Abu Dhabi, UAEWednesday 30 September 2020

Working from home could create surge in Gulf's AC bills and emissions

Air conditioning helps the region to function but there is a financial and environmental impact to manage

In centuries past, there was a seasonal pattern to life in the Gulf.

Winters were spent by the coast, while during the hottest parts of the year, refuge from the humidity was sought in tents in the desert or at oases such as Al Ain.

From about the 1950s, however, the oil boom changed the region and the development of air conditioning freed residents from climatic constraints.

Today, society in the Gulf depends more than ever on the cooling breeze of air conditioners, and energy consumption rocketed as a result.

Air conditioning on the rise

Between 1990 and 2016, according to World Bank figures, the amount of energy used to cool spaces in the Middle East jumped five-fold, from 25 terawatt-hours to 125 TWh. Air conditioning accounts for as much as 70 per cent of UAE electricity consumption.

“Gulf countries are consuming the majority of their electricity generation capacity in the air conditioning of buildings, and the hotter the weather gets, the less efficient the cooling process becomes and hence we consume more and more,” said Prof Amin Al Habaibeh, professor of intelligent engineering systems at Nottingham Trent University in the UK.

And that weather is getting ever hotter, with global temperatures increasing by about 0.2°C per decade, according to the Intergovernmental Panel on Climate Change.

The whole process is generating millions of tonnes of carbon dioxide every year

Stan Cox

In the Gulf – already one of the hottest and most humid parts of the world, with the mercury having reached 53.9°C at a meteorological station in Kuwait in 2017 – climate change is a particular concern, because the world’s hottest and coldest places are warming fastest.

But it is not only the Gulf that is experiencing a surge in demand for air conditioning. Between 1997 and 2007, the number of air-conditioned Chinese households doubled, while the US now has more than 100 million homes with the technology.

The tendency to now work from home and remain there for much of the day could fuel this rise further.

Anecdotally, UAE residents say they've already seen bills rise during a long summer at home, and realised how much they rely on AC throughout the day.

Office designs are at the heart of the issue

The increased use of air conditioning in offices – it is now becoming the norm in many temperate countries – results, experts say, from several factors.

High-rise offices with sheer expanses of glass have air conditioning integrated into their design, instead of achieving natural cooling and ventilation by other means.

“With higher buildings, wind speeds act against window opening and the solar gain through glass walls is generally very high, and opportunities for through-ventilation are generally minimal,” said Prof Gordon Walker of Lancaster University's Environment Centre in the UK.

The Al Bahar Towers in Abu Dhabi use a solar shading system to keep the building cool. Silvia Razgova / The National
Abu Dhabi's Al Bahr Towers, built in 2010, use a solar shading system to keep the building cool. Silvia Razgova / The National

More heat-producing electronic equipment has encouraged the adoption of air conditioning – and its use is set to accelerate further.

Cooling homes is heating the planet

Among nations in or close to the tropics, the number of air conditioning units is forecast by the World Bank to grow from 1.6 billion now to about five billion by 2050.

But as we cool our buildings and homes, we may be heating the planet further, notwithstanding initiatives by countries such as the UAE to decarbonise energy generation through solar and nuclear power.

“We’re burning fossil fuels, which is putting carbon dioxide into the atmosphere, to generate electricity, which is running almost 100 per cent of air conditioning,” said Stan Cox, author of the book Losing Our Cool: Uncomfortable Truths About Our Air-Conditioned World.

“The whole process is generating millions of tonnes of carbon dioxide every year, and the other problem is the refrigerants used as heat-transfer liquids: they themselves are potent greenhouse gases.”

Although air-conditioning systems are becoming more efficient, this may not be enough to counteract increased use. For example, from the mid-1990s to 2005, air-conditioner efficiency in the US increased 28 per cent, says Mr Cox, but energy consumption from it grew 37 per cent. So the answer may lie in cooling buildings in different ways.

Time for a new approach

One approach involves circulating cooled water within neighbourhoods – a mirror of the use of heated water in Scandinavia to warm buildings – with heat potentially exchanged with, for example, sea water or artificial water systems.

“Water has a much higher heat capacity than air, which means it can absorb more heat from air-conditioning systems,” Prof Al Habaibeh said.

“This makes pumping of heat much more efficient and helps reduce the heat-island effect, as the cooling process could happen far away from the city, since chilled water can be transported via cooling pipes.”

Another new technology is ice-powered air-conditioning, with ice produced at night when electricity demand is lower, and used for air conditioning at peak times.

Climate change is a global concern

Traditional ways of cooling could be incorporated into modern buildings. According to Gary Clark, who leads the UK, Europe and Middle East science and technology practice at architects HOK, which has offices in Dubai, old-style techniques could reduce power requirements.

There is, he says, “no one silver bullet with passive cooling”, but designers have “so much to relearn from the vernacular past”.

“We can still do it even with rising temperatures,” he said. “It doesn’t omit air conditioning, but it changes it and makes it more subtle.”

Limiting glass coverage helps – Mr Clark suggests a maximum of about 30 percent is needed in the Gulf – as does shading and even wind towers, a traditional feature used to create a breeze.

Gary Clark, head of the UK, Europe and Middle East science and technology practice at architects HOK. Courtesy: Gary Clark
Gary Clark from architects HOK. Courtesy: Gary Clark / HOK

Modern buildings praised for their shading include Abu Dhabi’s Al Bahr Towers and the King Fahd National Library in Riyadh.

“The twin Al Bahr Towers opt for a dynamic approach, whereby an array of origami-like sun shades are programmed to ‘bloom’ when the sun path aligns with different areas of the facade and contract when there is little or no sun exposure,” said Dr Greig Paterson, a Dubai design manager at consultancy Drees and Sommer.

The use of vernacular techniques allows, he says, natural ventilation to be used during the cooler months, cutting energy consumption and improving wellness.

“Furthermore, simple solutions such as ceiling fans contribute greatly to thermal comfort at a fraction of the energy cost of air conditioners,” he said.

To encourage such design – even outside of flagship eco-projects such as Abu Dhabi’s Masdar City – Mr Clark suggests legislation could specify the maximum power use for cooling in buildings.

Another approach is to accustom people to a wider range of temperatures – known as the adaptive comfort model – as this reduces the need for a constant temperature.

Mr Clark says that people can be comfortable indoors at several degrees Celsius above the levels engineers regard as the maximum.

“If you’re in a hot climate, and you’re adjusted to that hot climate, you can go higher,” he said.

“The upper limit, the engineers think it’s 26°C. If you follow adaptive comfort, it goes up to 32°C during the day."

Updated: September 13, 2020 01:33 PM

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