# Refrigerant: Building Code Definition

> How the IRC 2009, IFC 2009, IMC 2009 define refrigerant, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/refrigerant/
- Last updated: 2026-09-07
- Data source: 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.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IRC 2009, IFC 2009, IMC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 25 (counted across the codes hosted here) |
| Wording identical across codes | No (compare before citing one code's wording under another) |

## Direct answer

Refrigerant is a defined term in the International Residential Code (IRC) 2009, in Definitions. The code's own words are: “A substance used to produce refrigeration by its expansion or evaporation.” The IFC 2009 words it differently, in Building Services and Systems: “The fluid used for heat transfer in a refrigerating system; the refrigerant absorbs heat and transfers it at a higher temperature and a higher pressure, usually with a change of state.” The IFC 2009, IMC 2009 define the same term with different wording, so the controlling text depends on which code governs the question in front of you — the comparison below sets the versions side by side. The term is used in 25 chapters of this corpus, most often in Refrigeration (IMC 2009), Building Services and Systems (IFC 2009), Definitions (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](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Refrigerant** — IRC 2009, Definitions:

> A substance used to produce refrigeration by its expansion or evaporation.

![Labeled code-term definition diagram: Refrigerant: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/refrigerant/diagram-1344.webp)

*How the IRC 2009, IFC 2009, IMC 2009 define refrigerant, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

Three of the I-Codes in this corpus define **Refrigerant**, and the wording is not identical — read the version that governs your question.

| Code | Where it is defined | Definition |
| --- | --- | --- |
| IRC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | A substance used to produce refrigeration by its expansion or evaporation. |
| IFC 2009 | [Building Services and Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/building-services-and-systems.md) | The fluid used for heat transfer in a refrigerating system; the refrigerant absorbs heat and transfers it at a higher temperature and a higher pressure, usually with a change of state. |
| IMC 2009 | [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) | A substance utilized to produce refrigeration by its expansion or vaporization. |

## Where refrigerant is used in the code

The term appears in 25 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Refrigeration](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/refrigeration.md) | IMC 2009 | 231 |
| [Building Services and Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/building-services-and-systems.md) | IFC 2009 | 65 |
| [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) | IMC 2009 | 57 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | IRC 2009 | 7 |
| [Heating and Cooling Equipment](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/heating-and-cooling-equipment.md) | IRC 2009 | 6 |
| [Fire Protection Systems](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-protection-systems.md) | IBC 2009 | 4 |
| [Exhaust Systems](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/exhaust-systems.md) | IMC 2009 | 4 |
| [Means of Egress](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/means-of-egress.md) | IBC 2009 | 3 |
| [Means of Egress](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/means-of-egress.md) | IFC 2009 | 3 |
| [Scope and Administration](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/scope-and-administration.md) | IBC 2009 | 2 |
| [Compressed Gases](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/compressed-gases.md) | IFC 2009 | 2 |
| [Corrosive Materials](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/corrosive-materials.md) | IFC 2009 | 2 |

_13 further chapters mention the term._

### The term in use

How the code actually writes about refrigerant, quoted from the 2009 text hosted here:

> Refrigerant piping design and installation, including pressure vessels and pressure relief devices, shall conform to this code.

— [IMC 2009 §1101.1](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/refrigeration.md)

> Refrigeration systems having a refrigerant circuit containing more than 220 pounds (100 kg) of Group Al or 30 pounds (14 kg) ofany other group refrigerant shall be accessible to the fire department at all times as required by the fire code official.

— [IFC 2009 §606.5](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/building-services-and-systems.md)

> Refrigerant circuit access ports located outdoors shall be fitted with locking-type tamper-resistant caps.

— [IRC 2009 §M1411.6](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/heating-and-cooling-equipment.md)


## The terms refrigerant is built out of

The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what refrigerant covers:

- **[Refrigerating System](https://harth.build/resources/glossary/refrigerating-system.md)** — IRC 2009: A combination of interconnected parts forming a closed circuit in which refrigerant is circulated for the purpose of extracting, then rejecting, heat.
- **[System](https://harth.build/resources/glossary/system.md)** — IFC 2009: An assembly of equipment consisting of a tank, container or containers, appurtenances, pumps, compressors and connecting piping.

## Refrigerant: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IRC | Definitions | |
| Read the definition in the adopted IFC | Building Services and Systems | |
| Read the definition in the adopted IMC | Definitions | |
| Re-check the requirement that uses it | Refrigeration (IMC 2009) | |
| Re-check the requirement that uses it | Building Services and Systems (IFC 2009) | |
| Re-check the requirement that uses it | Definitions (IMC 2009) | |
| Re-check the requirement that uses it | Definitions (IRC 2009) | |
| Confirm the dependent definition | Refrigerating System | |
| Confirm the dependent definition | System | |
| 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](https://harth.build/resources/glossary.md)
- [Refrigerating System: Building Code Definition](https://harth.build/resources/glossary/refrigerating-system.md)
- [System: Building Code Definition](https://harth.build/resources/glossary/system.md)

## 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](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.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of refrigerant?

The International Residential Code (IRC) 2009 defines it in Definitions as: “A substance used to produce refrigeration by its expansion or evaporation.” 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.

### Do the I-Codes define refrigerant the same way?

No. IRC 2009, IFC 2009, IMC 2009 all define the term, but the wording is not identical, and a difference in wording can change which requirements are triggered. The comparison table above sets the versions side by side so you can read the one that governs your question.

### Which parts of the code depend on refrigerant?

In this corpus the term is used across 25 chapters, led by Refrigeration in the IMC 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 is the definition of a refrigerant?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IRC 2009 states, in Definitions: “A substance used to produce refrigeration by its expansion or evaporation.” It is defined in IRC 2009, IFC 2009, IMC 2009. Because it is a defined term, whatever the adopted edition says it means is what every section using it means — so check Chapter 2 of that edition and any local amendment before relying on this wording.

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