The econ is always a confusing one,
Stands for Economy
The climate control uses the engine heat and the air conditioning to maintain the desired temperature in the car when its set to auto ,one to heat and one to cool, how ever aircon does use more fuel so they added the ECON option, it uses the outside air rather than cooled air from the aircon to maintain the temperature. In winter this generally is fine as the outside air temp is quite cold, however in summer you may find it struggles to get the temp down so you may have to turn ECON off.