Sustainability & Economical Evaluation of the Smart and Energy Efficient Technologies for the Rammed-earth House in Accra Ghana : (Case Study in Accra, Ghana)

Abstract: The energy consumption of buildings contributes 18% of world greenhouse gas emissions (GHG). This fact, along with the current increase in new African buildings, leads to vast opportunities for building sustainable buildings in Africa. The research aims to find which smart and sustainable technologies are economical and suitable for the rammed-earth building project in hot and humid climate for sustainable development, as is the case in Accra Ghana. Two evaluation steps were conducted - technologies evaluation and scenarios evaluation - by simulating energy demand reduction compared to the baseline for economic evaluation in IDA Indoor Climate Energy (ICE) software, together with Microsoft Excel and market research. Ten technologies were initially chosen and applied to the five scenarios by consideration for economics and suitability. The result shows that four out of five scenarios were economical. However, only two scenarios were suggested for the project - Realistic with variable refrigerant flow air-conditioning (Realistic with VRF AC) and Economic Internet of Things (Economic IoT) - when net present value (NPV), payback period, benefit per cost ratio (B/C), and suitability are taken into account. Moreover, the sensitivity analysis demonstrates that the occupancy pattern affects the energy consumption to some extent, and infiltration rate relates to energy consumption. These methods can be applied for possible future projects, and the results can be used as a reference for projects in hot and humid climates with rammed-earth construction.