AC inspection, F-gas check or service: what to book and when
Updated 20 October 2026 · SEO Dons Editorial
What is a TM44 inspection?
"TM44" is the everyday name for the air conditioning energy inspection required by Part 4 of the Energy Performance of Buildings (England and Wales) Regulations 2012. The name comes from CIBSE Technical Memorandum 44, which CIBSE describes as the principal guidance for these inspections. The current edition was published in October 2012, and its focus is on systems that use refrigerants to produce cooling.
The inspection looks at energy, not safety. Government guidance says it is designed to improve efficiency, reduce energy use and running costs, and point out older or oversized systems that could be replaced with more efficient plant. It sits alongside, not instead of, the maintenance and leak checking a building already needs.
The rules described here apply in England and Wales. Buildings in Scotland and Northern Ireland have their own requirements.
Which air conditioning systems need an inspection?
The regulations apply to air conditioning systems with an effective rated output of more than 12kW. That threshold is not judged unit by unit. Where one person controls several units in a building, the units are treated as parts of a single system, so a floor of small wall-mounted splits can add up to an in-scope system even though no individual unit reaches 12kW.
To find the rating, government guidance points to the rating plate on each unit, the operating and maintenance manual or the manufacturer's website. Where a system has several units, the ratings on each plate may need to be added together. A maintenance contractor should also know the capacity and record it.
Responsibility follows control. In a multi-let building, the landlord is normally responsible for the central plant, while a tenant who has installed its own equipment is responsible for an inspection report for that equipment. The person in control is the one who controls the technical functioning of the system, not someone who only adjusts a thermostat.
There is no exemption that limits inspections to comfort cooling, although the government guidance is not written for dedicated process cooling. If a building mixes office cooling with IT or process cooling, an accredited assessor can confirm what is in scope.
How often does a TM44 inspection have to be done?
Inspections must be no more than five years apart. For a system first put into service on or after 1 January 2008, the first inspection is due within five years of that date. For older systems, the deadlines have already passed: 4 January 2009 for systems over 250kW and 4 January 2011 for systems over 12kW.
Two other duties catch people out:
- The person in control must keep the most recent inspection report.
- When control passes to someone else, the report must be handed over. If the new person is not given a report, the system must be inspected within three months of the handover.
A practical way to stay on top of the five-year cycle is to log the report date in the building's planned maintenance schedule, so the next inspection is booked well before the deadline. Readers who want that cycle managed alongside servicing can compare planned maintenance (PPM) contracts that include compliance tracking.
Who is allowed to carry out the inspection?
Only an energy assessor who is a current member of a government-approved accreditation scheme can carry out the inspection. Since 6 April 2012, assessors have had to lodge every air conditioning inspection report on the national register, and a report is only valid once it has been lodged and given a reference number.
The government's energy certificate service lets building owners find an accredited assessor for a business property, and it notes that the cost of an assessment varies by assessor and the size of the property. Before booking, it is sensible to check the assessor's scheme membership on the register.
The assessor will ask for documents before the visit. Useful items include the rating plates or equipment schedule, operating and maintenance manuals, commissioning records, recent maintenance reports and, where a building management system controls the plant, data exported from it. Missing paperwork can make the inspection longer and less useful.
What does the inspection report cover?
The regulations require the report to assess the efficiency of the system and its sizing compared with the cooling needs of the building, and to give advice on improvements, replacement and alternative solutions. Since a 2020 amendment it must also consider how the system can be set up to perform best under typical operating conditions.
In practice, government guidance says a report covers at least:
- the likely efficiency of the system and suggestions for improvement
- faults found during the inspection
- whether maintenance is adequate
- whether the controls and settings are suitable
- the size of the installed system against the cooling load
- a summary of findings and key recommendations
Two findings come up often. The first is fan energy: the guidance notes that fans may use more energy each year than the refrigeration plant itself. The second is controls, including heating and cooling running at the same time in the same space. The assessor reports these issues but does not reset controls or clean equipment as part of the inspection.
There is no legal requirement to act on the recommendations. They are, however, a useful starting point for a business case if the plant is ageing. Owners weighing up a replacement can read the guide to F-gas rules for commercial systems, because refrigerant restrictions often shape the options.
How is TM44 different from F-gas checks and servicing?
These three activities are often confused because the same plant is involved. They have different legal bases, different purposes and, often, different people doing them.
| Activity | Purpose | Legal basis or guidance | How often |
|---|---|---|---|
| TM44 energy inspection | Efficiency and sizing of the system | Energy Performance of Buildings Regulations 2012, Part 4 | At least every five years for systems over 12kW |
| F-gas leak check | Finding and fixing refrigerant leaks | GB F-gas regulations and government leak-check guidance | Depends on the amount of F gas and its global warming potential |
| Routine servicing | Keeping plant clean, safe and reliable | Manufacturer instructions and planned maintenance schedules such as SFG20 | Set by the maintenance plan, usually more often than TM44 |
Government guidance on TM44 says it does not cover inspection under the F-gas regulations, which sit outside the energy performance rules. Under the F-gas regime, the user of stationary air conditioning equipment is responsible for getting it checked for leaks, and a leak found during a check must be repaired as soon as possible and the test repeated within a month.
Servicing is different again. The TM44 guidance itself notes that inspection, maintenance and cleaning should happen more often than the energy assessment. For a task-by-task view of servicing frequencies, see the guide to SFG20 air conditioning maintenance. The SFG20 explainer sets out how SFG20 servicing differs from statutory duties such as the energy inspection.
What are the penalties for not having a report?
Local weights and measures authorities, usually Trading Standards, enforce the air conditioning inspection rules. The penalty charge for failing to have the system inspected, failing to keep the report, failing to pass it on, or failing to inspect within three months after taking over a system is £300 under regulation 38 of the 2012 Regulations. A further £200 penalty can be issued for not giving Trading Standards a copy of the report within seven days of being asked.
The fines are modest, but the commercial effect can be larger. Government guidance warns that a missing report, where one is required, may have a negative impact when a building is sold or let, because the other side's lawyers are likely to ask to see it.
Readers who need an inspection booked alongside servicing or remedial work can request quotes through the site's form, or look at how planned maintenance contracts handle compliance records.
Sources
- The Energy Performance of Buildings (England and Wales) Regulations 2012, Part 4 and regulation 38, legislation.gov.uk, checked 20 October 2026
- Air-conditioning inspections for buildings: a guide to air conditioning inspections, Ministry of Housing, Communities and Local Government (GOV.UK), checked 20 October 2026
- TM44 Inspection of air conditioning systems, CIBSE, checked 20 October 2026
- Checking F gas equipment for leaks, Environment Agency and Defra (GOV.UK), checked 20 October 2026
- Get a new energy certificate, GOV.UK, checked 20 October 2026
Common questions
Does a single 7kW split system need a TM44 inspection?
Not on its own, because the threshold is an effective rated output of more than 12kW. But if the same person controls other units in the building and their combined output is above 12kW, the units count as one system and an inspection is needed.
Can the usual maintenance contractor carry out the inspection?
Only if the person doing it is an accredited energy assessor and lodges the report on the register. Cleaning or adjusting controls is not part of the inspection, and government guidance says that work would need a separate arrangement.
Who is responsible when a facilities management company runs the plant?
A contract can make the facilities management or servicing company responsible for arranging inspections. Government guidance says the landlord or occupier still keeps a parallel duty to make sure the system has been inspected.
What if the last inspection report has been lost?
Reports lodged since 6 April 2012 are held on the national register. A copy can be downloaded using the report reference number, or by searching the building address unless the owner has opted out.
Does the report force a business to replace its air conditioning?
No. There is no legal requirement to act on the recommendations. The report is advice on efficiency, sizing, improvements and alternatives, which owners can use when planning upgrades.
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