When Keeping Cool, Socioeconomic Status Matters

Scientists have found that lower-income households raise water consumption, while higher-income households raise energy consumption to keep cool.

AsianScientist (Jan. 2, 2018) – Singapore households from different socioeconomic groups vary significantly in their use of water and electricity for heat relief, according to a study by researchers from the National University of Singapore (NUS). They published their findings in the journal Nature Communications.

In Southeast Asia, climate models project annual temperature to increase by 1–4 degree Celsius, and winter rainfall to decrease by 20 to 30 percent by 2070. Currently, only eight percent of the three billion people living in the tropics have access to air-conditioning, compared to over 90 percent in the US and Japan.

To better understand how socioeconomic status affects resource consumption for heat relief, scientists led by Associate Professor Alberto Salvo of NUS examined the demand for water and energy among Singapore households across the socioeconomic distribution.

The researchers obtained data on the water and electricity bills of about 130,000 households in Singapore from 2012 to 2015, examining each household’s consumption of water and electricity over time. They observed that when ambient temperatures rise, water demand increases among lower-income Singapore households.

For instance, with a one-degree Celsius increase in temperature, the average household living in a two-room apartment (about 50m2) raises water use by nine liters per day, amounting to an additional daily shower for every 2.3 households. At the time of the study, less than 20 percent of two-room apartments had an air conditioner.

In sharp contrast, heat induces larger shifts in electricity demand and no significant change in water consumption among higher-income households, such as those staying in five- or six-room apartments (110m2 or more). These households frequently have air conditioners, and the average increase in electricity demand was two kilowatt hours per day with every one-degree Celsius increase in temperature. This is equivalent to operating an air-conditioning unit for two more hours each day.

To complement the observational evidence from the study, a 300-person survey on heat relief behaviors by Singapore households was also conducted. Thirty-nine percent of respondents stated that on a very hot day, they would shower more often and longer. This is comparable to the 36 percent who indicated that they would turn on the air conditioner.

“As we face shifting temperature extremes and rainfall variability, the study can contribute towards improving demand forecasting for water and electricity in water-stressed cities in tropical Asia, where incomes are rising. This can facilitate better design and allocation of water and electricity grids,” said Salvo.

“Air conditioners powered by electricity generated from burning fossil fuels come at an environmental cost, but one added benefit is that they may reduce a household’s water demand when seeking relief from heat.”

The article can be found at: Salvo (2018) Electrical Appliances Moderate Households’ Water Demand Response to Heat.


Source: National University of Singapore; Photo: Pixabay.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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