As summer temperatures continue to rise, more people are turning to air conditioning to cool down. But temperature isn’t the only factor driving this demand.
Climate Central analyzed 240 U.S. cities based on their number of days where average temperatures exceeded 65 degrees Fahrenheit, the ideal engineering standard indoor temperature. Ninety-seven percent of the cities analyzed have seen an increase in days with an average temperature above 65 degrees since 1970. Arizona, Nevada and Utah were among the states with some of the largest increases.
Vijay Modi, a mechanical engineering professor at Columbia University, said higher daily temperatures over the past few decades have contributed to an overall increase in the number of days outside of that temperature "comfort zone." All it takes is one hour of the day past a certain temperature mark to raise that overall average.
“Those early days, we didn't have data and we didn't worry about what happens every hour,” Modi said. “Now we worry about what happens every hour.”
Modi did his own research on demands for heating and cooling across the United States. He found that several states in the Mountain West ranked among the highest in the nation for average cooling demands – with some of the biggest pockets of demand in Colorado and Utah.
But Modi believes Climate Central's numbers could be misleading, as the study only measured the daily average temperature.
“If at night it was 50 degrees Fahrenheit and in the day it is 90, then we kind of assume that that day is 70 and there is [less] cooling demand, which is somewhat inaccurate,” he said. “It is not a perfect measure by any means.”
The International Energy Agency reports that the global demand for cooling could “more than triple by 2050, consuming as much electricity as all of China and India today.”
This demand comes from more than increasing temperatures, though. Modi said more people are moving to hotter states, living in bigger homes, and relying on continuously-running central air conditioning over window units they can shut off when not in use.
“[It's] actually swamping and making the demand much higher then what might be suggested by climatic effects,” he said.
With more people using A/C units, there’s an increased strain on the power grid. And that could be disastrous if the grid goes down during a heat wave.
Modi said people should be more cognizant about which rooms need A/C and set indoor temperatures to higher than 65 degrees to lower the cooling demand. He also recommended having a backup cooling source in case of a grid disruption.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.