Evaluation of Carbon-Sorption Air Cleaner for the Removal of Volatile Organic Compounds

[[abstract]]空氣污染所導致的環境污染與身體健康危害的問題，已普遍受到民眾的關切，民眾購買室內空氣清淨機的數量急遽增加，各類產品不斷問市，然而缺乏其效能評估。本研究乃是利用控制環境條件，於不鏽鋼艙室（Chamber）中進行活性碳吸附空氣清淨機對揮發性有機物去除效率之研究，探討不同機型、不同環境因子及不同吸附材質對揮發性有機物去除之影響，並評估其再釋出作用及其對健康之影響，同時對國內活性碳空氣清淨機標準檢驗方法之建立提供基本參考資料吸附型空氣清淨機之效能可利用控制環境條件下於艙室中進行評估，其標準方法之建立，可參考美國AHAM AC-1 並加以改良，以有效處理風量（clean air deliverrate , CADR）來評估吸附型空氣清淨機去除揮發性有機物之效能。由甲苯吸附實驗結果顯示，僅具活性碳初濾網之空氣清淨機，在使用初期具有去除揮發性有機物之效能，但在使用短時間之後即無法再降低室內揮發性有機物濃度。具有活性碳初濾網及吸附濾材之空氣清淨機，其CADR 較僅具活性碳初濾網之空氣清淨機高出很多，揮發性有機物去除效果明顯較好。在相同操作條件下，室內溫度愈高，空氣清淨機之CADR 值愈低。僅具活性碳初濾網之空氣清淨機對甲醛吸附效果不佳。於室內高溫及高濕條件下， 若未及時更換已吸附飽和之濾網，空氣清淨機將形成一室內揮發性有機物污染來源，形成危害人體健康之潛在因子，尤其在高濕度條件下之污染最需加以防範。[[abstract]]People are indoors about 90% of the time, and indoor air pollutantconcentrations often substantially exceed outdoor levels--creating a staggeringhealthcare cost in Taiwan. There is a big market for air cleaner in Taiwan. However, The widely varying designs of air cleaner make it especially difficult to comparemodels. The purpose of this study is to evaluate the VOCs removal efficiencies ofdifferent air cleaners with carbon filters using controlled environmental chamber.Several experimental parameters including filter type, temperature, humidity and VOCs species have been examined. The CADR (clean air deliver rate) indicates volume of filtered air deliveredby an air cleaner. The results show that it is appropriate to use CADR as anindicator for evaluations of VOCs removing efficiencies between models. Underthe testing condition of 30 ppm of toluene in the chamber, the air cleaner withcarbon pre-filter can capture some toluene in beginning, but the toluene can passthrough the carbon pre-filter after operation time of 16 hours. Another air cleanerwith carbon pre-filter and multi-adsorbent filter shows higher efficiency to trapVOCs. The CARD tests for air cleaner with carbon pre-filter shows poor efficiencyto trap formaldehyde. Under higher temperature and humidity conditions, theindoor air quality and human health risk should be concerned due to there-emissions of VOCs from air cleaners.[[note]]NSC91-EPA-Z327-00