Large-Scale Solar-Assisted Water Heater for a Green Hospital

Concerns over the environmental impact of the high usage of fossil fuels to heat water in public, residential, commercial, and industrial sectors have triggered increased interest in solar energy. Hospitals and hotels utilize large amounts of energy in water heating. A case study of one such facility was conducted at the National University of Malaysia Hospital (HUKM). At the hospital, large amounts of LPG were consumed by two boilers resulting in the release of considerable amounts of greenhouse gases. A solar water heater (SWH) was designed and integrated with existing LPG burners to develop a hybrid SWH system. The SWH system is composed of 144 U-type pipe evacuated solar panels divided into three blocks. Each block consists of 12 strings of panels connected in parallel, with each string comprising 4 panels. In 2012, the annual average solar irradiation in Kuala Lumpur was 4.5 kW/m²/day. TRNSYS simulation software was used to predict the SWH performance before the design was finalized. Energy savings were expected to reach 60% based on the results of a simulation. However, 51% of LPG was saved according to data recorded throughout 2012. Solar water heating has promising industrial applications such as heat processing in textile factories, food processing, animal husbandry, dairy processing, aquaculture, swimming pool heating, and industrial and manufacturing facilities, with 59.9% annual average energy efficiency and 5.0% annual average exergy efficiency.