Experiments are conducted under typical humid ambient conditions of Singapore on an advanced airconditioning system wherein desiccant coated fin-tube heat exchangers (DCFTHX) are retro-fitted within the ducting of a conventional HVAC system with a watercooled condenser. The desiccant is regenerated using room-return air (specific humidity of 0.0109 kg/kg d.a.) and the low-grade heat (warm water at 35.5oC) from the condenser unit. During dehumidification, water from the cooling tower helps in maintaining low air temperature, thereby improving the adsorption performance of the DCFTHX. It is found that DCFTHX managed 39% of the cooling load thereby reducing the compressor load by the same percentage. The experiments prove the efficacy of such internally cooled/heated desiccant systems for practical applications.
Keywords desiccant dehumidification; heat exchanger; desiccant coated heat exchanger; air conditioning; HVAC