The working pressure is a critical factor, as this significantly impacts energy consumption. Sometimes it can be economical to use different compressors for different pressure ranges. The quality of the compressed air is not only a question of water content, but has increasingly become an environmental issue as well. Odor and the microorganism content are important factors that can affect the product quality, rejections, the working environment and the outdoor environment. The issue of whether the compressor installation should be centralized or decentralized may affect the floor space requirement and perhaps future expansion plans. From both a financial and ecological point of view it is becoming increasingly important to investigate the possibilities of recovering energy at an early stage for quick return on investment. It is important to analyze these types of issues with regard to current as well as future requirements. Only after doing so will it be possible to design an installation that offers sufficient flexibility.