2003 technology in review

AEI editors look back at some of the most significant production-intent innovations introduced over the past year.

The automotive community has been searching for an alternative to hydrofluorocarbon 134a (HFC-134a) refrigerant in mobile air-conditioning (A/C) systems to overcome renewed concerns about the effects of global warming. Options include enhancements to the existing HFC-134a system or use of new refrigerants such as HFC-152a and even carbon dioxide (CO₂). For the future, Denso believes CO₂ is the most promising alternative, and the company has developed the world's first non-fluorocarbon air conditioning system-which it is supplying to Toyota for its fuel-cell hybrid vehicle (FCHV) introduced in December 2002-using the refrigerant.

Denso says the global warming potential value of CO₂ is extremely low-about 1/1300 of HFC-134a. The refrigerant is said to have excellent cooling and heating capacities, which makes it applicable for use in electric or hybrid vehicles. However, CO₂ has an operating pressure 7 to 10 times higher than that of HFC-134a, but Denso was able to apply its technology and expertise in creating components that can withstand such high pressure.