Ask in the appliance forum.

And can I say I told you so?. lol ;)

Don't you have a kitchen plan/layout with specs for cabinets and appliances? You can't build something if you don't know what your end product is ...

I went with a 48"Modern-aire hood in a custom Rustic Brass finish. They have a 12 week lead time.

What brand is your gas range? Many have "matching" hoods available.

Your specs need to be complete. Whoever sold you the range, they should know the CFM requirements.

At this point in your build, copies of all appliance and plumbing specs should be handed over to plumbing, HVAC, electrician and cabinet maker.

Your "plumber" is putting in your vent hood?

Post in the Kitchen forum as well as the Appliance forum, if you haven't already.

Do you have your kitchen/cabinet plan already? Do you have room for a 42" range hood, for a larger capture area?

The plumbing/HVAC crew is doing the vent

The plumbing crew should be different from the HVAC crew. They are two different specialties. I had the HVAC crew put in my vent.

I've seen mechanical contractors who do plumbing, hvac and electrical but it's rare and they are usually different crews.

Since you have never cooked with a proper vent hood, is it possible you have done enough research on going with induction instead of gas? Most who spend time with both prefer induction.

If you stay under 400 cfm, you don't need make up air provisions. For a gas cooktop of that size, the vent hood capture area will need to be well planned to do an adequate job under 400 cfm.

It's almost certain you will need to provide for a makeup air supply for your 36" gas range. This should have been specified and reviewed as part of your building plans.

Are you DIY?

Nooooo - def not DIY. I will stick with a hood below 400cfm so won’t need to worry about the makeup air issue, but thanks for mentioning that important point .

FYI Momma K, it's the range that determines how many CFM are required, not the homeowner : ) .

I think hood design (low and wide) could be more important than range cfm recommendations. That's rare enough to agree with above though.

Staying below 400 will avoid code mandated make up air but doesn't change physics. You still risk backdrafting other gas appliances like fireplace, water heater and furnace as well as attached garage air.

More of a preference for safer, healthier and more durable homes. By understanding make-up air, you better understand why burning anything inside is a dying building practice.

Cooktop ventilation is important, gas or not. You could have an oversized vent hood fan and still miss pollutants with insufficient hood capture area. Make-up air supply delivery location could also be more important than cfm number. With that said, I agree with sticking to manufacturer recommendations.