Why does the "change filter" indicator on my thermostat keep coming on even when I have a new filter? - high flow thermostat

I recently had a new Bryant 80,000 BTU high-efficiency furnace with the changing thermostat first Bryant, who should have a filter change "light is if you consider changing the filter to be installed. The problem is that I come every two days, although the filter is less than a week, but not dirty. "One person suggested that my statement of cold air may be too small and the thermostat reads less as a barrier air filters / dirty. My question is, could be the explanation or the thermostat reading on the air diagnose if the filter is dirty? In addition, there are other possible explanations? way, I have two pipes back into the cold air in the house. One is oval, approximately 13.5 "8.5" (perhaps a 12 " tube that has shaved more the furnace room address is fixed) and the other is round with a 9 "diameter.