Work

Evaluating the Energy and Thermal Performance of a Water-Cooled Condenser Using Reverse Osmosis Effluent in Residential Purifiers

Year: 2025

Type: article

Abstract: Reverse osmosis (RO) water purifiers produce a large volume of reject water, which is typically discarded, leading to water wastage and resource inefficiency. This work proposes a novel approach to reusing RO effluent as a cooling medium in a water-cooled condenser integrated into a residential hot-and-cold water purifier. The system replaces a conventional air-cooled condenser with a water-cooled unit and was evaluated under controlled laboratory conditions (ambient temperature 25 °C). Experiments were conducted at various RO effluent flow rates ranging from 0.5 to 2.5 L per minute (LPM). Key performance metrics, including the coefficient of performance (COP), cooling time, and energy consumption, were measured and compared. Results showed that replacing a conventional air-cooled condenser with a water-cooled condenser configuration reduces energy consumption by up to 37.5% and shortens cooling times by up to 33%. Performance was maintained under intermittent RO effluent supply. However, an excessive flow rate (2.0 LPM) caused evaporator frosting and efficiency loss, indicating the importance of flow control. These findings demonstrate that internally reusing an RO effluent offers a sustainable, compact, and energy-efficient solution for next-generation water purifiers.

Source: Applied Sciences

DOI: 10.3390/app152111805

Author: Jae Won Lee

Institution: Korea Maritime and Ocean University

Language: English

Topic: Refrigeration and Air Conditioning Technologies

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Clean water and sanitation, Responsible consumption and production

Open Access status: gold

Estimated APC paid: $2,896