F-Gas vs TM44: What's the Difference?
F-Gas and TM44 are two of the most commonly confused terms in air conditioning compliance — and they are not interchangeable. One governs who is allowed to handle your refrigerant; the other governs whether your system has been independently inspected for efficiency. Understanding the difference helps building owners stay compliant and avoid penalties. Here is a plain-English comparison.
In short
F-Gas is a company certification that any business must hold to legally handle air conditioning refrigerant. TM44 is a separate legal inspection of systems over 12kW, required every five years to assess energy efficiency. F-Gas is about who does the work; TM44 is about checking the installed system.
F-Gas — about the people doing the work
F-Gas certification is a requirement placed on the installer or service company. Under the UK F-Gas Regulations, any business that installs, services, leak-checks or decommissions equipment containing fluorinated refrigerant must hold company-level F-Gas certification (for example through REFCOM), and its engineers must hold the relevant personal qualifications.
In short, F-Gas answers the question: "Is this company legally allowed to touch my refrigerant?" It applies regardless of system size — even a small domestic split must only be worked on by an F-Gas certified company.
TM44 — about the installed system
TM44 is a legal inspection placed on the building owner or operator. Where a building's air conditioning has an effective rated output over 12kW, it must be inspected by an accredited energy assessor at least every five years, and a valid Air Conditioning Inspection Report must be held.
TM44 answers a different question: "Is this installed system efficient and correctly sized for the building?" It is concerned with energy performance, not refrigerant handling, and only applies above the 12kW threshold.
How the two work together
The two are complementary. A compliant commercial building needs both: it must use an F-Gas certified company for any refrigerant work, and hold a current TM44 report if it exceeds 12kW. Neither replaces the other.
Tempest is set up to support both — carrying out installation and servicing to F-Gas standards, and helping you understand and plan your TM44 inspection cycle so nothing falls through the cracks.
- F-Gas applies to the company; TM44 applies to the building owner
- F-Gas covers refrigerant handling; TM44 covers energy efficiency
- F-Gas applies to all systems; TM44 only above 12kW
- F-Gas is ongoing certification; TM44 repeats every 5 years
- Commercial premises over 12kW need both to be compliant
- Neither requirement replaces the other
F-Gas vs TM44 compared
| F-Gas certification | TM44 inspection | |
|---|---|---|
| What it governs | Who can handle refrigerant | Efficiency of the installed system |
| Who it applies to | The installer / service company | The building owner or operator |
| Size threshold | All systems with refrigerant | Over 12kW effective rated output |
| Frequency | Ongoing certification | At least every 5 years |
| Carried out by | F-Gas certified engineers | Accredited energy assessor |
Frequently asked questions
Is F-Gas the same as TM44?
Do I need both F-Gas and TM44?
Does a domestic home need a TM44 inspection?
Which one is the installer responsible for?
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