The cooler is good. I tried everything like cross ventilation and ice cubes etc. But there was not much difference. One day an idea striked into my mind. I thought to put couple of bottles of cold water from refrigerator into this cooler. From that day (somewhere last week of May month) to this date (June) I am doing this. I feel now that I have purchased an air conditioner for 6 thousand rupees. After adding cold water from refrigerator (only two cold water bottles for around 1 bucket of water but without mixing each other. ) , this cooler gives air like perhaps 1 ton air conditioner. To get more out of cooler, I temporarily removed the back air filter panel which is removable and appears like net. I was sleeping in cool air from this cooler even my city was recording high temperatures around 46 degrees . Neither I am engineer nor I have any technical knowledge about coolers and their functioning, but I am getting desired cooling as I wanted.