Insulating building envelopes is crucial for maintaining indoor thermal comfort, particularlyin large-space enclosures like greenhouses having transparent envelopes. Transparent envelopesallow natural light but challenge temperature regulation due to their low thermal mass and highU-values, which enable significant heat transfer between indoor and outdoor environments. This fieldstudy aims to experimentally investigate whether warm wall confluent jets (WCJs) can maintain therequired indoor climate conditions in a greenhouse exposed to dynamic meteorological conditions inwinter. It analyzed the impact of the airflow rate, number of nozzle rows, and room air temperaturesetpoint on WCJ heating performance on the ceiling, external wall, and room air. Measurementswere performed with thermocouples and constant current anemometers, and the response surfacemethodology evaluated the effect of design variables on WCJ flow, thermal behavior, and the indoorenvironment. The results show that WCJs provided recommended air velocities and temperaturesindoors, with the airflow rate having the strongest effect on flow and thermal behavior, while thenumber of nozzle rows had a moderate effect. This study developed response surface models relatedto room air temperature, ceiling surface temperature, external wall temperature, and supply airtemperature. Supply temperatures between 27 ◦C and 40 ◦C suggest using low-exergy heat sources,like industrial waste heat, to sustain greenhouse operations during winter.