空調環境相對濕度對水分散失的影響

Abstract

台灣位處亞熱帶，氣候特徵為高溫多雨，全年平均相對濕度皆在70-90%之間，濕熱的環境使得冷氣幾乎成為家家戶戶必備電器。然而，我們自歐美國家引用的空調設備，其相對濕度設定大多低於50%，以台灣高溫高濕的氣候型態而言，實在不需要設定這麼低的相對濕度。本研究希望藉由具體數據說明國內空調系統規範之瑕疵，因地制宜，不僅達到人體舒適，同時符合節能減碳的國際趨勢。 本研究使用木瓜、奇異果及蘋果置入恆溫恆濕箱內，模擬人處於空調環境的情況，藉由調整溫、濕度設定值，觀察失水量的多寡及失水速率的快慢。另外，表面積也是很重要的因素，以單位體積的表面積作為實驗參數之一，並比較不同種類水果間的失水差異。 實驗結果顯示，表面積愈大、溫度愈高、相對濕度愈低，水分散失量愈大，散失速率愈快。當相對濕度從30%提高到45%，在25℃條件下，可減少13.67%的熱能消耗，30℃則可減少24.80%；當相對濕度從45%提高到70%，25℃時可減少14.96%熱能消耗，30℃則可減少22.27%。由此可見，若是將國內空調設備的相對濕度設定在國人習慣的50%-70%，不僅可增加熱舒適度，更能大幅節省能源。

The relative humidity of Taiwan is between 70-90% throughout the year. People living in Taiwan are used to a 50-70% humidity. However, the relative humidity of air-conditioning facilities are usually under 50%, which are not suitable for Taiwan’s climate. The objective of this study is to provide experimental data to explain the flaws of the regulations of Taiwan’s air-conditioning systems. Put papaya, kiwi, and apple into the temperature and humidity chamber to simulate the condition of people staying in air-conditioned space. Then investigate the amount and rate of water loss of the fruits under various temperature and relative humidity. The experimental results show that lager surface area, higher temperature and lower relative humidity lead to more and faster water loss. When the relative humidity increases from 30% to 45%, energy consumption can be reduced by 13.67% under 25℃ and 24.80% under 30℃; when the relative humidity increases from 45% to 70%, energy consumption can be reduced by 14.96% under 25℃ and 22.27% under 30℃. Therefore, set relative humidity for a higher value can not only improve thermal comfort but also save a lot of energy.