In a warm climate, what are the advantages and disadvantages of spray foam versus radiant barrier in attics?
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| Posted in Energy Efficiency and Durability on
What works best and why?
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Replies
Brad,
Briefly, the answer is spray foam.
But honestly, you need to provide more information.
1. Where do you intend to install these products? Under the roof sheathing or on the attic floor?
2. Is there any ductwork in the attic?
3. Is the air handler located in the attic?
4. What problem are you trying to address?
Brad...is you location warm-dry or warm-humid?
I wish the GBA would add "Job Location or Climate Zone" as a "required field" with every question!!!
Assuming you are in a hot climate, the answer in order of preference:
a well insulated ceiling using blown insulation and the ducts and air handler inside the conditioned space
a well insulated ceiling using blown insulation and very tight and well insulated ducts in the attic with an option to go for either a cool roof or a radiant barrier on the roof line if they are not expsnive -- the extra cooling savings might be about 0.1 kWh per square foot
I don't really see the scenario where the foam roof makes much sense unless you want a conditioned attic for other reasons. It's just too expensive given the other options to reduce cooling loads associated with attic and ducts