Tried it, cool little layout, but I have two issues:
1- Impossible to escape the fan once you're up there with the pickup. So there's no reason to go there unless you want to die, so there's no reason to venture at the center of the map and try to get the pickup up there. It makes the gimmick a bit pointless.
2 - You don't get sucked up by the fan as long as you don't leave the ground because the reverse gravity zone only starts 64uu above the ground.
Both of these issues can be fixed by extending the reverse-gravity zone to the ground. This way, players get sucked up as soon as they move inside the area underneath the fan. It alsogives players enough momentum to bounce on the central lamp under the fan and escape the gravity zone mid-bounce, making it possible to leave with the pickup instead of being 100% certain to die once stuck up there.
You must construct additional pylons.