Open Access

ARTICLE

Temperature Field and Energy Consumption of Natural- and Forced-Convection Radiator Heating in a Small Scale Insulated Greenhouse

Zhenghan Li, Yi Zhang, Yidi Wu, Guanghao Xu, Youtang Wang, Fang He^*
School of Transportation and Vehicle Engineering, Shandong University of Technology, Zibo, China
* Corresponding Author: Fang He. Email:
(This article belongs to the Special Issue: Enhancing Heat and Mass Transfer in Multiphase Systems)

Frontiers in Heat and Mass Transfer https://doi.org/10.32604/fhmt.2026.086816

Received 05 June 2026; Accepted 21 August 2026; Published online 27 August 2026

Abstract

Greenhouses are widely used in agriculture to increase crop productivity, and additional heating is often necessary at night. Conventional natural-convection radiators used in greenhouse heating normally lead to high temperature near the ceiling while low temperatures at the bottom, and thus results in low heat utilization efficiency and high heat loss. The objective of this study was to quantify the effects of forced convection, an easy way to change the temperature field, on temperature uniformity and energy consumption in a small-scale insulated greenhouse at night. A computational fluid dynamics (CFD) model was developed, and an experimental setup was constructed in Zibo, Shandong, China, to validate the model. The average deviation between simulated and measured temperatures at five vertically aligned monitoring points was below 1°C, under representative validation conditions with an outdoor temperature of 2°C and a measured wind speed of 2.3 m/s, confirming the accuracy of the model. Using the model, the effects of airflow velocities ranging from 1 to 3 m/s were analyzed. Results showed that vertical temperature uniformity was significantly improved with increasing airflow initially and then leveled off, while the energy-saving ratio first increased and then declined. Compared with natural convection, forced convection at 2 m/s reduced the maximum vertical temperature difference from 13°C to 2°C and achieved an energy-saving ratio of approximately 29%. The results provide a useful reference for heating operation in greenhouses.

---

Keywords

Greenhouse; forced convection; energy saving; numerical simulation; experimental validation

---