陽臺通風影響瓦斯熱水器一氧化碳累積之研究

Accumvlation of CO from Gas Water Heater on Balconies

每年冬天天冷或是寒流來襲時，因熱水器的使用或配置不當，造成全台各地一氧化碳中毒事件頻傳。然而造成一氧化碳中毒事件頻頻發生的主要原因是因天冷而緊閉門窗，使得通風不良，此時，瓦斯熱水器燃燒效率不佳、且熱水器老舊，再加上長期寒流來襲，大家都把熱水器火力調高，使得這些因素造成燃燒更不完全，產生大量的一氧化碳而造成人員的中毒。研究採用全新的熱水器並以氣體偵測器進行實驗的量測，實驗主要探討密閉空間、風向、開窗面積大小及導管的有無及門窗的阻隔等對於一氧化碳的累積或排除等影響。結果發現在體積約 14m3 的全密閉的陽台空間中，其一氧化碳濃度值可在 15 分鐘高達 1500ppm，人員於此濃度的暴露下即會造成人員昏迷、呼吸及心臟衰竭或死亡等情形；另外，有許多的民眾認為只要開了窗就不會發生中毒的情形，然而事實卻不盡然，實驗發現即使於陽台開了窗，但因開窗方式不佳或風向的影響下也可能導致一氧化碳擴散至室內，其因風向擴散至室內之一氧化碳可於 50 分鐘後達到 100ppm 以上，長時間的暴露也會有頭痛、虛弱的情形產生。因此，密閉空間、導管的有無、開窗對流面積的大小、門窗的阻隔及風向等皆會影響著一氧化碳累積的與否。故建議對於新安裝熱水器之民眾，應遵守剛通過之法令，由合格技術人員安裝熱水器，對於現有熱水器，應檢討安裝位置，除了絕對不可安裝在浴室內之外，對於安裝於密閉陽台的熱水器視為室內熱水器，應立即遷至室外，而陽台也應給予足夠的空氣對流面積產生有效對流以減少一氧化碳的累積。

CO poisoning induced by incomplete combustion of water heater gas has become a common occurrence in the winter in Taiwan. People are inclined to close their balcony windows tightly to keep the cold air out, which results in poor ventilation. In addition, they like to turn up the temperature of the water heaters which might cause incomplete combustion in old or over-used heaters. The large amount of carbon monoxide generated from the water heaters threatens users’ lives because of its poisonous nature. A study was carried out using new water heaters and gas detectors to investigate the characteristics of carbon monoxide accumulation by taking factors such as enclosed space, wind direction, and area of the windows into consideration. The concentration of carbon monoxide in one case reached 1,500 ppm in 15 minutes, which was high enough to cause human beings to pass out, experience breathing difficulties and heart failure, and die. According to one experiment, the concentration of carbon monoxide can reach 100 ppm within 50 minutes in the room next to the balcony even with the outside window of the balcony open. Long exposure to such a concentration can cause headache and dizziness. The study results suggest that new water heaters should be installed by qualified technicians, and that old heaters should be checked for their location. Water heaters installed on enclosed balconies should be treated as indoor heaters, and they should be moved outside immediately and enough air circulation areas must be provided to prevent the accumulation of CO.