The first TM44 Inspection conventions have been released.

These conventions, issued by CLG, and published by BRE, flesh out the vague parts of the TM44 inspection methodology.

The full report by BRE can be viewed here.

TM44 Inspection sampling rules.

Of particular interest to air conditioning inspectors, such as myself, is the sampling regulations. These include:

  • All central chiller plant must be inspected
  • A minimum or 10 or 30% of all AHUs must be inspected – this includes central air handling plant that does NOT provide cooling, but is part of a system that does. In other words, supply (cooled, heated or ambient fresh) and extract units that deliver to a zone which is cooled via another system, MUST also be inspected.
  • A minimum of 3 or 10% of all outdoor condenser units must be inspected – the same applies for indoor evaporator units.
  • Terminal units (FCUs) for centralised systems must have a minimum of 5 or 2% inspected, with a maximum of 20 units on large systems.

Whilst the minimum numbers above must be adhered to, the assessor must inspect at least one of each manufacturer present, also taking into account the age, size and capacity of the components.

This places quite a heavy burden on the assessor during inspection and system owners should be aware that any assessor cutting corners here, will reduce the effectiveness of his findings, and in any case would invalidate the final report. Make sure your assessor has been properly trained by a recognizable company, such as BRE, CIBSE, HVCA, RICS.