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 ??

8 k0 z  V. C# _4 d7 a- i9 h
) X" ~- `( I3 ?* N0 C" ?  c/ rwho can explain why use R30 for attic.

Thanks

爱城飞雪

1# KochFord
8 r$ H3 d# W  A' b$ x+ h. Z1 I3 bThe higher R value, The better insulation performance.
# A- W, T2 Z  J$ cIn 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.
1 ?# r+ P2 Z3 vHope my answer helps.

爱城飞雪

1# KochFord
2 d  p( W  O' x4 @2 \- a* w
6 V1 W. ~# w& U- m
R19 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