Air inlet performance during cold weather

At the beginning of this video you can see the air entering through ceiling inlets opened approxiamtely one inch with a static pressure of 0.10".  The outside temperature is 20 Fand the inside temperature is 80 F.  The cold air is mixing fairly well with the warm, humid inside air as evident by the fact that the condensation cloud is quickly dispersing.  Toward the end of the video the inlets are opened three inches, decreasing the static pressure to 0.04", resulting in poor mixing of the incoming air.  As a result the cold air/condensation cloud quickly drops to the floor.