This paper presents an evaluation of the effectiveness of removing air pollutants by installing green vertical walls filled with potted plants. Most people in urban areas spend 80-90% of their lives indoors, indicating the significance of indoor air quality. Carbon dioxide (CO2) and formaldehyde (HCHO) are the most common sources of indoor pollution; their levels can be reduced by using potted plants, which provide the additional benefit of beautification. In accordance with our previous study, for this purpose, we used bird nest fern (Asplenium nidus Linn.), which has a high rate of transpiration and is easy to grow indoors. Upon using 3 treatments involving the release of CO2, HCHO, or CO2 + HCHO, the experimental results showed that bird nest fern can reduce the concentration of CO2 from 2000 ppm to a safe 800 ppm at an average of 1.984 ppm·h−1 (per pot). By contrast, the concentration of HCHO was reduced from 2 ppm to the safe level of 0.1 ppm, at an average of 0.003 ppm·h−1 (per pot). Regarding temperature and humidity, the results showed a decrease of 2°C indoors and an increase of 10% relative humidity. These results show that bird nest fern has high rates of CO2 and HCHO removal, reduces temperature, and raises relative humidity.