Could you build a soffit in the garage to run ducting sideways to an exterior wall? I would not put in "good quality" range unless you had a "good quality" duct assuming you plan to actually use the range for cooking. If you don't cook much it's less of an issue.

Thank you Kas, I have searched other threads, but have not found anything with exact answers pointing to what I am trying to figure out. I live in Texas on a slab foundation-no basement, no crawl space. If I go thru the garage, I could go to the roof which is a pyramid shaped metal roof with a large skylight center. Not sure this would be a viable option. Outside wall would be approximately 50ish feet away as it is a 4 car garage. I think that is a long way to vent and not an easy straight shot either, but again, this is not something I am educated on. I am very thankful for any insight.

Sounds like a challenging problem (but I get the sense you already understand that). Sometimes people get frustrated when the recommendation is to bring in a professional but in your case it sounds like that's what is needed because whatever advice offered will need to be specific to your house (slab foundation, 2nd story, long duct runs, metal roof). Bring in an HVAC specialist if your general contractor doesn't have ideas before you start making too many compromises (such as choosing a recirculating hood).

Is the garage 4 x 1 or 2 x 2? In other words, can you get into the garage and take a turn to a back wall? Or a turn to a point under the sheet metal part of the roof?

Penetrating into the garage allows room for a silencer, which in concert with using a roof or wall exterior blower, will greatly reduce the noise at the cook's position in front of the range.

If the only garage impediment is a long duct run, then that can be accommodated with a blower having a suitable fan curve for the duct loss (which may, itself not dominate all the pressure losses impacting the ventilation system).

I claim no expertise in interfacing a duct assembly with a metal roof, although such roofs usually have to accommodate various penetrations such as DWV, furnace chimneys, fireplace chimneys, and roof mounted hood ventilation fans or ventilation duct caps for hoods with internal blowers.

The suggestion to bring in a HVAC specialist is a good one, as would discussing the issue with a metal roof contractor, but if you want to hold off for a bit, then I think we need a floor plan and a photo of the roof. The floor plan can be crude (even a scanned hand drawing or PowerPoint sketch) so that we can place the location of the range wall in the context of the house.

One last nosy question: Are you planning to gut the kitchen, or just replace a range?

kas

I am gutting the kitchen. It is the oddest kitchen ever. Or close to it. Currently there are 2 30" wall mounted Kitchen Aid ovens. WITH 2 WALL MOUNTED MICROWAVES ABOVE THE OVENS!! Who puts in 2 microwaves? Anyhow, the old SubZero is going away and so is the Jennair cooktop cabinets etc. I think I will have to consult someone as I don't want to make a mistake and I want quality appliances. I have a family of 5 and another 30 in Dallas so I do cook a lot!!

Start by posting your floor plan on the kitchen forum. They are some of the best when it comes to layout

You definitely want to plan the ducting from the beginning because it can impact what needs to get demolished and is one of the first things that will need to get installed once construction starts. If you are cooking for 30+ people with high-end appliances you'll want to get the ventilation right. You may need to make some compromises such as a soffit in a place you'd rather not have it; the range in a slightly different location than your first choice; or a box around the duct in an upstairs room so that you can get access to the attic and roof. I think you would be very, very unhappy with a recirculating ("ductless") hood.

In addition to the hood and ducting you'll need to look at Make Up Air (which in Dallas I think will require some planning since you have cold and hot/humid weather at different times of the year so pulling in outside air without heating/cooling it will be undesirable). You may also want to look into an external or remote blower to keep the noise down in the kitchen.

Doing it right can be complex and means you need to hire someone who knows what they are doing but the results will be worth it.

I think enough people are involved to justify more than one microwave oven, but none of these ovens should be blocking the venting of cooking effluent.