Many side wall fans have access issues where the ductwork is tucked above a chase way or permanent ceiling that is difficult if not almost impossible to get to. Also, continued access into ceiling tiles will require occasional replacement of the tiles as they were never really meant for continuous use every 3 or 6 months. I recommend installed hinges on the fans where inside access issues exist. Please note the structural support in the picture needed for proper sidewall fan hinges plus it is a good idea to set up a lock to keep unwanted guests out of the fan. It is like a door to the ductwork so you still need to secure it. This way, instead of crawling above a ceiling area with possible leaky access plates, you simply open up the fan similar to the roof mount upblast fans with hinges. Don't forget to install with the air intake facing DOWN!! This prevents rain from entering into the fan. You will also need to plan for additional flexible conduit to allow proper clearance. When complete, the cost for the side wall fan hinge is similar to an access plate, but far easier to use.
Don