Extreme weather triggers AC overload

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1. Tim Renouf

   July 23, 2018

   Very important climate story from California. Add to this the 30 people so far that have died in the current Japan 40degC heatwaves. Add to this the week long Victorian heatwave in January 2009 that killed 347 people. The common denominator? Radiation.

   It’s time for mandatory reflective foil insulation at roof level for all new housing across Australia, which strangely was put in motion in 2013 by Standards Australia, with wide support from several industries, but it died an unexplained death.

   The science of aluminium foil in reducing high intensity radiation is well established, the first sale of foil ‘sisalation’ occurring in 1953, to a church roof in Melbourne. I should know, my father Ted Renouf made the sale, and he went on to found RENHURST Industries making RENFOIL. The relevance of this personal history?

   AIRAH sits on Standards Committee BD58 responsible for the suite of three insulation standards, and needs to make a stand and publicly declare support for radiation control in residential roof spaces. In particular, the absolute necessity to have ‘real world, evidence-based’ thermal regulations, in order to reassure the public that when they are compelled to adopt thermal regulations, such regulations must be anchored on Australian standards that have ‘demonstrated real NET BENEFIT’. Air-conditioning ductwork must be protected from the impact of 50-70degC temperatures, which overwhelms the capacity of standard fibrous insulation around the outer circumference of the duct.

   Standard ductwork insulation is laboratory tested at Steady State for 4 hours at a ‘mean’ temperature of 23degC (derived between 33&13deg fixed temperature plates), as is all bulk insulation. In hot climates, when chilled air is traversing through residential ductwork, it frequently rises in temperature. One case story I have is from 9 to 19 degC, a rise of 10degC. Surely AIRAH members can’t be surprised to hear this? We are talking about systematic underperformance of certain insulation materials, and discussion withheld from the public.

   A revised thermal test method for ductwork, USA FR-72, has been inserted into the major revision of AS/NZS4859 ready for Final Committee BD58 Ballot in 2018. Time is running out. The test method is wrong, it is a heated box without any replication of a downward radiating roof for Australian climatic conditions.

   The independent Governance Review into Standards, April 2018, concluded that a major increase in public participation, at all stages, was needed, and that committees were susceptible to ‘capture’ by vested interests. More or less a repeat of the findings in the 2006 Productivity Commission into Standards Australia. Of course the public should know what is happening inside committees, when they the public are forced to use flawed standards called up in NCC regulations.

   The issues I raise here, if not addressed, will be made infinitely worse if mandatory disclosure of energy performance in residential buildings happens. Wrong insulation performance claims will influence the Star Ratings, that will no doubt form part of sale and rental documentation.

   As a manufacturer of foil insulation products, and having sat on Committee BD58 from 1998-2002, I have written on numerous occasions to Standards Committee BD58, ABCB and ACCC about this subject. Mandatory insulation regulations must be ‘fit for purpose’. Obviously.

   The public confidence about truth and reliability in many government regulations, has lost its moorings. The day of reckoning is here for energy efficiency in residential buildings, and that includes House Star Ratings, and over-insulation of houses in dominant hot climates which contributes to the ‘hox-box’ syndrome, where there is serious talk for splitting energy ratings into separate ‘winter’ and ‘summer’ categories. If you live in a perpetual ‘hot winterless climate’, you need to be extremely careful what insulation you choose, just as the 2014 NEEBP Pitt & Sherry report revealed for the Tropics, where two layers of aluminium foil at ceiling level was needed and no bulk insulation.

   In September 2016 I was profiled in ‘Equilibrium’ about my beliefs. Today I have been more explicit.

   I hope that AIRAH members realise what is at stake here – the Public Interest.

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