I recently bought a house that has a Jenn Air gas cooktop with
downdraft ventilation. I hate the way the ventilator sucks the flames
and heat away from the pans, while still managing to allow alot of the
smoke to set off my fire alarms. Especially with a wok, where the
downdraft is near useless.

I don't really want to reroute the ventilation piping. Is there any
kind of overhead hood I can suspend above the cooktop but route the
output down through where the downdraft goes now? I don't care if I
have some pipe hanging down from the hood to the cooktop, it's more
important to be able to cook properly.

any ideas of products or homebrew solutions for this kind of thing?