A comparative study of indoor and ambient temperatures in three housing types in the kathorus and Wakkerstroom areas, South Africa
The right to adequate housing, is defined in the Constitution of South Africa as a basic human right. Most townships in South Africa are predominantly comprised of low-cost houses, there has been limited research on the indoor temperatures experienced by residents of these homes. As a developing nation the price and availability of construction materials, often takes precedence over the potential thermal efficiency of the household. Occupants of low-cost houses are particularly vulnerable to climatic changes which may be exacerbated by increased warming in South Africa. This study focused on the relationship between indoor and ambient temperature in two study areas namely; Kathorus and Wakkerstroom. These areas were chosen because they experienced different micro-climatic conditions, with Kathorus having warmer ambient temperatures than Wakkerstroom (eSizameleni). Three housing types were included in the research (government funded apartheid era houses, government funded post-apartheid houses and informal houses (shacks)). The study included analysis of long-term temperature (maximum and minimum) trends, from 1960 to 2017, at the two sites. The daily indoor temperatures were studied over the course of a year. A total of 36 data loggers, 18 in each site were installed, by the end of the study however only 28 were retrieved. The houses studied were built with different materials, which are said to affect their thermal efficiency; apartheid era houses were made from clay brick, and post-apartheid low cost houses with maxi (cement) brick and shacks with corrugated iron as well as any scavenged materials. Clay brick, should offer increased thermal efficiency as a result of having the highest thermal mass (of the three), and shacks the least (as it had the lowest thermal mass). Furthermore, the study included semi-structured interviews where occupant’s perspectives on housing could be surveyed. Temperatures across both areas have largely been rising at an insignificant rate. However, the colder month temperatures in Wakkerstroom (Tmin and Tmax) and Kathorus (Tmin) were significantly increasing. Household temperatures in Kathorus and Wakkerstroom, both in the warmer and colder months fluctuated substantially throughout the day. There was an 8 °C, 9 °C and 14 °C fluctuation in daily indoor temperatures of apartheid-era, post-apartheid and shacks houses (respectively). The indoor temperatures of apartheid and post-apartheid homes were found to be 25 % and 36 % less associated with ambient temperatures when ceilings were installed, and yet less than 33 % of sampled houses (in Wakkerstroom, and none in Kathorus) had this feature. From the respondents it was determined that perceptions of thermal comfort were often not related to actual measured indoor temperature readings. The study’s findings suggest that a majority of low-cost houses are thermally inefficient, but none more so than post-apartheid era and shacks homes. For these houses a clear link can be made between ambient and indoor temperature fluctuations. Since a substantial portion of the South African population lives in these housing types, thermal inefficiency and by extension increased vulnerability to climatic changes poses several climate related health risks. For South Africa to contribute to Africa’s Sustainability Goals, low-cost adaptation strategies such as additions of ceilings should go a long way in increasing tenant’s resilience to potential climatic changes.
A Dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in fulfillment of the requirement for a Masters in Science