Page 24 - Climate Control News magazine July-August 2022

In Focus
Study confirms benefits of cool roof technology
will require double the energy to cool down com- pared to the same building in eastern Sydney.
Besides individual household energy savings, the city-scale deployment of cool roofs also pro- vides collective cooling benefits for entire sub- urbs, the study found.
With all Australian cities currently suffering from urban overheating, implementing cool roof technology and pavements will reduce tempera- tures in entire cities by up to two degrees Celsius over the summer period.
The research also shows that city-scale use of cool roofs would reduce the maximum peak out- door air temperature, which occurs at 2pm each day, by an average of 1.5 degrees Celsius to two degrees Celsius during summer.
Lower outdoor temperatures mean air- conditioning will run more efficiently. Along with lower energy consumption, energy grids will experience reduced demand at peak times during the summer months, thereby lowering emissions.
Cool roofs can reduce heat-related mortality by up to 25-30 per cent.
Despite a well-established manufacturing sector producing cool roof materials domesti- cally, a lack of legislation, policy support, accred- itation standards and awareness is holding the Australian cool roof industry back, the research report found.
If these barriers were addressed and cool roof technology widely implemented, then approxi- mately 150,000 new jobs would be generated in Australia, according to the study.
It found the infrastructure is already here as Australia has 10 different companies producing cool materials and exporting them all over the world. Cool roof technology is being used exten- sively overseas. ✺
A COST-BENEFIT ANALYSES of cool roof im- plementation by the University of New South Wales (UNSW) has found the technology would reduce energy bills, lower indoor temperatures, decrease urban heating and improve the health of vulnerable populations.
The study examined the adoption of cool roof technology across major Australian cities and was released soon after the NSW government scrapped a previous policy commitment to phase out dark roofs. The policy would have reduced ur- ban heating and energy costs for new homes.
Cool roofs reflect more solar radiation than they absorb so they stay cool in sunlight.
The analysis undertaken by the High Perfor- mance Architecture team at the School of Built Environment at UNSW Arts, Design & Architec- ture was part of a project funded by the federal Department of Industry, Science, Energy and Re- sources (DISER).
The aim of the study was to assess the appli- cability and cost-benefit of using cool roof tech- nology on buildings in Australia and to identify any barriers to adoption.
Chair in high performance architecture at UNSW School of Built Environment, Anita Law- rence, said the study investigated the climatic, social, economic and environmental impacts of implementing cool roofs around Australia.
“We used simulated climatic modelling to un- derstand conditions with and without cool roofs. The results showed urban areas, including West- ern Sydney, Perth, Melbourne, Adelaide, Darwin
and Brisbane, had the most to gain from cool roofs,” Lawrence said.
The analyses looked at 17 types of buildings, ranging from low to high rise, commercial to res- idential and stand-alone to apartment blocks.
Existing buildings with low insulation levels have the most to gain in energy savings by imple- menting cool roofs.
“EXISTING BUILDINGS WITH LOW INSULATION LEVELS HAVE THE MOST TO GAIN IN ENERGY SAVINGS.”
The research found that cool roof technolo- gy will significantly reduce cooling energy consumption. Indoor temperatures in residen- tial houses would be reduced by up to 4 de- grees Celsius with a cool roof, with the number of hours exceeding 26 degrees Celsius reduced by 100 hours per summer compared to con- ventional roofs, which absorb sunlight rather than reflect it.
If the whole of Sydney implemented cool roofs, energy consumption for cooling residential and commercial buildings would decrease by up to 40 per cent in total.
During summer, a building in Western Sydney
These apartment buildings combine solar and cool roof technology.
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