Thermal Performance of Earth-Air Heat Exchanger Systems for Cooling Applications in Residential Buildings

2018 ◽  
Author(s):  
Fadi A. Ghaith ◽  
Habib Ur Razzaq
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Residential Buildings ◽  
Ground Surface ◽  
Ambient Air ◽  
Design Parameters ◽  
Air Cooling ◽  
Analysis Tool ◽  
Optimized Design ◽  
The Earth

This paper addresses the thermal performance of integrating Earth Air Heat Exchanger (EAHE) systems with the conventional air conditioning systems in residential buildings in UAE. The proposed system was designed and simulated using a transient analysis tool TRNSYS. The system components were optimized by evaluating the effect of varying several design parameters on the performance of the system. It was found that the optimized design of the earth tubes could potentially reduce the temperature of the ambient air from 46 °C to around 29 °C, when the earth tubes were buried at 4 meters depth below the ground surface. This pre-cooled fresh (atmospheric) air from earth tubes was then mixed with the return air in the mixing chamber of conventional air cooling systems before supply to the building. In order to assess the system feasibility, the proposed system was modelled and implemented on a realistic case study represented by a four-floor residential building located in Dubai. This building comprised a total roof area of 400 m2 and an annual cooling load requirement of 366 kW. The results showed good potential of savings in terms of lowering the Annual Energy Consumption (AEC) and the consequent reduction in CO2 emissions.

Liquid-Coupled Indirect-Transfer Exchanger Application to the Diesel Engine

1979 ◽  
Vol 101 (4) ◽  
pp. 516-523 ◽  
Author(s):  
James C. Eastwood
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling System ◽  
Relative Effectiveness ◽  
Ambient Air ◽  
Air Cooling ◽  
Performance Curves ◽  
Air Cooling System ◽  
Cooling Function ◽  
Low Charge

The efficiency of turbocharged diesel engines can be increased by cooling the charge air. This paper presents a design approach for liquid-coupled indirect-transfer heat exchanger systems to perform the air-cooling function. The two advantages most commonly cited for this approach to charge-air cooling are (1) the heat exchangers involved are easily packaged so that their shapes can be controlled by judicious design, and (2) simple gas ducting allows for compact machinery arrangements and relatively low charge-air pressure drop. An analytical approach to the design of liquid-coupled indirect-transfer heat exchanger systems is presented. Performance curves are constructed on the basis of this analysis. Four important design conditions are evident from the observation of these performance curves including (1) the relative capacity rate combination of the three fluids (ambient air, coupling liquid, and engine charge-air) which yields the highest overall effectiveness, (2) an optimum coupling-liquid flow rate, (3) the relative effectiveness distribution for each of the two component heat exchangers (hot and cold components), and (4) a broad design range for the optimum area distribution between the hot and cold exchangers. These performance curves serve as a guide for the design of a liquid-coupled charge-air cooling system.

NUMERICAL SIMULATION AND PARAMETRIC STUDIES FOR EVALUATION OF BALANCED VENTILATION AND EARTH AIR EXCHANGERS SYSTEM COUPLED TO A DOMESTIC BUILDING

2013 ◽  
Vol 21 (01) ◽  
pp. 1350002 ◽  
Author(s):  
YOUNES KARTACHI ◽  
ABDELLAH MECHAQRANE
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
High Efficiency ◽  
Residential Buildings ◽  
Ventilation System ◽  
Primary Energy ◽  
Climatic Conditions ◽  
Design Parameters ◽  
Climate Data ◽  
The Impact

In this study, we analyze the impact of ventilation heat recovery with the heating and cooling potential of earth air heat exchanger in real climatic conditions in domestic buildings in the Middle Atlas region. In our case study, we calculate the primary energy used by a domestic building built as per the conventional house design parameters required by the Moroccan regulation. We use climate data for the city of Fes in Northern Moroccan. Three system configurations were considered. The first was the mechanical extract ventilation system both with and without heat recovery. The second was the mechanical extract ventilation system with earth to air heat exchanger system (EAHEX), and the third system was the mechanical balanced ventilation system coupled with EAHEX system. Primary energy use strongly influences natural resources efficiency and the environmental impacts of energy supply activities. In this study we explore the primary energy implications of the mechanical balanced ventilation system coupled with the EAHEX system in residential buildings. The results of this study shows that the use of a balanced ventilation system, with a high efficiency instead of a mechanical extract ventilation system, decreases the final and primary energy consumption. Moreover, it decreases or increases the CO2 emission depending on the primary energy sources.

A comparative study of thermal performance in three generations of Iranian residential buildings: Case studies in Csa Gorgan

2020 ◽  
pp. 174425912090624
Author(s):  
Shima Moolavi Sanzighi ◽  
Farzaneh Soflaei ◽  
Mehdi Shokouhian
Keyword(s):  
Thermal Comfort ◽  
Thermal Performance ◽  
Residential Buildings ◽  
Three Dimensional ◽  
Design Parameters ◽  
Design Strategies ◽  
Main Design ◽  
Geometrical Properties ◽  
Architectural Styles ◽  
The Impact

This article focuses on evaluating thermal performance of different types of residential buildings in Mediterranean climate (Csa) of Iran. The aim is to identify the main design parameters in nine research cases, selected from three distinct periods of history with different architectural styles, and evaluating thermal performance of these buildings. To that end, a library study was carried out to identify the most influential passive design strategies and to highlight their impact on thermal comfort and energy efficiency of residential buildings. A field survey was conducted to determine the most common types of average-income houses in Csa climate of Gorgan, Iran, with a historical overview from 19th century to present. Nine buildings were selected to study from three different period of times including the years from 1850 to 1925, 1925 to 1979 and 1979 to present. A three-dimensional numerical model was developed to assess the impact of four main design parameters including orientation, geometrical properties, openings and materials on indoor thermal comfort for each case, using Design Builder commercial software package. The correlation between these design variables and thermal comfort was presented; the results reveal that the contemporary residential buildings are not designed as efficient as traditional houses in this area, in terms of passive energy saving techniques.

Analysis of Intercooler in PEM Fuel Cell Systems

Volume 3 ◽  
2004 ◽  
Author(s):  
Takamasa Ito ◽  
Jinliang Yuan ◽  
Bengt Sunde´n
Keyword(s):  
Heat Exchanger ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Cooling System ◽  
Ambient Air ◽  
Proton Exchange ◽  
High Mass ◽  
Air Cooling ◽  
Cell Systems ◽  
Cold Stream

Heat exchangers are used in proton exchange membrane fuel cell systems (PEMFCs) for stack cooling, intercooling, water condensation and fuel reforming. Especially, the heat exchanger for the intercooling before the humidifier is investigated in this paper. It is found that, at high pressure or high mass flow rate, the need to cool the air (oxidant) is large. The heat exchanger uses coolant water from the stack cooling system or ambient air as the cold stream. With water-cooling, the volume of the heat exchanger will be small. However, difficulties exist because the small available temperature difference. Air-cooling can be used over a wide operating range but the heat exchanger volume will be large.

Enhancing the Performance of the Building’s Vapor Compression Air Cooling System Using Earth-Air Heat Exchanger

2017 ◽  
Author(s):  
Fadi A. Ghaith ◽  
Fadi J. Alsouda
Keyword(s):  
Heat Exchanger ◽  
Soil Temperature ◽  
Air Temperature ◽  
Cooling System ◽  
Ambient Air ◽  
Coefficient Of Performance ◽  
Maximum Deviation ◽  
Air Cooling ◽  
Vapor Compression ◽  
Air Cooling System

This paper aims to evaluate the thermal performance and feasibility of integrating the Earth-Air Heat Exchanger (EAHE) with the building’s vapor compression air cooling system. In the proposed system, the ambient air is forced by an axial fan through an EAHE buried at a certain depth below the ground surface. EAHE uses the subsoil low temperature and soil thermal properties to reduce the air temperature. The outlet air from the EAHE was used for the purpose of cooling the condenser of the vapor compression cycle (VCC) to enhance its coefficient of performance (COP). The potential enhancement on the COP was investigated for two different refrigerants (i.e. R-22 and R410a) cooling systems. A mathematical model was developed to estimate the underground soil temperature at different depths and the corresponding outlet air temperature of EAHE was calculated. The obtained results showed that the soil temperature in Dubai at 4 meters depth is about 27°C and remains relatively constant across the year. In order to estimate the effect of using EAHE on the performance of the VCC system, a sample villa project was selected as a case study. The obtained results showed that EAHE system contributed efficiently to the COP of the VCC with an overall increase of 47 % and 49 % for R-22 and R410a cycles, respectively. Moreover, the calculated values were validated against Cycle_D simulation model and showed good agreement with a maximum deviation of 5%. The payback period for this project was found to be around two years while the expected life time is about 10 years which makes it an attractive investment.

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