Energy Efficiency

13 Nov 2020

SANEDI’s Cool Roofs to Benefit Cape Town Communities in Summer

13 Nov 2020  by   

The South African Energy Development Institute (SANEDI) is rolling out 26,000m2 of cool roofing technology in Cape Town as part of the Cool Roofs and Insulation Collaboration.

SANEDI's cool roofs project is picking up again as the heat returns to Cape Town. Image: SANEDI.

The roll out is meant to show the power of passive cooling when cool coatings are used in conjunction with insulation.

SANEDI’s Project Officer: Energy Efficiency Cool Surfaces, Denise Lundall, explained this project is the first of its kind in South Africa. It is being undertaken in partnership with the Thermal Insulation Products and Systems Association SA.

“The intention is to use the collected data as evidence for the mandatory inclusion of passive thermal control in the Energy Efficiency Building Code 10400XA. Without needing to power mechanical cooling systems, cool roofs with insulation offer significant cooling to South African homes in the heat of summer,” she said.

Cool roofing involves coating roofs with a durable, reflective membrane which reflects the heat of the sun. It is inexpensive and a highly effective passive energy, low-tech cooling interventions. However, it is not a replacement for insulation. Cool coatings do not keep a house warm during winter.

“There was a misunderstanding when cool roofs first came to market, when it was suggested it could replace insulation. This is not the case. Rather we see the two solutions as complementary.

“The mandatory standard thickness for insulation is quite thin and few homes have more than the minimum requirements. Cool coatings can significantly cool a home to the effect of a four times thicker insulation layer. A quadrupled insulation layer would be incredibly costly with a 19- to 21-year return on investment. A cool-coat on a roof with standard insulation would offer the same cooling as a four-times thicker insulation at a fraction of the cost,” explained Lundall.

Community engagement crucial to obtaining buy-in for cool roofs project

The communities selected for this project include the Masonwabi settlement, Masiphumelele township and Morkel’s Cottage in Strand. “When selecting the areas for this proof-of-concept, it was necessary to ensure the houses were new enough to be in good condition with no broken roof tiles, but old enough to document the changes in temperature and engage with established residents,” said Lundall.

Community engagements and willing residents were vital to secure the roll out of the project without causing any unrest. Thus many site visits and face-to-face interactions were crucial. The project experienced delays because of the COVID-19 pandemic induced lockdowns. However, with the aid of many eager local painters, SANEDI is looking to set to wrap up in late December 2020 or early January 2021.

Employment through energy efficiency project is a win for the green economy

As with other cool roofing projects SANEDI used local unemployed people to implement this project, drawing especially on the youth and women.

“When unemployed local residents turn up to assist us we provide them with training and offer and artisan’s certificate, meaning they receive a recognised trade qualification. We also provide them with supervised painting experience across thousands of square metres.

This gives them a huge ‘bank’ of painting experience which will increase their chance of employment when entering the job market. In this way we are not only adding to the comfort of these communities, but also providing economic opportunities,” concluded Lundall.

SANEDI is one of the ten teams who received a $100,000 grant from the Million Cool Roofs Challenge to deploy solar reflective coating between August 2019 and December this year. The challenge is a $2 million global competition to rapidly scale up the deployment of cool roofs in developing countries to address heat stress and the lack of widespread access to cooling services.

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