A 42 inch solar ceiling fan usually works better in a 10x10 gazebo because the space is smaller in real life than it looks on paper. Once you account for posts, beams, furniture, lighting, and the area you actually sit in, the usable zone often feels more compact than the full 10x10 footprint.
That is why a 42-inch fan tends to make more sense for most buyers. It usually gives you enough airflow for a small covered seating area without making the ceiling feel crowded. It also matches common sizing guidance more closely. Hunter’s room-size guidance places a 10x10 room in the range where 36–44 inch fans make sense.[1] Home Depot says that when the longest wall is under 12 feet, the recommended blade span is 46 inches or less. [2] Both of those guidelines support 42 inch more directly than 52 inch for a true 10x10 layout.
Another reason to stay with the smaller size is visual balance. If you want your gazebo to feel open, comfortable, and well-scaled, a fan that fits the space proportionately usually looks better than one that pushes to the upper end of the range.