Dec. 8 marked the 100th anniversary of the mathematical formula devised by Willis Carrier that serves as the basis for air-conditioning calculations.

The “rational psychrometric formulae” - sometimes called the “Magna Carta of Psychrometrics” according to Carrier Corp. - helps figure out the right temperature-humidity combinations that make people comfortable year round.

Carrier showed the formula for the first time Dec. 8, 2011, at a meeting of the American Society of Mechanical Engineers, and tied HVAC to engineering forever.

"Dr. Carrier's development of the psychrometric formulae unlocked the potential of air conditioning for the world," said John Mandyck, chief sustainability officer at UTC Climate, Controls & Security Systems, Carrier’s parent company and part of United Technology Corp. "From his first installation that marked the birth of modern air conditioning, the psychrometric formulae enabled an entire global industry to flourish by meeting the comfort, productivity and health needs of people across the world.”

Carrier’s work is still influential, said Charles Williamson, the Willis H. Carrier professor at Cornell University's College of Engineering.

"Students of engineering today appreciate the tremendous work done by Willis Carrier,” Williamson said. “Without these early researchers, and the work they did with little or no equipment, we would not have the basis for the sophisticated systems for air conditioning we have today." Carrier was a Cornell graduate, something the university continues to celebrate.

"The Willis H. Carrier endowed professorship is a fitting and lasting tribute to the work of a pioneering inventor,” said Lance Collins, dean of Cornell University's College of Engineering. “We are very pleased that the Carrier name will be associated with Cornell in perpetuity.  Endowed professorships support our most esteemed faculty members, so that they can continue to advance their fields of knowledge."