Is the ZW521 bright enough for a lit classroom?

At 6,000 lumens it is aimed at rooms with ambient light and larger screens. It holds up better than typical 3,000 to 4,000 lumen classroom projectors, though direct sunlight on the screen still washes it out.

Do I ever need to replace a lamp?

No. It uses a laser light source rated for 30,000 hours, so there is no lamp to change. Brightness slowly declines over that life rather than failing suddenly.

Can it run all day, every day?

Yes. Optoma rates it for 24/7 operation, which suits digital signage and rooms in near-constant use.

What resolution does it project?

WXGA, 1280x800. That is fine for presentations, documents and video, but it is below 1080p, so fine text and detailed images look softer than on a full HD projector.

How is it managed across multiple rooms?

Through Optoma Management Suite, which lets IT monitor and control networked units centrally. That reduces trips to each room for status checks and settings changes.

What connections does it offer?

It provides standard business projector inputs including HDMI and network control, plus the management suite link. Check the exact port list for your source devices before installing.