2022 Kitchen Exhaust Requirements
Indoor air quality (IAQ) is an important part of today’s Gas vs Electric appliance debate. The 2022 energy code proposes additional steps to improve indoor air quality.
Indoor Air Quality
Gas furnaces and water heaters are designed to vent pollution outside. But stoves are often inefficiently vented; in many cases, they’re entirely unvented. Recent studies conducted or referenced by the EPA, Rocky Mountain Institute, Sierra Club and Harvard University have shown that on average, most kitchens’ indoor air quality falls within harmful levels.
Burning fossil fuels in your house is an obvious pollutant, but cooking itself creates IAQ issues, so it’s important to vent a stove, no matter what the fuel source is.
Cooking creates pollutants from heated oil, fat and spices, so choosing a cleaner -burning fuel source does not eliminate the need for local ventilation. The variety of pollutants released during cooking have been linked to health concerns including asthma, fatigue and headaches (see the Physicians for Social Responsibility for information and resources).
Range Hood Code Requirements
Good news: The most effective way to create a healthier kitchen environment is to install a high-efficiency range hood! To be considered high efficiency, the hood needs a high cubic feet per minute (cfm) rating for air changes and a low sones (noise) rating.
The 2022 Single Family Residential and Multi-Family code further defines the required Capture Efficiency Ratings (CE) per Dwelling unit floor area for both Electric and Gas ranges as the fraction of emitted tracer gas that is directly exhausted by a range hood.
Two items of note in the code:
- Hoods over natural gas ranges require a higher CE or CFM than those over electric ranges, and
- Homes with a smaller floor area have less opportunity to dilute cooking contaminants and therefore also require a higher CE or CFM.
Requirements are listed in Table 150.0-G
Table 150.0-G Kitchen Range Hood Airflow Rates (cfm) and ASTM E3087 Capture Efficiency (CE) Ratings According to Dwelling Unit Floor Area and Kitchen Range Fuel Type
| Dwelling Unit Floor Area (ft2) | Hood Over Electric Range | Hood Over Natural Gas |
| >1500 | 50% CE or 110 cfm | 70% CE or 180 cfm |
| >1000 – 1500 | 50% CE or 110 cfm | 80% CE or 250 cfm |
| 750 – 1000 | 55% CE or 130 cfm | 85% CE or 280 cfm |
| <750 | 65% CE or 160 cfm | 85% CE or 280 cfm |
Other Considerations for Kitchen Ventilation
Other exhaust fans, including downdraft fans, must meet a minimum of 300 cfm. For Enclosed Kitchens, a capacity of 5 Air Changes per Hour (ACH) would need to be calculated for the project.
Additionally, the energy code requires a HERS verification, stating that the hood is certified by the Home Ventilating Institute (HVI) or the Association of Home Appliance Manufacturers (AHAM), to provide at least one speed setting that can deliver 100 cfm at less than 3 sones. If the range hood has a minimum airflow setting of 400 cfm or more, they are exempt from the noise requirement. Interested in becoming a HERS Rater? Sign up for a free HERS Rater training using our interest form!
Energy Code Coaches provide personalized support to help building professionals navigate the Energy Code. Call a Code Coach today at (805) 781-4784 or submit an energy code question here!
Reference material: Section 4.6 of the SF Residential Compliance Manual covering sections 150.0 and 150.2.
CARB Indoor Air Pollution from Cooking
https://ww2.arb.ca.gov/resources/documents/indoor-air-pollution-cooking
