Simulation Study of Thermal Comfort in Residential Building Types: The Case of Lokoja, Nigeria (Published)
Thermal comfort is an important factor for the design of buildings that offers comfortable indoor environment for the wellbeing of building occupants. There are several residential building typologies at different locations in the world. These includes bungalows, duplexes and block of flats. Despite previous studies on thermal comfort in Nigeria, there is a lack of research data on the performance of different building types, especially in terms of thermal comfort. Hence, this study evolved to investigate three popular types of residential buildings in Nigeria. The research outcome aims to provide data for theoretical evolution on the thermal behavior of these building types. The paper used dynamic thermal simulation, natural ventilation mode to analyze three residential buildings in Lokoja, Nigeria using hourly weather data for a period of 10 years. The simulation results showed that the annual operative temperature for the three cases were 33.360C, 33.620C and 33.650C. This revealed that there is no significant difference between the operative temperatures of the three case studies. However, there were marked differences between both the monthly and annual solar gains of the case buildings. The total annual gains for the three case studies were 24118.27kWh, 20497.90kWh, and 39493.09kWh. Although there was no significant difference in the performances of the case buildings, there performed differently in terms of both operative temperature and solar gains. The simulation results confirmed thermal discomfort in residential buildings in the study area. This calls for improvement in the design of residential buildings in the study area to enhance thermal comfort and reduce energy demand due to overdependence on mechanical cooling systems. This study has provided data that is expected to guide design professionals and other stakeholders in the building industry in their decisions regarding the thermal performance of residential building types in the study area and in similar climates.
Keywords: Simulation, Thermal Comfort, building types, operative temperature, solar gains
AN EVALUATION OF THERMAL COMFORT CONDITIONS IN AN URBAN ENTERTAINMENT CENTRE IN HOT-DRY CLIMATE OF NIGERIA (Published)
The aim of this study was to evaluate the effects of environmental design parameters on thermal comfort conditions in an urban entertainment centre located in the hot-dry climate of Nigeria. Building designs in Nigeria now tend towards mix-use functions as in the case of an urban entertainment centre, therefore, making thermal comfort a necessity. Unfortunately in the hot-dry climatic regions of Nigeria, buildings fulfill this requirement through total dependence on mechanical means of cooling to solve for overheating. It was evident that some design parameters caused this undesirable situation. The study therefore focused on understanding and evaluating the effects of design-dependent elements such as materials of building envelop, thermal mass, the size and orientation of windows, shading and vegetation on thermal comfort conditions in the case study building. Data loggers were used to record temperature and humidity data in predetermined rooms. Data was collected during certain periods in April, May, and June 2013. Hypotheses were developed and statistically tested using ANOVA. The study showed that temperature based on ASHRAE standards 55-66 and OSAHS 1997 was above comfort range in all the spaces investigated. Further, the results showed that the effect of thermal mass was almost the same for most of the spaces, primarily due to the fact that most of the building had been constructed with thick concrete walls. In terms of thermal performance, the building materials used, number and orientation of the exterior walls, orientation and size of windows and also sun shading with surrounding vegetation were most effective design parameters for the spaces investigated.
Keywords: Building Orientation, Data Logger, Thermal Comfort, Thermal Mass, Urban entertainment centre, material of building envelope