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 ??

3 r" C: P* [1 U0 d4 k; P% @* y
who can explain why use R30 for attic.

4 b9 L3 ~: [+ sThanks

爱城飞雪

1# KochFord
, r  g2 A0 F/ P7 y2 RThe 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.
  W% }: q; C; x9 p, i" b, qHope my answer helps.

爱城飞雪

1# KochFord
9 M' t; A! Z) `. R, [; w

, t9 z% G. Z; HR19 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