In the USA truckers often spend the night in the driver's cab and use the engine during these rest periods to heat or cool the cab. This practice leads to environmentally detrimental pollutant and noise emissions as well as high fuel consumption. This prompted Behr GmbH & Co. to develop a device which eliminates these negative side-effects. Under normal driving conditions energy is extracted from the exhaust gas and stored in a zeolite reactor. When the vehicle is stationary for longer periods of time this stored energy can be used for cooling or heating the cab. In a variation of this system the exhaust gas heat exchanger is replaced by a fuel burner which is used to charge the zeolite reactor for the cooling process and which also serves as a direct source of heat for the cabin. Moreover, the materials used in the device are non-poisonous, ecologically compatible and recyclable.