Page 23 - Climate Control News magazine March 2022

Building Services
HEAT WAVE EXPOSURE
Rising global temperatures are creating imminent heat waves, which are set to impact poorer populations significantly more than wealthier ones.
Low income populations are more exposed to temperature extremes due to a lack of air conditioning and access to other heat adaptations.
This inequality is predicted to increase with global warming, according to an article published in the AGU Journal.
It found that lower income populations currently face a 40 per cent higher exposure to heat waves than people on higher incomes.
By the end of the century, the poorest 25 per cent of the world’s population will be exposed to heat waves at a rate equivalent to the rest of all the world’s population combined.
Fluorescent materials absorb solar radiation but immediately re-emit it as fluorescent radia- tion at a lower wavelength. Because the material can emit more than it absorbs, it compensates for the reflectivity loss, and can be used without causing glare.
The result is a material that, during the summer, has a surface temperature below the ambient temperature, providing cooling to the building.
During winter, it is above the average tempera- ture during the cooler months, providing heating. “In the recent study, we were not only able to overcome the overcooling issue, but we were able to decrease the peak summer ambient tempera- ture up to five degrees and increase the peak
winter temperature by 1.5 degrees,” he said. “Because the new materials rely less on reflec- tivity to reduce heat, they can also be used on
any level of a building.
“IT IS AN INTELLIGENT MATERIAL THAT IS ADAPTABLE TO ANY CLIMATE.”
“It’s an intelligent material that is adaptable to any climate, can be used at a low level, and can be of any colour, and does not create any glare.”
Santamouris said it is also durable, non-toxic, and will be affordable when produced at scale.
The team will continue to test the materials in new locations around the world with a view to making the materials commercially available.
“This technology has the potential to be used in all cities worldwide, which would reduce en- ergy costs and help combat the impacts of cli- mate change,” he said. ✺
The discussion paper examines many of the challenges facing the built environment.
Santamouris and his research team added new layers to the conventional super-cooling materials to help modify their solar reflectance and emissivity during colder periods without compromising the cooling efficiency.
The first layer is composed of a ‘phase change’ material which uses transitional metal oxides to modulate the reflectivity and emissivity during the seasons.
A second fluorescent layer then increases the cooling capacity of the material.
“We have integrated a new layer into the mate- rials which changes the reflectivity and emissivity as a function of the ambient temperature,” he said.
“We have also decreased the reflectivity of the materials to decrease glare by integrating [an- other] new layer that increases heat losses through fluorescence.”
MAIN: Researchers are looking at ways to mitigate urban overheating which is a problem for cities around the world.
RIGHT: The innovative materials can protect buildings from the elements in winter and summer.
building
Decarbonising
operations
THE AUSTRALIAN SUSTAINABLE Built Envi- ronment Council (ASBEC) is seeking input to its latest discussion paper entitled Least Cost Path- ways for Decarbonising Building Operations.
ASBEC interim executive director, Anne Mar- tinelli, said the council is seeking feedback on the challenges and opportunities the built envi- ronment faces in transitioning to a net zero economy.
“Australia has committed to delivering net zero emissions by 2050 and long-lived assets such as buildings must play a central role in meeting our international commitments,” Mar- tinelli said.
“Encouragingly, there is widespread support among Australia’s largest property companies to decarbonise building operations and tackle cli- mate change.
“However, guidance is needed on the least cost pathways to decarbonisation to support industry decision making and technology selection as well as assist policy makers plan for the physical and regulatory infrastructure that is needed.”
Martinelli said the discussion paper is an im- portant step in the next phase of working to- wards a net zero future.
Operational emissions from buildings in Aus- tralia account for approximately 100 million tonnes CO2 -e/annum, around one fifth of Aus- tralia’s total emissions.
Consultation closes 1 April 2022 with the final report due mid-year.
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