I have a 300 sq. ft. room located on opposite end of a 3 Ton package HP. This room has one 4 x 10 register outlet. Obviously for this size room it is not enough. Also this room is on a concrete slab. In order to prevent moisture buildup, I have been running a dehumidifier for several years which has been doing an adequate job. I am considering getting a 75 CMF register fan.

The velocity meter shows 600 ft/minute. Mind you, I don’t understand all I know about this, but if I am correct, the 4x10 outlet would translate to .277 sq.ft. x 600 = 166CFM. I love the concept of this fan because of the ease of installation, but would this register fan make a reasonable difference, or will I be wasting money?

This room it is not frequently used. I am not expecting a radical change in room temperature but maybe just enough to minimize the use of the humidifier.