This research sought to determine the optimal conditions for depositing thin silver layers in the fabrication of low-emissivity coatings. The study utilized an in-line semi-industrial high-vacuum magnetron sputtering system with rectangular targets, closely resembling those used in industrial settings. Trilayer AZO/Ag/AZO structures were deposited to enhance the wetting properties of the silver, and to protect it from the atmosphere. The effects of the power and argon flow on the sample properties were analyzed, along with variations in the silver thickness. The results demonstrate that a lower power (200 W) and higher argon flows (1000 sccm) lead to a higher transmittance and a lower sheet resistance, resulting in a reduced emissivity (up to 0.015 for 24 nm of silver). The identified optimal conditions offer valuable recommendations for producing more efficient and optically superior coatings. This study also reveals the importance of the silver thickness to the properties of the coatings, in accordance with previous research findings. These findings provide insights for improving the performance of low-emissivity coatings in various applications.