Noise coming from A/C at low fan speeds

Hey everyone -

I currently have approximately 62,000 miles on my 2013 Prius v wagon. Recently I've been getting some noise from the HVAC system. Here's what's going on:

• After the car has been sitting turned off for a while, and I power the car on and turn the HVAC system on a low fan speed, I begin to hear a consistent noise, as if you were to put a playing card in a wire-spoke bicycle wheel.
• When I increase the fan speed, the noise either is drowned out or goes away.
• When I turn the fan speed back down, the noise is gone. Likewise, when I turn the HVAC system off and then back on after this, the noise isn't there, even at low fan speeds.
• The performance of the A/C system does not appear to be affected by this.
• This all of a sudden started happening, I've been blasting the A/C in the hot Florida weather for almost an entire year with no issues.
• The noise happens regardless of whether it's using heat or air conditioning.
• It doesn't happen every single time I turn the A/C on after an extended period (6+ hours) of not driving the car.

The noise appears to be coming from the passenger side, near or underneath the lower glove box. If I'm not mistaken, this is where the blower motor is. Perhaps some debris got in the blower motor? I'm not the DIY type when it comes to ripping the dashboard open. If it is debris, would it be something that might eventually work its way out? I've heard of blower motor failures happening when the cars are older or have more miles, so it seems a bit premature for the motor to fail on mine...right?

EDIT: Possibly resolved - debris stuck in the air duct, see below.

 

I thought that the dealer replaced my cabin air filter during my last service but apparently they did not!

I didn't realize how easy the process was to clean / replace it. I pulled the glove box down, pulled the filter out (which will need replacing next go around), reached up in the air duct, and pulled out a pile of dust and debris the size of a gerbil.

The fan had a few tiny pieces in it, I think I got them out.

I did a quick test afterward and no noise, hopefully that solves my problem in the long term - we'll see. Thanks for the recommendation!

 

Even though I requested the 60,000 mile service, they did not change the filter, but they didn't charge me for it. Very weird.