Reliability and Economic Analysis of a Rainwater-Harvesting System for a Commercial Building with a Large Rooftop Area

The water shortage problem faced by manycountries requires a practical engineering solution. The reliabilityanalysis of a rainwater-harvesting system (RWHS) installed at acommercial building of AEON Taman Universiti located in JohorBahru, Malaysia, was based on the rainfall pattern, rainwater use,and rainwater storage tank. An economic analysis using the netpresent value (NPV), return on investment (ROI), and benefit-cost ratio (BCR) was performed to assess the optimal managementof a RWHS installed during the construction and retrofitted afterthe operation of a commercial building. The results showed thatthe balance of water supply and demand is reliable forimplementing a RWHS and the optimal management of a 1000 m(3) RWHS tank installed during construction could be more promising than that retrofitted after operation of the AEON TamanUniversiti commercial building. The operation of a RWHS installed during the construction of a building is obviously more feasiblebecause the NPV, ROI, and BCR values tend to be high. The reliability and economic analysis of RWHS installed duringconstruction and that retrofitted after operation of a commercial building demonstrated the benefit of RWHS installation willcontribute to effective water management as part of future building design.

Automated summary

This study conducted a reliability and economic analysis of a rainwater-harvesting system installed in a commercial building in Malaysia. The results showed that installing the system during construction is more promising than retrofitting it after operation, and it contributes to effective water management in future building design.