Design and control of MOFs-based indoor humidity pump integrated into the building’s ventilated façade in hot and humid climates

Abstract

Indoor humidity management is vital for both building and occupant health. Conventional methods that decouple the latent and sensible load use desiccant dehumidifiers integrated with vapor compression systems to supply cool dry air to the space and dilute the indoor generated moisture. Such methods remain energy-intensive, especially for high latent load spaces located in hot and humid climate. Direct removal of the indoor generated moisture via moisture migration through naturally ventilated building façade, proved to be a more energy-efficient alternative. However, this strategy suffers from different drawbacks in humid conditions, which impose an intermittent operation on the moisture control system. In this work, a continuous humidity pump system is proposed that integrates a metal organic frameworks-based desiccant dehumidifier to supply dry air to the ventilated building façade provided with breathable insulation. This creates a water vapor pressure gradient between the indoor and dry air to actively drive the indoor moisture to the outdoor environment, irrespective of its humidity conditions. Mathematical models are developed for the system’s subcomponents, which are then experimentally calibrated. Design and control strategies are presented for the proposed system and applied for a case study of a high latent load space located in the hot and humid climate of Beirut. Over the entire cooling season, the proposed system resulted in 66 % reduction in the investment cost and 86 % in the operating cost compared to conventionally employed hybrid desiccant – vapor compression cooling systems.