Hello,
Thank you for the feedback and support request.

Our support team has reviewed your case and all of the provided photos and details.

This is a powerful 600 CFM blower. A minimum 6' duct is required all the way through and the outside roof cap must also have a minimum square inch opening of 28' total.

Noise comes from air pressure. If the duct is too small, there is more than one 90 degree turn or if the outside vent cap is too small, air pressure will increase and lead to a noisy unit.

The Plane range hood has one of the quietest blowers on the market. Our support team strongly advises checking the ducting to ensure there are no blockages or other ducting concerns. Please check if any flaps are stuck or if any of the duct is blocked.

If you need further assistance, our team is here to help and can be reached at 1-800-394-4020 or support@victoryrangehoods.com

Thank you again for the feedback and we hope this ducting issue can be resolved.