Delphi Increases Comfort, Decreases Fuel Consumption

Air-conditioning systems help increase comfort while reducing fuel consumption and emissions


FRANKFURT -- At Delphi Corp. (PINKSHEETS: DPHIQ), passenger comfort is a top priority. But also important today is increasing vehicle efficiency. That is why Delphi Corporation engineers and scientists work daily to develop new products and systems to make heating and air-conditioning technologies even more efficient while maintaining or increasing passenger comfort.

“Comfort without regrets,” said James Giardino, general director of engineering, Delphi Thermal Systems. “That is our objective. We want to develop new technologies that keep passengers comfortable while reducing fuel costs and environmental impact.”

Powertrain cooling modules, new compressors and alternative refrigerants are the tools Delphi is using to lessen environmental impact while still keeping passengers and drivers comfortable.

The powertrain cooling module cuts weight, fuel consumption
Based on the “single-part” concept, Delphi’s powertrain cooling module cools the air conditioning condenser, engine and automatic transmission oil or engine oil of cars and trucks. This single part concept can help cut weight, lessen flow resistance and reduce fuel consumption. The module consists of the radiator, charge air cooler, condenser and fan-motor-shroud assembly.

“In one vehicle program our powertrain cooling module led to a weight savings of four kilograms, the electrical power consumption of the cooling fan was reduced by 350 W and flow resistance was improved,” Giardino said. “Additionally, if the thermal management is optimized fuel consumption can be reduced by up to 3 percent.”

Smaller and more effective: the air-conditioning compressor
Even with the heart of the air-conditioning system, the compressor, the trend is towards lighter and smaller systems without any loss of comfort for the passengers. Air-conditioning compressors are connected to the drive motor with belts and clutches. Current and future compressors will use electronics that allow the stroke to be controlled variably and to work without any clutches. This alone saves 1.5 kilograms of weight and allows the compressor to work according to the specific needs. This also allows for the fuel consumption for the compressor to be reduced by about 0.2 to 0.3 l per 100 km compared to conventional compressors with a coupling and a fixed stroke.

Additionally, car manufacturers today are using more compact compressors. Today, Delphi can cover almost all requirements with electronically controlled six-cylinder compressors with a stroke of 160 cubic centimeters. These compressors also need less refrigerant.

Modular design allows customized production
Delphi produces tailor-made compact heating and air-conditioning systems with modular designs. In these systems, the air is circulated, filtered, cooled and dried, the temperature is adjusted and the air is distributed through ducts in the dash.

It is now possible to develop single- to four-zone air-conditioning systems with air-conditioning valves behind the dash, or three- to four-zone systems with the air-conditioning valves behind the dash and a booster fan in the rear. The heating and air-conditioning system can be designed, depending on the customer’s wishes, as an under-floor solution with a multi-zone arrangement or, at the highest development level, with two separate air-conditioning devices for the front and rear passengers (in each case, with the air volume and temperature and distribution in two zones).

There are several reasons for this modular approach: the space available for the air-conditioning system behind the dashboard has been reduced to make room for airbags, navigations and infotainment systems. Delphi has responded with the consistent package enhancement of heat exchangers, evaporators and the device architecture. In the last 15 years, the design depth of these heat-exchanger components has been reduced by up to 50 percent.

With a sophisticated modular system, the air-conditioning functions can be varied within a platform and can even be adjusted together with the overall package and performance across various platforms. In this way, tried and tested components can open up economies of scale and development costs can be reduced.

Alternative refrigerants to help cut global warming
Heating, ventilation and air-conditioning (HVAC) systems contribute to global warming due to energy usage during operation and by refrigerant leakage into the atmosphere. The climate impact of the refrigerant itself is defined as its Global Warming Potential (GWP). In 2006, the European Union banned the use of refrigerants with a GWP that is greater than 150 for all new Type-Approvals (new vehicle platforms) from 2011 and for all new vehicles as of 2017. The current refrigerant, R-134a, has a GWP of 1430.

Delphi is currently developing several options below the 150 GWP level, including R-744, R-152a and refrigerant blends to help automakers meet the legislation in a way that is both cost effective for automakers and drivers in the global community.

“We believe that too many uncertainties exist, at the present time, to get consensus on a single solution for the global market,” said Giardino. “The environmental impact, costs, service readiness, reliability and safety are just a few reasons why a global switch to just one alternative refrigerant may not be possible right now. Delphi’s goal is to offer a range of possible viable refrigerant solutions to global automakers to meet the European legislation.”

“As we did 15 years ago with the conversion to R-134a, we’re going to use our expertise and knowledge to help lead the industry’s next refrigerant transition,” he said. “We’re actively engaged in helping our OEM customers and the industry identify and implement the best solution possible.”

For more information visit www.delphi.com.