To be short, there is a difference between a dock seal and a dock shelter.
It all starts with your loading dock. What trucks or trailers does your dock use? A dock seal captures a tight variance in trailers, and offers a better “seal”. A shelter encloses the truck or trailer body. This keeps out air and allows for a large variance of trailers in relativity to a seal. It also allows for full opening access to a truck or trailer.
Either is determined by preference. Do you prefer a tighter seal and have a tight variance of trucks that are encountered by this product? Or do you prefer to enclose the opening while not restricting the variance in trucks that can use the product?
A motivating factor is a dock that sees trailers and trucks with irregular tail end projection. This includes steps, lift gates, and bumpers. A shelter is best fit for allowing the capture of both trucks or trailers with these projections as well as those with no irregular ends. If you build out a seal to capture these projections, you may not use it for trailers without them as it will over compress.
Both encourage a sealed off-loading dock and help lower energy consumption by your facility.
