The increasing global population and the challenges faced by the food production sector, including urbanization, reduction of arable land, and climatic extremes, necessitate innovative solutions for sustainable agriculture. This comprehensive review examines advancements in improving the energy performance of agricultural greenhouses, highlighting innovations in thermal and energy efficiency, particularly in heating and cooling systems. The methods include a systematic analysis of current technologies and their applications in optimizing greenhouse design and functionality. Key findings reveal significant progress in materials and techniques that enhance energy efficiency and operational sustainability. The review identifies gaps in the current knowledge, such as the need for more research on the economic viability of new materials and the development of predictive models for various climatic conditions. The conclusions emphasize the importance of integrating renewable energy technologies and advanced control systems to achieve energy-efficient and sustainable agricultural practices.

In Mediterranean countries such as Portugal, summer heatwaves increasingly threaten agricultural productivity by disrupting crop physiological processes. Greenhouse cultivation often exacerbates heat stress, while conventional cooling systems such as air conditioning and evaporative cooling impose unsustainable energy demands. This study investigates an Earth-to-Air Heat Exchanger (EAHE) system consisting of a five-tier helical PVC pipe configuration (29 m, buried at a depth of 3 m), installed in a prototype polycarbonate greenhouse in Covilhã, Portugal, and monitored under real summer conditions. Four ventilation scenarios were simulated in EnergyPlus 25.1, and a segmented NTU thermal model, implemented as a Python plugin via the pyenergyplus API, predicted the EAHE outlet temperature with CV(RMSE) values of 1.47% at 30 m³/h and 3.0% at 50 m³/h. The IPMA meteorological dataset provided the best simulation accuracy (RMSE = 2.31 °C, R² = 0.978). In simulations based on the experimentally calibrated models, EAHE preconditioning reduced accumulated heat stress degree-hours above 28 °C by 9.1 to 9.5% and lowered peak indoor temperature by up to 2.60 °C, at system COPs of 6.9 to 10.6, which are 2.3 to 3.5 times higher than conventional vapour-compression cooling; propagated measurement uncertainties confirm the robustness of this COP advantage. A model-based parametric scale analysis indicated that geometrically scaled circuits (DN200, DN400) achieve degree-hour reductions of 67 and 91%, supporting EAHE scalability through geometric proportioning, pending experimental validation at larger scales.

Earth-to-air heat exchangers (EAHEs) use ground thermal inertia to precondition ventilation air, but their representation in whole-building simulation is limited by the simplified geometry and internally defined heat-transfer formulation of the native EnergyPlus ZoneEarthtube model. This study develops a Python/EMS methodology that dynamically couples EnergyPlus with a segmented effectiveness–NTU model driven by the Kusuda–Achenbach ground-temperature formulation. A vertical helical EAHE installed in Covilhã, Portugal, was represented using measured pipe-path lengths and burial depths, with temperatures monitored at five locations (A–E). The model was calibrated using the first 96 observations of dataset E1 at 27.9 m³ h⁻¹, temporally evaluated against the remaining 67 observations, and transferred without refitting to dataset E2 at 51.3 m³ h⁻¹. Across A–E, RMSE values were 1.446 °C for calibration, 1.123 °C for temporal evaluation, and 1.885 °C for transfer. At point E, ZoneEarthtube yielded lower RMSE than the NTU model for the E1 hold-out (0.332 vs. 0.621 °C) and E2 transfer dataset (1.424 vs. 1.603 °C), but showed a larger negative bias in E2 (−1.259 vs. +0.427 °C). Over 8760 h with identical weather forcing, the two EnergyPlus implementations showed close outlet-temperature consistency (RMSE 0.413 °C, MAE 0.351 °C, MBE +0.048 °C). Native annual precooling and preheating differed by −3.18% and +1.86%, respectively, with different mass-flow treatments. The results support the EMS–NTU framework as a flexible, experimentally anchored alternative for EAHEs requiring segment-specific depths and user-defined thermal parameters.

Earth-to-Air Heat Exchangers (EAHEs) use shallow-ground thermal inertia to pre-condition ventilation air. This study combines summer monitoring, segmented NTU modelling, climatological contextualisation, and multi-regional screening for a compact square-helical EAHE in Covilhã, Portugal. Five summer datasets (2025–2026; 30 and 50 m³ h⁻¹) were analysed. Calibration used the two 2025 datasets; in 2026, only the deepest monitored point (E) and the physical outlet were valid. Maximum reductions up to point E were 16.40–22.40 °C, and median daily range attenuation was 89.3–95.8% at point E and 69–72% at the outlet, owing to daytime heat gain in the outlet riser. The 3U model gave hold-out RMSE of 0.94–1.22 °C and within-2025 transfer RMSE of 1.32–1.80 °C; in an exploratory 2026 test (1.09–1.98 °C), it had no skill over the ground-only baseline. With the installed 24 W fan, the sensible COP was 2.3–5.9 at point E and 1.8–2.7 at the outlet, where the net saving was negative; 9–45 refers to a hypothetical circuit-sized fan. Only sensible heat was evaluated; condensation could not be excluded. Across 9094 locations, 95.59% had a positive summer cooling indicator under a +5 °C surface offset (country-balanced: 83.97%; USA: 78.9% of the archive). The indicators support pre-feasibility screening only.