Yea my hood fan was surprisingly difficult to install and I even had to have my welder buddy cut my shroud peices in order for it to fit. The fan itself is super highly reviewed for the price from Costco, however their customer service was shit, Ancona brand
The island hood fans also are a bit harder cause you need everything perfectly in place as well as some heavy duty backing to mount it free floating. I'm super happy with the end result though