going into the vent) and the cold air coming out of the vents then there is nothing wrong with the unit itself. it just means it is so hot outside that your unit cannot keep the temperature up. check to make sure there are no windows open and that any sliding glass patio doors are not cracked open. another thing to check is to make sure the sliding glass doors and windows in your house have a proper seal. some seals on doors and windows will rip or come loose over time thus letting precious cold air escape outside.
answer 6 – set the thermostat a few degrees higher (from 76 