Is makeup air neccessary for a 600 CFM hood?
I'm in the middle of renovating my new old(1982) house. The plan is to put a 42" semi-pro (monogram/viking/...) cooktop and matching hood in/above my kitchen island.
That was the plan until I had an HVAC guy over for an estimate on a new furnace. He saw the demo in the kitchen and told me to make sure to keep under 300 CFM on the hood to avoid pulling the furnace exhaust back into the house.
From what I have found I see three options:
1. Ignore the HVAC guy, do it anyway and see what happens
2. Install a makeup air system. (heated/unheated)
3. Skip the hood and go with a DIY downdraft solution.
Each seems to have it's negative:
1. Dangerous? Against Code?
2. Heated looks to cost $2000+ unless I rig something up myself. Unheated, Minnesota winters, how quick would that cool the house down? How about the rooms closest to the vent?
3. Bad reviews on most of the downdraft products being sold. I'm not sure if my DIY solution would be any better or worse.
I'm planning on putting a breakfast bar counter behind the cooktop. The half wall to support the breakfast bar could also hold ducts. I could install two ducts with vents behind the cooktop. The ducts would go down to the utility room directly below and each duct would attach to a 200 CFM blower motor and be exhausted out the side of the house. I would setup each blower on a separate switch. This way I could use 200 CFM on the left or right side without concern or gamble and go 400 over the whole surface.