###### Abstract
By appropriately increasing the airflow rate, the transpiration rate of the crop can be significantly enhanced, thus reducing the occurrence of tip burn in the lettuce. Similarly, [PERSON] et al. (2019) found that increasing the inlet air velocity resulted in a reduction in air temperature and an increase in indoor relative humidity levels within small plant factories [12]. This indicates that manipulating the air supply can help regulate the temperature and humidity conditions, thus creating a more favorable environment for crop growth. However, it is important to note that simply increasing the inlet airflow does not always result in improved climate uniformity within the crop canopy. [PERSON] et al. (2022) highlighted in their study that a high inlet mass flow does not necessarily lead to better uniformity. Instead, they found that by carefully designing the layout of inlets and outlets, favorable climate uniformity within the crop canopy can be achieved even at lower inlet mass flow rates [28]. This emphasizes the significance of considering the overall ventilation design and air distribution system in plant factories. Simply increasing the inlet airflow may not always be the most effective solution for achieving climate uniformity in plant factories. According to the current mainstream classification method, plant factories can be divided into three categories: natural light plant factories, natural light and artificial light combined plant factories, and artificial light plant factories. Due to the differences in structure and light source between natural light plant factories and artificial light plants, the environmental control methods they use are also significantly different. For natural light-type plant factories that mainly rely on natural light sources, the main heat source comes from the external environment, and the indoor environment control needs to be adjusted according to parameters such as the external solar radiation intensity and the indoor and outdoor temperature difference. Therefore, their main methods of environmental control are ventilation devices (such as natural or mechanical ventilation through side openings and top windows), movable sunshades, wet curtain-fan cooling systems, internal circulation fans, etc. For plant factories that use artificial light sources, their external structure is an opaque, highly heat-insulating closed structure, and the indoor heat source mainly comes from the heat dissipation of artificial light sources. Therefore, the main environmental control method for this type of plant factory is air conditioning plus fan air supply. Extensive research has focused on improving the uniformity of indoor climate in plant factories by manipulating the position of airflow inlets and outlets, the form of local air supply, and the velocity or volume of air supply. These studies have examined the distribution of airflow, air temperature, and relative humidity within the plant factory. However, some studies have overlooked the effect of crop cultivation on airflow and have not considered the impact of the air supply system on indoor climate when analyzing the effect of crop presence on airflow [29]. In comparison to well-established greenhouse ventilation techniques [30; 31; 32; 33], this study aims to incorporate the influence of crop cultivation patterns and changes in inlet airflow on indoor airflow, temperature, and relative humidity distribution and uniformity. In order to investigate the effects of crop cultivation patterns and indoor ventilation on airflow and heat transfer above the crops in a plant factory, CFD simulations are employed. The objective of the simulation is to investigate the airflow velocity, temperature, and relative humidity distribution above the crop canopy at different crop densities and _ACHs_ in the plant factory. In addition, the joint effects of crop transpiration and heat generated by artificial lighting on the airflow patterns are also considered.