I asked that question a long time ago (and so did countless others) and the answer was "down draft does not work, period".
Sorry, I don't have any links but Google-search the forum and you'll find them, I am sure.

Well, I don't think that's a cook top issue but more of a "what am I cooking" issue. If you're stir-frying, just as an example, all that smoke has to go somewhere, and up is where it generally goes. I agree with eleena.

Okay. Thanks. Up, up, and away.

To answer the question a little less categroically than Eleena, donwdrafts can work "okay" with induction because you are not dealing with waste heat, combustion byproducts (mostly water vapor), and you are not blowing the flames around as downdrafts tend to do with gas cooktops. But, as joeboldt ponts out, what and how you cook has a lot to do with how unsatisfactory or satisfactory down-drafting will be for you.

The basic problem is that down-drafts are fighting physics, rowing against the tide, etc.

Plenty of postings on them recently if you do a search. Lots of variation between units, particuarly when it comes to height. The taller the unit, the less unsatisfactory it is likely to be. Heights range from 7 or 8 inches on up to 16 inches high for the intakes. Price rises steeply, too, and the taller ones are a lot more expensive.

Basically, the consensus seems to be that down-drafts are one of those things you go to when you don't have other choices.or if your other choice is an unvented recirculating hood

Up, up and away is better.

This post was edited by JWVideo on Fri, May 3, 13 at 18:02

If you can possibly get a vent hood that vents to the outdoors, do it. You won't regret it.
We were not able to do that, so we replaced a JennAir downdraft with an induction cooktop and a telescoping downdraft behind it. I chose an induction cooktop with the largest burner toward the back.

The setup is better than nothing, but it's not perfect. Same with the old JennAir version. Very little of my cooking requires venting anyway. Each person's needs are different, though.

Updraft is definitely better. But downdraft is better than nothing. I have a downdraft currently. It does indeed suck stink and vapors. Mine, however, works better than most because it's not ducted outside--it just dumps directly under my house so there's no run of ductwork to inhibit its performance.

Ewww. Don't do THAT.

Something else to consider if looking at the telescoping downdraft units --- maximum height. Some of the brands I researched were barely as high as my largest soup pot. Because steam rises, I wanted one that was at least a few inches taller.

Thanks all for words of wisdom. Really helps to avoid mistakes.

I am fighting space & visual sense. There is absolutely no problem venting to the outside in our cottage. The issue is the bulk of an exhaust fan (which we need for we cook 3 meals every day -- and I do mean COOK.).

We live in a old-fashioned 845 s.f. cottage which we have made very energy efficient: one big room (kitchen/Living room), bath & bedroom & tiny back entrance/laundry. The 9' ceilings and french doors on the south help prevent claustrophobia, but I need to avoid upper cabinets and bulk on the walls to not feel closed in. Not to mention limited counter space.

This means a 24" cooktop. Unfortunately, the only electric one I can find is radiant. (Miele makes a perfect (for us) 3 burner induction for Canada & Europe but doesn't plan on USA option. At least they do offer a 24" 3 burner smooth top.) The matching vent hood is a very modernistic, in-your-face one that would not go in our home. Will probably install cabinet just to hide sleek under-cabinet hood. Downdraft seemed best solution design-wise but obviously not best for other issues.

I am working several issues: need to vent smells/humidity, need to vent heat (gets very hot in tiny, tight house), bulkiness (everything small sized), old-fashioned but needs to be able to be cleaned easily (69-year-old arthritic joints).

It really helps to hear from people living with downdraft to know we'd regret the decision. Life's trade-offs. Your advice is much appreciated.

I can say I had a Thermador telescope and was surprised how well it worked after having a JennAir downdraft that didn't do much of anything except make noise. With the telescope the back burners worked very well and the front ones I found keeping a lid tilted so the steam was directed to the telescope worked. If it is your only choice go for at tall one with a decent size motor. For those that say they are worthless, I am not saying it is as good as a hood vent.

One big advantage using downdraft with induction is you can "Kick up" the downdraft when needed and still simmer sauces, and use low heat , whereas, doing such with gas will , more often than not, extinguish the flame, (Per posts seen here in Garden Web).

Like most, I would recommend overhead venting, but if you can't or won't, It's very "Unlikely" the sucking from the downdraft will extinguish the "Induction Flame"!

Gary

JW,

I did not say it was my opinion, I said I was told what by GW-ers. I was just passing the info. :-)

I couldn't believe that a Gaggenau down draft wouldn't work as they had such good reputation. Since then, I learned that their ventilation is not all that great in general.

djdoggone,

You can import a (properly rated) 24" cooktop from Europe if you get an OK from your home insurance company. At least one GW-er did. I am attaching a link to her kitchen tour but I don't have links to her GW posts when she talked about it. You can Google search GW for them. Here screen name is plllog.

If you REALLY cook, you'd be so much happier with induction.

Another version I seriously considered was having two Miele units: 12" two-burner gas and 15" induction. It takes only 3" extra. If you cannot do gas, you can do a 12" electric but still have an induction unit.

Unfortunately, their induction has only one hob. However, it would be a worthy trade-off for me, because I also do cook. To make up for a "lost" hob, you can have a portable unit.

In the end, I went with two Gaggenau units (one gas and one induction, both two-burner, but they take up 32"). My gas unit hasn't yet been hooked up and I have been using just the induction for a few weeks. Tell me tell you that you don't want to miss out on that experience, LOL.

GL!

Here is a link that might be useful: Kitchen with 24

You can supllement a downdraft with a Panasonic ceiling exhaust unit generally used in bathrooms. Units are quiet and can use a remote blower motor.

eleena, thanks for the pointers. Thought -- after insurance -- the stumbling block was that Miele would not honor warranty. Worth checking for myself. Thanks.

dan1888, nice thinking outside the box. Planning Panasonic in bath and above laundry -- sort of a do-it-yourself air exchange system for tight cottage -- but might work with 3rd in kitchen.

See why I love this site. Thanks.

Using a bath fan in a kitchen is a BAD idea. There is no filter mechanism so any grease particulates just build up on the vent grill and ductwork. Grease buildup equals a fire hazard. And you create competing air currents if you also have a downdraft. More air turbulence means more yucky stuff stays in the kitchen rather than exits. Besides, if you've got room to do a bath fan, you've got the room to do a real overhead hood that you can clean and duct the steam and heat externally.

I've never considered a downdraft myself, but was wondering what they cost compared to overhead venting? I mean, if it doesn't work nearly as well, it ought to be a much cheaper option, right? How much of a premium will folks place on form over function???

Hadn't thought of that, hollysprings. I'm sure you're right. Thanks for the warning.

cooksnsews:

Seems to me there was a discussion of cost and brands a couple of months ago but for some mysterious reason, I can't find the thread. Oh well, here's what I remember from the thread and from having looked into "telescoping" vents for a friend about a year ago.

The most basic downdrafts are just a vent louver in the stove or countertop, the most infamus being those on the Jenn-air stoves. Those are the ones for which folks here say, "down draft does not work, period" as eleena reported. (BTW, eleena, I apologize if my response came across as saying that was your opinion. I understood you were talking about GW postings. I would have been clearer if I had said: "opinons are not so categorical.")

The basic telescoping (or pop-up) downdrafts start at around $500, but only rise up to six or seven inches. The lack of height means that they basically only work for frying pans on back burners and otherwise don't really work very well.

The mid-range versions rise up to around 10 to 12 inches and costs gor from around $900 to $1500, price depending on brand and blower CFM capacity (generally 400 to 600 CFM). I think Bosch has one that goes up to 14 inches high and costs IIRC around $1300.

There are units by Dacor, Thermador (similar to Bosch which is part of the same company) and Gagennau. IIRC, these rise up to a bit over 14 inches, have a variety of options including blower placement (internal, inline and outside) plus other options. My recollection was that these cost upwards of $1900 when you get all the components together. The Thermador, if memory serves, ran about $2200.

djdoggone:

A cabinet-hung slim hood might be your best bet. That's what I did with the small kitchen in my small old house. Putting glass in the cabinet doors keeps the old-fashioned look and keeps the cabinet from seeming to loom over the room. I've also seen double and triple glazed windows placed behind cabinets. (I'm trying to remember where I've seen pictures of this. Maybe try the Fine Homebuilding magazine web site.) That could helps with your concern about light.

I thoroughly agree with Holly Springs that a bath fan would be a bad idea for a kitchen. With a nine-foot ceiling and all the windows, you could consider installing a celing fan to help drive smoke when you get it and that supplements the range hood.. I've done this in my own kitchen and it does help when good cooking goes badly awry, as it sometimes does.

Some other points to consider.

First,downdraft and telescoping systems eat space behind and beneath a cooktop. You may not be able to fit an oven beneath the cooktop if that is what you were planning on doing.. Look at installation diagrams. (The AJ Madison and Lowe's appliance sites often have links to the manuals if you have trouble finding them on manufacturer web-sites.)

Second, you apparently have made up your mind to get a 24" cooktop. I do not remember seeing any 24" pop vent systems. They all seemed to be 30" and wider.

Third, Summit makes the only 24" induction cooktop which I recall seeing for sale in North America. I believe it is carried by at least AJ Madison for around $850.

JWVideo: I'm convinced. Downdraft would be a mistake. We agree that the best option would be a slim cabinet-hung hood, opting for glass in the cabinet doors.

Thanks for the pointer on the cooktop. We are not sure about induction because of the number that fizzle at the four year mark and can't afford to re-buy every 4 years. And, as you say, it impedes installing an oven beneath. Still researching...

JWVideo, I was not offended! Love your posts, btw.

Yes, self-importing from Europe would void the warranty but with brands like Miele or Gaggenau, I'd take my chances.

I am pretty sure I have seen discussions about installing ovens below induction. I think it's possible. A showroom here has a Gaggenau 36" oven under their cooktops.

Good points. A new idea often needs some refinements to work. This use is not as a completed product ready for you to go out and buy.
A straight bath setup may have some drawbacks. But I doubt some of us would find them insurmountable.
The goal is to leave the sightline open. Panasonic makes a remote fan unit and possibly adding removable filter screens from another manufacturer at ceiling level would be a solution..

If one is going to use a remote fan for a ceiling vent, then a bathroom fan is not the best way to go. Use one or more heat registers on the ceiling (they are available in a tremendous number of sizes from Hart & Cooley. (You want a register not a diffuser.) These can sit flush with the ceiling if the rafters or joists are boxed out to fit.

Use galvanized steel ducting to a fan on the roof. Use a damper above the register. Use a furnace filter behind each register to capture grease and lint and change it regularly. The filter box that adapts to the register may need to be fabricated by a HVAC distributor or sheet metal shop. If the ceiling is white then the register won't need to be painted.

This will remove odor eventually, and some fine aerosol grease, but in general, without a proper hood capturing and containing the rising effluent that a side draft pop-up vent can't capture, grease produced by any significant cooking effort will coat the interior of the room, albeit gradually and initially imperceptibly.

kas

kaseki, I couldn't eat breakfast after reading your post :-) Now I want to wash the ceiling, walls, floor and the dog.

Hubby always says, "The right tools for the right job." Uncle! Clearly a proper vent hood is the way to go or I'll be feeling grease droplets while eating dinner.

Pretty counts, but so does cleanliness. I think we've EXHAUSTED (pun intended) this design idea.

Can't thank you people enough for the help. I feel really good about giving up the idea of a downdraft.

We have a downdraft with our induction unit; both are Bosch. We live in an early 80's colonial, only venting Is down and out. If we were to do an overhead vent, we'd affect the entire main floor ceiling down. It currently has popcorn which will not be removed anytime soon since it was painted and any changes to it would require a total first floor ceiling renovation. Changing the venting would be extensive with ceiling issues, cabinet issues, exterior venting issues, so down and out it goes.

We do not grill inside except occasionally grilling shrimp on a Le Creuset grill pan. The Bosch unit vent is taller than my largest Tramontina pot so we are good to go here. Nothing drips on us.

Much of your success with a downdraft depends on your style of cooking. While folks here may tell you overhead is the only way to go and yes, it does have its benefits, it is not always do-able for every soul.