To conduct the Air Conditioning Energy Inspection (ACEI) an accredited assessor will visit your premises to complete the assessment.  This will be arranged with you in advance and it is really helpful if you have someone available to escort the assessor that is familiar with the building, the systems and their maintenance.  This not only enables the inspection to be conducted in a safe manner, it is also faster and helps to ensure your final report accurately reflects your system and the management processes you have in place.
During the inspection the assessor will examine the refrigeration and air moving equipment that are part of any air conditioning systems present and their controls.  They will also examine any documentation that helps users to understand the system, or indicates the extent to which the system has been maintained.  The energy assessor is also required to estimate whether the system is suitably sized for the cooling loads in the treated spaces and to provide advice on ways in which the performance of the system might be improved.  If you have thermal modelling information and/or a Building Log Book, these should also be made available to the assessor.
Access will be required to equipment that may be located in plant rooms, or outside the building, including rooftops or other locations with limited provision for access.  In all cases the building owner or manager must agree the means for safe access with the energy assessor.  The energy assessor may need to be accompanied by the responsible building manager or maintenance agent to complete the assessment in a safe and efficient manner.
Some additional access may be needed, for example to the inside of air handling units or ducts.  This must be provided and supervised by the responsible building manager or maintenance agent with due regard to the safety of the energy assessor and to building occupants.  Where this requires the system to be turned off, arrangements may need to be made for this outside working hours to avoid disruption to business.  Similarly, the energy assessor may need to access a sample of components, such as fan coil units, which may be hidden above suspended ceilings.  Again, access should be provided by the building manager or maintenance agent.
The building owner or manager should not expect the Air Conditioning Energy Inspection to identify hazards or unsafe aspects of the installation, operation or maintenance of systems.  These should be identified and addressed by other arrangements including regular maintenance inspections.  The survey is also a non-invasive visual inspection only.  The energy assessor cannot fix any problem identified as part of the inspection.  However, as a professional expert in their field, they are always happy to share best practice with you and will highlight any obvious deficiencies or safety concerns that they find.
Equally, Air Conditioning Energy Inspections carried out for the purposes of the Energy Performance of Buildings Regulations are not designed to assess any risks to public health that the system may pose.  However, the assessor will review the management records of the system as part of the assessment and the energy assessor is required to inform the building owner or manager of any potential issues they find.  Additionally, the energy assessor is required to confirm that the relevant person has undertaken the necessary checks to ensure any legionella or other biological risks are properly managed as required by the The Control of Substances Hazardous to Health Regulations 2002.  Again, they are confirming the existence of this documentation, not its accuracy which is best assessed by other specialist professionals.
Further information is available in the Government publication Improving the energy efficiency of our buildings – A guide to air conditioning inspections for buildings, December 2012,  Department for Communities and Local Government, ISBN: 978-1-4098-3725-1.