EXTERNAL OVERVIEW COMMENTARY – PREPARED FEBRUARY 2008

 

TO: Australian Fibreglass Insulation Industry

 

PLEASE EXPLAIN

 

In 1975 you recommended to government** home ceiling insulation - fibreglass thickness levels of:

100mm for Canberra,   75mm for Sydney Melbourne Hobart,

50mm for Adelaide” 

NB: 1975 R-value equivalents 100mm=R2.0, 75mm=R1.5, 50mm=R1.0

     

SO HOW DO YOU JUSTIFY YOUR CONTRADICTORY PRESENT DAY RECOMMENDATION OF R5 (210mm) & R6 (260mm) BATTS ?

 

**Mineral Wool Manufacturers’ Association of Australia – 1975 Submission to Government:

“Mandatory Domestic Insulation-Potential Energy Savings” see keys pages 10,63,72 . 

Report focus: only with heat flow through ceilings under winter conditions.

 

 

 

THE FOLLOWING INDEPENDENT TECHNICAL PAPERS REFUTE THIS RECOMMENDATION:

 

THE LAW OF DIMINISHING RETURNS      *increasing R-value over R2.5 is of little benefit

Refer to CSIRO quotes: http://www.concertinafoilbatts.com/FOIL%20BATT%20FACTS-8.pdf

 

The Diminishing Benefit Of Extra Home Insulation, J.Fricker - 18 April 2002.

The Effect Of Thermal Bridging At Higher R Values, J.Fricker - January, 2003.

***click direct web links

 

AS2627.1(1993) “RECOMMENDED LEVELS OF INSULATION”- IN CEILINGS AND WALLS

Formally withdrawn January 2007, and can no longer be referenced by the building industry or

any energy efficiency regulations or advice bodies.

This Standard(1983 & 1993 versions) was originally funded by the fibreglass industry.

Explanation for the withdrawl: http://www.concertinafoilbatts.com/FOIL_BATT_FACTS-9.pdf

 

____________________________________________________________________________

 

ANY SUGGESTION THAT SINCE 1975, DRAMATICALLY INCREASED R-VALUE LEVELS IN CEILINGS CAN BE JUSTIFIED, BECAUSE OF THE CURRENT DAY WIDESPREAD USE OF REFRIGERATIVE AIRCONDITIONING, IS NOT CORRECT.

 

WHY? BECAUSE BULK INSULATIONS, REGARDLESS OF THICKNESS, ARE

NOT TESTED FOR HIGH TEMPERATURE RADIATION EFFECTS, WHICH IS ONE OF THE TESTING PROTOCOLS LISTED IN THE INSULATION STANDARD AS/NZ4859.1(2002)

BUT NOT ENFORCED.

 

BULK INSULATIONS ARE PERMITTED TO REVEAL R-VALUES MEASURED AT

 “STEADY STATE” AT A MAXIMUM TEMPERATURE OF 33degC CONDUCTED HEAT -

NOT TYPICAL ROOF SPACE RADIANT HEAT EFFECTS OF 60-70degc.

FURTHER REFERENCES: http://www.concertinafoilbatts.com/foilfacts.htm ____________________________________________________________________________

 

CLICK HERE to view Mineral Wool Association Submission to Government (PDF)