CPD PROGRAMME | HVAC an air conditioning inspection to satisfy the requirements of the EU Energy Performance of Buildings Directive. TM44:2012 still provides a standard reference for the various regulatory authorities across the UK. It includes methods, checklists and schedules to inform the completion of a standardised set of reporting templates that may then be used to formally lodge a record of the inspection with the appropriate authority. TM44 provides methods for two levels of air conditioning assessment, known as levels 3 (simple packaged) and 4 (complexed central), that are tied to the accredited competence of the air conditioning assessor. Level 3 assessors would broadly be expected to have the capability to inspect packaged air-to-air heat pumps; unitary packaged units, such as through the wall units; split units (single indoor unit), and multi-splits (with several indoor units) connected by refrigerant pipework to a single outdoor unit; and VRF systems. Any systems that include a significant distribution of air or chilled water are likely to be categorised as complex and require the services of a level 4 assessor. Guidance for both level 3 and level 4 systems include inspections of refrigeration equipment and associated heat exchangers to ensure appropriate operation and effective heat rejection and distribution. Air moving systems for example, fan-powered, ducted ventilation systems are likely to take a more significant place in a level 4 assessment. This includes all components, starting from the external intake grilles through to the registers (such as grilles and diffusers) that deliver the conditioned air into the space, and embraces all the principal components along the way. The operational procedures and system controls, which may be integrated through building management systems, are assessed in some detail, since they are likely to have a significant influence on the operation of the air conditioning systems. The building owner or operator would be expected to provide any available documentation for the systems in readiness for the inspection. The quality, extent and accessibility of relevant information provided prior to an inspection of the system has important consequences for the effectiveness and cost of an air conditioning system inspection. TM44 provides more detailed examples of what information can usefully be provided. Part of the assessors work will be to gauge whether the information properly reflects the installed system. Documentation that clearly evidences that equipment and systems are already subject to regular good practice and appropriate checking and maintenance procedures, Demanding minimum performance requirements for chillers, room air conditions and other packaged units Cooling Air movement fan power and air leakage Minimum energy performance requirements for complete systems Minimum performance requirements integrating building and system characteristics Better operational practice: inspections and energy audits Reduced fresh air in spaces where smoking is now prohibited 0 20 40 60 80 100 120 140 160 180 200 Potential 10-year saving (TWh, 2014-2024) Figure 1: Realisable 10-year savings, 2014-24, from interventions to business as usual in European energy consumption for air conditioning3 will potentially allow the assessor to reduce the extent of the inspection. For the building owner and operator, an inspection should deliver more than simply meeting the statutory requirement, with significant benefit deriving from the knowledge and expertise of the assessor as they highlight how the operation of existing systems can be improved, or identify opportunities to replace older, less energy efficient, or oversized systems. The inspection report would typically include: The likely efficiency of the system and any suggestions for improvement Any faults identified during the inspection and suggested actions The adequacy of equipment maintenance and any suggestions for improvement The adequacy of the installed controls and control settings and any suggestions for improvement The current size of the installed system in relation to the cooling load and any suggestions for improvement Consideration of the capabilities of the system to optimise its performance under typical operating conditions. Advice may also be given on systems that operate with refrigerants that are being phased out, or may have their use and supply restricted owing to environmental regulations. In these cases, the energy assessor may give advice on possible options for future system adaptation to use other refrigerants, or the need for refurbishment and replacement. Only air conditioning inspection reports that have been produced and lodged on the register by accredited energy assessors are accepted as valid by the UK authorities. The intent is that the building operator will act on the advice and key recommendations and, by rectifying faults or by making the appropriate improvements, will contribute to the efficient running of air conditioning systems. This will reduce carbon emissions as well as building operating costs, and the resulting well-run, energy-efficient site could also save on maintenance and reduce the likelihood and the resulting consequences of unexpected systems failures. Air conditioning systems and sensors interrogated and analysed by conditionbased monitoring software, increasingly employing machine learning and big data, can provide intelligence on the need for preventative maintenance to BEFORE ENROLLING A LAY INSPECTOR Before considering site access by a lay inspector, an appropriate health and safety risk assessment should be undertaken and training provided that is appropriate to the site and the expected activity. It is vital that the lay inspector properly understands that access to some areas may temperatures, high pressures, noxious gases and other hazards, as well as the direct or indirect risk they pose to others through their actions. Appropriate personal protective equipment (PPE) would need to be supplied and worn. Lay inspectors must be properly trained so as not to be tempted to open (or potentially make contact with) certain pieces of equipment while they are still operational and, since most systems are automatically controlled, be aware that equipment may suddenly switch on. The building operator would need to ensure that such activities do not compromise insurance and statutory requirements. 78 September 2021 www.cibsejournal.com CIBSE Sep 21 pp77-80 CPD 184.indd 78 27/08/2021 13:58