Does not consider presence absence of reflective barriers.
Roof insulation r value per inch.
For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721.
The higher the r value the greater the insulation performance.
Does not consider internal convection effects.
All these have r values ranging from r 3 2 to r 3 8 per inch.
The r value of closed cell foam is r 6 5 7 per inch.
Air gap or air film 3 4 air space insulating properties.
Know exactly how much you need with our project calculators.
To convert rsi to r value multiply the rsi by 5 67826.
When determining how much insulation you need don t guesstimate calculate.
Closed cell spray foam has a far better r value per inch than other less effective insulations like cellulose fiberglass or even open cell foam.
To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826.