Maybe you should have your dealer take a look at it. Maybe you have a bad
motor, i have seen one winding bad and they will make noise like that.
Later Paulbm

I would look at improper return duct or dirty filter. If it does not get enough air flow it will suck it in from any place that is not sealed good. It could be blower motor or wheel but sounds more like airflow.

Maybe you should have your dealer take a look at it. Maybe you have a bad
motor, i have seen one winding bad and they will make noise like that.
Later Paulbm

Why would the noise stop when air handler goes to 100%? I will also call dealer to look at noise problem.

Like i said you could have a low speed winding messing up and when go to faster speed you are on a different winding in that blower motor. If its under warranty try changing the motor. later paulbm

Dealer said the whirring noise is beacause the return duct is not supplying enough air. The manager will contact us next week with solutions concerning the return duct. What would you recommend to solve this problem?