** Conditions **
Current Unit: KitchenAid 36" 400 CFM Single Blower 6" duct
New Unit: Kobe 36" 1100 CFM Dual Blower 8" duct
Cooking Stove: Whirlpool Gas total 15000BTU
Custom Wood Hood

We cook a lot, mainly Chinese food and many of them are high frame cooking. I have already checked the new unit will fit in the current custom wood hood.

Question #1: The old unit uses 6" duct and my new unit is 8" duct. I want to minimize my work and don't want to make the hole on the wall bigger. So I bought a duct reducer which will sits on the new range hood. It will reduce the duct size from 6" to 8". Do you think this will work in terms of airflow?

Question #2: The new unit has electrical components in the same room as 2 powerful blower. I was expecting the electrical components should be in isolated room. Is this ok? I am worry about how moisture and oil will damage the electrical components since they are all located in the same room.

Any suggestions and advice are appreciated.

 

#1: Reducing to a smaller size duct will reduce the airflow negating some of the benefit of your new hood.

#2: Yes, grease and other cooking deposits are probably not good for the controls. If the electronics are well sealed it shouldn't be a problem but I would be worried about grease & oil getting into the connectors.

 

Not only will it be degrading to air movement..... a reduction will be noisy.
Reducing the duct size is not something I'd recommend.