JSR

This research investigates different passive design measures to improve residential buildings’ energy efficiency and mitigate the effects of climate change. To identify the best passive design strategy for the climate under study, a four-Bedroom one-storey modern residential building for single-family was picked within the hot-dry climate zone of Nigeria as a case study. A questionnaire survey was adopted to ascertain the thermo-physical properties of the building envelope, energy consumption by taking meter readings, occupancy behaviour and electricity supply schedule. The base case model was then designed in IES VE software, and the construction materials and profiles were made to conform to the standard regulations and guidelines of Nigeria. The base model was subjected to two different scenarios (Traditional building envelope and thermal insulation of Modern building envelope) and the results of the simulation were analysed and compared to the actual energy consumption using ASHRAE 2014 standard guidelines. A sensitivity analysis was carried out using visual PROMETHEE II software to ascertain the robustness and stability of the results. The results of the study show that an average of 9–10 h of electricity is supplied to residential buildings per day. Additionally, the base case building’s actual and simulated electricity consumption is 10.43 kWh/m2 year and 45.1 kWh/m2 year respectively and cooling load accounts for 35.6% (14.5 kWh/m2 year) of the total annual energy consumption of the building. There was a reduction in annual electricity consumption and cooling load by 20.4% (35.9 kWh/m2 year) and 36.6% (9.2 kWh/m2 year) respectively when the use of a traditional building envelope (strategy 1) was adopted. Similarly, the adoption of thermal insulation of the modern building envelope (strategy 2) leads to a reduction in annual energy consumption and cooling load by 21.3% (35.5 kWh/m2 year) and 47.6% (7.6 kWh/m2 year) respectively. Strategy 2 performed better when compared to the base model and strategy 1 as 50% of the months achieved a PPD of less than 15%. Additionally, the sensitivity analysis result shows the use of thermal insulation in the modern building envelope (strategy 2) is the best compared to the traditional building envelope (strategy 1). The adoption of any of these approaches in the design of residential buildings in Nigeria can not only lead to comfortable indoor environments and energy savings associated with cooling but can also cause a reduction in carbon-dioxide emissions by 23.2% and 28.4% when strategy 1 or 2 is used respectively and cost of electricity savings by 20.4% and 25.7% when strategy 1 or 2 is adopted respectively.

passive design; energy efficiency; indoor thermal comfort; building simulation; cooling loads; climate responsive design; IES VE software; climate analysis; sensitivity analysis; Visual PROMETHEE II Software