Design and Deployment of a Regulation-Compliant Infrared Heating System for UK Field Trials.

Free-air warming systems are essential for simulating climate change in field conditions, yet most are not designed to meet UK or EU health and safety standards. We present the design and field deployment of a hexagonal temperature-free air controlled enhancement (T-FACE) system that meets UK and EU health and safety requirements for outdoor electrical equipment, as advised by our institutional Health and Safety team. The system uses real-time, temperature-responsive control with multiple sensors to maintain a consistent temperature differential between heated and ambient temperature experimental plots, achieving a mean warming of +4°C against a target of +5°C. We describe its engineering design, performance, costs, and key operational challenges, particularly related to heater reliability under continuous use. We tested the T-FACE system during the winter months of a field sown wheat crop. As a proof-of-concept, phenotypic evaluation in a single season showed preliminary effects of heating on heading date (7-14 days earlier), plant height, spike length, and spikelet number, consistent with the system inducing biologically meaningful warming. This proof-of-concept provides a scalable, regulation-compliant approach for studying crop responses to climate warming under realistic field conditions.