The effect of building integrated photovoltaic system (Bipvs) on indoor air temperatures and humidity (Iath) in the tropical region of Cameroon

Abstract

The building sector accounts for around 40-50 % of the energy consumed in developing countries and contribute over 30 % of CO 2 emissions. In Cameroon, the electricity access is less than 5 % in rural areas against 50 % in urban areas. All sectors combined the Cameroonian final energy consumption amounts to approximately 5235 kilo-tonnes of oil equivalent (Ktoe) and 73 % of this energy are assigned for residential use. This energy can be considerably reduced with the development of low energy buildings using Building Integrated Photovoltaic (BIPV), since it has been proven an effective solution to achieve significant energy savings and conservation. However, photovoltaic (PV) panels produce a substantial amount of heat, while generating power. Consequently, BIPV's concept, where the photovoltaic (PV) panel is integrated on the building envelops has significant influence on the amount of heat transfer through the building fabrics, and could affect the indoor air temperatures and the comfort of the occupants, since, it changes the thermal resistance of the building envelops. In this paper, the effect of the BIPV on the indoor air temperatures and humidity (IATH) of a multiple storey buildings under the tropical climatic conditions of Yaoundé, Cameroon has been modelled and analysed. Two cases of BIPV made of 290 m 2 area of PV have been considered, i) roof integrated and ii) façade integrated. In addition, building orientation, roof pitch and the building materials are also been explored and optimised to provide the best combination. It has been observed that for both cases, BIPV increases the building's indoor air temperature by about 4 °C, when compare to a building of the same size without PV integrated.

A review of building integrated photovoltaic: case study of tropical climatic regions

“…Over the years researchers have investigated the application of BIPV in tropical areas [17]- [19]. Recent study [20] shows that for tropical climate, the BIPV can increase the quantity of heat transfer through the building structure, thereby influencing the inner temperature and discomforting the residents. Another study [21] investigated the heat comfort and adaptive actions for occupants in naturally ventilated areas and proposed certain adjustments to the acceptance of the heat burden on the occupants; one is the improvement of the velocity of the air and adopting cross-ventilation, and the other is reducing the insulations related to the building.…”