無塵車間(jian)壓差(cha)控制的(de)基(ji)本原理是控制送(song)風(feng)、回(hui)風(feng)和排風(feng)。當送(song)入潔凈室的(de)風(feng)量適當大于(yu)回(hui)風(feng)量和排風(feng)量時，室內可以(yi)保持一定的(de)正壓值。此時，在室內外靜壓差(cha)的(de)作用下，通過松散圍護結構(gou)向(xiang)外泄(xie)漏的(de)風(feng)量與進出(chu)機械的(de)風(feng)量之差(cha)相(xiang)等。

壓差(cha)維(wei)持(chi)的(de)(de)(de)難點在于(yu)機(ji)械送(song)(song)風(feng)量(liang)(liang)(liang)(liang)和(he)出(chu)風(feng)量(liang)(liang)(liang)(liang)的(de)(de)(de)動(dong)態變化(hua)。對于(yu)潔凈空(kong)調(diao)系統，過濾器積聚(ju)的(de)(de)(de)灰塵會(hui)增加(jia)新(xin)(xin)風(feng)和(he)送(song)(song)風(feng)管道(dao)的(de)(de)(de)阻力，影響(xiang)風(feng)量(liang)(liang)(liang)(liang)，排(pai)(pai)風(feng)設備的(de)(de)(de)開啟(qi)和(he)停止也會(hui)導致(zhi)排(pai)(pai)風(feng)量(liang)(liang)(liang)(liang)的(de)(de)(de)變化(hua)。此(ci)外，與走廊、室外相(xiang)鄰也會(hui)因熱壓、風(feng)壓的(de)(de)(de)變化(hua)而影響(xiang)房間的(de)(de)(de)壓差(cha)。因此(ci)，需要經常檢查潔凈室的(de)(de)(de)壓差(cha)，并相(xiang)應調(diao)整(zheng)新(xin)(xin)、送(song)(song)、回、排(pai)(pai)風(feng)通道(dao)的(de)(de)(de)閥門。

維持壓(ya)(ya)(ya)(ya)(ya)差的(de)(de)控(kong)(kong)制(zhi)措(cuo)施(shi)有(you)：(1)回(hui)(hui)風(feng)(feng)口(kou)控(kong)(kong)制(zhi)，即(ji)通(tong)(tong)過(guo)(guo)改(gai)變回(hui)(hui)風(feng)(feng)口(kou)上(shang)(shang)的(de)(de)百(bai)葉(xie)可(ke)(ke)調(diao)格(ge)柵或(huo)阻尼層的(de)(de)阻力(li)(li)來調(diao)節(jie)回(hui)(hui)風(feng)(feng)量(liang)(liang)，從而(er)控(kong)(kong)制(zhi)室(shi)(shi)(shi)內(nei)壓(ya)(ya)(ya)(ya)(ya)力(li)(li)。這是最簡(jian)單(dan)的(de)(de)控(kong)(kong)制(zhi)方(fang)(fang)法，特點是結(jie)構簡(jian)單(dan)，經(jing)濟。格(ge)柵控(kong)(kong)制(zhi)調(diao)節(jie)方(fang)(fang)便，但格(ge)柵不易密(mi)(mi)封，調(diao)節(jie)范圍不大，也會影響氣流方(fang)(fang)向。一(yi)(yi)般采用(yong)初(chu)效泡沫塑料或(huo)初(chu)效無(wu)紡布作為阻尼層，通(tong)(tong)過(guo)(guo)改(gai)變回(hui)(hui)風(feng)(feng)口(kou)的(de)(de)阻力(li)(li)來調(diao)節(jie)回(hui)(hui)風(feng)(feng)量(liang)(liang)，從而(er)控(kong)(kong)制(zhi)室(shi)(shi)(shi)內(nei)外潔凈(jing)室(shi)(shi)(shi)的(de)(de)壓(ya)(ya)(ya)(ya)(ya)差。隨著阻尼層使(shi)用(yong)壽(shou)命的(de)(de)增加，其(qi)阻力(li)(li)增大，室(shi)(shi)(shi)內(nei)正(zheng)(zheng)(zheng)壓(ya)(ya)(ya)(ya)(ya)趨于(yu)(yu)增大，應定期(qi)清洗，阻尼層可(ke)(ke)重復使(shi)用(yong)。(2)余(yu)(yu)壓(ya)(ya)(ya)(ya)(ya)閥(fa)(fa)(fa)(fa)(fa)控(kong)(kong)制(zhi)：手動(dong)或(huo)自動(dong)調(diao)節(jie)余(yu)(yu)壓(ya)(ya)(ya)(ya)(ya)閥(fa)(fa)(fa)(fa)(fa)上(shang)(shang)的(de)(de)平(ping)衡(heng)壓(ya)(ya)(ya)(ya)(ya)塊，改(gai)變壓(ya)(ya)(ya)(ya)(ya)力(li)(li)閥(fa)(fa)(fa)(fa)(fa)的(de)(de)閥(fa)(fa)(fa)(fa)(fa)開(kai)度，實現(xian)室(shi)(shi)(shi)內(nei)壓(ya)(ya)(ya)(ya)(ya)力(li)(li)控(kong)(kong)制(zhi)。余(yu)(yu)壓(ya)(ya)(ya)(ya)(ya)閥(fa)(fa)(fa)(fa)(fa)一(yi)(yi)般位于(yu)(yu)潔凈(jing)室(shi)(shi)(shi)的(de)(de)背風(feng)(feng)墻上(shang)(shang)。采用(yong)這種(zhong)措(cuo)施(shi)時(shi)，潔凈(jing)室(shi)(shi)(shi)中(zhong)應有(you)足夠的(de)(de)剩(sheng)余(yu)(yu)正(zheng)(zheng)(zheng)壓(ya)(ya)(ya)(ya)(ya)。如(ru)果排(pai)氣量(liang)(liang)發生(sheng)變化，應重新(xin)調(diao)整(zheng)余(yu)(yu)壓(ya)(ya)(ya)(ya)(ya)閥(fa)(fa)(fa)(fa)(fa)。余(yu)(yu)壓(ya)(ya)(ya)(ya)(ya)閥(fa)(fa)(fa)(fa)(fa)安(an)裝簡(jian)單(dan)，但長期(qi)使(shi)用(yong)后(hou)關(guan)閉不嚴(yan)密(mi)(mi)。如(ru)果余(yu)(yu)壓(ya)(ya)(ya)(ya)(ya)閥(fa)(fa)(fa)(fa)(fa)全(quan)關(guan)時(shi)室(shi)(shi)(shi)內(nei)正(zheng)(zheng)(zheng)壓(ya)(ya)(ya)(ya)(ya)值仍低于(yu)(yu)要(yao)求值，則需要(yao)用(yong)其(qi)他方(fang)(fang)法控(kong)(kong)制(zhi)控(kong)(kong)制(zhi)室(shi)(shi)(shi)內(nei)部(bu)壓(ya)(ya)(ya)(ya)(ya)差。(3)根(gen)據檢(jian)測到的(de)(de)室(shi)(shi)(shi)內(nei)壓(ya)(ya)(ya)(ya)(ya)力(li)(li)值調(diao)節(jie)回(hui)(hui)風(feng)(feng)閥(fa)(fa)(fa)(fa)(fa)或(huo)排(pai)風(feng)(feng)閥(fa)(fa)(fa)(fa)(fa)，調(diao)節(jie)回(hui)(hui)風(feng)(feng)管(guan)(或(huo)排(pai)風(feng)(feng)管(guan)道)上(shang)(shang)的(de)(de)電動(dong)閥(fa)(fa)(fa)(fa)(fa)，改(gai)變回(hui)(hui)風(feng)(feng)量(liang)(liang)(或(huo)排(pai)風(feng)(feng)量(liang)(liang))，控(kong)(kong)制(zhi)潔凈(jing)室(shi)(shi)(shi)的(de)(de)壓(ya)(ya)(ya)(ya)(ya)力(li)(li)值。(4)差壓(ya)(ya)(ya)(ya)(ya)變送器(qi)(qi)控(kong)(kong)制(zhi)，通(tong)(tong)過(guo)(guo)差壓(ya)(ya)(ya)(ya)(ya)變送器(qi)(qi)檢(jian)測室(shi)(shi)(shi)內(nei)壓(ya)(ya)(ya)(ya)(ya)力(li)(li)，然后(hou)調(diao)節(jie)新(xin)風(feng)(feng)量(liang)(liang)，開(kai)啟(降低)新(xin)風(feng)(feng)(OA)管(guan)道上(shang)(shang)的(de)(de)電動(dong)閥(fa)(fa)(fa)(fa)(fa)(MD)。