Sustainable air conditioning for everyone

Case studies in sustainable design from the third world that involve attractive commercial opportunities are relatively rare. This paper presents a case study that demonstrates the potential for sustainability improvements driven by strong commercial interest. Air conditioning brought one of the largest improvements in productivity in the USA. However, extending this technology for most people living in hot and humid climates poses insurmountable sustainability challenges. The vast majority of third world inhabitants live and work in buildings that do not have effective insulation. Conventional air conditioning in such locations requires far more energy than the world can feasibly provide within reasonable resource limits and the cost is unaffordable for most of the people who could benefit from it. This paper describes how a small portable air conditioner can provide personal comfort for one or two people using only 270-330 Watts of power, 75%-85% less than the power of a conventional room air conditioner. With such low power consumption, this technology could provide air conditioned comfort for everyone living in hot and humid climates without requiring large increases in electric energy production. It runs conveniently from solar energy or a battery backup power supply when grid power is not available. New storage technologies could provide affordable off-grid solutions using solar power. The cooling unit exploits localised cooling technology that focuses the cooling effect only where it is needed, on just the face and upper body of a user. It is not necessary to cool a whole room. For night time use, the air conditioner is used with a specially designed fabric enclosure to retain a layer of cool dehumidified air above a bed. The enclosure provides a comfortable sleeping environment for one or two people, also keeping biting insects away at the same time.