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Range Hood for Gas Cooktop doesn't require Venting?!?

C

Chuck_M

REGISTERED
Joined
Feb 11, 2022
Messages
26
Location
Charleston, South Carolina
Hello Everyone,

Hope you guys can help me out on the building code.
I'm having a house built by a production builder and I asked why my Gas Cooktop has a recirculating range and not a vented one. Their answer was it isn't required in South Carolina. I've asked to pay for it to be vented and they refused. They've told me if you can show it is violating the code they will do it as right now the production builder sub contracts the HVAC and Kitchen Appliances to one supplier. So they just don't wait to pay for it if it's required.

I've been doing some digging for about two weeks and even reached out to the City's inspectors. They pointed me to the IRC 2015

Section M1503 Range Hoods

M1503.1 General

Range hoods shall discharge to the outdoors through a duct. The duct serving the hood shall have a smooth interior surface, shall be air tight, shall be equipped with a back-draft damper and shall be independent of all other exhaust systems. Ducts serving range hoods shall not terminate in an attic or crawl space or areas inside the building.
Exception: Where installed in accordance with the manufacturer's instructions, and where mechanical or natural ventilation is otherwise provided, listed and labeled ductless range hoods shall not be required to discharge to the outdoors.


They are considering a recirculating fan a mechanical ventilation... It's pushing the air back in the room... I find it kind of pointless, the carbon filters will catch some of the grease and bad smell but the Carbon Monoxide, Formaldehyde, and Moisture will just be recirculating in the room.



======> Question 1. Is a recirculating vent acceptable?



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
MINIMUM REQUIRED LOCAL EXHAUST RATES FOR ONE- AND TWO-FAMILY DWELLINGS
AREA TO BE
EXHAUSTED		EXHAUST RATES
Kitchens100 cfm intermittent or 25 cfm continuous
Bathrooms-Toilet
Rooms		Mechanical exhaust capacity of 50 cfm
intermittent or 20 cfm continuous
For SI: 1 cubic foot per minute = 0.0004719 m3/s.


======> Question 2. Does this mean it has to be exhausted to the outside?



Thank you in advance :)
 
Your answer is in Table M1507.4 for the kitchen exhaust requirement. Typically this is accomplished with a kitchen hood exhaust to the outside
 
Wait a second. On top of the two questions above.

Section M1503 Range Hoods

M1503.1 General

Range hoods shall discharge to the outdoors through a duct. The duct serving the hood shall have a smooth interior surface, shall be air tight, shall be equipped with a back-draft damper and shall be independent of all other exhaust systems. Ducts serving range hoods shall not terminate in an attic or crawl space or areas inside the building.
Exception: Where installed in accordance with the manufacturer's instructions, and where mechanical or natural ventilation is otherwise provided, listed and labeled ductless range hoods shall not be required to discharge to the outdoors.


============> M1507.4 is only for Mechanical Ventilation. So I don't know if the Kitchen item would apply. Would it?


Section M1507 Mechanical Ventilation

M1507.1 General

Where local exhaust or whole-house mechanical ventilation is provided, the equipment shall be designed in accordance with this section.
 
No access to the SC codes but there is no requirement for domestic cooking exhaust in the IRC except for open top broilers. Where it is provided it must be in accordance with 1503.3, which allows it to be ductless, which is recirculating. Apparently there is also not a requirement for them to satisfy a customer who is willing to pay for it.
 
Sifu said:
No access to the SC codes but there is no requirement for domestic cooking exhaust in the IRC except for open top broilers. Where it is provided it must be in accordance with 1503.3, which allows it to be ductless, which is recirculating. Apparently there is also not a requirement for them to satisfy a customer who is willing to pay for it.
Click to expand...
What about

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
MINIMUM REQUIRED LOCAL EXHAUST RATES FOR ONE- AND TWO-FAMILY DWELLINGS
AREA TO BE
EXHAUSTED		EXHAUST RATES
Kitchens100 cfm intermittent or 25 cfm continuous
Bathrooms-Toilet
Rooms		Mechanical exhaust capacity of 50 cfm
intermittent or 20 cfm continuous
For SI: 1 cubic foot per minute = 0.0004719 m3/s.
 
That is not a hood over a cooking appliance. That is an exhaust fan used in a local exhaust system. I imagine your house is not using a local exhaust system, rather it is using a whole house system. Either way, even if you are using a local exhaust system that is typically an exhaust fan in the ceiling somewhere in the kitchen, and at those minimum rates would have little effect on cooking. Typical range hoods are 200cfm intermittent to well in excess of 600cfm. The local exhaust you are referencing is not meant for cooking.
 
Thank you!

I'm trying to figure out a way to force them to put the range vent to exhaust outside. I'm shocked that it is legal to have an indoor fire without requiring external venting...
 
What about ASHRAE 62.2 ventilation requirements?
I see this a silver bullet. No?



Indoor Air Quality Understanding ASHRAE 62 2 | Springtime Builders

A blog focusing on building and construction in the Asheville area including information on energy efficiency, indoor air quality and passive solar design.
www.springtimebuilders.com www.springtimebuilders.com
 
Forcing isn't a good strategy. I would have concerns that they don't want to given that you wish to pay them. How confident in the FORCED work would you be anyway. If you are set on getting it then hire your own contractor and do it separately. Codes don't require the exhaust since the appliances are typically used sporadically and under constant supervision, unlike a furnace or water heater that needs dedicated venting. Compliance with ASHRAE isn't required in most places. Unless there is an amendment requiring it in your state code or local adoption then there is no requirement.
 
Recirculating residential range hoods are not permitted in California. Residential range hoods are not required in California. In my case the hood exhausts to the exterior and my wife opens a window or two whenever she is cooking on the stove. Her olfactory sensitivity is amazing.

I am with sifu on this. You should hire a contractor to install a vented hood. The builder might object but having no hood is not healthy.
 
Last edited:
Sifu said:
Forcing isn't a good strategy. I would have concerns that they don't want to given that you wish to pay them. How confident in the FORCED work would you be anyway. If you are set on getting it then hire your own contractor and do it separately. Codes don't require the exhaust since the appliances are typically used sporadically and under constant supervision, unlike a furnace or water heater that needs dedicated venting. Compliance with ASHRAE isn't required in most places. Unless there is an amendment requiring it in your state code or local adoption then there is no requirement.
Click to expand...

I got a quote for doing it now pre-drywall would be 600$.
Doing it AFTER would be 4000$.
 
ICE said:
Recirculating residential range hoods are not permitted in California.
Click to expand...
Do you have a reference for this, I have heard this before and I couldn't find it. I think this should be true and I would love to have some "ammo" to back this up. Thanks!
 
Joe.B said:
Do you have a reference for this, I have heard this before and I couldn't find it. I think this should be true and I would love to have some "ammo" to back this up. Thanks!
Click to expand...
I looked for it too but couldn't find it. I did not look at the Energy Code.
 
and

Pollutant Exposures from Natural Gas Cooking Burners: A Simulation-Based Assessment for Southern California (Technical Report) | OSTI.GOV

Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants and they are typically used without venting. The objective of this study is to quantify pollutant concentrations and occupant exposures resulting from NGCB use in California homes. A mass balance model...
www.osti.gov www.osti.gov
 
Had this issue come up not too long ago. This is what I found. We made them go directly to the outside.

2019 Building Energy Efficiency Standards Residential Compliance Manual 4.6.7 Local Exhaust

Local exhaust (sometimes called spot ventilation) has long been required for bathrooms and kitchens to remove moisture and odors at the source. Building codes have required an operable window or an exhaust fan in bathrooms for many years and have generally required kitchen exhaust either directly through a fan or indirectly through a recirculating range hood and an operable window. The Energy Standards recognize the limitations of these indirect methods of reducing moisture and odors and requires that these spaces be mechanically exhausted directly to outdoors, even if windows are present. Moisture condensation on indoor surfaces are a leading cause of mold and mildew in buildings. The occurrence of asthma is also associated with high interior relative humidity. Therefore, it is important to exhaust the excess moisture from bathing and cooking directly at the source.
 
Mr209Smith said:
Had this issue come up not too long ago. This is what I found. We made them go directly to the outside.

2019 Building Energy Efficiency Standards Residential Compliance Manual 4.6.7 Local Exhaust

Local exhaust (sometimes called spot ventilation) has long been required for bathrooms and kitchens to remove moisture and odors at the source. Building codes have required an operable window or an exhaust fan in bathrooms for many years and have generally required kitchen exhaust either directly through a fan or indirectly through a recirculating range hood and an operable window. The Energy Standards recognize the limitations of these indirect methods of reducing moisture and odors and requires that these spaces be mechanically exhausted directly to outdoors, even if windows are present. Moisture condensation on indoor surfaces are a leading cause of mold and mildew in buildings. The occurrence of asthma is also associated with high interior relative humidity. Therefore, it is important to exhaust the excess moisture from bathing and cooking directly at the source.
Click to expand...
Can you send me a link to this.
 
I'll be one of the first people to say that indoor ranges should be vented directly outside, and I've heard many people say something to the effect of "Recirculating residential range hoods are not permitted in California." As of yet I have not found anything in the 2019 Ca Building Standards Code to back this up. The document you reference is a compliance manual, not the code. I feel citing this as a way to "make them go directly outside" is thin at best.
 

B. Ventilation Rate for Demand-Controlled Local Exhaust

A minimum exhaust airflow of 100 CFM is required for vented kitchen range hoods, and 300 CFM or 5 ACH is required for other kitchen exhaust fans. A minimum exhaust airflow of 50 CFM is required for bathroom fans.

The 100 CFM requirement for the range hood or microwave/hood combination is the minimum to adequately capture the moisture, particulates, and other products of cooking and/or combustion. Only in kitchens that are enclosed, the exhaust requirement can also be met with either a ceiling or wall-mounted exhaust fan or with a ducted fan or ducted ventilation system that can provide at least five air changes of the kitchen volume per hour. Recirculating range hoods that do not exhaust pollutants to the outside cannot be used to meet the requirements of ASHRAE Standard 62.2 unless paired with an exhaust system that can provide at least five air changes of the kitchen volume per hour.

The 2019 Title 24 Part 6 standards require verification that range hoods are HVI-certified to provide at least one speed setting at which they can deliver at least 100 CFM at a noise level of 3 sones or less. Verification must be in accordance with the procedures in Reference Residential Appendix RA3.7.4.3. Range hoods that have a minimum airflow setting exceeding 400 CFM are exempt from the noise requirement. HVI listings are available at:

https://www.hvi.org/proddirectory/CPD_Reports/section_1/index.cfm

ASHRAE Standard 62.2 limits exhaust airflow when atmospherically vented combustion appliances are located inside the pressure boundary. This is particularly important to observe when large range hoods are installed. Refer to Section 4.6.8.4 below for more information.
 
See the California Energy Commission Blueprint 131.

Blueprint Newsletter, July-Sept 2020, Issue 131

Nonresidential Mechanical Acceptance Testing New 2019 Energy Code Resources Available on the ORC 2019 HERS Reference Card 2019 ATTCP Reference Card 2019 Water Heater Guides 2019 Energy Code Envelope Air Sealing Fact Sheet 2019 Energy Code Presentations
www.energy.ca.gov www.energy.ca.gov

Does a recirculating range hood with no exhaust to the outdoors meet the mandatory requirements?
No. When a recirculating range hood without outdoor exhaust is installed, another system must also be installed that exhausts to the outdoors and meets the local kitchen exhaust flow rate and sound requirements in ASHRAE 62.2.

While it isn't code, it certainly speaks to the intent of the code.
 
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Banning recirculating range hoods came up in a class several years ago so I am convinced that there is a code to back that up. I didn’t encounter many of them. The fans are more of a decoration than a functioning appliance.
 
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