The potential for domestic thermal insulation retrofits on the South African Highveld

Abstract

The South African Highveld is a portion on the inland plateau characterized by low winter ambient temperatures. Studies done in several climatic regions around the world have found a positive relationship between inadequate housing and low indoor temperatures during the winter season. Prolonged exposure to low indoor temperature is a threat to human physical health. This study characterizes indoor human thermal comfort conditions in typical low-income residential dwellings during the winter season. Mapping indoor human thermal comfort can assist in exploring the potential for domestic thermal insulation retrofits interventions. In-situ temperature measurements were done in 2014, 2016 and 2017 across three Highveld settlements of kwaZamokuhle, kwaDela, and Jouberton. The sample included a mixture of old (pre-1994), post 1994 Reconstruction and Development Programme (RDP) as well as non-RDP structures. Findings were that 88% of sampled dwellings in Jouberton 2016, 86% in Jouberton 2017, 62% in kwaDela and 58% in kwaZamokuhle had daily mean temperatures below the WHO guideline of 18°C. These low indoor temperatures indicate poor insulation in these sampled dwellings. Across all settlements, insulated dwellings had higher daily mean indoor temperatures than non-insulated dwellings. These findings indicate the potential to use thermal insulation retrofits in improving indoor thermal conditions as the majority of dwellings are non-insulated thereby exposing occupants to low indoor temperatures.

Risks of Indoor Overheating in Low-Cost Dwellings on the South African Lowveld

“…These two adaptation strategies can be of help to regulate indoor thermal conditions. The study findings concur to studies by Makaka and Meyer (2005), Naicker et al (2017), Matandirotya et al (2019) which also estimated that low-cost dwellings are sensitive to ambient temperature changes because of poor insulation. In a study by Mavrogianni et al (2010), 53% of livingrooms average indoor temperatures were above thermal comfort levels of 24 C while 86% of recorded temperatures could result in sleep impairment.…”

“…Similar to indoor measurements loggers were set to collect data at a 30-min temporal resolution over a 24-h cycle. Before deployment, all sensors were calibrated and tested for accuracy in the laboratory by the manufacturer (Matandirotya et al 2019). Supplementary ambient air temperature data were obtained from the South African Weather Service (SAWS) nearest weather station.…”

State of ambient air quality in a low-income urban settlement of South Africa

“…Furthermore, in developing countries, it is estimated that 85% of particulate matter is from the combustion of biomass [21] . This is true for South Africa where an estimated 70% of low-income households rely on solid fuels (wood, & coal) to satisfy their domestic energy requirements (cooking and space heating) leading to Household Air Pollution (HAP) [ 10 , 26 ]. Besides, there are also other air pollution sources which include dust storms, coal powered thermal power stations, vehicle emissions, industries, unpaved roads, smokestacks waste and agriculture [ 6 , 23 ].…”

“…Solid fuel combustion is also proven to be a major source of ambient emissions. ‘dirty fuels’ are defined as “fuels that have high emission levels and a direct impact on human health like coal, wood, paraffin, and biomass burning” [26] .…”

Intra-urban variability of PM2.5 in a dense, low-income settlement on the South African Highveld

“…These activities contribute to poor air quality which often exceeds National Ambient Air Quality Standards (NAAQS) aimed at protecting public health (DOE, 2012). As an economic hub, large parts of the region are densely populated, and air quality management remains a challenge due to the high concentration of industrial and residential sources in the region (Matandirotya et al, 2019). Air quality is expected to decline even more as urban areas on the Highveld become more populated.…”