A multi-criteria review and geospatial analyses for air conditioner (AC) condensate water reuse

Abstract

Air conditioner (AC) condensate water is a promising water source for potable and non-potable purposes. There is evidence from multiple studies showing the potential of AC condensate water in contributing to a sustainable water supply. However, there exists a literature gap and a clear deficit of publications that furnish structured, practical decision-making frameworks for using AC condensate water as potable and non-potable water. Using the PRISMA literature review approach, 21 existing studies were sampled and reviewed from Scopus and Google scholar databases. Five main criteria were set to evaluate AC condensate water studies via the Analytic Hierarchy Process and Multicriteria Decision-Making Analysis. Water quality analysis (WQA = 32.87%) and well-defined research methods (WDM = 26.10%) appeared as the most important criteria often looked at when considering AC condensate water for use. Criteria like cost–benefit analysis (CBA = 15.10%) and roadmap for installation (RMFI = 8.5%) were the least considered criteria despite their importance in the water recovery process. A 15-year Geospatial analysis shows high humidity (> 80%) in Ghana, favourable for AC condensate water capture. Meanwhile, CBA for mini and large institutions with approximately 10–20 ACs had a payback on investment in 6.41–3.21 years. A pictorial RMFI of AC water systems and the Strengths, Weaknesses, Opportunities and Threats (SWOT) of this system was provided. The findings of this study are significant to implementers; they support decision-making and assist organisations in setting priorities when consulting studies as guides to AC condensate water use in countries where water supply is under intense stress.