Optimizing Pipe Design for Greenhouse Root-Zone Cooling with Horizontal Ground Heat Exchanger: Impact of Length and Diameter

The aim of developing a horizontal ground heat exchanger (HGHE) is to significantly increase the accuracy of material size to achieve the maximum or ideal temperature decrease, increasing the system's overall efficiency. The purpose of this paper is to examine the impact of different pipe sizes and lengths buried to reduce the inlet water temperature for greenhouse root-zone cooling. The HGHE was installed using 240-m long by 25 mm, 40 mm, and 50 mm high-density polyethylene pipes and buried at a depth of 2.0 m. A parametric analysis was done to look into how pipe lengths and pipe sizes affected the system's exit water temperature. The findings indicate an inverse correlation between the pipe length and the exit water temperature. The study found that the ideal pipe length for designing a system ranged from 180 and 240 meters. Additionally, using a smaller pipe diameter of 25mm is better than using a larger diameter as it improves the system's performance and reduces the overall installation cost.