# Cooktop Vent Violation



## Gordon H. (Mar 11, 2018)

My sister In law had major flood damage to her home in Boca Raton. One of the items
we replaced was the cooktop on the center island in her kitchen. The original was a
GE Premier 36" cooktop with a Premier downdraft vent.  We replaced the cooktop with
a GE Monogram 36" unit and a new Premier 36" downdraft vent (GE no longer makes
a downdraft vent in the Monogram series).  Now the contractor is telling her, the
Inspector states the new cooktop/vent is in some kind of code violation and we should
replace the new cooktop with the original Premier style unit.  Both the Monogram and
Premier units are 36",  5 burner, the largest being 18,000 BTU.  The total Monogram
output is 62,000 BTUs,  the Premier is 57,000 BTUs.  The vent is rated at 370 CFM.
I checked the Florida codes and the only thing I could find was a 100 CFM requirement
for downdraft vents.

Could someone advise me of what code requirement(s) we are in violation of, and a
possible solution ( other than another $1,000 on a new cooktop ) ?

Many thanks.


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## cda (Mar 11, 2018)

You need to ask directly and nicely to the inspector,,,

The code book, edition and the sections that are being cited for the violation.

Then, get a copy of those sections from the city so you can see what they say
and if they are being applied correctly.

Plus publish what code and sections they are here, so we can review them also.

Was the replacement of the appliances part of the work that was permitted??


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## cda (Mar 11, 2018)

Welcome also


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## Gordon H. (Mar 11, 2018)

Thank you for your reply, I will get that info and post it here.
I'm not sure what you are asking:
_Was the replace part of the work that was permitted??_


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## cda (Mar 11, 2018)

Was the replacement of the cooktop, told "up front" to the city and permitted
if needed??


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## Gordon H. (Mar 11, 2018)

This is a vacation home that suffered a burst water supply to one of the bathroom toilets.
No one was there at the time, and the flooding went unnoticed for several days.  The
damage was extensive.  Floors, walls, plumbing fixtures, cabinets in addition to the
cooktop/vent, were replaced.   A permit was obtained for the work.  As far as the
specifics of the cooktop/vent, I'm not sure.


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## cda (Mar 11, 2018)

Get the code sections and post them,,,

Should have said also, if they cannot produce them, than there is no violation.

Have you seen the written violation?? Should say what the problem is.


Plus makes no sense to tell an owner to install the old stuff???  The violation should say this is wrong fix it, or remove the cooktop.

Inspector may have suggested a fix would be to install the old one??


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## steveray (Mar 12, 2018)

Maybe makeup air for the new hood? >400cfm?


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## mark handler (Mar 12, 2018)

*Range Hood Fan Size*
The basic rule of thumb when determining the fan size of a range hood is that it should move a minimum of 100 CFM of air for every 12” of stove width. So if you have a 30” wide stove, you would need a range hood with a fan that moves at least 250 CFM of air:
2.5′ wide stove x 100 = 250 CFM minimum range hood fan size
*Room Size*
You should also take into account the size of your kitchen in cubic feet when calculating the size range hood fan needed, since a larger kitchen needs more venting to clear the air than a smaller room.
A range hood should be able to exchange the air in the kitchen at least 15 times per hour or every four minutes. For example, if your kitchen is 16’ long x 16’ wide with an 8’ ceiling, it would contain 2,048 cubic feet of space:
16’ wide x 16’ long x 8’ high = 2,048 cubic feet
To find the fan needed for your size kitchen, multiply the number of cubic feet in the room by the number of air exchanges (15), then divide by the number of minutes in an hour (60).
For example:
2,048 cubic foot room x 15 air exchanges = 30,720 cubic feet moved per hour
30,720 cubic feet ÷ 60 minutes = 512 CFM range hood fan or higher
An easier way to make the calculation above is to divide the number of cubic in the room by four minutes:
2,048 cubic foot room ÷ 4 minutes = 512 CFM range hood fan or higher
*Gas Stove*
The burners on a gas stove produce a lot more heat than those on an electric range, so a kitchen with a gas stove requires a larger capacity range hood vent fan.
To calculate the fan sized needed for a gas stove, combine the BTU ratings for all the burners on your stove (gas burners range from 5,000-15,000 BTU per burner, with an average of about 10,000 BTU per burner and a total of about 40,000 for a standard 4-burner stove), then divide by 100 to find the minimum CFM needed for a kitchen with a gas stove. For example:
40,000 BTU gas stove ÷ 100 = 400 CFM range hood fan or higher
*Range Hood Ductwork*
The size, shape, length, turns, and cap on the range hood ductwork adds resistance which reduces the amount of air the vent fan can move, requiring additional CFM for the fan.
When using smooth, round 8” diameter, metal pipe, add one CFM per foot of pipe, plus 25 CFM for each elbow, and 40 CFM for a roof cap.
For example, if the vent pipe was 10’ long with two elbows and a roof cap, you would need to add 100 CFM more to the fan size ratings above:
10 pipe length + 25 elbow + 25 elbow + 40 roof cap = 100 CFM
Calculating Range Hood CFM Vent Fan Size
To make the final calculation, take the larger of the CFM rating for stove width, room size, and stove burner. Add the additional CFMs needed for the ductwork to arrive at the minimum CFM range hood to buy.
In the examples used above, if your kitchen has a 30” stove (250 CFM minimum) in a 16’ x 16’ x 8’ room (512 CFM minimum), and a 40,000 BTU gas stove (400 CFM minimum) you would want a fan rated at 512 CFM or higher, plus 100 CFM for the ductwork for a total of 612 CFM or more.
The burners on a gas stove produce a lot more heat than those on an electric range, so a kitchen with a gas stove requires a larger capacity range hood vent fan. 
To calculate the fan sized needed for a gas stove, combine the BTU ratings for all the burners on your stove (gas burners range from 5,000-15,000 BTU per burner, with an average of about 10,000 BTU per burner and a total of about 40,000 for a standard 4-burner stove), then divide by 100 to find the minimum CFM needed for a kitchen with a gas stove. For example:
40,000 BTU gas stove ÷ 100 = 400 CFM range hood fan or higher
*Range Hood Ductwork*
The size, shape, length, turns, and cap on the range hood ductwork adds resistance which reduces the amount of air the vent fan can move, requiring additional CFM for the fan.
When using smooth, round 8” diameter, metal pipe, add one CFM per foot of pipe, plus 25 CFM for each elbow, and 40 CFM for a roof cap.
For example, if the vent pipe was 10’ long with two elbows and a roof cap, you would need to add 100 CFM more to the fan size ratings above:
10 pipe length + 25 elbow + 25 elbow + 40 roof cap = 100 CFM
Calculating Range Hood CFM Vent Fan Size
To make the final calculation, take the larger of the CFM rating for stove width, room size, and stove burner. Add the additional CFMs needed for the ductwork to arrive at the minimum CFM range hood to buy.
In the examples used above, if your kitchen has a 30” stove (250 CFM minimum) in a 16’ x 16’ x 8’ room (512 CFM minimum), and a 40,000 BTU gas stove (400 CFM minimum) you would want a fan rated at 512 CFM or higher, plus 100 CFM for the ductwork for a total of 612 CFM or more.
https://www.todayshomeowner.com/how-to-calculate-kitchen-range-hood-fan-size/


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## cda (Mar 12, 2018)

So how about a downdraft??

Per manufacture or does IRC address it??


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## mark handler (Mar 12, 2018)

IRC  2012
M1503.2 Duct Material 
Single-wall ducts serving range hoods shall be constructed of galvanized steel, stainless steel or copper. 
Exception: Ducts for domestic kitchen cooking appliances equipped with down-draft exhaust systems shall be permitted to be constructed of schedule 40 PVC pipe and fittings provided that the installation complies with all of the following: 
1. The duct is installed under a concrete slab poured on grade; 
2. The underfloor trench in which the duct is installed is completely backfilled with sand or gravel; 
3. The PVC duct extends not more than 1 inch (25 mm) above the indoor concrete floor surface; 
4. The PVC duct extends not more than 1 inch (25 mm) above grade outside of the building; and 
5. The PVC ducts are solvent cemented. 
M1503.3 Kitchen Exhaust Rates

Where domestic kitchen cooking appliances are equipped with ducted range hoods or down-draft exhaust systems, the fans shall be sized in accordance with Section M1507.4.

M1507.4 Local Exhaust Rates 
Local exhaust systems shall be designed to have the capacity to exhaust the minimum air flow rate determined in accordance with Table M1507.4. 
TABLE M1507.4   EXHAUST RATES --Kitchens  100 cfm intermittent or 25 cfm continuous

M1503.4 Makeup Air Required 
Exhaust hood systems capable of exhausting in excess of 400 cubic feet per minute (0.19 m3/s) shall be provided with makeup air at a rate approximately equal to the exhaust air rate. Such makeup air systems shall be equipped with a means of closure and shall be automatically controlled to start and operate simultaneously with the exhaust system.


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## cda (Mar 12, 2018)

Never saw a downdraft install, not my area,

But where is the exhaust fan at normally??

Built into the appliance

Or some where in the exhaust duct system?


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## Msradell (Mar 12, 2018)

Everybody's missing the point that the inspector just wants the old cooktop installed. It was still 36"and had a downdraft fan so those items are not issues. The difference is new one is a little higher BTU but??

Answer you when have suggested the OP needs to get the code reference that the inspector is referring to when he saying that it doesn't meet code.


cda said:


> Never saw a downdraft install, not my area,
> But where is the exhaust fan at normally??
> Built into the appliance
> Or some where in the exhaust duct system?


They are normally built into the appliance although there are some that mount in back of the cooktop. Most of them are fixed location although some of the fancier ones go up and down automatically.

The fan for them is either under the cabinet or in the basement or other remote location. They still sent directly to the outside like any other type range hood would.


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## Gordon H. (Mar 24, 2018)

The house is built on a slab, the downdraft is vented via pvc under the slab to the outdoors. The ducting is to code and hasn't been changed since the original downdraft. The original cooktop was a 36" gas unit, the new cooktop is a 36" gas unit. The old and new downdrafts were/are 36"
The CFM of the new downdraft is 370.
*M1507.4Local exhaust rates.*
Local exhaust systems shall be designed to have the capacity to exhaust the minimum air flow rate determined in accordance with Table M1507.4.
Table M1507.4 states:
Kitchens 100 cfm intermittent or 25 cfm continuous

*I see no reason why this installation isn't up to code.*
...still waiting to hear from the inspector


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## Gordon H. (Mar 24, 2018)

Here is the downdraft install manual for anyone who wants to see the fan location, exhaust location etc.
http://products.geappliances.com/Ma...RequestType=PDF&Name=49-80777-1_HIRESr1s0.pdf


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## cda (Mar 24, 2018)

So what code section did the inspector say it was in violation of??

And what was the specfic violation/ problem?


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## Gordon H. (Mar 24, 2018)

Still waiting to hear from the inspector as I stated above


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## cda (Mar 24, 2018)

Gordon H. said:


> Still waiting to hear from the inspector as I stated above




Missed that

Just let us know


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## Gordon H. (May 2, 2018)

It's been a while and this still hasn't been resolved but I have been having communication with the inspector.
He replied:
_My decision is in accordance with the hood manufacturer’s installation manual. Code reference FBCR-M1307.1._ 

M1307.1 is about as vague and general as it gets:
_Installation of appliances shall conform to the conditions of their listing and label and the manufacturer’s installation instructions. The manufacturer’s operating and installation instructions shall remain attached to the appliance._

I pressed him to be a little more specific, and today I finally received a definitive answer:
_This hood shall not be used with an open flame cooktop as per manufacturer manual._

This is where it get's interesting. I have read through both the installation and user manuals so many times, I can recite it from memory...nowhere in either manual does it state anything even remotely about not being used with an open flame cooktop. As a matter of fact, the install manual states the downdraft vent and cooktop can share the same electrical outlet if used with a *Monogram gas cooktop* (the cooktop we are using with it).

I don't know if I mentioned it, but this is my sister-in-law's vacation home in Boca and we are in NY so I haven't been physically able to view the installation (only some pictures) but here's what I think may be happening:
Either:
1. The GC bought a different downdraft vent than the one we spec'd out (we will check his invoice tomorrow but the pictures I have seen look like its the correct unit).
or
2. The inspector is looking at the wrong manual - the original downdraft vent was a POS, the manual may have still been around somewhere and possibly that is what he was looking at.

I can't think of any other explanation.


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## cda (May 3, 2018)

Getting closer!!!


Was the old cooktop open flame??


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## Gordon H. (May 3, 2018)

cda said:


> Getting closer!!!
> 
> 
> Was the old cooktop open flame??


Yes, it was a GE Premier 36" Gas Cooktop, it was already in place when they bought the house so it may very well have been installed without a permit.


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## cda (May 3, 2018)

Gordon H. said:


> Yes, it was a GE Premier 36" Gas Cooktop, it was already in place when they bought the house so it may very well have been installed without a permit.




My question is

“”Now the contractor is telling her, the
Inspector states the new cooktop/vent is in some kind of code violation and we should
replace the new cooktop with the original Premier style unit. “”


Both open flame devices

So is the inspector changing the violation

Or misunderstanding of original violation??


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## cda (May 3, 2018)

So do an online search for the install and specs on the new vent

See what it says

Maybe post a link to it


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## ADAguy (May 3, 2018)

Has the code or manufacturers manual changed since the original cooktop was installed?
Where does the vent daylight too, is it below the finish floor?
How is water prevented from entering from the outside?

MH, thank you for an excellent breakdown of the calculations.


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## Gordon H. (May 3, 2018)

cda said:


> “”Now the contractor is telling her, the
> Inspector states the new cooktop/vent is in some kind of code violation and we should
> replace the new cooktop with the original Premier style unit. “”


That information was second hand, coming from the GC. It didn't make sense to me and is why I decided to go directly to the inspector.


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## Gordon H. (May 3, 2018)

ADAguy said:


> Has the code or manufacturers manual changed since the original cooktop was installed?
> Where does the vent daylight too, is it below the finish floor?
> How is water prevented from entering from the outside?


The cooktop/vent are located on an island in the kitchen. The duct runs under the slab (6" PVC) outside it turns vertically to about 18" above grade and is protected by a rain cap - this is all to code and is not what the inspector is finding fault with.
*His specific statement was that the vent was not to be used with an open flame gas cooktop per the manufacturer's installation manual.*
I suspect he may have grabbed the manual from the original vent (which was a cheap model). The previous homeowner left all the manuals in a kitchen drawer so it is a possibility.
I have contacted GE directly and they told me they will do a little research and give me a definitive answer shortly - I wanted to do this to be sure before I confronted the inspector again...I'm a mechanical engineer, and as you may know, we're a pretty anal bunch. Funny thing, my company holds a mechanical contractor's license in the State of Florida.
Vent Installer's Manual: http://products.geappliances.com/Ma...RequestType=PDF&Name=49-80777-1_HIRESr1s0.pdf
See pages 9 & 12 where installing the vent with the Monogram cooktop is specifically addressed.


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## conarb (May 3, 2018)

Gordon:
Why don't you detail your proposed installation on your company's letterhead and affix your mechanical engineer's stamp. Most reasonable AHJs will accept an engineer's detail over any prescriptive regulation.  Of course, if you are dealing with an unreasonable CBO this may not work.


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## Gordon H. (May 4, 2018)

GE Tech Support sent me a definitive Email that the downdraft vent is absolutely compatible with the Monogram cooktop so come Monday morning I will be sending the inspector an Email with all the evidence I have collected, I can't see how he will not sign off on the installation given the information I have...we will see.
BTW, Tech support also questioned where he was getting this information from and stated that he was mistaken.
Fingers crossed.


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## cda (May 5, 2018)

Yep

Let us know the next chapter


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## Gordon H. (Jun 15, 2018)

OK, it's been more than a month and I know you guys have been on pins and needles waiting to see how this turns out! LOL
I sent an Email to the Boca Building Dept. outlining the pertinent parts from the Installers Manual and the Email from GE Tech Support.
I received a reply from the Mechanical Inspector stating that he never saw this manual leading me to believe someone left the manual from the old downdraft laying around and that is what he based his determination on. We left the new (correct) manual with the downdraft and scheduled an appointment  for a new inspection, voila!   He approved the installation.
I thought we were done (silly me). It turns out that although every aspect of the rough mechanical permit has been approved, the FINAL mechanical permit has yet to be approved. I'm not sure if this is just a formality or if there is something more we need to do...I guess I'll be contacting the Building Dept. once again on Monday....it never ends!


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## Msradell (Jun 15, 2018)

Thanks for the update!


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## cda (Jun 16, 2018)

Gordon H. said:


> OK, it's been more than a month and I know you guys have been on pins and needles waiting to see how this turns out! LOL
> I sent an Email to the Boca Building Dept. outlining the pertinent parts from the Installers Manual and the Email from GE Tech Support.
> I received a reply from the Mechanical Inspector stating that he never saw this manual leading me to believe someone left the manual from the old downdraft laying around and that is what he based his determination on. We left the new (correct) manual with the downdraft and scheduled an appointment  for a new inspection, viola! he approved the installation.
> I thought we were done (silly me). It turns out that although every aspect of the rough mechanical permit has been approved, the FINAL mechanical permit has yet to be approved. I'm not sure if this is just a formality or if there is something more we need to do...I guess I'll be contacting the Building Dept. once again on Monday....it never ends!




Your government at work


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## Gregg Harris (Jul 3, 2018)

Gordon H. said:


> The cooktop/vent are located on an island in the kitchen. The duct runs under the slab (6" PVC) outside it turns vertically to about 18" above grade and is protected by a rain cap - this is all to code and is not what the inspector is finding fault with.
> *His specific statement was that the vent was not to be used with an open flame gas cooktop per the manufacturer's installation manual.*
> I suspect he may have grabbed the manual from the original vent (which was a cheap model). The previous homeowner left all the manuals in a kitchen drawer so it is a possibility.
> I have contacted GE directly and they told me they will do a little research and give me a definitive answer shortly - I wanted to do this to be sure before I confronted the inspector again...I'm a mechanical engineer, and as you may know, we're a pretty anal bunch. Funny thing, my company holds a mechanical contractor's license in the State of Florida.
> ...


 

My guess would be that he was referencing an open burner and not a sealed burner as your cook top is


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## ADAguy (Jul 12, 2018)

congratulations on your persistence.


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