Earth to Air Heat Exchanger ETAHE or Air Ground Heat Exchanger (AGHE) is a renewable technique based on geothermal source used for many centuries in arid and desert regions and considered as a principal element of vernacular and traditional architecture. Arid regions are characterized by a severe winter and summer weather conditions leads to a large thermal discomfort for the big part of the year. Many researchers studied the potentials of this technique to ensure thermal comfort inside buildings for summer and winter seasons. The present study is a review of numerical, experimental, parametric and economic studies of an earth to air heat exchanger with a focus on its application in semi-arid and arid regions. Using an air-to-ground heat exchanger for thermal comfort requires a deep understanding of geothermal deposits and these natural potentials and particularly in desert and arid regions.

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This manuscript reports numerical data of computational analyses of oil flows in twodimensional horizontal rectangular cross section pipes with upper and lower wallplaced staggered solid flat baffles and fins. The physical properties of fluid (oil) and solid (Al) are constant. The flow is assumed to be steady, turbulent, and incompressible. The velocity profile at the entrance is uniform one-dimensional. The fluid temperature is set equal to 298 K at the inlet section. The upper pipe surface was put in a constant temperature condition, as the lower surface was thermally insulated. The atmospheric pressure is prescribed at the pipe outlet. Impermeable boundary and no-slip wall conditions are applied for the pipe walls and the baffle plates. The radiation mode of heat transfer is neglected according to other modes of heat transfer. Two various baffled pipe configurations are treated. The technique CFD is applied in the calculation. The Reynolds number is varied from 12,000 to 32,000, and different fields, i.e., dynamic pressure, velocity-magnitude, turbulent kinetic energy, and turbulent viscosity, are presented and analyzed numerically.

The subject of the study is mainly based on thermal reinforcement by an oily fluid containing nanometer particles of carbon. The study is carried out by the presence of discontinuous bars in two different shapes, i.e. flat and V, inside a horizontal heat exchanger. The study relies on simulations in thermal and dynamic terms from the literature. The turbulence effect is diagnosed by applying the k-ε model, while the flow hydrothermal transport relationships are modeled based on the finite volume technique. Both the flow and heat-transfer aspects of all channel regions are studied and analyzed. The new heat-exchanger structure has been enhanced in the presence of these discontinuous bars by reducing the friction coefficient and eliminating stations with poor transfer of heat behind these deflectors.

In the current study, this way was adopted numerically in order to optimize the performance of a HEC through the use of extended solid sections in the form of 'W' (W-baffles: WBs). All limit conditions of the channel have been defined, with all the thermo-physical properties of the HTF (heat transfer fluid) used. The FVM (Finite-Volume-Method) has been adopted with some necessary numerical schemes in order to give the numerical solution, which allows us to visualize dynamically the flow filed and to deduce all the energetic characteristics contained by this HE. Dynamically, the HTF flow velocity at the HEC outlet section reached about 1.812 m/s, in the case of the lowest Re value. While, it passed 4.8 m/s in the case of the largest value of the same variable, i.e. 1.726 to 4.648 times better than the Uin within the limits of Re numbers used. Thermally, areas with very hight TGs (temperature gradients) were observed near the top deflector’s sides, which reflects the effect of the W-baffles. This highlights the importance of the adopted obstacles in changing characteristics of the HEC to the best.