TM44 Air Conditioning Inspections: Does Your Building Need One?
If your commercial building has more than a small amount of air conditioning or comfort cooling, you may have a legal requirement to arrange an air-conditioning energy inspection.
In England and Wales, air-conditioning systems with a combined effective rated output of more than 12 kW must be inspected at least once every five years.
The statutory requirement comes from the Energy Performance of Buildings (England and Wales) Regulations and is commonly referred to as a TM44 inspection, after the CIBSE guidance used for air-conditioning energy assessments.
An important point for building owners, landlords and facilities managers is that the 12 kW threshold does not necessarily apply to each individual unit. Several smaller systems under the control of the same person can together bring a building within scope.
Understanding what equipment is installed, who controls it and when the last inspection was carried out can therefore help prevent a compliance gap while also identifying opportunities to reduce energy consumption and operating costs.
What is a TM44 inspection?
A TM44 inspection is an independent energy assessment of an air-conditioning system carried out by an accredited air-conditioning energy assessor.
The inspection considers areas such as:
- The size and effective rated output of the air-conditioning system
- How the equipment is controlled
- Operating hours and temperature settings
- Maintenance arrangements
- The condition and efficiency of the system
- Whether the system appears appropriately sized for the building
- Opportunities to improve efficiency and reduce energy use
Following the inspection, an Air Conditioning Inspection Report (ACIR) is produced and lodged on the relevant Energy Performance of Buildings Register.
The purpose of the report is not simply to produce another compliance document. It should provide useful recommendations that can help the person responsible for the system improve its operation and potentially reduce energy costs.
Which air-conditioning systems require a TM44 inspection?
In England and Wales, an air-conditioning system requires an inspection where its effective rated output is more than 12 kW.
This can apply to one large air-conditioning system or a number of smaller systems within the same building.
Do small split systems count towards the 12 kW threshold?
Yes.
A common misconception is that an inspection is only required when an individual air-conditioning unit exceeds 12 kW.
That is not necessarily the case.
For example, a building containing five separate 3.5 kW split air-conditioning systems under the same person’s control could have a combined effective rated output of:
5 × 3.5 kW = 17.5 kW
Although every individual system is relatively small, the combined capacity exceeds 12 kW and the installation may therefore fall within the inspection requirements.
Care must be taken when calculating capacity. Indoor and outdoor unit capacities should not simply be added together, as this can result in the same cooling capacity being counted twice.
The correct approach is to establish the effective rated output of the air-conditioning systems under common control, using equipment data, manufacturers’ information, operation and maintenance manuals and asset records where required.
What does “under one person’s control” mean?
The legislation places responsibility on the person who controls the technical operation of the air-conditioning system.
Depending on how the building is occupied and managed, this could be:
- The building owner
- A landlord
- A commercial tenant
- An occupier
- A facilities-management organisation
- Another party responsible for operating the building services
Simply being able to adjust a room thermostat does not necessarily mean that person legally controls the system.
Lease agreements, maintenance contracts and facilities-management arrangements may need to be considered when establishing responsibility.
Does process cooling require a TM44 inspection?
Dedicated process cooling should not automatically be assumed to be exempt.
Government guidance for air-conditioning inspections is primarily focused on systems that provide cooling for building occupants. However, the regulations do not contain a blanket exemption for every system used solely for process cooling.
Buildings containing specialist refrigeration, server-room cooling, process cooling or a mixture of comfort and process cooling should therefore be reviewed individually.
Where the application is unclear, it is sensible to obtain advice from an accredited air-conditioning energy assessor rather than relying only on the description shown on an equipment asset list.
How often is a TM44 inspection required?
For systems within scope, no more than five years should pass between air-conditioning energy inspections.
This means building managers should record the date of the current Air Conditioning Inspection Report and arrange the next inspection before the five-year deadline is reached.
Waiting until the report is already out of date can create an avoidable compliance gap.
What happens when you take over a building?
If you purchase, lease or otherwise take control of a commercial property, ask for a copy of the current Air Conditioning Inspection Report as part of the building documentation.
You should establish:
- Whether the building’s air-conditioning system exceeds the 12 kW threshold
- Who controls the technical operation of the system
- The date of the most recent inspection
- When the next inspection is due
- Whether the report has been correctly lodged
- Whether the assessor was appropriately accredited
Where control of an air-conditioning system that is subject to the regulations passes to a new person and the existing report is not provided, the system will generally need to be inspected within three months of the new person taking control.
This makes TM44 documentation an important part of commercial property handovers and facilities-management mobilisation.
What does a TM44 assessor look at?
The exact inspection will vary depending on the size and complexity of the installation.
An accredited assessor will normally consider information such as:
Air-conditioning equipment
The assessor may review indoor and outdoor equipment, system configuration, model information, cooling capacities and the overall effective rated output.
Controls
Controls can have a significant effect on energy consumption.
The inspection may consider:
- Time schedules
- Temperature set points
- Centralised controls
- Local controllers
- Zoning
- Simultaneous heating and cooling
- Building Management System operation
Operating hours
Air-conditioning systems that operate for unnecessarily long periods can consume significantly more energy than required.
Operating schedules may therefore form part of the assessment.
Maintenance
Maintenance records and the apparent condition of the equipment may be reviewed.
Dirty filters, blocked coils, poor airflow, faulty sensors or incorrectly operating controls can all affect energy performance.
System sizing
The assessor may consider whether the installed air-conditioning equipment appears oversized or undersized for the building and its current use.
This is particularly relevant where buildings have been altered or their occupancy has changed since the system was originally installed.
What recommendations might appear in a TM44 report?
Recommendations will depend on the individual building, but they could include:
- Adjusting air-conditioning operating times
- Changing heating and cooling set points
- Improving zoning
- Correcting control faults
- Preventing simultaneous heating and cooling
- Cleaning or maintaining equipment
- Repairing faulty sensors or controllers
- Improving maintenance procedures
- Upgrading controls
- Replacing older or inefficient air-conditioning equipment
- Reviewing systems that appear oversized
Some recommendations can be inexpensive to implement but still produce useful reductions in energy consumption.
Do you have to carry out the recommendations in a TM44 report?
The Energy Performance of Buildings Regulations do not generally require the building operator to implement every energy-saving recommendation contained within the report.
The statutory requirement is primarily to ensure that an appropriate inspection is carried out and the report is produced and lodged correctly.
However, recommendations can highlight opportunities to reduce energy consumption, improve comfort and lower operating costs.
Any safety defects or issues covered by other legislation should, of course, be dealt with under the relevant requirements.
Is a TM44 inspection the same as air-conditioning maintenance?
No.
A TM44 inspection and routine air-conditioning maintenance have different purposes.
TM44 inspection
A TM44 inspection is an accredited energy assessment that looks at the efficiency, control, sizing and operation of the overall air-conditioning system.
Air-conditioning maintenance
Routine maintenance is intended to keep the equipment operating correctly.
Depending on the equipment, maintenance may include:
- Cleaning filters
- Cleaning heat exchangers and coils
- Checking condensate drains
- Inspecting fans and motors
- Checking electrical components
- Checking controllers and sensors
- Checking refrigerant operation
- Inspecting equipment condition
- Identifying developing faults
A valid TM44 report does not replace regular maintenance.
Likewise, having the equipment serviced annually does not remove the requirement for a TM44 inspection where the system falls within scope.
Is a TM44 inspection the same as an F-Gas inspection?
No.
TM44 requirements and F-Gas requirements are separate.
F-Gas obligations relate principally to fluorinated greenhouse gases used as refrigerants and can include requirements relating to leak prevention, leak checking, records and appropriately certified personnel.
Whether particular F-Gas requirements apply depends on factors including the refrigerant type, refrigerant quantity and the system.
A building may therefore have obligations relating to both TM44 inspections and F-Gas compliance.
A simple TM44 compliance check for facilities managers
If you are unsure whether a building is compliant, start by gathering an up-to-date air-conditioning asset list.
Ideally, record:
- Outdoor unit manufacturer and model
- Indoor unit manufacturer and model
- Cooling capacity
- System type
- Which indoor units connect to which outdoor systems
- Building or area served
- Control arrangement
- Date of installation where known
- Maintenance history
Then establish which systems fall under common technical control.
If the combined effective rated output is around 12 kW or greater, have the system capacity reviewed properly to establish whether it exceeds the statutory threshold.
You should also locate the current Air Conditioning Inspection Report and check when the next inspection is due.
Frequently Asked Questions
What size air-conditioning system needs a TM44 inspection?
In England and Wales, an air-conditioning energy inspection is required where the effective rated output of the air-conditioning system is more than 12 kW.
Is the 12 kW TM44 limit per air-conditioning unit?
No.
Several smaller systems can count towards the threshold where they form air-conditioning systems under the control of the same person.
Do multiple split air conditioners count together?
They can.
For example, several 2.5 kW, 3.5 kW or 5 kW split systems may individually be below the threshold but collectively exceed 12 kW.
The installation and control arrangements should be reviewed to establish the effective rated output of the relevant system.
How often does a TM44 inspection need to be carried out?
No more than five years should pass between inspections for an air-conditioning system that falls within scope.
Is annual air-conditioning maintenance the same as a TM44 inspection?
No.
Routine servicing maintains the equipment. A TM44 inspection is an accredited energy assessment of the air-conditioning system.
One does not replace the other.
Who is responsible for arranging a TM44 inspection?
Responsibility normally rests with the person who controls the technical operation of the air-conditioning system.
Depending on the building arrangements, this may be the owner, landlord, tenant, occupier or facilities manager.
What happens if I take over a building without a TM44 report?
Where you take control of an air-conditioning system that is subject to the regulations and the existing report is not provided, an inspection will generally need to be arranged within three months of taking control.
Does a TM44 inspection include air-conditioning servicing?
No.
The assessor may consider maintenance condition and records, but the inspection should not be treated as a replacement for routine planned preventative maintenance.
Do I have to carry out every recommendation in the TM44 report?
Not necessarily.
The report contains recommendations intended to improve the energy performance of the system. The Energy Performance of Buildings Regulations do not generally require every recommendation to be implemented, although other legal or safety obligations may apply to particular defects.
Air-Conditioning Surveys, Maintenance and TM44 Remedial Work
Aircon Services supports commercial property owners, facilities managers and businesses across Buckinghamshire, Oxfordshire, London and the South East with the management and maintenance of commercial air-conditioning systems.
We can help with:
- Air-conditioning asset surveys
- Equipment identification and asset registers
- Cooling-capacity checks
- Planned preventative maintenance
- Investigation of control and efficiency issues
- Remedial works arising from TM44 recommendations
- Air-conditioning replacement and upgrade projects
- Commercial air-conditioning servicing
- F-Gas compliant refrigerant works
If you are unsure whether your building’s air-conditioning system exceeds the 12 kW threshold, cannot locate the previous inspection report or need assistance with recommendations identified during a TM44 inspection, contact Aircon Services to arrange a review of your air-conditioning equipment and maintenance requirements.
Next step
Unsure whether your building is in scope, or need help acting on a TM44 report? Contact Aircon Services for a review of your air-conditioning assets, controls and maintenance requirements.
Internal-link suggestions
Sources checked
