Flexible ducting is used in commercial and residential air conditioning to join the room opening (diffuser) to the air conditioning unit.
Prior to the early 1990's, all flexible ductwork that was insulated used glasswool. Over the intervening period, polyester has gained in market share. Factors that have contributed to the popularity in polyester include it's cost advantage over glasswool at very low grammages. However, these cheap polyester insulation products are not good insulators. A lack of testing and policing of insulation performance has allowed these products to flourish.
However, in recent times we have seen a renewed focus on the performance of flexible duct insulation, for both commercial and residential buildings due to changes in the BCA aimed at improving the energy efficiency of new buildings. These changes call for higher levels of insulation for flexible duct insulation as shown in the new BCA requirements laid out in the PDF available in the attachments section below.
Further, government bodies such as the DEWHA and the ACCC have identified that these are issues with poor performing flexible duct insulation and have taken steps to ensure that manufacturers' product meet the performance requirements that are claimed.
Fletcher Insulation™ markets a range of glasswool insulation products for flexible duct including R1.0, R1.5 AND R1.8 and guarantees the performance of these products.