MahaMetro to use geothermal AC system for saving 15% power
Mahametro decided to lower power further by going in for geothermal air conditioning system at its under-construction office opposite Deekshabhoomi. The system is expected to reduce operating cost by 10% to 15%.
The MahaMetro official said geothermal heat pump is a central cooling system that transfers heat to or from the ground. “It uses earth as a heat sink. This design takes advantage of the moderate temperatures in the ground to boost efficiency and reduce the operational costs of heating and cooling systems. The temperature in the ground below 20 feet is roughly equal to the mean annual air temperature.”
He said the heat pump consists of an array of 80-100 meter deep bore wells with a double u-tube, along with manifolds for connection of array of such boreholes. “The vertical bores provide heat dissipation medium in the ground. Since, water at 80-100 meter depth below ground is at constant temperature, the cooling from geo-exchange are in a constant zone of temperature between 25 to 30°C,” he added.
Dr. Brijesh Dixit ( MahaMetro managing director )said the agency has decided to go in for this system due to increasing concerns over cost and availability of electricity and water. “We will install a 175 thermal response (TR) cooling system. The installation of a test borehole and a thermal response test (TRT) was conducted. The rest of the closed loop borehole field is under progress,” he added.
“The ground loop array will be connected to a water cooled chiller that primarily delivers cooling to the building. A significant element in the evolution of this installation is the procurement of the borehole field material from Indian manufacturers and suppliers. Use of this technology will offer a significant reduction in CO2 emissions compared to the existing systems,” Dixit further said.