Optimum Energy, one of our 11 companies to watch in air conditioning, has landed $4.5 million in equity financing to help it scale up.

Optimum essentially makes software that dynamically controls the chillers – huge, honking machines that cool water for air conditioning systems in skyscrapers. An average building might require 1 to 1.4 kilowatts of energy to chill a ton of water for its air conditioning system, CEO Nathan Rothman told us earlier this year. A building made to LEED platinum specs might require 0.7 per ton. Rothman says Optimum can reduce it to 0.5 kilowatts per ton.

One of Optimum's systems, destined for Adobe's headquarters in San Jose, Calif., will shave 750,000 kilowatt hours off of the building's annual load. Air conditioner power can be both cut for office space and data centers.

"There are 150,000 buildings that meet our criteria," he said. If the software were implanted in each one, 75 gigawatts could be taken off the grid, he asserted. (We've got a more complete profile here. Rothman also has an unusual career: Before air conditioners, he owned a hippie clothing store and a yacht builder.)

The company also named Bert Hogue chief financial officer and Gary Gigot, Microsoft and Visio alumnus, to chief marketing officer.

Let me repeat: Buildings consume 40 percent of the energy in America and 76 percent of electricity. This total includes computers and things like that, but space cooling consumes about 13 percent of the power consumed in buildings, according to statistics from the Precourt Energy Efficiency Center at Stanford presented at the recent Green Building Forum. Heating and ventilation take up 12 percent and 7 percent respectively. Thus, in all, controlling air temperature and flow takes up 32 percent of the power in buildings or 12.8 percent of the total energy consumed in America. It's a big issue.

Source: Precourt