scholarly journals HVAC design for college auditorium

2016 ◽  
Author(s):  
Rutvik Lathia ◽  
Jaymin Mistry
Keyword(s):  
Ozone Depletion ◽  
Hvac Systems ◽  
Environmental Condition ◽  
Minimum Level ◽  
Standard Process ◽  
Indirect Emission ◽  
Air Conditioning Systems ◽  
Online Sources ◽  
Comfort Condition ◽  
Ozone Depletion Potential

In Today’s life, it is being indispensable to live healthier life and for that environment must be free from hazardous effects but it is not easy to achieve comfort condition in every season and every place. For better environmental condition in specific arena we have used HVAC (Heating, Ventilating & Air conditioning) systems. from literature survey and online sources we found that there is no any standard process for designing the HVAC systems so, this poster provides standard process with an example, we consider place as Auditorium in Changa, Gujarat, India and season is summer and according to that situation we developed most efficient HVAC plant with all design aspects. It is designed as that so ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) will maintain at minimum level and indirect emission will also not take place.

scholarly journals Solar-Driven Air-Conditioning Cycles: A Review

2007 ◽  
Vol 4 (1) ◽  
pp. 48 ◽  
Author(s):  
A. M. Abu-Zour ◽  
S. B. Riffat
Keyword(s):  
Ozone Depletion ◽  
Air Conditioning ◽  
Fossil Fuel ◽  
Peak Load ◽  
Fossil Fuel Combustion ◽  
Cooling Systems ◽  
Air Conditioning System ◽  
Conventional Cooling ◽  
Air Conditioning Systems ◽  
Ozone Depletion Potential

Most conventional cooling/refrigeration systems are driven by fossil fuel combustion, and therefore give rise to emission of environmentally damaging pollutants. In addition, many cooling systems employ refrigerants, which are also harmful to the environment in terms of their Global Warming Potential (GWP) and Ozone Depletion Potential (ODP). Development of a passive or hybrid solar-driven air-conditioning system is therefore of interest as exploitation of such systems would reduce the demand for grid electricity particularly at times of peak load. This paper presents a review of various cooling cycles and summarises work carried out on solar-driven air-conditioning systems. 

scholarly journals DEVELOPMENT OF A NEW CO2-BASED DEMAND-CONTROLLED VENTILATION STRATEGY USING ENERGYPLUS

2017 ◽  
Author(s):  
Behrang Chenari ◽  
Francisco Bispo Lamas ◽  
Adélio Rodrigues Gaspar ◽  
Manuel Gameiro da Silva
Keyword(s):  
Energy Efficiency ◽  
Indoor Air ◽  
Energy Use ◽  
Energy Savings ◽  
Environmental Condition ◽  
Ventilation Strategy ◽  
Controlled Ventilation ◽  
New Strategy ◽  
Demand Controlled Ventilation ◽  
Air Conditioning Systems

A significant amount of energy is being used by ventilation and air conditioning systems to maintain the indoor environmental condition in a satisfactory and comfortable level. Many buildings, either new or existing (throughout their renovation process) are subjected to energy efficiency requirements but these must not be in the expenses of indoor environmental conditions. For instance, indoor air quality (IAQ) has to be considered while improving energy efficiency, otherwise occupants might be exposed to inappropriate indoor environment.Demand-controlled ventilation (DCV) is a method that provides comfortable IAQ level with lowest energy use. In this paper, the main objective is developing a new CO2-based DCV strategy and simulating it using EnergyPlus. The IAQ and energy consumption associated to this strategy have been compared with the results of CO2-based DCV strategies previously developed by the same authors in another article. The comparison shows that the new strategy performs better, both in energy use and IAQ. The recorded energy savings ranged between 6-14% comparing with the previously developed strategies while IAQ slightly improved.

scholarly journals Targeted knockout of the gene OsHOL1 removes methyl iodide emissions from rice plants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martina Carlessi ◽  
Lorenzo Mariotti ◽  
Francesca Giaume ◽  
Fabio Fornara ◽  
Pierdomenico Perata ◽  
...  
Keyword(s):  
Public Health ◽  
Genome Editing ◽  
Methyl Iodide ◽  
Iodine Deficiency ◽  
Health Problem ◽  
Ozone Depletion ◽  
Public Health Problem ◽  
Rice Varieties ◽  
Major Player ◽  
Ozone Depletion Potential

AbstractIodine deficiency represents a public health problem worldwide. To increase the amount of iodine in the diet, biofortification strategies of plants have been tried. They rely on the exogenous administration of iodine to increase its absorption and accumulation. However, iodine is not stable in plants and can be volatilized as methyl iodide through the action of specific methyltransferases encoded by the HARMLESS TO OZONE LAYER (HOL) genes. The release of methyl iodide in the atmosphere represents a threat for the environment due to its ozone depletion potential. Rice paddies are among the strongest producers of methyl iodide. Thus, the agronomic approach of iodine biofortification is not appropriate for this crop, leading to further increases of iodine emissions. In this work, we used the genome editing CRISPR/Cas9 technology to knockout the rice HOL genes and investigate their function. OsHOL1 resulted a major player in methyl iodide production, since its knockout abolished the process. Moreover, its overexpression reinforced it. Conversely, knockout of OsHOL2 did not produce effects. Our experiments helped elucidating the function of the rice HOL genes, providing tools to develop new rice varieties with reduced iodine emissions and thus more suitable for biofortification programs without further impacting on the environment.

scholarly journals Dynamic simulation of indirect air conditioning systems with optimized computational time

2019 ◽  
Vol 111 ◽  
pp. 04042
Author(s):  
Nicolás Ablanque ◽  
Santiago Torras ◽  
Carles Oliet ◽  
Joaquim Rigola ◽  
Carlos-David Pérez-Segarra
Keyword(s):  
Air Conditioning ◽  
Energy Savings ◽  
Control Strategies ◽  
Model Potential ◽  
Hvac Systems ◽  
Object Oriented Programming ◽  
Computational Time ◽  
Air Conditioning System ◽  
Numerical Resolution ◽  
Air Conditioning Systems

The simulation of HVAC systems is a powerful tool to improve the energy efficiency in buildings. The modelling of such systems faces several obstacles due to both the physical phenomenology present and the numerical resolution difficulties. The present work is an attempt to develop a robust, fast, and accurate model for HVAC systems that can interact with the other relevant systems involved in buildings thermal management. The whole system model has been developed in the form of libraries under the Modelica language to exploit its advantageous characteristics: object-oriented programming, equationbased modelling, and handling of multi-physics. The global resolution is carried out dynamically so that not only steady-state predictions can be conducted but also control strategies can be studied over meaningful periods of time. This latter aspect is crucial for optimizing energy savings. The libraries include models for all the system individual components such as pumps, compressors or heat exchangers (operating with twophase flows and/or moist air) and also models assemblies to account for vapour compression units and liquid circuits. An illustrative example of an indirect air conditioning system is detailed in the present work in order to highlight the model potential.

Optimization Process of a Visi-Cooler Using Ternary Mixtures of R134a and Hydrocarbons

2017 ◽  
Vol 25 (02) ◽  
pp. 1750019 ◽  
Author(s):  
Srinivas Pendyala ◽  
Ravi Prattipati ◽  
A V Sita Rama Raju
Keyword(s):  
Ozone Depletion ◽  
Operating Conditions ◽  
Ternary Mixtures ◽  
Coefficient Of Performance ◽  
Optimum Operating ◽  
Taguchi Technique ◽  
Capillary Length ◽  
Evaporator Temperature ◽  
Safe Limit ◽  
Air Conditioning Systems

Ozone depletion and global warming phenomenon necessitates the replacement of widely used refrigerants which consist of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) in refrigeration and air-conditioning systems. In this paper, experimental analysis on the performance of hydrofluorocarbon/hydrocarbon (HFC/HC) mixture as a possible drop-in replacement for R134a refrigerant is presented. The influence of capillary length, composition of the mixture and refrigerant charge at various evaporator temperatures on coefficient of performance (COP) are investigated. The optimum operating conditions are obtained by applying Taguchi technique for the acquired experimental results. The results of analysis of variance indicated that for a given evaporator temperature, HFC/HC mixture charge amount is the most influencing parameter. At the optimum condition, the simulation showed that the amount of charge required for HFC/HC mixture in visi-cooler is 120[Formula: see text]g which is 50% lower than required quantity of R134a for the same system. The HC mixture quantity amounted to 90[Formula: see text]g in the HFC/HC mixture which is lower than the safe limit of 150[Formula: see text]g. This eliminates the risk of flammability of HC in the proposed mixture while reducing the quantity of R134a by 87.5%.

Optimal Setpoints for HVAC Systems via Iterative Cooperative Neighbor Communication

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Matthew Elliott ◽  
Bryan P. Rasmussen
Keyword(s):  
Energy Savings ◽  
Optimization Technique ◽  
Optimal Solution ◽  
Hvac Systems ◽  
Global Optimum ◽  
Cost Information ◽  
Steady State Condition ◽  
Air Conditioning Systems ◽  
The Cost ◽  
Dynamic Subsystem

Heating, ventilation, and air conditioning systems in large buildings frequently feature a network topology wherein the outputs of each dynamic subsystem act as disturbances to other subsystems. The distributed optimization technique presented in this paper leverages this topology without requiring a centralized controller or widespread knowledge of the interaction dynamics between subsystems. Each subsystem's controller calculates an optimal steady state condition. The output corresponding to this condition is then communicated to downstream neighbors only. Similarly, each subsystem communicates to its upstream neighbors the predicted costs imposed by the neighbors' own calculated outputs. By judicious construction of the cost functions, all of the cost information is propagated through the network, allowing a Pareto optimal solution to be reached. The novelty of this approach is that communication between all plants is not necessary to achieve a global optimum. Since each optimizer does not require knowledge of its neighbors' dynamics, changes in one controller do not require changes to all controllers in the network. Proofs of convergence to Pareto optimality under certain conditions are presented, and convergence under the approach is demonstrated with a simulation example. The approach is also applied to a laboratory-based water chiller system; several experiments demonstrate the features of the approach and potential for energy savings.

scholarly journals Iodine oxide in the global marine boundary layer

2014 ◽  
Vol 14 (15) ◽  
pp. 22217-22243 ◽  
Author(s):  
C. Prados-Roman ◽  
C. A. Cuevas ◽  
T. Hay ◽  
R. P. Fernandez ◽  
A. S. Mahajan ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Chemistry ◽  
Ozone Depletion ◽  
Marine Boundary Layer ◽  
Geographical Pattern ◽  
Mixing Ratios ◽  
Field Campaigns ◽  
Ozone Depletion Potential ◽  
Ubiquitous Presence ◽  
Inorganic Precursors

Abstract. Emitted mainly by the oceans, iodine is a halogen compound important for atmospheric chemistry due to its high ozone depletion potential and effect on the oxidizing capacity of the atmosphere. Here we present a comprehensive dataset of iodine oxide (IO) measurements in the open marine boundary layer (MBL) made during the Malaspina 2010 circumnavigation. Results show IO mixing ratios ranging from 0.4 to 1 pmol mol−1 and, complemented with additional field campaigns, this dataset confirms through observations the ubiquitous presence of reactive iodine chemistry in the global marine environment. We use a global model with organic (CH3I, CH2ICl, CH2I2 and CH2IBr) and inorganic (HOI and I2) iodine ocean emissions to investigate the contribution of the different iodine source gases to the budget of IO in the global MBL. In agreement with previous estimates, our results indicate that, globally averaged, the abiotic precursors contribute about 75% to the iodine oxide budget. However, this work reveals a strong geographical pattern in the contribution of organic vs. inorganic precursors to reactive iodine in the global MBL.

scholarly journals Ozone depletion potential of CH3Br

1998 ◽  
Vol 103 (D21) ◽  
pp. 28187-28195 ◽  
Author(s):  
Malcolm K. W. Ko ◽  
Nien Dak Sze ◽  
Courtney Scott ◽  
José M. Rodríguez ◽  
Debra K. Weisenstein ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Ozone Depletion Potential ◽  
Depletion Potential
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