Inventor Offers Misty Relief in a Can : Aerosol Spray Cools Sun-Baked Car Interiors

When you climb into your sun-baked car in the shopping mall parking lot and crumple behind the wheel, gasping in a Saharan inferno, it’s time for a few squirts from Domingo Tan’s handy air conditioner in a can.

Tan, a Chinese-born physicist who lives in suburban Alexandria, Va., invented Instant Car Kooler, an aerosol spray containing 10% ethyl alcohol and 90% water mixed with a mint fragrance.

Those cardboard windshield “sunglasses” are no competition, Tan says.

To demonstrate, he opened the door of his aging Dodge sedan, which had been parked in the sweltering sun for a couple of hours with a cardboard sunshade in place. A large circular thermometer dangling over the front seat registered 122 degrees Fahrenheit.

Tan leaned into the car and pointed his can of Instant Car Kooler. “Psst-psst-psst.”

Within half a minute, the thermometer had plunged 42 degrees to a more bearable 80 degrees. He said the sunshade alone reduces heat by only 10 to 15 degrees.

Tan, 57, began working on his invention about 10 years ago, when his young son complained frequently about the suffocating heat in the family car.

“It’s like making rain inside the car, but the difference is that we don’t make the whole car wet. Instead of rain there are drops of spray so fine that they vaporize right away,” he said.

Tan added ethyl alcohol, or ethanol, to the car spray to make the water vaporize faster and reduce the air temperature even further.