一、屋頂通風器的工作原理
屋頂通風器是(shi)依靠(kao)自然風壓(ya)(ya)和(he)熱壓(ya)(ya)實(shi)現(xian)室(shi)內外(wai)空氣的(de)流(liu)動與置(zhi)換,從而達到改善(shan)空氣質(zhi)量的(de)目(mu)的(de)。風壓(ya)(ya)和(he)熱壓(ya)(ya)是(shi)屋頂(ding)通風器最基本的(de)動力。
1、風壓作用下的自然通風
當(dang)風(feng)(feng)(feng)吹向建(jian)筑(zhu)物時(shi),建(jian)筑(zhu)物對風(feng)(feng)(feng)有(you)(you)阻擋(dang)作(zuo)用,在(zai)迎(ying)風(feng)(feng)(feng)面產(chan)生正壓(ya)(ya)(ya)力(li),在(zai)建(jian)筑(zhu)的(de)(de)(de)(de)各個側面及背面形(xing)成負壓(ya)(ya)(ya)力(li)。屋頂自然通(tong)(tong)(tong)風(feng)(feng)(feng)器(qi)(qi)風(feng)(feng)(feng)壓(ya)(ya)(ya)通(tong)(tong)(tong)風(feng)(feng)(feng)就是利用建(jian)筑(zhu)的(de)(de)(de)(de)迎(ying)風(feng)(feng)(feng)面和(he)背風(feng)(feng)(feng)面之間的(de)(de)(de)(de)壓(ya)(ya)(ya)力(li)差(cha)實現空(kong)氣的(de)(de)(de)(de)流通(tong)(tong)(tong)。壓(ya)(ya)(ya)力(li)差(cha)是影響通(tong)(tong)(tong)風(feng)(feng)(feng)的(de)(de)(de)(de)關(guan)鍵(jian)因(yin)素。壓(ya)(ya)(ya)力(li)差(cha)的(de)(de)(de)(de)大小與(yu)建(jian)筑(zhu)的(de)(de)(de)(de)造型、建(jian)筑(zhu)周圍環境和(he)建(jian)筑(zhu)與(yu)風(feng)(feng)(feng)向的(de)(de)(de)(de)夾角(jiao)有(you)(you)關(guan)系。另(ling)外,屋頂通(tong)(tong)(tong)風(feng)(feng)(feng)器(qi)(qi)流動空(kong)氣的(de)(de)(de)(de)壓(ya)(ya)(ya)力(li)隨其(qi)速度的(de)(de)(de)(de)增加而減小,這樣(yang)就形(xing)成了低壓(ya)(ya)(ya)區。根據(ju)屋頂自然通(tong)(tong)(tong)風(feng)(feng)(feng)器(qi)(qi)的(de)(de)(de)(de)這種原理,在(zai)設(she)計屋頂自然通(tong)(tong)(tong)風(feng)(feng)(feng)器(qi)(qi)時(shi),要注意通(tong)(tong)(tong)風(feng)(feng)(feng)器(qi)(qi)的(de)(de)(de)(de)安裝位置。
2、熱壓作用下的自然通風
屋(wu)(wu)(wu)頂通(tong)(tong)(tong)風(feng)器(qi)的(de)(de)(de)(de)另一原(yuan)理是利用(yong)(yong)建筑(zhu)內(nei)部(bu)空氣(qi)(qi)的(de)(de)(de)(de)熱壓(ya)差(cha)(cha),即(ji)通(tong)(tong)(tong)常講的(de)(de)(de)(de)“煙囪(cong)效(xiao)應(ying)”來(lai)實現(xian)建筑(zhu)的(de)(de)(de)(de)自然通(tong)(tong)(tong)風(feng)。利用(yong)(yong)熱空氣(qi)(qi)上(shang)升的(de)(de)(de)(de)原(yuan)理,在建筑(zhu)上(shang)部(bu)設排風(feng)口(kou)(kou)可將污濁的(de)(de)(de)(de)熱空氣(qi)(qi)從室(shi)(shi)內(nei)排出(chu),室(shi)(shi)外新鮮的(de)(de)(de)(de)空氣(qi)(qi)則(ze)(ze)從建筑(zhu)周(zhou)圍的(de)(de)(de)(de)通(tong)(tong)(tong)風(feng)口(kou)(kou)被(bei)吸(xi)人。熱壓(ya)作(zuo)用(yong)(yong)與(yu)進、出(chu)風(feng)口(kou)(kou)的(de)(de)(de)(de)高差(cha)(cha)和(he)室(shi)(shi)內(nei)外的(de)(de)(de)(de)溫差(cha)(cha)有(you)關,室(shi)(shi)內(nei)外溫差(cha)(cha)和(he)進、出(chu)風(feng)口(kou)(kou)的(de)(de)(de)(de)高差(cha)(cha)越(yue)大(da),則(ze)(ze)熱壓(ya)作(zuo)用(yong)(yong)越(yue)明顯。屋(wu)(wu)(wu)頂通(tong)(tong)(tong)風(feng)器(qi)在建筑(zhu)設計中(zhong),可利用(yong)(yong)建筑(zhu)物內(nei)部(bu)貫穿多層的(de)(de)(de)(de)豎向(xiang)空腔(qiang)。在夏季,可將閥(fa)板打開,就像是大(da)型的(de)(de)(de)(de)天窗(chuang)。這樣(yang),經(jing)過屋(wu)(wu)(wu)頂通(tong)(tong)(tong)風(feng)器(qi)冷(leng)卻的(de)(de)(de)(de)冷(leng)空氣(qi)(qi)便(bian)可吹向(xiang)內(nei)部(bu),而(er)室(shi)(shi)內(nei)的(de)(de)(de)(de)熱空氣(qi)(qi)則(ze)(ze)由屋(wu)(wu)(wu)頂通(tong)(tong)(tong)風(feng)器(qi)排出(chu)。除此(ci)以外,屋(wu)(wu)(wu)頂通(tong)(tong)(tong)風(feng)器(qi)還(huan)設有(you)調(diao)節室(shi)(shi)溫的(de)(de)(de)(de)啟閉系統。
二、屋頂通風器的優點
1、省電:屋(wu)頂通(tong)風(feng)器不需要使用(yong)電力,通(tong)過自然氣流實現通(tong)風(feng),具有(you)節能環保(bao)的優點。
2、安全:相(xiang)比(bi)于(yu)電力驅動的通(tong)風(feng)設備,屋頂通(tong)風(feng)器不易發生火災(zai)和爆炸(zha)等事故(gu),提高了安全性(xing)。
3、通(tong)風效果(guo)好:屋頂通(tong)風器(qi)能(neng)夠通(tong)過自(zi)然氣流(liu)形成氣流(liu)循環(huan),從而能(neng)夠有效地排出內的有害氣體和煙霧,保(bao)持空氣清新。
4、低(di)維(wei)護成本:由(you)于屋頂通(tong)風器沒有電動部分,因此維(wei)護成本相對(dui)較低(di)。
5、安裝方便:屋頂通風器的安裝相對(dui)較簡單,不(bu)需要(yao)進行復雜的電氣布線等工作。
三、屋頂通風器的缺點
1、受(shou)天氣(qi)影(ying)(ying)響(xiang):屋頂通風(feng)器的通風(feng)效(xiao)果會受(shou)到天氣(qi)因(yin)素的影(ying)(ying)響(xiang),如無風(feng)或風(feng)速較(jiao)低時,通風(feng)效(xiao)果不佳。
2、不能精(jing)確調節(jie):由于屋(wu)頂通(tong)風(feng)器不能精(jing)確調節(jie)通(tong)風(feng)量,因此在(zai)某些情況下可能需要輔(fu)助(zhu)使用其他通(tong)風(feng)設備(bei)。
3、風噪音較(jiao)大(da):在風速(su)較(jiao)高時,屋頂通(tong)風器可能會產生較(jiao)大(da)的(de)噪音,影響工作環境(jing)。
4、適用范圍有限:屋頂通風器的(de)(de)通風效果和(he)受到(dao)大小和(he)結構的(de)(de)限制,不適(shi)用于某些特殊工藝和(he)環境。