Saving energy is important for sustainability and environmental protection. Household appliances such as vacuum cleaners and blenders are significantly less powerful than older models. Energy-saving lamps have forced the old incandescent bulbs out of the range. Shower heads mix the water jet with air. And refrigerators, washing machines and ovens all seem to be pushing to get into the top energy efficiency class. But can reality and appearance still be distinguished here? Doesn’t a less powerful vacuum have to run longer to remove the same amount of dirt? In the end, won’t an aerated shower simply lengthen the showering process, but not save any water? And under what conditions, which are usually hidden in the small print, do ice boxes, etc. really fulfill their energy promises? Last but not least, the change in climate awareness in domestic households is proving to be a brilliant business model for an industry that appeals to customers’ consciences if they haven’t yet converted to more environmentally friendly technology. Experts have long been advising that the best way to protect the environment is to make maximum use of the lifespan of old devices.