how much difference between R19 and R20 insulation, need help, thanks

KochFord

how much difference in price and quality between R19 and R20 per square feet ??

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3 [9 b: `9 h2 |' t/ |! _9 pwho can explain why use R30 for attic.
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0 e4 A0 H8 p, o7 j) [- n4 IThanks

爱城飞雪

1# KochFord
8 ~7 Y9 Q0 b' x( ]The higher R value, The better insulation performance.
In winter, the hot air always floats up due to thermal buoyancy, so R value for the roof is normally higher than that for exterior wall.
  a5 [) `0 T4 M3 U; [Hope my answer helps.

爱城飞雪

1# KochFord
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& e( o# e* u7 q# N! V" L5 iR19 is not commonly used.

chic-yong

R值固然重要，但隔热材料更重要。即使R值相同，不同的隔热材料性能也是不一样的。

KochFord

谢谢楼上两位