Have you tried posting this in the electrical forum? Someone there might know.

The installation instruction for a 36" Frigidaire here shows 12" of clearance. The unit is $893. Miele here requires a minimum of 9/16" or 15mm. clearance to an oven installed under the cooktop. Same clearance to a protective base shelf. They want a 3' gap at the rear and suggest a 2" gap at the front for ventilation if one is installed. A protective base isn't required. 3" clearance to a drawer bottom is required if you put a drawer under a unit. A wire drawer sounds like a good consideration. Safety clearances on page 56 and following. $3300. Miele has an upgraded 7000 series of full surface units(6 pan recognition) at the same price points for sale in Europe. US versions aren't yet available. Bosch has 36 and 37" units from $1800-3000. They want airflow cutouts with 4" from the top of the unit to the top of a drawer in addition.Here.

I am the person who originally posted. I am not the one that was offended by the name. Someone else had posted something regarding the name. People are offended for so many ridiculous things now, I didn't bother asking. On a side note, I ended up having an overhead vent installed over an induction. We cook a lot and could not find a downdraft vent that was powerful enough to keep the air in our home free from particulates that can cause health issues. We chose health over style and then realized, once installed, that it did not look as horrible as I feared.

For a ceiling hood to be effective requires excessive aperture size, containment volume, internal baffling and CFM's. Otherwise they are only slightly better than downdraft. They are nirvana for open plan commercial kitchens but the install cost is about 5-7x the cost of a standard hood and operational cost about 3x (in cold climates) so are very rarely installed. The effluent plum at the ceiling is quite different than at 3' above the range. It is cooler and much less dense which works against good capture and containment. Closer to the range the heat of the effluent helps to contain it in the hood (hot air rises) until it can be exhausted. Even just 3' higher the byproducts that you need to exhaust are less dense by a factor of about 4 (so you have to exhaust 4x as much volume to exhaust the same amount of particulates) and it has cooled resulting in the need of nearly twice the containment volume.