According to a study, the San Francisco metropolitan area has some of the fewest air-conditioned homes in the United States

ALAMEDA, Calif. (KGO) — When it's hot, air conditioning can be a lifesaver – but not for everyone.

According to a Brookings Institute study, the San Francisco metropolitan area has one of the highest percentages of homes without air conditioning in the country. Lower-income households and renters are even less likely to have air conditioning.

But that could change.

Data from Zillow's 2024 Consumer Housing Trends Report shows that air conditioning is the most important feature for homebuyers nationwide. About 83% say air conditioning is “very” or “extremely important” in their home buying decision. This number has increased over the last six years.

The number of houses with air conditioning is also on the rise locally. New data from the U.S. Census Bureau American Housing Survey shows that for the first time ever, half of households in the San Francisco metro area have air conditioning.

The ABC7 News Data Team compiled research showing the share of homes with air conditioning in San Francisco, Oakland, Hayward and surrounding cities rose to 50% in 2023, up from 45% in 2021 and from 36% in 2015.

Baker Salman is a senior HVAC technician at Hometown Heating and Air Conditioning and has been responding to calls throughout the day due to the current heat wave.

“We normally prepare for the heating season in October. But the demand in the last few weeks and the last few days when it comes to air conditioning is due to the weather,” Salman said.

Air conditioning isn't often needed in Alameda – it's an island with lots of ocean breezes. But new data suggests that warmer weather is pushing the once-luxury of air conditioning into the realm of “necessity” for many.

MORE: Here's how extreme heat waves affect Bay Area residents personally and financially

“It's pretty hard putting little kids to bed in the heat,” said Scott Farrar, who moved to Alameda from Oakland. “Luckily it cools down overnight.”

Salman was at his house to repair his air conditioner.

Data from Realtor.com shows demand for air conditioning in the Bay Area peaked during the pandemic as people worked from home. Farrar says air conditioning wasn't a top priority when moving to Alameda, but it was still an important factor.

“Our previous place had no air conditioning. And we were really happy that this place had one,” Farrar said. “Until today (the air conditioning) was working perfectly.”

SCHEDULE: Record highs almost certain again with dangerous heat threat across the Bay Area

The experts would like to remind homeowners to clean or replace the air conditioning filter regularly to keep the unit running efficiently. A dirty filter can reduce device performance by more than 10%.