九九在线视频精品福利_鉴黄师免费下载app_国产黄a大片真人免费观看_亚欧免费无码?Ⅴ在线观看_被暴雨淋湿的上司躲雨中文字_悠悠中文字幕亚洲精品_人与动另类z0z0欧美视频_一级 片内射视频播放_色婷婷久久综合一区二区三区_gogogo高清在线观看中国

R-value is the measuring tool we use to rate the level of thermal resistance. Essentially, the higher the R-Value the more effective the insulation is.

‘Up’ R-values describe resistance to heat flow upwards (sometimes known as ‘winter’ R-values).

‘Down’ R-values describe resistance to heat flow downwards (sometimes known as ‘summer’ R-values).