Using the following for reference: http://publicecodes.citation.com/icod/irc/2012/icod_irc_2012_15_sec003.htm
Range hoods shall discharge to the outdoors through a single-wall 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 installation 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.
Single-wall ducts serving range hoods shall be constructed of galvanized steel, stainless steel or copper. Where domestic kitchen cooking *appliances *are equipped with ducted range hoods or down-draft exhaust systems, the fans shall be sized in accordance with Section M1507.4.
Exhaust hood systems capable of exhausting in excess of 400 cubic feet per minute (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.
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: **All that is REGARDLESS of the fuel-type of the range appliance - Correct? A gas range appliance should have an exhaust hood that discharges outside, just like an electrical range appliance should.