Paper Conference

Proceedings of BSO Conference 2022: 6th Conference of IBPSA-England


Quantifying the effect of roof insulation on indoor comfort and cooling loads in Nigerian residences

Henry Odiri Igugu, Jacques Laubscher
Tshwane University of Technology

Abstract: Nigerian urban residences largely depend on energy- intensive mechanical techniques to achieve a temperate indoor climate. Mechanical devices are powered with electricity from fossil-fuelled power stations. However, roof insulation as an effective passive measure of lowering indoor cooling loads is not standard construction practice in Nigeria. This study assesses the efficiency of using Extruded Polystyrene (XPS), Glass wool and Spray Polyurethane Foam (SPF) roof insulation materials to reduce annual cooling loads while maintaining optimum indoor thermal conditions. Using the Lagos metropolis as a case study, the dynamic simulations indicate improved comfort levels with cooling load reductions of approximately 7%-8% under an annual average outside dry-bulb temperature of 27.4oC and an ASHRAE recommended indoor temperature setpoint of 22oC. Furthermore, the results suggest an optimum roof insulation R-value range of 2.5 m2K/W to 3.0 m2K/W. Including insulation as part of the roof construction could alleviate the challenge of increased energy consumption in Nigeria's rapidly growing residential building population while reducing GHG and Carbon emissions during its operational lifetime.
Keywords: Indoor thermal comfort, cooling loads, residential buildings, building energy simulation, Nigeria