SCIENTISTS MAY DEBATE THE EXISTENCE of global warming for years to come, but Delphi's Thermal Systems division has identified a trend that sheds significant light: Demand for automotive air conditioning in densely populated emerging markets is soaring like temperatures in July.

And by the end of next year, Delphi hopes to be in production with a new variable compressor that is smaller, more efficient and ideally suited for small city cars in developing markets.

Most important, this compact variable compressor, being marketed as 5CVC, will cool stifling cabins more quickly whether the vehicle is idling in heavy traffic or cruising the highway.

Most conventional scroll or fixed-displacement compressors used in emerging markets are not robust enough to provide cool air in all conditions, says Prasad Kadle, director-advanced engineering at Delphi Thermal Systems.

Kadle recalls visiting India four years ago and driving his father's small car.

“On that particular car, when you changed gears and tried to put on the AC, it would stall,” Kadle says.

“There was not enough power with that fixed-displacement compressor coming on.”

Delphi's 5CVC “will not do that,” Kadle says during a recent interview.

The supplier claims it is the most fuel-efficient compressor in the market and is compatible with both types of refrigerant, R-134a and R-1234yf.

Traditional compressors provide air conditioning, oddly enough, by mixing cold air from the evaporator with warm air from the heater core in a process known as series reheat.

Delphi's new 5-cyl. compressor uses a solenoid-based control valve that allows the air-conditioning system to provide the required passenger-selected cooling without any mixing of warm air.

“The system can meet the varying needs of the powertrain and passenger compartment comfort,” Kadle says. “It can be precisely calibrated to achieve outstanding drivability and energy efficiency.”

Older fixed-displacement compressors must cycle on and off to maintain the desired temperature.

“When it gets too cool, the compressor cycles off and then cycles back on when the air warms up slightly,” Kadle says. This process of turning the compressor on and off not only is inefficient but also affects noise, vibration and harshness in the cabin.

“This cycling can be felt by the passenger, especially at higher ambient temperatures and is referred to as ‘clutch feel,’” he says.

Delphi introduced variable compressors years ago on General Motors vehicles. Both the Ferrari California and '11 Chevy Cruze use Delphi's clutchless electronically controlled compact variable compressor, marketed as 6CVCe.

The smaller 5CVC, which uses a clutch, is less expensive and intended for smaller vehicles, especially in emerging markets. It is available with mechanical or electronically controlled valves.

Production of the electronically controlled version begins next year likely in South America first, followed by Europe, says James Bertrand, president of Delphi Thermal Systems.

A decade ago in Brazil, less than half of new cars were sold with air conditioning. Today, the penetration rate is about 80%, he says. In India, the 30% take rate for AC is expected to rise quickly.

“Even in many emerging markets, the AC penetration rates are already pretty high,” Bertrand says. “And the systems are not necessarily that great.”

The U.S. pioneered and popularized automotive air conditioning. Some 99.6% of domestic cars and 98.7% of domestic light trucks in the U.S. have AC, according to Ward's data for the '10 model year.

Europe was a late bloomer in the AC market. Less than 20 years ago, only about 25% of vehicles there had it, Kadle says.

“Look at it now, and the rate is almost 100%,” he says. “It rose quickly in the early 1990s.”

Bertrand says the 5CVC compressor is too small for U.S. vehicles but should help drive up AC installation rates in emerging markets. The product represents opportunities with new customers for Delphi, he says.

“This will take us down into a range of vehicles and a customer base we haven't really approached previously because our prior offering was premium and slightly larger,” Bertrand says.

“This will take us into new territory.”