TM44 INSPECTION BACKGROUND

Since the 4th January 2011 The Energy Performance of Buildings Directive (EPBD) requires buildings with an effective rated comfort cooling capacity of more than 12 kW to have regular TM44 Air Conditioning inspections completed by an accredited TM44 inspector.

The effective rated output of more than 12kW is defined as buildings that include Air Conditioning systems consisting of individual units which are less than 12kW but whose combined effective rated output is more than 12kW, or single systems rated above 12KW.

Building owners or managers are responsible for ensuring these regular TM44 inspections take place on their buildings Air Conditioning systems throughout the UK, with separate legislation introduced in England and Wales, Scotland and Northern Ireland. Fines for Non-Compliance are £300,

The TM44 inspection frequency is set by the accredited TM44 inspector. However, in England, Wales and Northern Ireland the next inspection must be carried out within five years.

Types Of TM44 Inspection

The two types of Air Conditioning TM44 inspections are:

Simple Level 3 Inspections

These generally exclude centralised cooling systems such as chillers supplying a chilled water flow/return system and/or mechanical ventilation systems.

Typical systems include variable refrigerant flow (VRF) systems that are not used in conjunction with centralised mechanical ventilation systems, unitary packaged units, split packaged units and multi-split packaged units.

Complex Level 4 Inspections

In addition to items covered by simple level 3 inspections these generally include centralised Air Conditioning systems located within basement, rooftop or other plant room locations. They may contain a combination of equipment such evaporative cooling towers, dry air coolers, air cooled chillers, water cooled chillers that produce chilled water distributed to a range of fan coil units or air handling units throughout the building. Centralised Building Management Systems (BMS) controls systems may also exist to help manage the systems sequencing and maximise energy efficiency.

TM44 INSPECTION PROCESS

The TM44 inspection process required under the EPBD will examine the refrigeration equipment and air movement systems that are part of Air Conditioning systems, including their controls. It will also examine any documentation that helps understand the systems, or indicates the extent to which the systems have been maintained. We are 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 improvement might be made to the energy efficiency of the system.

TM44 INSPECTION REPORT

The purpose of the TM44 inspection report (also known as a TM44 inspection certificate) is to ensure that the building owner or manager is provided with information regarding the efficiency of the Air Conditioning systems that they control. This includes advice on how to improve the energy efficiency of the system, to identify opportunities to save energy and to reduce operating costs.

TM44 INSPECTION SCOPE

Refrigeration

Refrigeration equipment and its associated heat exchange systems are checked only briefly during the HVAC TM44 inspection of Air Conditioning systems. The TM44 Air Conditioning inspection looks primarily for indicators of damage or lack of maintenance that would significantly reduce efficiency from the ‘as new’ state, and does not provide a high level of detail.

Air movement systems

Where installed as part of the system to provide cooling, air movement systems are an important aspect of the TM44 Air Conditioning inspection. The contribution that fans make to the total annual energy consumption of the combined cooling system is likely to be higher than that of the refrigeration plant itself, and there may be a greater potential for improvement.

Controls

Air Conditioning system controls are inspected in more detail. There could be considerable scope to identify inefficiency due to inappropriate control methods, incorrect control settings and poorly located sensors, and there could be much potential for improvement at low cost. Although discovered ‘faults’ may only be time switches or cooling or heating sensors being incorrectly set, the TM44 inspector would not have any authority to reset them but only to report to the manager.

Documentation

A number of the issues to be assessed as part of the procedure may be found by examining documentation describing the installed Air Conditioning systems and their commissioning results. As an example, the specific fan power (SFP) of air supply and exhaust systems may be calculated from details of the installed plant and commissioning flowrates, for comparison with current guidance.

Maintenance

Evidence is sought of any existing planned maintenance schedules, or of other recent maintenance activities. Where documentation clearly shows that AC equipment and systems are already the subject of regular good practice checking and maintenance procedures, a number of aspects of the required TM44 inspection and provision of advice may be omitted.

Advice On Improvement Options

Three levels of practice are likely to be encountered when Air Conditioning systems are inspected:

• systems where efficiency is clearly impaired due to faults, neglect or misuse
• systems where efficiency is likely to be lower than currently ‘accepted’ due to aspects of design or use
• systems that are acceptably efficient.

Given the need for simplicity and consistency, the TM44 inspection will mostly provide a combination of aspects of 1) and 2) only. However, best practice aspects may be provided on a generalised basis by providing reference to other published guidance sources.

A further category of advice which may also be given concerns some systems which may be older and operate with refrigerants which are being phased out, or having their use and supply restricted, under regulations relating to ozone depleting substances. In these cases the TM44 inspector may give advice on possible options for future system adaptation to use other refrigerants, or complete replacement. This advice will need to be supplemented by a more detailed assessment when modifications or replacement are to be undertaken.

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