Thermal performance of a nearly zero energy passive house integrated with the air–air heat exchanger and the earth–water heat exchanger

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.

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Numerical Assessment of Earth to Air Heat Exchanger with Variable Humidity Conditions in Greenhouses

Energies ◽

10.3390/en14051368 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1368

Author(s):

Di Qi ◽

Chuangyao Zhao ◽

Shixiong Li ◽

Ran Chen ◽

Angui Li

Keyword(s):

Heat Exchanger ◽

Relative Humidity ◽

Thermal Performance ◽

Heat Exchangers ◽

Energy Savings ◽

Volume Flow Rate ◽

Fluid Dynamic ◽

Small Diameter ◽

The Earth ◽

The Impact

Earth to air heat exchangers are widely utilized to cool or heat passive buildings for energy savings. They often need to deal with high humidity air conditions, especially in the greenhouse due to plant transpiration, and the condensation phenomenon is frequently observed during the cooling process. To evaluate the effect of humidity and condensation on thermal performance, a three dimensional computational fluid dynamic (3D-CFD) model was developed. The distribution of relative humidity in each pipe was investigated, and the impact of inlet air relative humidity on the integrated performance of the earth to air heat exchanger was discussed. The effects of inlet air temperature and volume flow rate were also analyzed. Moreover, the influence of the heat exchanger configurations on the performance of the air condensation was researched. The results indicated that condensation had few effects on the airflow distribution uniformity of the earth to air heat exchanger, while it acted observably on the thermal performance. In addition, humid air in a small diameter pipe tended to condense more easily. Humidity and condensation should be taken into consideration for the design of earth to air heat exchangers in greenhouses during engineering applications.

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Numerical study of a new earth-air heat exchanger configuration designed for Sahara climates

International Journal of Energetica ◽

10.47238/ijeca.v5i1.116 ◽

2020 ◽

Vol 5 (1) ◽

pp. 22

Author(s):

Abdessamia Hadjadj

Keyword(s):

Heat Exchanger ◽

Thermal Performance ◽

Arid Regions ◽

Arid Zone ◽

Numerical Study ◽

Airflow Rate ◽

The Novel ◽

Populated Area ◽

Pipe Length ◽

The Earth

Thermal performance for cooling and heating in the building can be achieved by the novel shape of the earth–air heat exchanger (EAHE). In a heavily populated area such as City, Due to the limited ground space. EAHE systems are rarely used, for most residential andcommercial utilization.This paper presents a numerical investigation of the thermal performance of a spiral-shaped configuration Spiral Earth to Air Heat Exchanger SEAHE intended for the summer cooling inhot and arid regions of Algeria. A parametric analysis of the SEAHE has been performed toinvestigate the effect of diameter, depth, pipe length and of airflow rate on the outlet air in theexchanger. Results show that the specific heat exchange is used to cool in an arid zone (south-east of Algeria). When the ambient temperature varies between 40°C and 45 °C, the coolingtemperature varies between 25°C and 29 °C. Temperature difference inlet and outlet airexchanger 18°C, these values are quite acceptable with for cooling the building.

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Geographical aspects of the diffusion of passive houses

International Review of Applied Sciences and Engineering ◽

10.1556/irase.4.2013.2.9 ◽

2013 ◽

Vol 4 (2) ◽

pp. 151-156 ◽

Cited By ~ 3

Author(s):

G. Kozma ◽

E. Molnár ◽

K. Czimre ◽

J. Pénzes

Keyword(s):

Energy Consumption ◽

Energy Resources ◽

Substantial Part ◽

Renewable Energy Resources ◽

Passive House ◽

The Earth ◽

Passive Houses ◽

The Individual ◽

Geographical Locations ◽

Over Time

Abstract In our days, energy issues belong to the most important problems facing the Earth and the solution may be expected partly from decreasing the amount of the energy used and partly from the increased utilisation of renewable energy resources. A substantial part of energy consumption is related to buildings and includes, inter alia, the use for cooling/heating, lighting and cooking purposes. In the view of the above, special attention has been paid to minimising the energy consumption of buildings since the late 1980s. Within the framework of that, the passive house was created, a building in which the thermal comfort can be achieved solely by postheating or postcooling of the fresh air mass without a need for recirculated air. The aim of the paper is to study the changes in the construction of passive houses over time. In addition, the differences between the geographical locations and the observable peculiarities with regard to the individual building types are also presented.

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