The effects of vertical farming on indoor carbon dioxide concentration and fresh air energy consumption in office buildings

Abstract

Common pollutants in indoor air include carbon dioxide (CO2), particulate matter (PM) and volatile organic compounds (VOC). Apart from ventilation and dilution method, there are currently many practical filtration and absorption methods for PM and VOC pollutants. However, most of these approaches are not applicable for reducing indoor CO2 concentration. The introduction of vertical farming (VF) into buildings is one of the latest directions in ecological design, which can absorb CO2 and release oxygen based on the plant photosynthesis. Office buildings are particularly suitable for integrated VF due to their spatial form, working hours and other characteristics. In this study, the effect of VF on indoor CO2 concentration was investigated in an enclosed office. Additionally, the reduction in building ventilating energy consumption by using the VF was assessed. Results concluded that the CO2 absorption rate of the VF vegetables can be up to 9.2 times higher than that of shade-loving landscape plants owing to higher net photosynthetic rate (NPR). And also, for a normal 30 m2 office with 1–3 occupants, the indoor CO2 concentration of a 100-plant-scale VF could be reduced by 25.7%–34.3% resulting in a reduction in building ventilating energy consumption by 12.7%–58.4% on the basis of the number of occupants and growth status of VF.