Manufacturer page.

The OMICRON Zero S4 is a multi-purpose unit designed for applications requiring simultaneous heating and cooling, such as buildings with varying insulation and occupancy. It is powered by natural refrigerant R290 (propane), which has a GWP of 0.02 and an ODP of 0. The unit operates in multiple modes—cooling, heating, and combined—adjusting automatically to optimize energy use. Its construction features a modular, weather-resistant frame, and it includes hermetic scroll compressors, axial fans, and hydrophilic-coated finned coil heat exchangers to enhance performance and minimize maintenance. The axial fans are directly coupled to three-phase electric motors with integrated thermal overload protection and feature optimized shrouds to enhance efficiency and reduce noise emissions.