Bought a double conversion online UPS and received it today. Connected to mains and flipped the switch. At the very moment i got shocked that, that UPS is sounding like a car waiting in idle running. Pretty disappointed. When i spoke to that dealer he said fan will be running only when UPS running in full load. But, that stupid UPS fan running all the time. One of the Emerson brand spec mentioned that max noise level 45db. But, this stupid local make from NanTech, Chennai is giving more than 50db. My wiring doesn't support to keep outside the room. Really don't know what to do. Spent almost 15k for 1KVA UPS.