Make-Up Air for Stove

[DogwoodTales]

ome of you may recall my thread from a couple years ago about venting a kitchen stove with a higher CFM unit and make-up air.
Well I'm finally getting around to this! (life is busy for this family man)
I will be installing a Zephyr 600cfm unit with a make-up air kit.

My question to you here is where do you think is the best place for the make-up air to enter the kitchen?
I have a small kitchen and I have 3 options for where the make-up air can enter the kitchen (see image below or click here for link).

Option A - install make-up air unit directly behind the stove and install a wide/narrow vent to direct the make-up air to the top of the stove.
Option B - install make-up air unit directly behind the stove and just let it find it's way behind and around the stove
Option C - install the make-up air at the basement level and direct the make-up air to a vent in the toe-kick of the kitchen cabinet.

Option A seems like it will reduce the efficiency of the make-up air.
Option B might cause the range to work harder to stay hot.
Option C offers cross ventilation, but it is more work and sacrifices some storage space we have above cabinets along that wall in the basement.
I'm kinda leaning towards option C.

So what would you do?
thanks for your replies!

[Roly]

Does it get cold in your location ? With option C what would be the outside air temperature in the winter ?  Seems like 10 degree air across your feet would not be a good idea.  Roly

[DogwoodTales]

Does it get cold in your location ? With option C what would be the outside air temperature in the winter ?  Seems like 10 degree air across your feet would not be a good idea.  Roly

Good point. Yes, it does get cold in Cincinnati. I could instead have this feed into the air duct that feeds the kitchen with back draft prevention. That will also be next to where this would go otherwise. But that doesn't help if the heat is not on at the moment.
Also, I don't think the make-up air kicks on at the lowest setting. So we could just use that when the extra heat is welcome while still venting out the cooking grease and gases.

I don't know if the cross ventilation is necessary. But it does seem like the best option for efficiency.
Perhaps option B would be best.

[daddo]

Unclear as to what type of makeup air system you are using. Is this a duct from outside air into an existing return duct? Then your return system will be your makeup air- there won't be any location other than your existing ducting.
You must install a filtered duct to the outside in a location where it won't pick up obnoxious odors, chemicals, exhausts, or be covered by snow or rain.
At 600 cfm, you'll be adding an equivalent 1.5 ton conditioning load to the house. It's like placing a fan in an open window.


How tight is your house?

[Roly]

   
The drawing was there before, now it has disappeared.  Roly

[DogwoodTales]

Unclear as to what type of makeup air system you are using. Is this a duct from outside air into an existing return duct?  Then your return system will be your makeup air- there won't be any location other than your existing ducting.
You must install a filtered duct to the outside in a location where it won't pick up obnoxious odors, chemicals, exhausts, or be covered by snow or rain.
At 600 cfm, you'll be adding an equivalent 1.5 ton conditioning load to the house.  It's like placing a fan in an open window.


How tight is your house?

I have an older house and it's not tight, but of course I don't want to draw air in from outside all over the house and through who knows what crevices drawing into the house dust etc from inside the walls (not to mention the potential CO from the furnace and hot water heater)  and thus put the re-conditioning load onto the house hvac that you mention. 

My current hvac does not have any sort of outside air exchange. This make-up would be independent and at least screened, but I am considering including some sort of filter. 
It will be clear of the potential hazards you mention.

The make-up unit only kicks on when the range hood is turned up to medium or high positions, so it's not going to draw air in unless the range demands it and even then the exchange would be from the point the make-up air enters the kitchen to the range hood with the range somewhere in between with little effect to the rest of the air conditioning in the house.

Here is the link to the make-up air unit I'm planning on getting.
https://store.zephyronline.com/en/make-u...al/mua006a

After looking at that thing again, I realized that I might have to install this at the basement level do to the mechanisms involved. I don't think I'll have room behind the stove for all that. But I can still direct the make-up air to around and/or behind the stove as in option A or B and not across the kitchen as in option C.

[DogwoodTales]

   
The drawing was there before, now it has disappeared.  Roly

thanks
I think I fixed the image. At any rate, the link should still work.

[daddo]

I wouldn't install it in a room where doors can be closed and block the flow. Installing it in other rooms/section of the house and your still letting infiltration in to all the rooms in that line of flow. You'd do better to install it well filtered (merv 10) and to the return duct- - you will get no more infiltration into the house this way than wherever you install it.

But, it your install. I thought you wanted experienced advice.

[blackhat]

I agree that it should be tied into the return duct. I would also interlock it to start the furnace fan when its activated.

[DogwoodTales]

Say what daddo? Of course I want experienced advice!

Regardless of the point of intake, the make-up AIR will NOT be blocked behind closed doors. Instead it will be readily directed by air ducts into the kitchen to somewhere near the range.

Such a direct system (so-to speak) like this is one way I’m finding some pros on line do it and tying into the return duct is a way some other pros are doing it. Obviously both methods work, but it seems to me that directing the make-up air into the hvac demands the hvac to condition that air before it is introduced into the house.  Plus running the whole house fan in the winter time without the heat turned on will cool down the house  - I guess that will then cause the heat to kick on, so maybe a mute point lol.

It just seems to me that a straight exchange between the make-up air and the exhaust would be more efficient with much less impact on the house HVAC. No?