cguro kung malamig ang panahon ok lang mag blower ka lang if you dont want to choke on other vehicles' emissions. pero kung mainit panahon, no use turning on the blower while your a/c is off... just roll down your windows na lang... check if if air circulation is set to re-circulating or fresh air introduction. 2 buttons nyan na usually magkatabi kasama A/C controls... it would of course shorten your batteries life kung palagi mong pinpatakbo ang blower mo while the engine is off...