This paper presents a numerical study of the air-conditioning of a room by a two-phase thermosyphon loop using meteorological data from the Mamou region (Guinea). The room is composed of a rectangular roof and a passenger compartment in the form of a parallelepiped. In addition, the air-conditioning unit that operates with methanol is composed of an evaporator, a condenser, a riser and a downcomer. The heat transfer modelling governing the habitat model and the air conditioning loop is based on the nodal method. The coupling of the system is done by convective transfer between the internal air of the habitat and the surface of the evaporator. The equations are solved by the implicit finite difference method. Thus, this resolution made it possible to determine the influence of the parameters on the model. This work presents results of the habitat with and without the air-conditioning loop for typical days in March of Mamou. These results show that the use of the air conditioning loop can contribute to lowering the internal air temperature. The value of the maximum temperature of the indoor air of the habitat with the air conditioner is about 299 K while that of the air without air conditioner is about 303 K. The variation of parameters such as temperature, wall thickness, incident solar flux, air exchange rate and evaporator surface has a significant impact on the operation of the air conditioner and on the temperature of the conditioned room. A low wall thickness or a high air exchange rate contributes to the temperature increase in the room. For a wall thickness of 10 cm, 15 cm or 40 cm, the air temperatures are 301.5 K, 297 K and 296.9 K respectively. However, for a habitat without an air conditioner the temperature is 303 K when the wall thickness is 15 cm.

The two-phase thermosyphon loop is an efficient solution for space cooling. This paper presents the simulation results of numerical studies on the heat transfer and thermal performance of a two-phase thermosiphon loop for passive air-conditioning of a house. The fluid considered in this study is methanol, which is compatible with copper and is environmentally friendly. These numerical results show that the temperature at the evaporator wall drops from 23˚C to 13˚C and increases at the condenser. The solar flux density has a strong influence on the condenser temperature. The mass flow rates and masses at the evaporator and condenser increase with temperature. The variation of evaporating and condensing temperature affects the performance of the system. For a constant evaporating and condensing temperature of 2˚C and 29˚C, the COP is 0.77 and 0.84 respectively. With these results, the use of the two-phase thermosyphon loop in air conditioning is possible to obtain a thermal comfort of the occupants acceptable by the standards but with a large exchange surface of the evaporator.