy-efficient solution to provide buildings with an optimal indoor thermal environment. This study focuses on quantifying the impact of two types of free hanging ceiling absorbers (horizontal and vertical), on the cooling performance of the TABS and the implications this has on the occupants´ thermal comfort.

This paper presents a first-order physics based model which reasonably accounts for the fundamental heat and mass transfer of vapor from humid air feed side to permeate side. This model comprises two membrane mass transfer submodels (i.e. microstructure model and performance map model); moreover, we adopt a segment-by-segment methodology for discretizing heat and mass transfer governing equations. The reported model is capable of simulating both dehumidifiers and energy recovery ventilators with cross-flow, counter-flow and parallel-flow. The model has been validated with measurements of a working device.

In this study, development of a novel system for combined water heating, dehumidification, and space cooling is discussed. This system benefits from multiple technologies developed in Nanostructure Energy System Laboratories at the University of Florida. The membrane-based absorption technology utilized in the system confines the absorbent to alleviate the liquid entrainment issue encountered in the conventional packed bed absorbers. The ionic liquid utilized in the system alleviates the crystallization issue and widens the cycle operating temperature conditions. This system collects the space sensible and latent heats from an air stream and transfer them to hot water.

A 25 ton solar thermal heat pump/chiller (STHP/C) has been commissioned at a hotel in Desert Palm Springs, California. Thermal heat pumps are powered by heat vs electricity. They deliver good energy and cost savings even when powered by natural gas. With renewable heat, and when chilling is co-produced, the savings increase dramatically. This STHP/C is powered by 500,000 BTU/hour of 250°F heat from a solar thermal collector. A backup natural gas heater enables 24/7 operation. The domestic hot water heating is 800,000 BTU/hour at 130°F. The chilling co-product is 25 tons at 44°F.

Use of absorption equipment has gained momentum in the HVAC industry due to improvements in the technology and versatility of new equipment and the recent drop in utility rates. Absorption chillers are almost always used where there is high grade waste heat such as in cogeneration systems. But is it feasible to use direct fired absorbers with current energy prices? This study presents economic performance of absorption technology with respect to the type of equipment, application, geographical location and cost of utilities.

Residential and commercial buildings play a significant role in the energy consumption sector. Buildings account for approximately more than 30 percent of total energy consumption which proves that energy management in buildings should be prioritized. One of the energy-efficient and cost-effective solutions in energy management is utilizing thermal energy storage. The main benefit of Thermal Energy Storage (TES) is to overcome mismatch between energy generation and energy use. This research is based on the concept of supplying multi-family houses space heating and cooling demands by implementing water-source heat pump which is connected into a buried sensible seasonal storage tank.

Eliminating or minimizing the defrost penalty of air source heat pumps will increase their energy efficiency and their market penetration. Preliminary research suggests that coating the outdoor coil of a heat pump with an icephobic coating will lead to reduced (or delayed) frost accumulation and defrosting requirements. Additionally, the coatings may allow faster shedding of ice and shorten the defrost duration. Prior research in nanotechnology has shown that a normal layer of polymer with particles for surface texture approximately 10 to 20 microns thick impacted the heat transfer characteristics of a metal substrate.

Most U.S. homes are heated by natural gas, particularly in the Midwest and Northeast. Over 80% are heated by warm-air furnaces which range in efficiency from 80% to 98% AFUE. Recently, higher efficiency “condensing” models have saturated the market, particularly in Northern states, and shifting federal standards will further drive adoption of “condensing efficiency” heating equipment. Looking ahead, an emerging class of gas-fired heat pumps could continue this drive towards high-efficiency gas heating. The authors review findings from a recent development and demonstration of a residential-scale gas heat pump (GHP) for space heating, including results from laboratory and field evaluations.

R123 has been used successfully as a low ODP replacement for R11 since the ban on R11’s production after December 31, 1995, imposed by the Montreal Protocol. However, the Montreal Protocol ban on use of R123 after December 31, 2019, in developed countries is becoming imminent. This paper provides a description of the environmental and thermo­dynamic characteristics of R514A as a replacement for R123. The thermodynamic properties of R514A result in comparable performance to R123. The performance of two centrifugal compressor-based chillers was measured in laboratory tests with R123 as a baseline and with R514A as a replacement.

As the phase-out date for R-123 in approaches, alternative low pressure refrigerants are being identified and qualified for use in new and existing chiller products. This paper summarizes chemical stability evaluations that were conducted in the laboratory and in operating equipment to evaluate the system chemistry of refrigerant alternatives R-514A and R-1233zd(E). Chemical stabilities of refrigerants 514A and 1233zd(E) were proven to be similar to or better than R-123, and both refrigerants have been qualified for application in a range of centrifugal compressor-based chiller products. R-1233zd(E) has higher operating pressures than R-123 and is applied in new equipment designs.

This paper reports on laboratory and field investigation of the effect of refrigerant charge level on DX packaged air-conditioner electric power demand, cooling capacity, and energy efficiency. In the laboratory, numerous performance parameters were analyzed as refrigerant charge level was incrementally adjusted above and below the manufacturer nameplate charge amount at a range of operating conditions. Automated charging controls along with performance monitoring systems were installed on package units at field sites in three climate zones: 3A (temperate-humid), 3B (hot-dry), and 2A (hot-humid).

Supermarket refrigeration systems are large contributors to greenhouse gas (GHG) emissions, which impose ever-increasing and global environmental concerns. It is important to quantify the GHG emissions that occur over the lifetime of supermarket refrigeration systems, for baseline refrigerants and systems, as well as for newer, low-global warming potential (low-GWP) refrigerants and systems. A commercially available simulation tool was used to model four refrigeration systems in a large supermarket, in two locations in California. GHG emissions from direct refrigerant release and indirect emissions due to energy consumption were considered.