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 ??
' {5 `1 [$ D9 u7 N" a. [
0 l. E0 E6 l; Z7 ^& G& s
2 `5 v% k* q4 _8 }; n$ Iwho can explain why use R30 for attic.
$ T/ L( o' s' g7 C$ i5 j
2 N3 b+ q- V2 n) k) H6 r* oThanks

爱城飞雪

1# KochFord
' O5 }, f# V% s$ P) V, gThe 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.
Hope my answer helps.

爱城飞雪

1# KochFord
. M  U! S/ g  U& a
* [/ o0 ?5 X4 @9 p
5 k. I  F6 y; Y% ]3 cR19 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