Are Kitchen Exhaust Hoods Required?

Today’s PHW Inspections Question: Are Kitchen Exhaust Hoods Required?

Many building codes require exhaust ventilation for indoor cooktops or cooking ranges to remove smoke, steam, and cooking odors from the kitchen. This ventilation can be provided through a range hood or an overhead exhaust fan or ventilated microwave meeting UL923 standard.

In general, building codes and regulations regarding exhaust vents for cooktops or cooking ranges can vary by location and may depend on several factors such as the type of stove or range, the fuel source (solid fuel, liquid fuel, gas, or electric), and the design of the kitchen. Even in areas if not required by code, it is generally a good idea to have some form of ventilation for indoor cooking to improve air quality and prevent the buildup of moisture and odors in the home.

Florida Building Code (FBC) 2020,

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.

The code outlines the requirements for mechanical ventilation in buildings that house cooking appliances. The section specifies that mechanical ventilation is required for all cooking appliances that produce smoke, grease, or moisture. This includes ranges, cooktops, ovens, and grills that burn solid fuel, liquid fuel, or gas.

The FBC allows for two types of ventilation systems for cooking appliances: vented and recirculating.

Vented systems exhaust the air to the outdoors through a duct or hood. Vented system ensures that the pollutants are effectively removed from the building and do not accumulate indoors. In addition, the ventilation system should be capable of exhausting at a rate of not less than 100 cubic feet per minute (CFM) for ranges or cooktops.

Recirculating systems capture and filter the air before returning it to the room. However, recirculating systems must meet certain requirements to be effective at removing pollutants from the air. Recirculating ventilation systems must be equipped with an effective filtering system that is capable of removing grease, smoke, and other contaminants from the air. The filter should be replaced or cleaned regularly to maintain its effectiveness. Additionally, recirculating systems should have a fan that is capable of moving air at a rate of not less than 50 cubic feet per minute (CFM) for electric cooktops.

The purpose of ventilation is to ensure that the air quality in buildings with cooking appliances is maintained at a safe and healthy level by removing harmful contaminants that are produced during cooking that can accumulate and potentially cause health problems for occupants or contribute to the growth of mold and mildew. Vents are to be installed at a minimum of 18”-24” above cooking surface.

To summarize, recirculating ventilation is required at a minimum. The ONLY time exterior vented exhaust is required by International Code is with an open-top broilers.

It’s important to note that specific requirements for ventilation systems may vary depending on the location, building design, and other factors. Therefore, it’s recommended to consult with local authorities or a licensed contractor to ensure compliance with all applicable codes and regulations for ventilation systems in your specific location.