Dehumidifying chilled radiator system for hot and humid climates

The application of room radiators for the purposes of cooling and dehumidification in buildings for hot and humid climates is investigated. The radiator is purposely brought below the dew point temperature of the room air thereby creating condensation on the radiator surface. The condensate is then collected at the base of the radiator and removed. A mathematical model describing the heat transfer regime within a room when this system is used has been verified using climate chamber tests. Results show the importance of the radiant transfer component for thermal comfort and suggests that more emphasis should be placed on this aspect during design. Furthermore, the possibilities for the chilled radiator system as an alternative to conventional air conditioning systems by partially or fully matching the sensible and latent component of the radiator output to the load requirements of a building is discussed. A careful examination of ventilation strategy will be an important design consideration due to the inherent requirements of fresh air for the occupants, and to ensure the system's effectiveness for humidity control. Since the temperature difference between the air and the radiator surface is small (typically 17-18 K) in this cooling application, larger surface areas are required than usual for the heating application. However, advantages can accrue from this in that the hot water temperature can be reduced for the heating mode. This allows the use of heat pumps to provide both hot and cold water at higher coefficients of performance than normally achievable. (C) 1999 Elsevier Science S.A. All rights reserved.