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.
Chilled beam
Active chilled beams are mounted in a suspended ceiling and then anchored to the overhead structure, because T-bar ceilings cannot support the typical operating weight of a chilled beam. They are generally wide, and require less than of overhead space. A typical wide chilled beam system generally weighs about per length of the beam. Chilled beams are generally installed so that the center of each beam is no more than from the center of the next beam. Some architects and end-users dislike the beams because they do not cover the entire ceiling so ducts, wiring, and other infrastructure can be seen. Some designers have installed one chilled beam system around the building perimeter (where temperature differences can be the greatest) and another in the interior of the building, to better control temperature throughout the structure. Higher system performance may be obtained by increasing the static pressure of the air in the building. The systems generally need little cleaning (vacuuming of dirt and dust from the fins every five years).