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The new City of Toronto Paramedic Services Multifunction Paramedic Station is a two-storey building and the city is seeking to future proof their emergency response building by aligning with the carbon emissions goals set by the city. A couple of major client driven goals of the project is the ability of the building to operate during extreme situations resulting in power outages and considering an all-electric vehicle fleet for future. Some other prominent project goals include optimizing the building mechanical systems for optimum space thermal comfort utilizing the ASHRAE Standard 55 and provide industry leading indoor air quality which surpasses ASHRAE 62.1 Standard for air quality and acoustics. This conference paper will focus on the techniques and processes followed to minimize energy requirement to operate city buildings. The conference paper will explain in detail the comprehensive approach taken by the design team to achieve these desired targets specified by the clients and create a healthy, future ready high-performance building for the paramedics. Overall, a comprehensive systems thinking approach is explained and disucced in detail how it can be replicated to develop highly efficient mechanical system for traditional city buildings and optimize different components of building design to reduce the annual energy consumption and carbon emissions associated with it. [ABSTRACT FROM AUTHOR]

Liquid Desiccant Air Conditioning and Dehumidification (LDAC) has been emerging in the past 10 to 15 years as an energy-saving alternative design for applications that require high moisture removal and a Cleantech solution that has the potential to provide significant energy savings when applied to more broad markets. Buildings are the primary users of electricity in the U.S., consuming about 75% of the total electricity produced and about 40% of all U.S. primary energy use and associated greenhouse gas (GHG) emissions. A substantial portion of that energy is used for air conditioning and dehumidification. Furthermore, the U.S. Department of Energy (DOE) reports that U.S. buildings account for 35% of the U.S. carbon dioxide emissions that drive the climate crisis. One specific application that requires significant moisture removal is the indoor cultivation of legal cannabis. It is estimated by the DOE that by the end of this decade, electrical energy usage by indoor cannabis operations will be on par with the electrical energy consumed by either data centers or for the recharging of electrical vehicles. More recent projections indicate cannabis sales are expected to double from 2021 to 2030. As such, more efficient and economical methods of climate control are necessary for more widespread application in cannabis operations to reduce the energy requirements. The added emphasis should be on methods to first reduce the energy required before building the electrical generating infrastructure to support such growing industries. Climate control of indoor cannabis cultivation is one such aspect where energy-efficient air conditioning and dehumidification can contribute to reducing the projected energy usage by end of this decade. This paper gives an overview of a standalone LDAC system and a hybrid LDAC combined with an air handling unit. This paper will present indoor grow room case studies from a side-by-side installation of a hybrid LDAC unit and Desiccant Wheel (DW) air handling system in two identical cannabis grow rooms. Integration with a Combined Heat and Power (CHP or cogeneration) plant onsite supplying energy for both the technologies will be examined. Further, comparative energy analyses of LDAC, DW technology, and other widely used technologies in the HVAC indoor growing environment will be discussed. This will be the first comprehensive, side-by-side performance and energy analysis of competing desiccant (LDAC and DW) technologies in a controlled, indoor agriculture environment. [ABSTRACT FROM AUTHOR]

Energy efficiency in the building sector can lead to a significant reduction of the total carbon footprint in the environment produced by buildings. Hence, designing efficient building systems and controls is crucial to decreasing building energy consumption and carbon emission. This paper proposes to utilize both ducts of the dual VAV system configuration simultaneously to minimize energy usage and maximize efficiency. One air handling unit can be operated as a dedicated outdoor air unit to serve the ventilation load while the other serves the building load. To attain the benefits of a dual VAV system in this way, a specific control sequence is proposed in this paper. Single duct VAV, single duct fan-powered VAV, dual duct with common outdoor intake, and dual VAV systems are modeled for a case study multi-zone building to demonstrate this concept. Annual heating, cooling, and fan energy consumption of these four systems are then compared to evaluate the energy savings. After that, field studies are performed for a single duct VAV system as the baseline and dual VAV system in the fully instrumented HVAC lab at the University of Cincinnati, Ohio. It is observed in the simulation studies that using both VAV systems simultaneously leads to significantly lower heating and fan energy consumption for the case study building. Moreover, the field experiment result validates the simulation results, and about 29% fan power savings are obtained over 24 hours by using this configuration. Thus, this study demonstrates the potential of adopting a dual VAV system widely over the other three baselines to achieve energy efficiency with the proposed sequence of control in multizone buildings. [ABSTRACT FROM AUTHOR]

This paper demonstrates the opportunity for UK local authorities to utilise waste heat from local industry to accelerate their success with meeting net zero emissions targets. It presents the results of a feasibility study for an urban area in Yorkshire, UK aimed at driving clean growth and decarbonisation in local industry together with investment in low carbon energy systems. This is an ambient loop district heating network design with sharing of heating between buildings and heat recovery from a local industry source, including mine water. This adapts the GreenSCIES concept developed initially for Islington, London, tailored to local council demands and local industry energy sources. The scheme would be based on a low temperature heat network with large, decentralised heat pumps to raise temperatures to that required in the connected buildings/dwellings. The heat source is low-grade waste-heat from a local glassworks which is readily accessible with minimal disruption to 24/7 operations. The scheme considered thermal storage and the integration of a 20MW solar PV farm and a 10MW windfarm. The results show that that it is possible to decarbonise large parts of the borough including their social housing stock. In addition, using old mine workings as a means of storing and recovering heat, allows seasonal storage of heat to act both as back-up and top-up to the heat available from the glassworks. This novel approach uses natural resources and builds on local industry to accelerate economic regeneration paving the way to net zero carbon emissions. [ABSTRACT FROM AUTHOR]

Currently used legacy refrigerants for air conditioning and refrigeration applications such as R-410A, R-404A and R-134a have high global warming potentials (GWP). Due to this, these refrigerants have become targets for phase-down as part of global carbon emission reduction initiatives (Kigali amendment to the Montreal Protocol, EU F-Gas Regulation, etc.). Refrigerant alternatives for existing systems to be used in aftermarket applications are required to be nonflammable. Similar performance in efficiency and capacity while providing a reduction in GWP are required. Refrigerant manufacturers have developed options that attempt to fulfill these needs. However, the reduction in GWP often leads to blends that impose a gliding temperature profile in the heat exchangers besides other factors that need to be considered for drop-in situations like operating pressures, compressor discharge temperatures or material compatibility, among others. This paper evaluates the agreement between different refrigerants and the requirements for existing legacy refrigerants in air conditioning and refrigeration applications. A focus on temperature glide and inherent performance impact is evaluated and related to possible considerations for use. Refrigerant options with similar performance and operating characteristics for R-410A, R-404A and R-134a are identified with R-466A, R-448A/R-449A/R-407H and R-513A/R-456A, respectively. A close evaluation of material compatibility and detailed system modeling beyond this screening evaluation are needed to confirm viability for the specific application. [ABSTRACT FROM AUTHOR]

This paper draws on three recent case studies which have shown encouraging economic results in meeting net-zero carbon emissions targets through Smart Local Energy Systems (SLES) in different localities across England, based on the GreenSCIES model. The blueprint for the GreenSCIES SLES was developed in Islington, London, and consists of a 5th generation ambient loop district heat network using heat from a large data centre, also including electric vehicle charging, storage and solar PV. This allows for heat sharing between buildings and applications for heat recovery from local sources. In Sandwell, Birmingham, where the heating demand is nearly ten times higher than the cooling demand the design is based on a 4th generation heat network with waste heat from a local metal foundry and some cooling supply and heat storage in the aquifer. The design for a study in Barnsley, Sheffield, explored waste heat from a local glass factory and considered old mine workings as a means of storing and recovering heat, providing seasonal storage of heat for resilience to a single source industry. With additional work, the Barnsley scheme could be further expanded, increasing the available carbon emissions savings. These examples provide practical, feasible and economic SLES projects which demonstrate the importance of collaboration between researchers, local government and industry. They also illustrate how the original GreenSCIES concept can be adapted successfully to provide a pathway towards netzero carbon for a diverse range of urban locations with different housing density and waste heat sources. [ABSTRACT FROM AUTHOR]

Aligning with the global movements towards mitigating CO2 emissions and regulations to phase-down HFC refrigerants, many low-Global Warming Potential (GWP) refrigerants are being tested and proposed as fourth-generation refrigerants. R1234yf (HFO-1234yf) is a refrigerant with GWP <1 (0.31) and has replaced R134a (HFC-134a), which has GWP 1300, in automobile air conditioning systems and has a high potential to replace it in domestic refrigerators. In this paper, an energy performance evaluation and a life cycle climate performance assessment for R1234yf were conducted and compared to R134a. The study involved two identical domestic refrigerators with the same refrigerant charge that is recommended by the manufacturer. R1234yf showed resulted in similar cabinets air and refrigerant temperatures. However, the discharge temperature for the R1234yf refrigerator was relatively higher temperature than that for R134a. Also, R1234yf demonstrated higher daily energy consumption and more extended compressor run-time than of R134a. On the other hand, R1234yf proved significantly lower direct emissions and higher indirect emissions than those caused by R134a. Overall, R1234yf resulted in 3% reduction in the Lifecycle Climate Performance (LCCP) CO2 emissions compared to R134a. [ABSTRACT FROM AUTHOR]