HVAC ENGINEER ’ S COMMENT From initiation , the structure , orientation and construction of the new building were considered to ensure minimum heat gain . The air-conditioning system consists of a Chiller assist Thermal Energy
Storage ( TES ) system . The system operates on the principal that the load chiller , sized to cater for 50 % of the building ’ s total cooling load , will charge the thermal storage tank sized to store 50 % of the required load at night . During the day , both the chiller and the thermal storage system will operate to produce the required 100 % load . The system results in a higher efficiency by only requiring half the peak electrical energy of that compared to an equivalent chilled water system .
This system enables a significant reduction in installed chiller capacity and enables the building owner to utilise low tariff electricity to create significant running cost savings and is used for peak lopping but is also ideal technology for providing a back-up air-conditioning solution during power failures and load shedding . During a power failure or scheduled load shedding , stored energy is released and only the pumps , controls and fans in the air-conditioning units need to operate under emergency power to effectively cool the building . The size of the generators can be reduced and , subsequently , the emergency power usage cost will decrease .
The Cristopia thermal storage system used is a ‘ closed loop ’ system that consists of a storage tank , filled with glycolled water in which is suspended plastic spherical nodules that are filled with a phase change material ( PCM ).
Note that the same amount of kW hours of cooling would be required as with a standard chilled water system , but a considerable portion of the energy consumption can be “ shifted ” to after hour consumption . The theory is that the load chiller , sized to cater for 50 % of the building ’ s total cooling load , will charge the thermal storage tank sized to store 50 % of the required load . During summer , both the chiller and the thermal storage system will operate to produce the required 100 % load . The 100 % cooling load would only be required for 3 to 4 months in the year . For the remainder of the time , only 50 % of the cooling load would be required , and all the cooling would
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