While researching various Passive Strategies and Technologies for the Building Envelope, we came across ‘Cool Roofs‘. We realized that this is a simple, low cost technology with large potential benefits. These include – Energy savings, Reduction of Urban Heat Island Effect and Greenhouse Gas Emissions, enhanced Durability of roofs, and Resilience to extreme heat 1.
Thus, this week’s Article and Video are dedicated to this important idea. The Video 2 , 3 , 4 outlines the Need for Cool Roofs and how they Protect Buildings. In the Article, we cover Initiatives by various parties working in the direction. We also look at some successful Case-Studies that could become models for future developments.
Due to multiple possible benefits, the technology has caught the attention of International actors, Indian central, state and local governments, as well as the Private sector. Their attempt is to use Cool Roofs for large scale Impact at the Building and Urban scales.
- The Bureau of Energy Efficiency [(BEE), Government of India, Ministry of Power], has prepared a ‘Cool Roof Design Manual‘ 2 to spread technical information about Cool Roofs for the Composite Climate Zone of India.
- A Fact Sheet 5 and Issue brief 6 have been released by Natural Resources
Defense Council (NRDC) and Partners to showcase local projects, and to spread the message, so that action can be scaled up.
- Green Building Rating systems like LEED, GRIHA, IGBC need compliance with the Energy Conservation Building Code (ECBC) norms. ECBC specifies minimum cool roof values (reflectance and emittance), for roofs with different slopes 6.
- IIIT Hyderabad Cool Roof Calculator – The simulation tool by IIIT Hyderabad, uses a base and design case for testing various roof conditions in certain cities of India. A percentage change in cooling energy can be compared 2 , 7.
The above efforts are helping common people as well as experts to understand and utilize Cool Roofs, by providing technical information, tools and answers to common questions. The following examples showcase successes in the field.
- Ahmedabad’s Cool Roof Initiative, as part of its ‘Heat Action Plan‘ aims to convert 3000 roofs in 6 zones to Cool Roofs. This is being undertaken by city staff and student volunteers. They are using white lime paint, which costs as little as ₹0.50 per square foot 5.
- Hyderabad is also witnessing a Cool Roof Initiative as part of its Building Energy Efficiency Program. The Pilot included 25 city roofs in low income areas. A High-Density Polyethylene (HDPE) cool roof membrane (costing ₹13 per square foot in Hyderabad) was supplied by Dupont as part of their CSR initiative 1.
- The Indore and Surat ‘Cool Roof Project‘ is using local success stories to make a case for cool roof policies in the future. The project consists of over 100 households. They are using simple materials such as lime concrete, broken earthen pots, China mosaic tiles 6.
- A Joint study was conducted by International Institute of Information Technology, Hyderabad (IIIT) and Lawrence Berkeley National Laboratory (LBNL) on 2 office buildings in Hyderabad. The studies saw a drop of approximately 20°C in Roof surface temperatures after application of cool roof coating 2.
We leave you with the following questions –
- Have you used ‘Cool Roofs’ in your Project? Do you know of any projects using ‘Cool Roofs’?
- What Benefits have you felt after application of the ‘Cool Roof’ technology?
- What Problems did you face?
- What kind of Assistance if any, did you receive from the Government or any other organisations?
Let us know! We would love to provide a platform, to showcase your project and spread more useful information.
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- Jaiswal A, Bhagavatula L, Awasthi A, Sarkar S. Keeping It Cool: Models for City Cool Roof Programs. National Resources Defense Council. https://on.nrdc.org/2jLgLPJ. Published 2018. Accessed November 27, 2018.
- Bureau of Energy Efficiency. Cool Roofs for Cool Delhi: Design Manual. http://shaktifoundation.in/wp-content/uploads/2017/06/cool-roofs-manual.pdf. Accessed November 27, 2018.
- Majumdar M. Cooling homes…heated pockets. The Economic Times Blogs. https://economictimes.indiatimes.com/blogs/IssuesonSustainableHabitats/cooling-homes-heated-pockets/. Published 2013. Accessed November 27, 2018.
- Panchkula gets energy-efficient, green government building. Indian Express. http://archive.indianexpress.com/news/panchkula-gets-energyefficient-green-government-building/1049101/. Published 2012. Accessed November 27, 2018.
- International Institute of Information Technology Hyderabad, Administrative Staff College of India, Indian Institute of Public Health Gandhinagar, Mahila Housing SEWA Trust. Keeping It Cool: How Cool Roofs Programs Protect People, Save Energy and Fight Climate Change.; 2018. https://on.nrdc.org/2FIxYas. Accessed November 27, 2018.
- International Institute of Information Technology Hyderabad, Administrative Staff College of India, Indian Institute of Public Health Gandhinagar, Mahila Housing SEWA Trust. Issue Brief – Cool Roofs: Protecting Local Communities and Saving Energy.; 2018. www.phfi.org. Accessed November 27, 2018.
- Cool Roof Calculator v3. CBS, IIT – Hyderabad. http://coolroof.cbs.iiit.ac.in/. Accessed November 27, 2018.