This is the long version of a roof fan installation. Channing and Will work through the BigAir 400 frame, the roof opening, the seal and the fan itself. Most of the time is spent on the part you cannot fix by simply changing fan speed: making a clean, weather-tight roof opening.
Let the corrugations set the position
The angled marks on the adapter frame line up with the raised roof corrugations. That tells the crew which way the frame belongs before they mark or cut. Channing also points out that an older container roof can have dents and low spots. Pick a location where water can run away from the frame rather than collecting against it.
The seal is the job
After cutting, they clean up the steel shavings so they do not rust into the roof paint. A couple of temporary rivets hold the frame in alignment while the remaining holes are drilled. Then the crew applies sealant where the frame touches the raised steel, around the small gaps in the folded metal, and between the frame and the fan housing. The video is a good reminder to inspect every edge before the final rivets go in.
The removable mesh filter slides in from inside the container. It serves as a bug barrier when the fan is not running and can be taken out for cleaning.
Plan the air coming in
The fan is rated at 400 CFM, but that number is not a promise of airflow in every container. Channing shows a project planned with three roof fans and four lower wall intakes. The intakes are essential to the idea: an exhaust fan needs replacement air. The fan runs directly from sunlight, so its output changes with the sun. Check the current kit instructions and sealant requirements before cutting your roof.
Watch the original full-length video or read the source post. This article is a practical summary of the spoken walkthrough; always use the instructions supplied with your exact product.