wa8yxm wrote:
sch911 wrote:
Airflow CFM is directly proportional to current draw. Less airflow = less fan current.
For a free standing fan.. Likely true
For the blower in the A/C..... Complex
Closing most of the vents WILL cause back pressure but how much?
Back pressure means less air will flow (Hence the ice up comments)
But it also means the blower is working harder against the pressure
This INCREASES the current draw.
Come on Dave, you know better than that! Work is defined in physics as a force causing the movement (displacement) of an object. If you don't "move" the air, there is no work done. Less movement means less amps from the blower motor.
Did you ever put your hand over the end of a vacuum cleaner hose? The motor speeds up due to less work. Also draws less amps. Get an clamp on amp meter and check me out. You can totally block off the vents and the motor will speed up due to almost no load on the motor.
