The rubber meets the road on reflectix s website where it says no air space no reflective insulation benefit.
Reflective bubble insulation r value.
If you install 2 layers of a reflective insulation does the r value double.
If the product is simply doubled with no air space between the layers a very minimal benefit is obtained r 1 1 per layer for the reflective double bubble.
Standard insulation is tested as a material with an r value per inch of thickness for example r 13 for 3 5 quot.
Any bubble insulation that is approximately thick can only achieve an average r value of 1 to 1 5 on its own.
Air space equals r value.
After all the trouble of trying to keep the bubble wrap off the ducts the total r value would be 2 instead of 1 which may be insufficient to prevent condensation under some conditions.
Some products say r4 r6 or r8.
In contrast reflectix is always tested as part of an assembly e g.
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All our reflective double bubble products.
Of owens corning fiberglass and r 5 per inch with foamular foam board.
Are two layers of polyethylene industrialized air bubbles bonded between exterior.
Double bubble insulation is the most effective bubble insulation with highest r value.
The approximate r value of the air space would be about 1.
Although prodex total is not a foil faced bubble wrap we will answer the author s question because foil faced bubble wrap is a reflective insulation that deserves a defense.
With multiple layers of product and airspaces between each layer enhanced performance will be gained.
It does as you point out change the conductive properties.
An r 1 1 is provided from the product itself for the reflective double bubble material.
Insulation companies who make metallic bubble wrap or their distributors like to boast about their products attributes and often add the equivalent reflective r values to the conductive values giving an overall equivalent r value.
A simulated wall with 2x4 studs dry wall an air space and layer of reflectix.
Any additional r value is achieved by the use of dead air spaces around the reflective product or in used in conjunction with other mass insulation products like fiberglass foam etc.
Our double bubble products are ideal for metal buildings where the control of condensation is necessary.
Double bubble insulation provides the maximum efficiency and highest r value for bubble insulation.
Key benefits of this foil faced double bubble include.
The r value of reflective insulation is not measured by the inch.
400sqft double bubble reflective foil insulation 4 x 100 ft roll industrial strength commercial grade no tear radiant barrier wrap weatherproofing attics windows garages rv s ducts more 4 4 out of 5 stars 56.