to properly credit the information that they use. Its primary goal is to make it so easy for student researchers to cite their information sources, that there is virtually no reason not to. Because someday the information that someone else wants to use will be yours.
All floor register sizes are measured and displayed by the size of the vent opening that they fit. Overall there are two sets of measurements for each floor register-inside and outside. The inside measurement is the one that all floor registers are displayed as. It is a equal to the opening that it fits. The outside mesurements are the top part of the floor register-the part that will be seen from the outside.
Heating and air conditioning registers are located on the outside walls of structures, air return vents on the inside walls. This is because the warmed or cooled air at the outside perimeter of a room forces the cooler or warmer air already in the room toward the center of the structure.