MAC developments

While in the mobile air-conditioning (MAC) sector, R&D is focusing on alternative refrigerants to R134a (see "In the news" below), some other research projects or achievements are noteworthy: - The National Renewable Energy Laboratory in Colorado, US, will test an alternative MAC system that uses thermoelectrics. Basically, semiconductors that produce a hot and cold side when an electrical current is passed through them would be placed throughout the car. The biggest obstacle will be the scarcity of the material - bismuth telluride - that is used to manufacture the modules. Beyond the re-engineering of MAC systems, the NREL is looking at other ways to reduce air-conditioning use, including the use of solar-reflective glass and paint that can lower the interior temperature by 35%. The NREL will partner with Ford which was recently awarded USD 4.2 million by the US Energy Department to improve MAC efficiency and develop a thermoelectric air-conditioning system. - Sentience Research, UK, has developed an Enhanced Air-Conditioning (EAC) control system for hybrid cars using Internet-enabled mobile communications, GPS and other available real-time navigational technologies to predict when the vehicle is likely to need to stop and even on-line monitoring for traffic jams. The EAC control system is able to pre-cool the cabin slightly, immediately prior the vehicle stopping, so that the hybrid engine can be switched off as part of its stop-start functionality. For UK summer conditions, the tests indicate that a fuel saving of 9% is achieved by ECA. - The world's lightest bus air-conditioning unit developed by Konvekta, Germany, was delivered starting in August 2009 to well-known European manufacturers. The "UL" (Ultra Light) unit allows 30% weight savings (60-75 kg compared with traditional systems) thanks use of a new durable construction material able to integrate all necessary components while ensuring a robust and safe installation on all bus types. From 2010, the air-conditioning units will also be available with CO2 as a refrigerant.