Building Code Glossary
Vented Wall Furnace: Building Code Definition
How the IRC 2009 define vented wall furnace, where the wording differs, and which chapters depend on the term.
On this page
Last updated September 7, 2026 · Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.
Direct answer
Vented wall furnace is a defined term in the International Residential Code (IRC) 2009, in Fuel Gas. The code's own words are: “A self-contained vented appliance complete with grilles or equivalent, designed for incorporation in or permanent attachment to the structure of a building, mobile home or travel trailer, and furnishing heated air circulated by gravity or by a fan directly into the space to be heated through openings in the casing. This definition shall exclude floor …” No other I-Code in this corpus defines it, so the IRC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Fuel Gas (IRC 2009), Heating and Cooling Equipment (IRC 2009), Specific Appliances, Fireplaces and Solid Fuel-burning Equipment (IMC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted.
Content and cited inputs reviewed by Scott Barrington, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.
What does this term mean?
Vented Wall Furnace — IRC 2009, Fuel Gas:
A self-contained vented appliance complete with grilles or equivalent, designed for incorporation in or permanent attachment to the structure of a building, mobile home or travel trailer, and furnishing heated air circulated by gravity or by a fan directly into the space to be heated through openings in the casing. This definition shall exclude floor furnaces, unit heaters and central furnaces as herein defined.
What must be verified before using this guidance?
Vented Wall Furnace is defined once in this corpus, in the Fuel Gas chapter of the International Residential Code (IRC) 2009:
A self-contained vented appliance complete with grilles or equivalent, designed for incorporation in or permanent attachment to the structure of a building, mobile home or travel trailer, and furnishing heated air circulated by gravity or by a fan directly into the space to be heated through openings in the casing. This definition shall exclude floor furnaces, unit heaters and central furnaces as herein defined.
Where vented wall furnace is used in the code
The term appears in 3 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Fuel Gas | IRC 2009 | 10 |
| Heating and Cooling Equipment | IRC 2009 | 8 |
| Specific Appliances, Fireplaces and Solid Fuel-burning Equipment | IMC 2009 | 6 |
The term in use
How the code actually writes about vented wall furnace, quoted from the 2009 text hosted here:
A Type B-W gas vent shall have a listed capacity not less than that of the listed vented wall furnace to which it is connected.
The terms vented wall furnace is built out of
The definition above leans on 4 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what vented wall furnace covers:
- Appliance — IRC 2009: Utilization equipment, normally built in standardized sizes or types, that is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, etc.
- Structure — IPC 2009: That which is built or constructed or a portion thereof.
- Building — IBC 2009: Any structure used or intended for supporting or sheltering any use or occupancy.
- Shall — IRC 2009: The term, when used in the code, is construed as mandatory.
Vented Wall Furnace: what to open, and in what order
Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.
| Check | Where | Confirmed |
|---|---|---|
| Read the definition in the adopted IRC | Fuel Gas | |
| Re-check the requirement that uses it | Fuel Gas (IRC 2009) | |
| Re-check the requirement that uses it | Heating and Cooling Equipment (IRC 2009) | |
| Re-check the requirement that uses it | Specific Appliances, Fireplaces and Solid Fuel-burning Equipment (IMC 2009) | |
| Confirm the dependent definition | Appliance | |
| Confirm the dependent definition | Structure | |
| Confirm the dependent definition | Building | |
| Local amendment to any of the above | Jurisdiction's amendment list |
A research aid, not a code determination. The authority having jurisdiction decides which edition and which amendments apply.
Where can you explore related guidance?
- Explore all glossary guidance
- Structure: Building Code Definition
- Appliance: Building Code Definition
- Building: Building Code Definition
Sources and method
Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The ICC code library publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.
Source links
Frequently asked questions
What is the code definition of vented wall furnace?
The International Residential Code (IRC) 2009 defines it in Fuel Gas as: “A self-contained vented appliance complete with grilles or equivalent, designed for incorporation in or permanent attachment to the structure of a building, mobile home or travel trailer, and furnishing heated air circulated by gravity or by a fan directly into the space to be heated through openings in the casing. This definition shall exclude floor furnaces, unit heaters and central furnaces as herein defined.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.
Which parts of the code depend on vented wall furnace?
In this corpus the term is used across 3 chapters, led by Fuel Gas in the IRC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.
What are the code requirements for furnace venting?
Venting is a separate defined term. The IRC 2009 defines it as: “Removal of combustion products to the outdoors.” That is not the same as vented wall furnace, which the IRC 2009 defines as “A self-contained vented appliance complete with grilles or equivalent, designed for incorporation in or permanent attachment to the structure of a building, mobile home or travel trailer, and furnishing heated air circulated by gravity or by a fan directly into …” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
Related pages
- Vent System: Building Code Definition
Vent System — IRC 2009 definition: Piping installed to equalize pneumatic pressure in a drainage system to prevent trap seal loss or …
- Vent: Building Code Definition
Vent — IRC 2009 definition: A pipe or other conduit composed of factory-made components, containing a passageway for conveying combustion products …
- Vented Room Heater: Building Code Definition
Vented Room Heater — IRC 2009 definition: A vented self-contained, free-standing, nonrecessed appliance for furnishing warm air to the space in which it …
- Ventilated: Building Code Definition
Ventilated — IRC 2009 definition: Provided with a means to permit circulation ofair sufficient to remove an excess of heat, fumes …
- Ventilation Air: Building Code Definition
Ventilation Air — IMC 2009 definition: That portion of supply air that comes from the outside (outdoors), plus any recirculated air that …
- Ventilation: Building Code Definition
Ventilation — IBC 2009 definition: The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air …