Range hoods (appliances, lawyers, house)

[nrk32t]

Are range hoods required by NC state code? I have an electric cooktop and although I was reading the mechanical codes, I didn't understand it. Can you put a roof type exhaust that is on the ceiling only?

[BoBromhal]

since I know you can use a downdraft, a hood cannot be the code.

[take57]

I suspect you would have to have some manner of venting specific to the use of an installed cooktop. I've got a electric induction cooktop and while the surface doesn't get hot, rest assured I can still burn food and smoke the place up

[Poggly Woggly]

Originally Posted by nrk32t

Are range hoods required by NC state code? I have an electric cooktop and although I was reading the mechanical codes, I didn't understand it. Can you put a roof type exhaust that is on the ceiling only?

That's a good question My range hood is unvented to the exterior. When you turn the fan on it exhausts right into your face. What's the good of that. I'm thinking about removing the hood and installing a microwave shelf in it's place

[take57]

As we say in the broadcasting business, LET'S CHECK THE TAPE...

From 2012 NC Mechanical Code:

507.2.1 Type I hoods. Type I hoods shall be installed where cooking appliances
produce grease or smoke. Type I hoods shall be installed over heavy-duty and extraheavy-duty
cooking appliances. Type I hoods shall be installed over light-duty cooking
appliances and medium-duty cooking appliances that produce grease or smoke.
507.2.2 Type II hoods. Type II hoods shall be installed above dishwashers and
light-duty appliances and medium-duty appliances that produce heat or moisture and
do not produce grease or smoke, except where the heat and moisture loads from
such appliances are incorporated into the HVAC system design or into the design of
a separate removal system. Type II hoods shall be installed above all light-duty appliances and medium-duty appliances that produce products of combustion and do
not produce grease or smoke. Spaces containing cooking appliances that do not
require Type II hoods shall be ventilated in accordance with Section 403.3.
Exceptions:
1. Under-counter-type commercial dishwashing machines.
2. AType II hood is not required for dishwashers and potwashers that are provided
with heat and water vapor exhaust systems that are supplied by the appliance
manufacturer and are installed in accordance with the manufacturer’s instructions.
3. Light-duty electric convection, bread, retherm or microwave ovens. The additional
heat and moisture loads generated by such appliances shall be accounted for in the
design of the HVAC system.
4. A Type II hood is not required for the following electrically heated appliances:
toasters, steam tables, popcorn poppers, hot dog cookers, coffee makers, rice
cookers, egg cookers, holding/warming ovens. The additional heat and moisture
loads generated by such appliances shall be accounted for in the design of the HVAC
system.
5. Low-temperature commercial chemical-type dishwashers.

Here a link about Oregon's Mech code:
http://www.cbs.state.or.us/bcd/progr...ce_dry-out.pdf
The commentary is much clearer, albeit older and not NC specific although these things tend to all be derived from national standards.

Happy venting...

[pdocstr]

"shall be" seems like really wimpy wording, are they saying "required and will fail if not", or "maybe kinda sort depends on who ya ask?"?

Someone put some balls on whoever writes these "codes".

[take57]

Originally Posted by pdocstr

"shall be" seems like really wimpy wording, are they saying "required and will fail if not", or "maybe kinda sort depends on who ya ask?"?

Someone put some balls on whoever writes these "codes".

Gotta keep the American Bar Association in clover. There's no money in interpreting the term "required"...

[pdocstr]

Originally Posted by take57

Gotta keep the American Bar Association in clover. There's no money in interpreting the term "required"...

Touché and good point!

[MOD]

In terms of building codes, "shall be" is a requirement. There is no need for lawyers (or anyone else) to interpret that part.

Also, take57 made the mistake of quoting the full mechanical code, which isn't what you should be looking at for a residence. The appropriate document is the "abridged for residential" version, which says:

SECTION 505
DOMESTIC KITCHEN EXHAUST EQUIPMENT
505.1 Domestic systems. Where domestic range hoods and
domestic appliances equipped with downdraft exhaust are
located within dwelling units, such hoods and appliances shall
discharge to the outdoors through sheet metal ducts constructed
of galvanized steel, stainless steel, aluminum or copper.
Such ducts shall have smooth inner walls and shall be air
tight and equipped with a backdraft damper.
Exceptions:
1. Where installed in accordance with the manufacturer’s
installation instructions and where mechanical
or natural ventilation is otherwise provided in accordance
with Chapter 4, listed and labeled ductless
range hoods shall not be required to discharge to the
outdoors.
2. Ducts for domestic kitchen cooking appliances
equipped with downdraft 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:
2.1. The duct shall be installed under a concrete
slab poured on grade.
2.2. The underfloor trench in which the duct is installed
shall be completely backfilled with
sand or gravel.
2.3. The PVC duct shall extend not more than 2
inches (50 mm) above the indoor concrete
floor surface.
2.4. The PVC duct shall extend not more than 2
inches (50 mm) above grade outside of the
building.
2.5. The PVC ducts shall be solvent cemented.
505.2 Makeup air required. Exhaust hood systems capable of
exhausting in excess of 400 cfm (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.

Note that nowhere does it require a kitchen vent, it only discusses the requirements if they are installed.

for further clarification, you can check the fuel gas code (again, residential version) for any requirements that may apply to gas stoves only. There we find:

501.8 Appliances not required to be vented. The following
appliances shall not be required to be vented.
1. Ranges.
2. Built-in domestic cooking units listed and marked for
optional venting.
3. Hot plates and laundry stoves.
4. Type 1 clothes dryers (Type 1 clothes dryers shall be
exhausted in accordance with the requirements of Section
614).
5. A single booster-type automatic instantaneous water
heater, where designed and used solely for the sanitizing
rinse requirements of a dishwashing machine, provided
that the heater is installed in a commercial
kitchen having a mechanical exhaust system. Where
installed in this manner, the draft hood, if required,
shall be in place and unaltered and the draft hood outlet
shall be not less than 36 inches (914 mm) vertically and
6 inches (152 mm) horizontally from any surface other
than the heater.
6. Refrigerators.
7. Counter appliances.
8. Room heaters listed for unvented use.
9. Direct-fired makeup air heaters.
10. Other appliances listed for unvented use and not provided
with flue collars.
11. Specialized appliances of limited input such as laboratory
burners and gas lights.
Where the appliances listed in Items 5 through 11 above are
installed so that the aggregate input rating exceeds 20 British
thermal units (Btu) per hour per cubic feet (207watts perm3) of
volume of the room or space in which such appliances are
installed, one or more shall be provided with venting systems
or other approved means for conveying the vent gases to the
outdoor atmosphere so that the aggregate input rating of the
remaining unvented appliances does not exceed 20 Btu per
hour per cubic foot (207 watts per m3). Where the room or
space in which the appliance is installed is directly connected
to another room or space by a doorway, archway or other opening
of comparable size that cannot be closed, the volume of
such adjacent room or space shall be permitted to be included
in the calculations.

This is not the entirety of relevant codes, but it covers what was asked- well, other than that I have no idea what a "roof type exhaust that is on the ceiling only" is. All said, I think a vent is a good idea regardless. Especially in a well sealed house.

[pdocstr]

Originally Posted by MOD

In terms of building codes, "shall be" is a requirement. There is no need for lawyers (or anyone else) to interpret that part.

So where is it written that lack of compliance with the "shall be" clauses will definitively result in legal penalty? Because without that, the interpretations will always be floating in the wind.

If a house is built in such a way that does not meet the condition stated in "shall be" above, who takes the fall? The builder? The inspector who fails to find the fault? The homeowner who sells the house to someone else without ever having been aware of the shall be?