Thank you Shannon but it was not a mistake haha. I don't think you can accurately state all of that without understanding the layout of a home. I appreciate the opinion though! We don't cook a ton and I do believe a downdraft is much more visually appealing. Plus many, MANY people have down drafts and have found ways to successfully use them. Some ranges even have ductless vents.

Can you share your current kitchen plan, with indications of what the adjacent spaces are? No harm in seeing if the folks here might be able to come up with a design you like that doesn't have the complication of a downdraft vent.

We’re building a 9 foot island. I understand the physics of cooking, but so many people have downdrafts in their islands. I really can’t imagine this being that big of a mistake. I will try to share my kitchen plan. It’s a difficult space design. We’ve had three professional cabinet makers come and each one has the same design and agreed on the location of the range.

If you’re absolutely determined to do a downdraft, my advice is that you need a LOT of fan power to make it work. Skip using any in-appliance fan and use a remote exterior wall mounted fan (commercial kitchen type). Not only will it be quieter with the fan being remote, it will likely have CFM capacity to possibly be effective. Put it on a rheostat to vary fan speed, based on need (steam evacuation vs. smoky grease). For best outcome, consult with an engineer to properly design and specify the system.

Electric ranges don't require much as there is no open flame consuming oxygen. Read their requirements in the range install instructions.

There are several flush to ceiling hoods that work as well as downdrafts. The downdraft pipe can be sheet metal or large PVC.

Have fun!

A few more fun facts.

1. Toasters burn, don't require a hood...maybe should.

2. Microwaves boil, but don't require a hood...maybe should.

3. so many people never turn on their hood.

You have 3 choices. Here in order of desirability:

1. Overhead hood. See if you can run a duct between the ceiling joists and to the outside.

9. Rear downdraft vent - They rise up out of the counter top about 8"-12". Elegant but not very effective.

10. Downdraft. Pretty worthless.

I have a Jenn-Air downdraft. Like I say, pretty much worthless.

(Note: There's nothing between 1 and 9 above but that how bad the rear downdraft and downdraft vent are!!!)

sktn77a: I suppose we could scale the merits of various overhead hoods -- effective to poseur -- to fit them into the 1 - 9 zone.

Collins Cameron: Against my better judgment I will comment re: your "haha" and related perspectives.

One can always define some minimal level of cooking such that a side-draft venting system ("Desirability level 9" above) can remove some of the steam from boiling eggs or capture barely warm grease particulates from some simmering food. If you are OK with the remainder of the cooking plumes condensing on the walls, ceiling, and fabrics in the residence, I certainly don't want to stand in the way of your aesthetic taste.

Otherwise, we can consider the physics. Hot cooking produces hot cooking plumes that rise and expand. Velocities can reach 1.2 m/s. The plumes have momentum. You cannot easily change the momentum vectors of the plume components toward the intake slots of a side draft venting system. Particulates that pass close to the side draft panel may be pulled in, but farther away there is little effect.

The requirement for complete diversion is that the transverse air velocity must be at least commensurate with the plume velocity across the entire plume section. But the velocity of the air away from the panel drops rapidly. See Fig. 6, page 30.4, 2003 ASHRAE HANDBOOK, HVAC Applications. For any likely volumetric air flow rate that can be sustained through the small aperture areas of these panels, the velocity away from the panel at the plume will be too low to achieve diversion. You could need more than 200 ft/s transverse flow at the plume, and a high multiple of that at the slots. You will not successfully divert hot cooking plumes into this vent; and even those generated over rear burners will be captured only partially.

On the other hand, the efficient (why they are used commercially) overhead hood only needs 90 ft/min or less at the hood entry aperture for almost all residential cooking. This is practical for existing hoods and available blowers operating under the corresponding hood and duct pressure loss conditions (given adequate make-up air).

Only you can weigh among performance, aesthetics, and cost. And we don't know just what you cook, or may want to cook. There is a big difference between airing out a bunch of cilantro at the base of the pop-up side draft, and capturing and containing the plume from searing a steak, or from wok cooking at the caramelization level.

May I suggest that you read various hood threads on this forum, and also make-up air (MUA) threads, as MUA will be needed for any configuration needing more air than the house can leak at near zero pressure differential relative to outside.

Ducting through a crawl space should not be that difficult.

I had a kitchen with a downdraft. One of those old JennAir things. Electric. The downdraft worked okay. Not great, and lighting was bad, but quite a bit better than nothing. But mine probably worked better than most because it was ducted into the crawlspace, period. No ductwork. So I didn't use it. I like my grease and steam where I can see it.

There are better downdrafts available now--the popup ones. They'll mess with a gas flame. At least go with induction.

I would encourage you to get a big ceiling hood because they really do work better, but I'm not going to tell you that you're a terrible person who is doing everything wrong just because you want a downdraft. :P

Just because many people have downdrafts doesn't mean they actually work effectively. Many people prefer to go with form over function. So the downdraft looks nifty but it doesn't do the job it's suppose to do.

Order a balsa wood and paper fan from Hong Kong, Open a window in another room. When cooking, fan the cooking fumes from the cook-top to the open window.

Won't work? Exactly. Same with a downdraft vent

The downdraft you may wish to consider is the Best Cattura

Using an induction range from Frigidaire at a lower price point or Bosch at a bit higher price would be my recommendation. Gas won't work with downdraft very well.

Install-

https://www.youtube.com/watch?v=NZ2AsChtmjc

All that the video shows is steam being sucked into the vent. I guess if all you cook is pasta the Cattura downdraft would be great.

After cooking with an overhead hood and seeing all the grease in the filters, I would never. ever. ever. put in a downdraft vent if I could help it (and my hood is probably undersized). I wouldn't buy a house with one either. I also wouldn't buy a house with an island range unless I could afford the remodel to get it on a wall, but I digress. If you have the option to vent overhead, do it.

If insisting on downdraft (not advisable), definitely do not cook with gas. Combustion byproducts are hazardous to human health, and a downdraft will not protect you from this source of air pollution. You'll need induction cooking to avoid negative health impacts.

You can cut down some on the need for venting by using a glass lid when frying. Speeds the process up also.

Putting a lid on a skillet or fry pan when sauteing food changes the cooking process from sauteing to half sauteing, half steaming. If you're trying to get the food crispy, the steam will make it soggy and wet. You can't fry and brown something that's wet and that will happen when you turn the food item over.

Let the steam out and replace the lid or have the lid partially open. You control it. Things brown and crisp up wonderfully. Everything happens faster and obviously with less mess. Like anything, it's a skill you develop. It's an option like using a steam oven. I'm sure you already use this method for cheese omelets and cheeseburgers without negatives.

For the record you're not limited to just cooking pasta. LOL

You can cook:

hot dogs

vegetables

soups

stew

rice

eggs

sea food

& Jail House Chili

Just don't let the water evaporate.

We have addressed flush ceiling vents several times here, and these threads may be worth reviewing. In the context of a choice limited to pop-up side draft vs. flush ceiling, then I would have to vote for flush ceiling, so long as the requirements are met. This is because most cooking plumes will reach the ceiling, albeit spread out by plume expansion and by cross drafts and people motion caused turbulence. I think the following requirements are important, in no particular order:

• Ceiling joist revision must be practicable and structurally sound.
• Make-up air must not short out the plume path to the vent aperture. To introduce the MUA, use another room, hall, the kitchen floor, several toe kicks, or a ceiling diffuser with vanes directed away from the vent register.
• The vent register area must accommodate at least a 10-degree from vertical expansion from the locus of pan bases. The tangent of 10 deg. is 0.176. This value times the distance from cooktop to the ceiling is the overlap required past the cooktop edge all around the cooktop. This may require more than one ceiling unit. Even larger than this may be needed based on whatever the normal room air motion is.
• The plume velocity vs. angle is a distribution function; some plume exists at wide angles. Hence the farther a ventilation system is from a cave like shape, the greater the potential for escape of small amounts of plume. So expect some of the cooking effluent to be removed (or deposited) as a room ventilation process rather than a vent hood process.
• A means of cleaning needs to be determined that will keep safe the cooktop surface as well as any counter top stone not exceptionally well supported.
• I have no plume velocity data applicable to the ceiling distance above a pan, but I would expect some reduction from normal hood separation distance due to increased cooling. If we go with 0.6 m/s, or 120 ft/min, and assume a 50% fill by the ceiling baffles or mesh filter, then I'd aim for 60 ft/min average across the large vent area. This makes the required volumetric flow rate (CFM) equal to the total venting area in square feet times 60 ft/min. The blower rated CFM will need to be 1.5X that flow rate for pressure loss compensation. A real analysis based on pressure losses due to whatever the filtering is may be helpful.
• A flush ceiling unit generally has zero reservoir volume. Large cooking transients may not be fully captured and contained even with these requirements met.
• Blower power control will have to be brought to the island or a nearby wall. An induction motor blower may be the easiest to obtain a controller for. Some ceiling units may be supplied with remote controls simplifying this otherwise awkward wiring necessity.
• As usual, the duct size to the outdoors should be such that the air velocity in the duct is in the 1000 to 2000 ft/min range.
• Successful testing (with MUA functional) requires watching the plume behavior when subjected to smoking peanut oil, not just watching steam rise.

"so many people never turn on their hood"

That's usually because the hoods they have are ineffective and aren't worth the noise!