Feasibility analysis of the hybrid dehumidifier–air conditioner technology for small-scale household applications in the tropics

Abstract

Household air conditioners (ACs) with cooling capacities of less than 6 kW are popular in the tropics but are highly energy intensive because of the humid ambient condition. The hybrid dehumidifier–AC concept was studied here to improve the energy efficiency of such systems. Feasibility of the concept was investigated by looking at the design complexity, expected performance, and economic aspects. From the design analysis, it was concluded that small desiccant wheels are most practical for portable and window ACs, while no dehumidification concept was found ideal for split-type room ACs. Performance of the system was benchmarked with data from a 6.4 m² room under tropical ambient conditions with air change rates of 1–4 changes per hour. It was found that an average load reduction of up to 8.1% was obtainable. The corresponding potential power saving was 9.4%. The performance data were then used for the economic analysis. It was found that the hybrid system is financially attractive mostly when cooling capacity, usage rate, and electricity price are high. Furthermore, the system should have a cooling capacity of at least 4 kW and 4 air changes per hour to be financially justifiable, particularly in places with low electricity prices.