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

[Chuck_M]

So ASHRAE 62.2 is not a code but a recommendation to the code?

Is it a code?

 

[Ed Cooke]

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
Kitchens	100 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

I do not wish to taint your thoughts or opinion. I am in Ca. which is not where you are, so my words are only to meet a point. The contractor is correct that an exterior exhausted hood is not required, but they must meet all of the other ventilation requirements, ASHRAE, for your specific jurisdiction. If you speak to the code authority, make it a Plan Reviewer or Building Official.
As a personal thought, outside is the best way to remove cooking odors, you are on the right track!!

 

[Chuck_M]

I do not wish to taint your thoughts or opinion. I am in Ca. which is not where you are, so my words are only to meet a point. The contractor is correct that an exterior exhausted hood is not required, but they must meet all of the other ventilation requirements, ASHRAE, for your specific jurisdiction. If you speak to the code authority, make it a Plan Reviewer or Building Official.
As a personal thought, outside is the best way to remove cooking odors, you are on the right track!!

Thank you Ed!
I agree with you, there is no situation where an indoor gas flame is healthy in the long term. Specially if you have children kids in the house.

 

[Sifu]

Dare I say millions have been installed without a hood, as have non-vented gas decorative appliances. You are presenting what may be a best practice and a preference. That said, if there is a code, amendment or standard that has been legally adopted that requires hoods then it should be administered for everybody governed by that adoption.

 

[Chuck_M]

Dare I say millions have been installed without a hood, as have non-vented gas decorative appliances. You are presenting what may be a best practice and a preference. That said, if there is a code, amendment or standard that has been legally adopted that requires hoods then it should be administered for everybody governed by that adoption.

You know that there are still people that smoke. Doesn't mean it is healthly.
Also did you know there are houses that still have Asbestos! Doesn't mean it's healthy.

I dont want to debate this. It comes down to simple math for me.
Is the chances of getting carbon monoxide poisoning lower when there exhaust is to the outside? Yes. Forget about humidity and all the other issues that are also avoided when the exhaust is vented out.
On a new build, I understand pre production homes want to save every penny but saving on health of the home owner is a very low bar.

 

[ICE]

I dont want to debate this.

Oh but you do.

 

[ICE]

I do not wish to taint your thoughts or opinion.

Oh but you have.

 

[mtlogcabin]

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.

[RB] VENTILATION. The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from, any space.

A recirculating fan does not meet the definition of mechanical ventilation. A window in the kitchen that can be opened meets the definition of natural ventilation. Do you have a kitchen window that can be opened? If yes then the recirculating hood meets code

 

[mark handler]

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.

ICE where does that come from? "Residential range hoods are not required in California."


California Mechanical Code, Section 402.1.2 says that ventilation requirements for single-family dwellings shall be in accordance with Chapter 4 of the California Mechanical Code or ASHRAE 62.2. “ASHRAE” stands for American Society of Heating, Refrigerating and Air-Conditioning Engineers.

ASHRAE 62.2 is a standard that was developed to regulate ventilation requirements for residential buildings that are 3 stories or less, so it is applicable to one- and two-family dwellings but not to apartment complexes. It states that kitchen areas must contain mechanical ventilation to meet residential ventilation requirements.

https://energycodeace.com/site/custom/public/reference-ace-2019/index.html#!Documents/46indoorairqualityandmechanicalventilation.htm

2019 Building Energy Efficiency Standards
4.6 Indoor Air Quality and Mechanical Ventilation
"...Opening and closing windows and continuous operation of central fan-integrated ventilation systems are not allowable options for meeting dwelling unit ventilation requirements. The requirements of ASHRAE Standard 62.2 focus on providing continuous dwelling unit mechanical ventilation, as well as local exhaust ventilation at known sources of pollutants or moisture, such as kitchens, bathrooms, and laundries.
Limiting the sources of indoor pollutants is one important method for protecting indoor air quality. Kitchen ranges used for preparation of food have been identified as a source of indoor air pollution that must be addressed, and builders should adhere to the requirements of Section 4.504 of the California Green Building Standards Code for the selection of materials and finishes that have no or low emissions of air pollutants such as formaldehyde and volatile organic compounds (VOCs). The California Air Resources Board (CARB) also provides guidance for reducing indoor air pollution in homes..."

 

[mark handler]

2018 South Carolina Mechanical Code
505.3 Exhaust Ducts
Domestic cooking exhaust equipment 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, shall be air tight, shall be equipped with a backdraft damper, and shall be independent of all other exhaust systems. Installations in Group I-1 and I-2 occupancies shall be in accordance with the South Carolina Building Code and Section 904.13 of the South Carolina Fire Code.

Exceptions:
In other than Groups I-1 and I-2, where installed in accordance with the manufacturer's 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.
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 1 inch (25 mm) above the indoor concrete floor surface.
2.4. The PVC duct shall extend not more than 1 inch (25 mm) above grade outside of the building.
2.5. The PVC ducts shall be solvent cemented

 

[ICE]

ICE where does that come from? "Residential range hoods are not required in California."

Mechanical ventilation for a kitchen is required but it does not have to be a range hood.

Note the cliff that California jumped off:
Kitchen range hood fans are now required to be verified by a HERS Rater. The new verification protocol requires comparing the installed model to ratings in the Home Ventilating Institute (HVI) directory of certified ventilation products to confirm the installed range hood is rated to meet the required airflow and sound requirements specified in ASHRAE 62.2. See section 4.6.7 below for more detail. Kitchen range hood fans that exhaust more than 400 CFM at minimum speed are exempt from this requirement.

A HERS Rater for a range hood????? When they finally run out of goofy ideas a day will come when a pile of ashes from a pile of burnt money will be required.

 

[Chuck_M]

[RB] VENTILATION. The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from, any space.

A recirculating fan does not meet the definition of mechanical ventilation. A window in the kitchen that can be opened meets the definition of natural ventilation. Do you have a kitchen window that can be opened? If yes then the recirculating hood meets code

Well it is not a prison, so there are windows...lol
It is an open concept, there is only 2 window in the front ( living room ) but non in the back (garage) and none on the side since it is a middle unit. Is there any requirements on where the locations are? Distance and size?

2018 South Carolina Mechanical Code
505.3 Exhaust Ducts
Domestic cooking exhaust equipment 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, shall be air tight, shall be equipped with a backdraft damper, and shall be independent of all other exhaust systems. Installations in Group I-1 and I-2 occupancies shall be in accordance with the South Carolina Building Code and Section 904.13 of the South Carolina Fire Code.

Exceptions:
In other than Groups I-1 and I-2, where installed in accordance with the manufacturer's 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.
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 1 inch (25 mm) above the indoor concrete floor surface.
2.4. The PVC duct shall extend not more than 1 inch (25 mm) above grade outside of the building.
2.5. The PVC ducts shall be solvent cemented

This is where the builder says, we are building in accordance to the manufacturer's instructions.

 

[klarenbeek]

Just throwing this out there, but this is a good example of where codes are the minimum standard, not necessarily best practice. In the ICC world at least, hoods are not required above ranges of any kind other than open top broilers within a dwelling unit. Not required in the IRC, and IMC 505.6 Spells out that they are only required in other than group R occupancies. Listed recirculating hoods are allowed in all cases.

 

[Genduct]

You know that there are still people that smoke. Doesn't mean it is healthly.
Also did you know there are houses that still have Asbestos! Doesn't mean it's healthy.

I dont want to debate this. It comes down to simple math for me.
Is the chances of getting carbon monoxide poisoning lower when there exhaust is to the outside? Yes. Forget about humidity and all the other issues that are also avoided when the exhaust is vented out.
On a new build, I understand pre production homes want to save every penny but saving on health of the home owner is a very low bar.

Chuck, it is clear that you have your heart set on a (California) hood exhaust that removes the cooking orders to the outside.

Your Code quote said: "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."

It CLEARLY Says Listed and Labeled AND Natural Ventilation is provided!
Well Natural Air Changes is the reality of all structures and when the blower door test shows less than 1/3 ACH then you have a make up fan to positively provide the Outside Air to dilute the Problem you mention.

Your Code recitation shows your Contractor is correct for your State, according to the Code you posted.

So, ask him how much to get it done the way you PREFER is my suggestion. The Code supports his POV

IMHO, Mike B

 

[Chuck_M]

What is considered natural ventilation? Anywhere in the code that has clarity ?

 

[Genduct]

What is considered natural ventilation? Anywhere in the code that has clarity ?

Nat Ventilation is the Infiltration that happens when the wind blows or the temp diff that creates the stack effect.
The inside air goes out and is replaced through cracks in the windows and doors or even the building itself.

many people don't realize that a "TIGHT" house has 1/3 of the air in your home exchanged with the outside EVERY HOUR. That is a Tight House. Older homes can be from a little less to more than the entire volumn of your home exchanged with outside EVERY HOUR

You're not living in a submarine, a sealed bottle

 

[Chuck_M]

Nat Ventilation is the Infiltration that happens when the wind blows or the temp diff that creates the stack effect.
The inside air goes out and is replaced through cracks in the windows and doors or even the building itself.

many people don't realize that a "TIGHT" house has 1/3 of the air in your home exchanged with the outside EVERY HOUR. That is a Tight House. Older homes can be from a little less to more than the entire volumn of your home exchanged with outside EVERY HOUR

You're not living in a submarine, a sealed bottle

Not exactly. The builder does a blow door test after drywall and he told me on the last phase of the identical town homes the middle townhouses got between 0.8-1.75ACH. The outer units are much worse between 2 - 4ACH.

I've also had an inspector there twice and was very picky on the fireblock everywhere and there isn't a vent for the cooktop So I won't be surprised if I get 0.8 ACH or better. Which is pretty tight.

 

[BN4537]

This is outside of the range of my experience, and you may already know more about this than I do.

Your house is very tight. If you want a range hood, you will have to find a way to bring more air into the house to compensate for what is exhausted from the house. If you have to bring in air from outside, it kind of defeats the purpose of having your house that tight. There are recirculating systems out there for that purpose, but I don't have any experience with them.

Me personally, if I were building a house that was that tight, I would hire a mechanical engineer to spec out a balanced system for the whole house. I am not usually the kind of person who would call in an engineer, but this area is over my head.

 

[Chuck_M]

They need to have a score below 5ACH to pass final inspections.

 

[mark handler]

Mechanical ventilation for a kitchen is required but it does not have to be a range hood.

Note the cliff that California jumped off:
Kitchen range hood fans are now required to be verified by a HERS Rater. The new verification protocol requires comparing the installed model to ratings in the Home Ventilating Institute (HVI) directory of certified ventilation products to confirm the installed range hood is rated to meet the required airflow and sound requirements specified in ASHRAE 62.2. See section 4.6.7 below for more detail. Kitchen range hood fans that exhaust more than 400 CFM at minimum speed are exempt from this requirement.

A HERS Rater for a range hood????? When they finally run out of goofy ideas a day will come when a pile of ashes from a pile of burnt money will be required.

Yes, in the 2019 CA Energy code, they are required to have a HERS Rater for a range hood.

 

[mark handler]

Well it is not a prison, so there are windows...lol
It is an open concept, there is only 2 window in the front ( living room ) but non in the back (garage) and none on the side since it is a middle unit. Is there any requirements on where the locations are? Distance and size?


This is where the builder says, we are building in accordance to the manufacturer's instructions.

You are required to comply with both the state code and the manufacturer's instructions.
The manufacturer's instructions, may say not required but the State says it is, therefore it is required.

 

[Chuck_M]

What about this section of the code?


Section G2407 (304) Combustion, Ventilation and Dilution Air

G2407.1 (304.1) General

Air for combustion, ventilation and dilution of flue gases for appliances installed in buildings shall be provided by application of one of the methods prescribed in Sections G2407.5 through G2407.9. Where the requirements of Section G2407.5 are not met, outdoor air shall be introduced in accordance with one of the methods prescribed in Sections G2407.6 through G2407.9. Direct-vent appliances, gas appliances of other than natural draft design, vented gas appliances not designated as Category I and appliances equipped with power burners, shall be provided with combustion, ventilation and dilution air in accordance with the appliance manufacturer's instructions.

Exception: Type 1 clothes dryers that are provided with makeup air in accordance with Section G2439.5.


G2407.12 (304.12) Protection From Fumes and Gases

Where corrosive or flammable process fumes or gases, other than products of combustion, are present, means for the disposal of such fumes or gases shall be provided. Such fumes or gases include carbon monoxide, hydrogen sulfide, ammonia, chlorine and halogenated hydrocarbons.

In barbershops, beauty shops and other facilities where chemicals that generate corrosive or flammable products, such as aerosol sprays, are routinely used, nondirect vent-type appliances shall be located in a mechanical room separated or partitioned off from other areas with provisions for combustion air and dilution air from the outdoors. Direct-vent appliances shall be installed in accordance with the appliance manufacturer's instructions

 

[Genduct]

Not exactly. The builder does a blow door test after drywall and he told me on the last phase of the identical town homes the middle townhouses got between 0.8-1.75ACH. The outer units are much worse between 2 - 4ACH.

I've also had an inspector there twice and was very picky on the fireblock everywhere and there isn't a vent for the cooktop So I won't be surprised if I get 0.8 ACH or better. Which is pretty tight.

Chuck, You are correct about the test. I was going to the next step after the Blower door test to the assumptions made to translate the Test value into Natural Air Changes. Of course the actuals are going to be affected by wind and temperature so the Actual / natural value will always change with conditions

I didn't mean to confuse the conversation

 

[steveray]

And then the kitchen exhaust needs make up air too....