Wall mounted air conditioning systems, or split system air conditioners, comprise of two different units; the indoor and outdoor unit. Changing expectations have helped to drive that trend: around 90 percent of new homes are now fitted with AC. Affluent homes are more likely to use centralized air conditioning systems that cool the entire building; poorer homes rely on smaller, room-based air conditioning units fitted to windows or walls. He hoped eventually to use his ice-making machine to regulate the temperature of buildings and even considered cooling entire cities with a system of centralized air conditioning units. The clever solution for a cool indoor climate are our compact and portable air conditioning units.