div class=trans-pagebuttonPage 1button div class=trans-image amp-img class=trans-thumb alt=Page 1: VSH – 2 VSH – 1a VSH – 1b VSH – 3 VSH – 7 VSH – 6b VSH – 6 src=https:reader031fdocumentscoreader031viewer202201292061c7af75acfb8204e21baa0ahtml5thumbnails1jpg width=142 height=106 layout=responsive amp-img divpDIRECTION OF VENTILATIONp pSHAFT LOUVERSp pLEGEND:p pVENTILATION SHAFTp pVSH – 4p pVSH – 5p pVSH – 3p pVSH – 1ap pVSH – 1bp pVSH – 2p pVSH – 6p pVSH – 6bp pVSH – 6ap pVSH – 7p pVSH – 8p pVSH – 11p pVSH – 10p pVSH – 9p p714pdiv