What range hood does an ADU kitchen need under the 2025 Energy Code?

Your ADU kitchen needs a range hood, or other kitchen exhaust, vented to the outdoors that meets either a minimum airflow or a minimum capture efficiency from Table 150.0-G. The required level depends on the ADU's own floor area and whether the range is electric or gas, and an ECC rater (formerly HERS rater) verifies the hood's certified ratings.

The Table 150.0-G requirements

A vented range hood must meet either the capture efficiency (CE) or the airflow listed for your unit's size and fuel type:

• Under 750 sq ft: electric range 65% CE or 160 cfm; gas range 85% CE or 280 cfm.
• 750 to 1,000 sq ft: electric 55% CE or 130 cfm; gas 85% CE or 280 cfm.
• Over 1,000 to 1,500 sq ft: electric 50% CE or 110 cfm; gas 80% CE or 250 cfm.
• Over 1,500 sq ft: electric 50% CE or 110 cfm; gas 70% CE or 180 cfm.

Smaller units face higher targets because cooking pollutants concentrate in less air. Capture efficiency is rated under ASTM E3087 and must appear in a product directory approved by the CEC.

Other kitchen exhaust options

• Other kitchen exhaust fans, including downdraft units, must provide at least 300 cfm (Table 150.0-E).
• An enclosed kitchen may instead use continuous exhaust of 5 air changes per hour based on kitchen volume (Table 150.0-F).
• The CEC's Compliance Manual states kitchens must have local exhaust vented to the outdoors, so a recirculating hood does not meet this requirement.

Sound and verification

• The hood must be HVI- or AHAM-certified, and the Compliance Manual says it must offer at least one setting of 100 cfm or more at 3 sones or less. Hoods whose minimum airflow setting exceeds 400 cfm are exempt from the noise requirement.
• The ECC rater verifies the certified airflow or capture efficiency and the sound rating under Section 150.0(o)2B. The CEC's ADU FAQ confirms that a newly installed vented range hood requires this verification.
• The installer must measure the as-installed airflow, or install a duct system that meets the prescriptive sizing in Table 150.0-H, which is limited to 25 feet or less of duct with no more than three elbows.

Design tips

• Electric ranges carry lower thresholds in Table 150.0-G, which can make the hood easier to select.
• Keep the duct short and straight, and include the backdraft damper that Section 150.0(m)7 requires on fans that exhaust to the outside.
• If any vented combustion appliance sits inside the ADU, the Compliance Manual notes that ASHRAE 62.2 limits exhaust airflow, so large hoods need extra review.

What it means for your mechanical plan

The plan should list the hood make and model, its certified airflow or capture efficiency, its sone rating, the duct size, length and termination, and the range fuel type, all consistent with the ADU's floor area. See how mechanical plans handle ventilation and what HERS (now ECC) testing covers.

Sources: energy.ca.gov, energy.ca.gov, energy.ca.gov.