It is necessary to understand humid air condensation because of its various applications, such as water harvesting, and environment control and life support systems. Improvement of the heat transfer rate by facilitating condensate removal (shedding of droplets) from the surface can decrease operational costs. Droplets can be shed by using airflow. Parameters such as relative humidity (RH), airflow velocity, and subcooling (T_sc) play a substantial role in condensation and heat transfer rate. Therefore, understanding the effect of these parameters is essential to analyze and evaluate the performance of the systems reliant on condensation. Firstly, this work is dedicated to investigating the influence of airflow on the condensation heat transfer coefficient (HTC) of humid air on a horizontal surface. A mini closed-looped wind tunnel was used to simulate the condensation environment and control condensation parameters. Airflow velocities from 1 to 15 m/s were investigated because the condensate's shedding usually happens in this range. Also, an RH of 1080% and T_sc of 010C were used to achieve both single-phase and condensation regimes. Transient and instantaneous heat flux measurements were required to study the relationship between condensate morphology and HTC. To facilitate this, a transient inverse heat conduction method was used to characterize the time-varying surface heat flux and associated HTC. A 5-fold decrease in response time was found for the transient method compared to the steady-state method. The effect of condensation parameters on the HTC and the relationship between condensate morphology and HTC is discussed. The results show that HTC for the subcooling of T = 0C is smaller than for other temperatures. Also, the effect of RH on condensation was investigated, and higher HTC was found for higher RHs. The results clearly show that the shedding of condensate kept the average droplet size low and doubled heat transfer performance improvement
