Anyone have any code refference to clearences between the Oven cooktop and the exhaust hood?
Hi Tim;
This was discussed some time ago.
http://www.nachi.org/forum/showthread.php?t=2924&highlight=exhaust+hoods
I just bought one from Sears myself and the minimum mounting height off the stove was 30" to the top. 15" above the stove , no way for me.
I had a custom built cabinet built at 15" in height in lieu of 18" and removed the other one.
The microwave hangs 1" below the 30" wall cabinets and puts it about 16" above the stove. Much better.
Hope this helps.
Marcel 
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Hello Tim, each manufacturer has specifications based on the BTU output of the stove and other factors, the link in the previous post has some good info.
Is there a maximum clearance? Meaning, how high can the exhaust fan be installed and still be of any benefit? I know it probably depends on the fan. The reason I am asking, is I had a fan last week that was installed 6 feet above the cooking surface. I called it out as being too high to be of any benefit. The buyer agreed. (no cabinets installed above stove, combo light fixture/fan was installed at ceiling height) I could not find any info on maximum installation heights from manufacturers.
GE requires the cabinet (above the stove) to be 30" minimum from stove top with no maximum level stated for the hood. (see page 9).
http://products.geappliances.com/ProdContent/Dispatcher?REQUEST=ITEMID&itemid=003679600
If your intuition tells you that the hood is too high, recommend a lower installation. Pretty simple.
David;
These are the same requirements that Sears put out. 30" to top of the micro-wave which means you need a 15" cabinet, mine was 18" which would have met the criteria, but did not fly in my book. Way to close to the stove top. Remember these quotes from the manufacturer is maximum or minimum, almost like the IRC isn’t it.
Marcel 
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Can’t recall a code, must have been manufacturers instructions. We did allot of combination microwave/range hood installs in a condo upgrade project.
Always had to have the upper cabinet shortened up 3-4" and a separate circuit run and receptacle installed in the upper cabinet…
I’m thinking it was 16-18" above stove or cooktop. These were maytag products.
Regards,
Bill
If the cabinet the range hood hangs off of above the stove is combustible, the OBC requires the cabinets to be no lower than 23 5/8ths" from the top of the stove, as long as the metal range hood is in place and attached to the underside. (section 9.10.21.2 (2)(b)(ii)
Just fyi.
Ross
This link shows that the average height of an above stove micro wave unit is about 16" +/- in height.
The standard counter top is 36". The top of standard cabinet wall hung heights is 84". Upper cabinets are 30" high. That leaves 18" between the countertop or stove top to the underside of the cabinets.
Microwaves should not hang down more than an inch below the bottom of the wall cabinets.
Now, let’s do the Math.
Range height= 36"
Counter to bottom of upper cabinets= 18"
Upper Cabinet height = 30"
Microwave height = 16"
Now the math. 36" + 18" + 30" = 7’0" -15"=69"-16"=53"-36"= 17"
Well finally, the magic dimension, 17" above the Range top or 4’-5" above the floor.
Wfuee, that was hard work.
Marcel 
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