Cooling cars down without heating up the planet
With the EU having banned inefficient air conditioning (AC) refrigerants in cars, a need to create new solutions that consider the environment and minimise greenhouse gases has emerged. The EU-funded project 'Low cost and high efficiency CO2 mobile air conditioning system for lower segment cars' (B-Cool) studied how to develop AC using CO2, also known as R-744 refrigerant. The idea was to would replace other refrigerants such as R-134a, which can be harmful to the environment and exacerbate greenhouse gases, with CO2. The project began by assessing performance, annual fuel consumption and environmental impact of old and new systems, as well as addressing safety-related issues. It then worked on prototypes of new AC systems for two specific car models. Rigorous testing procedures were also elaborated to measure efficiency under different temperatures. The project team identified the type of compressor needed, testing both 28 cc compressors and smaller 15 cc compressors in different ambient conditions. They concluded that the smaller ones would be more efficient for the envisioned AC. While in the short term the costs of switching to R-744 or CO2 will be higher than the current technology using R-134a; however, the costs are expected to fall once production increases. More work is needed to guarantee reliability of the system and cost effectiveness of the promising new technology. It ultimately represents a new paradigm for manufacturing AC systems destined for small and medium-sized cars.
