實(shi)驗室通(tong)(tong)(tong)風(feng)系統(tong)，其中(zhong)，主要的(de)(de)是實(shi)驗內容和有害物(wu)(wu)的(de)(de)性(xing)質(zhi)。通(tong)(tong)(tong)常規定(ding)，一般無毒(du)(du)的(de)(de)污染物(wu)(wu)為(wei)(wei)(wei)0.25―0.38m/s，有毒(du)(du)或(huo)(huo)有危險的(de)(de)有害物(wu)(wu)為(wei)(wei)(wei)0.4―0.5 m/s ，劇毒(du)(du)或(huo)(huo)有少量放射性(xing)為(wei)(wei)(wei)0.5―0.6m/s，氣狀(zhuang)物(wu)(wu)為(wei)(wei)(wei)0.5m/s，粒狀(zhuang)物(wu)(wu)為(wei)(wei)(wei)1m/s。為(wei)(wei)(wei)了確保這樣的(de)(de)風(feng)速，排(pai)風(feng)機(ji)應有必要的(de)(de)靜壓，即空(kong)氣通(tong)(tong)(tong)過通(tong)(tong)(tong)風(feng)管(guan)(guan)道(dao)時(shi)的(de)(de)摩擦阻力。另外，確定(ding)風(feng)速時(shi)還須(xu)***注意(yi)噪(zao)(zao)音問題。通(tong)(tong)(tong)過空(kong)氣在管(guan)(guan)道(dao)內流動(dong)時(shi)以7―10m為(wei)(wei)(wei)限(xian)，超(chao)過10m將產生噪(zao)(zao)音，通(tong)(tong)(tong)常實(shi)驗室的(de)(de)(室內背景噪(zao)(zao)聲級)噪(zao)(zao)聲限(xian)制值為(wei)(wei)(wei)70dBA。增加管(guan)(guan)道(dao)裁(cai)面積會降(jiang)低風(feng)速，也(ye)就降(jiang)低了噪(zao)(zao)音。考慮到管(guan)(guan)道(dao)的(de)(de)經費(fei)和施工問題，須(xu)***慎重選擇管(guan)(guan)道(dao)及排(pai)風(feng)機(ji)的(de)(de)功率。
