CENTRALIZED HVAC SYSTEM ENERGY AND WATER CONSERVATION FOR SURANAREE UNIVERSITY OF TECHNOLOGY HOSPITAL (SUTH)
Keywords:
Energy water conservation, HVAC, hospital, TRNSYSAbstract
The heating, ventilation, and air conditioning (HVAC) of hospitals is one of the main consumers of energy and water. Energy and water conservation of the HVAC system at Suranaree University of Technology Hospital was evaluated in this study. A year-round numerical simulation of the system was conducted using TRNSYS, a transient simulation program. Exergy and water recycling analyses were applied assuming the setting temperatures of the HVAC were 22ºC, 24ºC, and 26ºC. To reuse the blow-down water from the cooling tower, treatments by reverse osmosis (RO) filtering, mixing with RO water, and mixing with harnessed condensed water were evaluated. The results show that usage at the 24oC temperature setting provides least exergy destruction, compared with those of the temperature settings at 22ºC and 26ºC. The percentages of the average exergy destruction at the chiller, fan coil unit/air handling unit, chilled water pump, condenser water pump, and cooling tower are 72.2%, 11.6%, 10.8%, 5.3%, and 0.02%, respectively, when the temperature setting is 24ºC. The water consumption and water withdrawal amounts at 22ºC, 24ºC, and 26ºC temperature settings are 32.1 and 38.52 m3/day, 23.3 and 27.96 m3/day, and 17.4 and 20.88 m3/day, respectively. It can be seen that the water consumption is about 0.83 of the water withdrawal. Recycling blow-down water by mixing it with condensed water provides the least energy intensity scoring at 0.1 kWh/m3. Mixing brine with the condensed water reduced the electricity and water cost by 1.6 % of the system’s operational cost.
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