Evaluation of the humidity performance of a novel radiant cooling system connected with an Airbox convector as a low exergy system adapted to hot and humid climates

• An Airbox convector prevents moisture condensation on radiant ceiling panels.
• The supply humidity ratio can be redesigned to 9.5 g/kg instead of 8 g/kg.
• The Airbox convector shortens the time necessary to activate a radiant panel system.
• This system is well adapted to hot and humid spaces.
• This system saves energy in the supply and further dehumidification of air.

This paper presents the moisture performance of a novel radiant cooling system connected in series to an Airbox convector adapted to hot and humid climate. Radiant cooling systems have a major benefit in terms of energy savings; however, there is a risk of condensation on the surface of the chilled panel when a room has outside humid air infiltration or high internal moisture gains. Therefore, in order to activate the radiant cooling system, the air in the space needs to be dehumidified to a steady state humidity ratio below 13 g/kg, which causes a significant time delay before startup. Implementing an Airbox convector system connected to the radiant ceiling panel reduces the risk of moisture condensation because it simultaneously dehumidifies indoor air and increases the surface temperature of the chilled panel. This study shows the findings on its humidity performance and ability to reduce the risk of condensation by means of numerical modeling and experimentation. This novel system is sufficiently effective to be used in environments with high infiltration of humid outdoor air because the Airbox convector reduces the time delay when activating the radiant panel system, dehumidifies indoor air and increases the dew point temperature of the ceiling panels.