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 ??

: R7 Z. t& }9 f" {5 m, D% p
who can explain why use R30 for attic.

Thanks

爱城飞雪

1# KochFord
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.
2 [: \5 }+ @& S. xHope my answer helps.

爱城飞雪

1# KochFord
- X; ~: ^& f* }; i& @1 W( d/ u
/ k& l! T: U- n5 Q# |
: d( T5 E5 x8 H6 k4 C$ Z9 k. ^* RR19 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