scholarly journals Effects of Time to Unactuate Air Conditioning on Fire Growth

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3100
Author(s):  
Teng-Yi Wang ◽  
Kuang-Chung Tsai

Air conditioning systems have become essential equipment in many buildings. However, fire safety design and management in buildings rarely consider whether to turn the system off or keep it on in a fire. This study ignites a stack of wood in a room center or corner to explore the influence of air inlet actions of a fan coil unit (FCU) with the door opened or closed. Simulation results using Fire Dynamics Simulator (FDS) demonstrate that the heat release rate (HRR) and room temperature obviously decrease when the room doorway is closed, regardless of whether the air conditioner is turned on. The air supply for combustion is poor. When the door of the room is opened, turning off the air conditioner can effectively reduce the HRR and the room temperature in the early stages of fire growth. However, along with the fire growth, turning on air conditioning can help decrease the heat radiation feedback and the consequent HRR. Therefore, the conclusion that air conditioning always enhances a fire because it provides oxygen may not always be correct.

2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.


2014 ◽  
Vol 672-674 ◽  
pp. 54-60 ◽  
Author(s):  
Ting Xiang Jin ◽  
Xiao Feng Xu

As coal, oil, natural gas and other non-renewable energy consumption and increasing energy demand, the utilization of solar energy as a new energy is greatly enhanced. In this work, a grid connected photovoltaic solar air conditioning system is designed, mainly comprised of solar panel, controller, inverter, room air conditioner and other parts. Air conditioning systems rely mainly on solar photovoltaic power; achieve the effect of energy conservation and environmental protection. The experimental result indicates that the system can achieve stable operation and the utilization of solar energy driving air conditioning system to save electricity. This air conditioning system is compared with the ordinary air conditioning system, SEER can increase 10.6 ~ 29.4%, HSPF can increase 6.25 ~ 18.5%.


Author(s):  
A. Anthony Adeyanju ◽  
K. Manohar

Thermoelectric devices use the Peltier effect which creates a heat flux between the junctions of two different types of materials. The thermoelectric module also referred to as a heat pump transfers heat from one side to the other when a DC current is applied. This study carried out the theoretical and experimental analysis of a thermoelectric air conditioning system. A prototype thermoelectric air conditioner of 286 W cooling capacity was built and a testing enclosure made from plywood and Styrofoam was also constructed in order to validate the theoretical result with an experimentation. It was discovered that thermoelectric air conditioning took 4 minutes to reach its desired temperature of 22℃ whereas the standard air conditioning system (Refrigeration Cycle) took 20 minutes to cool to a room temperature. Economically it was also discovered that thermoelectric air conditioning system is 50% cheaper than the refrigeration cycle air conditioning systems. The thermoelectric air conditioner has cheaper maintenance and greater estimated life span of 7 years more than the refrigeration air conditioner. This is because the air conditioner that operates on the refrigeration cycle uses a rotating compressor while the thermoelectric air conditioner uses thermometric module.


2018 ◽  
Vol 931 ◽  
pp. 920-925
Author(s):  
Zohrab Melikyan ◽  
Naira Egnatosyan ◽  
Siranush Egnatosyan

Centralized air conditioning systems are widely used in buildings at present. In these conditioners, the outside air gets required temperature, humidity, purity, and other features, necessary for creating comfort microclimate in inside areas of houses, and by the help of fans and air ducts the processed air moves to all rooms of a building. As a result, the creation and maintenance of comfort conditions in buildings become complicated and expensive activity. From this point of view, it is becoming more expedient to install local air conditioners in each room instead of single central one for the whole building. For this reason new local air conditioner is developed.


Author(s):  
Jianghong Wu ◽  
Shuangfeng Wang ◽  
Yunting Ge

Two type condensers of R22 residential air conditioning systems were investigated in this study. Two R22 residential air-conditioning systems, one with a microchannel condenser and the other with a round-tube condenser, were examined experimentally, while the other components of the two systems were identical except the condensers. Based on the principle of the microchannel condensation, the analysis of heat transfer along parallel heat exchanger was conducted. The non-uniform air velocity distribution at the face of the microchannel condenser and refrigerant distribution in headers were taken into account in this research. The mechanism and possibility of the superior thermal performance as compared with conventional fin-tube heat exchangers were discussed. In addition, the maximum of thermal performance influenced by the running parameter was experimentally measured. The experimental results show that with one third face area of round tube heat exchanger, microchannel condenser’s pressure drop increase around 12–23% and refrigeration output increase 2–5%, refrigerant charge decreases around 50%, it is found to be a promising candidate for residential air conditioning condenser.


Author(s):  
Ahmed Almogbel ◽  
Fahad Alkasmoul ◽  
Zaid Aldawsari ◽  
Jaber Alsulami ◽  
Ahmed Alsuwailem

AbstractInterest for air-conditioning systems (ACs) has exponentially expanded worldwide throughout the most recent couple of decades. Countries with booming economies including Saudi Arabia report high growth of sales of room air conditioners. With the expanded (GDP) and warming climates, interest for room air-conditioning systems is required to additionally increment. Meeting the expanded need for electricity energy will be a challenge. Expanded utilization of energy-efficient air conditioners impactsly affects lowering the electricity demand. In an ordinary AC, the blower runs at a fixed speed and is either ON or OFF. In an inverter AC, the compressor is consistently on; however, power drawn relies upon the demand for cooling. The speed of the compressor is adjusted appropriately. In this paper, the energy consumption of non-inverter and an inverter AC of the same capacity was assessed in an average office room, under comparative operating conditions, to find the differences in the energy saving, Carbon Dioxide (CO2) emission, and power consumption of air conditioner. Energy consumption was measured for about 108 days, which is from July 16th to October 31st, 24/7, and compared. The experiment is conducted with the same conditions and same capacity air conditioners (18,000 BTU). Results show that the day-by-day normal vitality utilization, the inverter will save up to 44% of electrical consumption compared to a non-inverter of 3471 kWh/year and 6230 kWh/year respectively. Furthermore, the Total Equivalent Warming Impact (TEWI) analysis shows that inverters can save 49% of CO2 emissions.


2012 ◽  
Vol 260-261 ◽  
pp. 357-361
Author(s):  
Zhi Zhang ◽  
Peng Du ◽  
Pei Zhang

This paper analyzes the automotive air conditioning refrigeration cycle system, to establish the mathematical model of the compressor, condenser and evaporator. Using the Matlab to build a simulation model of the automotive air conditioning and refrigeration systems. by the simulation model of automobile air conditioning compressor, condenser and evaporator match the condensing temperature, evaporating temperature, air inlet temperature ,it is shown this model is reasonable


2013 ◽  
Vol 278-280 ◽  
pp. 111-116
Author(s):  
Zheng Zhang ◽  
Jin Feng Wang ◽  
Jing Xie ◽  
Yi Tang

In this article, the application of Computational Fluid Dynamics (CFD) technology in the field of Heating Ventilation & Air Condition was introduced, and the research progress in optimizing the simulation of air-conditioned room was summarized. Some domestic and foreign studies on air conditioning operation and energy saving were illustrated about the effects of different installation locations, blow angles and air supply modes, which would provide a theoretical basis and scientific guidance for air-conditioning systems to optimize the design. Based on previous results, the development of further research on CFD in the simulation of air-conditioning in future was analyzed.


Author(s):  
Azridjal Aziz ◽  
Muhammad Rif’at Syahnan ◽  
Afdhal Kurniawan Mainil ◽  
Rahmat Iman Mainil

Split air conditioning systems produce reasonable amount of condensate which is usually not utilized and thrown away to the environment. On the other hand, it consumes a lot of energy during operation. The aim of this study is to investigate the improvement of air conditioning systems performance utilizing condensate. A direct evaporative cooling using condensate is incorporated on a 0.74 ton-cooling capacity of split air conditioning to decrease the air temperature before entering the condenser. Performances of the split air conditioning with and without direct evaporative cooling are compared and presented in this paper. The results show that the use of direct evaporative cooling using condensate into the air before passing through the condenser reduces the compressor discharge pressure. The decrease of the condenser pressure led to 4.7% and 7% reduction of power consumption for air conditioner without cooling load and air conditioner with 2000 W cooling load, respectively. The cooling effect and coefficient of performance (COP) increase with the decrease of compressor power. The use of direct evaporative cooling with condensate into the air before entering the condensing system can enhance the system performance and protect the environment.


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