TM44 Air Conditioning Inspections Explained
Who needs an air conditioning energy inspection, how the 12kW threshold is calculated, how often inspections are needed and how to prepare.
Last reviewed 11/10/2026 · General guidance, not legal advice
What is a TM44 inspection?
A TM44 inspection is an energy assessment of an air conditioning system, named after the CIBSE technical memorandum that sets out how it should be done. In England and Wales it is a legal requirement under the Energy Performance of Buildings Regulations for larger systems. The aim is to identify ways to improve efficiency and reduce energy use.
Who needs one
The requirement applies to air conditioning systems with an effective rated output of more than 12kW. Importantly, the outputs of individual units under the control of the same person in a building are added together, so several small split systems can together exceed 12kW.
The duty falls on the person who controls the operation of the system, often the building owner or occupier. Air-to-air heat pumps used for cooling are generally treated as air conditioning for this purpose.
How often
Systems must be inspected at intervals of no more than five years. New systems need their first inspection within five years of installation. The inspection must be carried out by an accredited air conditioning energy assessor, and the report lodged on the national register.
What it covers
- A review of system documentation and maintenance records
- Inspection of refrigeration equipment, air handling and controls
- Assessment of whether the system is appropriately sized for the cooling load
- Recommendations for improving efficiency, controls or operation
- Advice on replacing older or oversized systems
Enforcement
Local authority trading standards officers enforce the regulations and can issue penalty notices where a valid inspection report cannot be produced. There is no legal requirement to implement the report’s recommendations, but they often identify worthwhile savings.
How to prepare
- List all air conditioning units in the building and their rated outputs
- Gather installation, commissioning and maintenance records, including F-Gas logs
- Make plant and controls accessible
- Check when your last inspection was, if any
A well-maintained system with good records makes the inspection quicker and the outcome more useful. Our planned maintenance keeps that information in order, and we can work alongside your accredited assessor.
Need help with compliance?
Site surveys, written proposals and maintenance contracts across East Anglia.
Questions about this topic
Do several small units count towards 12kW?
Yes, if they are in the same building and under the control of the same person, their outputs are added together.
Can you carry out TM44 inspections?
TM44 inspections must be carried out by an accredited energy assessor. We maintain systems and provide the records and access the assessor needs.
Is TM44 the same as an F-Gas leak check?
No. TM44 is an energy efficiency inspection; F-Gas leak checks are about preventing refrigerant leaks. Both may apply.