I know these are not popular, but I'm just curious as to how they work exactly. Do they vent outside? Is a special cabinet required for the cooktop? Thanks for your help!
Yes, downdrafts vent outside - you will need ducting from the downdraft to the outside somehow. I don't know if you need a special cabinet but there will need to be room for the downdraft itself plus the ducting. I assume you're talking about a pop-up downdraft, not a flushmounted Jenn-Air downdraft.
Either or, really. Do the cooktops with downdraft venting themselves work differently? Thanks again for the information.
Well the Jenn-Air cooktop with a flushmounted downdraft vents the same way but is not very effective. If you have to go with a downdraft, a popup is a lot better but an overhead hood is much better if that's at all an option.
Consumer Reports says that downdrafts are never as effective as overhead hoods. Since heat rises, the downdraft has to counteract the natural direction of the heat flow to capture it. The optimal overhead hood is one that is positioned above ALL your range burners. Many are only partly over the front burners. But then you don't want one that sticks out so far that it gets in the way.
I think I should be able to vent with a hood. In fact, I already have a real wood cookstove vented through the ceiling where I am thinking of putting my cooktop in my redo. I'm hoping I can use that with modifications, if necessary. I was curious about the downdrafts because I don't really want a hood as a focal point in my kitchen. Ventilation is not a big issue for me as I don't have it now and it's not a problem, but I want to include it in my plan since I'm taking on the whole kitchen anyway.
We selected a downdraft because we didn't want a hood either. A hood would have been obtrusive and blocked the view of the walk in bay window. We had a Thermador cooktop with the pop up ventilation for 18 years and it worked well. Obviously it can't compete with a hood.
We remodeled 2 years ago and went with a Dacor cooktop and pop up ventilation. This has a larger CFM rating and is much more effective than the old Thermador. It works very well for our purposes. But we don't stir fry very often or have a cooktop with 22,000 BTU burners that might really need the hood.
I was concerned that the ceiling over the cooktop might discolor if we didn't have a hood - but that hasn't happened. I think we went about 10 years before repainting the kitchen - but that was because we changed color scheme, not because of the ceiling.
Our downdraft vents under the kitchen floor and to the outside. We have a remote blower and motor mounted outside the house so that there is significantly less noise in the kitchen when the fan is on. The housing is fairly unobtrusive - it's mounted near the ground and isn't very large, an evergreen easily hides it. Remember that the lenth of the run and number of right angles diminishes the effectiveness of the venting. Having a remote motor also allows more space in the cabinet for storage.
Hope this helps.
Thank you mcmann for all the additional info!
mcmann covered most of my points in selecting a downdraft, including installation and exterior remote blower. I would just like to add that I too have a Dacor downdraft (and would not recommend Dacor products in general - long story) but I find that it is still too low and pulls the flame on the back burners. At least once it scorched the protective felt-like material at the edge of the box that keeps the raised part from scratching as it moves up/down. In addition, simmer settings on all burners cannot be used in combo with the dd since they are blown out by the dd. The Thermador downdraft rises much higher (about 15" compared to Dacor 9-10") than the Dacor and I think this would mitigate much of the problem.
for various reasons (no gas- modules swap out- size) i am looking at the 43" jenn air electric cooktop. i have had jenn air cooktops for over 20 years at different houses and i am aware they are getting flimsier with each "upgrade" but my question is what would keep you from using a hood to vent it even if it has the downdraft built in? where we are now it would be hard to get a downdraft vent all the waty outside the closest place we can get it is a crawl space under the porch which is cement walled but has a few vents or a crawlspace under the house.