EcoRenovator - View Single Post - Space Suit = Multi-Layer Insulation (MLI)

gtojohn · 08-23-14, 04:05 PM

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[/IMG]I've been trying a multi layer radiant attic myself. No veil, just large breezy air gaps. Spray on radiant on the decking, kitchen foil on 2x4 rafters, radiant [IMG][IMG]

[/IMG][/IMG]double bubble across the collar ties and now the attic floor with r-6 foil faced fiberglass duct wrap. A roll is 4'x75' and if I remember costs me around $120. Temperature on the top of the attic floor foil has been no more than 2 degrees over outdoor high temp, 104f on a 102f day. On the few recent days we've had below 100 I've had a few max temps below outdoor max. Temp measured below the foil and r-6 has been about 4 degrees below outdoor ambient, 96 on a 100 degree day. All of this is on top of a R-38 attic. The additional benefit of the floor barrier is it covers the R-8 Flex and reduces heat gain into the ductwork.

08-23-14, 04:05 PM	#14
gtojohn Journeyman EcoRenovator Join Date: Jul 2014 Location: Austin, TX Posts: 314 Thanks: 39 Thanked 50 Times in 45 Posts	[IMG][/IMG]I've been trying a multi layer radiant attic myself. No veil, just large breezy air gaps. Spray on radiant on the decking, kitchen foil on 2x4 rafters, radiant [IMG][IMG][/IMG][/IMG]double bubble across the collar ties and now the attic floor with r-6 foil faced fiberglass duct wrap. A roll is 4'x75' and if I remember costs me around $120. Temperature on the top of the attic floor foil has been no more than 2 degrees over outdoor high temp, 104f on a 102f day. On the few recent days we've had below 100 I've had a few max temps below outdoor max. Temp measured below the foil and r-6 has been about 4 degrees below outdoor ambient, 96 on a 100 degree day. All of this is on top of a R-38 attic. The additional benefit of the floor barrier is it covers the R-8 Flex and reduces heat gain into the ductwork.