Transient Analysis of a Flat Heat Pipe Working as a Passive Air Conditioning System in Residential Buildings

In this study, a flat heat pipe is proposed to use the enormous heat capacity of the soil as a heat sink to remove heat from the ambient and a the same time provides a heat pathway for the external irradiation so that the thermal insulation of the construction is significantly improved. Heat pipes offer an effective and attractive alternative since they work with a small temperature budget. Heat pipes use the latent heat of vaporization as a heat transfer mechanism and provide a very high effective conductivity. Heat pipes are not thermodynamics cycles then do not suffer from the Carnot limitation. Temperature drop in the vapor core is very small and the vapor provides an almost isothermal condition. The operational temperature of a heat pipe is controlled by the conditions in the condenser (in this case, the soil). So, providing an effective heat transfer pathway in the condenser, the vapor temperature will be closed to the temperature of the soil. Soil temperature does not fluctuate bellow certain distance from the surface and in a tropical climate is always cooler that the ambient and can function as a heat sink. As part of this research, a full transient analysis of the operation of a flat heat pipe is carried out. With the insight of numerical results, a flat heat pipe thermal panel can be constructed and tested to verify the feasibility and actual performance of the flat heat pipe panel.