INNOVAL
The hot climate at Le Port led the team in charge of the INNOVAL project to prepare a cooling strategy for different seasons. During the winter, natural ventilation is sufficient to cool offices and during the mid-season between the winter and the summer, natural ventilation is completed with ceiling fans. However, during the summer, natural ventilation coupled with ceiling fans are not sufficient, consequently, air conditioning has to be used. In buildings in Reunion Island, a significant percentage of the energy consumed is due to air conditioning, therefore, the air conditioning system selected here is an efficient one with a Variable Refrigerant Flow ensuring reliability and energy savings. Moreover, a software tool automatically regulates the power of cooling in relation to office use. Finally, while in Reunion Island, people are used to cooling below 24 °C, the air conditioning of the building cannot cool below 26 °C which is adequate with ceiling fans and natural ventilation. Indeed, with the assistance of ceiling fans, the felt temperature is reduced by 5 °C allowing a final felt temperature of 21 to 22 °C. In order to optimize the refrigerated unit power, the temperature adjustment consists of applying a difference of 5 °C between the outside and the inside. For example, if the outside temperature is 34 °C, the temperature adjustment will be 29 °C. All these choices in operation have led to a decrease from 100 kW to 30 kW in the power required by the refrigerated unit.
Air conditioned clothing
One advantage of air-cooled clothing is that it requires much less energy to cool people down than to cool down their entire environment. For instance, an air cooled shirt uses 4,400 mAh of power for 8.5 hours on the fastest fan setting, while an average central air conditioning unit uses 3000 to 5000 watts of power. In some cases, the purpose of air-conditioning is not to cool down the objects in the room, but the people. Directly ventilating clothing is therefore far more efficient. A 2012 New York Times article reported that gases commonly used in air conditioning absorb some 2,100 times more infrared radiation per ton than carbon dioxide, and due partly to increasing use of air conditioning in the developing world (particularly in tropical areas like India, Malaysia, Indonesia, Brazil, and southern China), air conditioning is projected to contribute to some 27% of the overall greenhouse gas emissions by 2050. Although there are some ideas for room air conditioning units that do not significantly contribute to producing greenhouse gases, none of those options are yet on the market.