This ac runs runs for hours and still the temperature(house) remains the same or increase slightly. Place a thermostat in one of the air vent, and the temperature remains approximatly 69 degs faht.

After you have inspected and sure that the filter is clean,made sure the evaporater coil is very clean,the outside condenser is clean and clear of old leaves and pollen,, if all this is done you should get a HVAC tech to check the freon for proper pressures. This is something you can`t do yourself without the proper tools and licenses to handle freon,, hope this helps