We are interested in maintaining healthy indoor air quality, and are seeking advice as to how to do this.

We live in a 990 sq ft condo on the first floor of a 2 story building in the SF Bay Area. We live inland in a dry, warm (summers can get hot and smokey) climate.

We are doing a kitchen remodel, and are replacing our gas range with an electric one (with induction cooktop). New range will be 30” (would love a 24”, but can’t find an induction range this small).
Range is located along an interior wall. Currently, we have a recirculating vent above our stove. When we cook, we open the kitchen window and turn on the kitchen ceiling fan.

We have no other combustion appliances in our unit. We have radiant baseboard heating. Boilers for this are located at end of building in an outside shed. Water boiler is also located here. Also, we do not have A/C and rely on passive cooling (open windows at night, close them during the day; extensive use of multiple ceilings fans).

We cook with minimal oil, and eat mostly vegetables. For dinner, during Salmon season, I do like to make a salmon dish that involves searing at high temperature. And I will, very occasionally, cook a steak for supper.

Our current plan is to run a duct from the hood, along a soffit to the exterior, and then up through the roof overhang. The route involves 3 90 degree bends, 25 vertical feet, and 8 lateral feet. Duct diameter is likely to be limited to 6” (could pursue larger but would likely require an engineering plan).

We are hoping that opening the kitchen window will be sufficient for make up air, as adding an additional wall penetration would also likely require an engineering plan.

What vent hood specs would be sufficient for our plan? Do you recommend that we pursue a larger duct? Do we need to consider a makeup air unit?

Thank you in advance for your thoughts!