Those are just the standard compressor/r410 systems with reversing valves. There are number of systems designed to work well below 0F. https://www.mitsubishico

Those are just the standard compressor/r410 systems with reversing valves. There are number of systems designed to work well below 0F. https://www.mitsubishicomfort.com/benefits/hyper-heating https://www.mitsubishicomfort.com/benefits/hyper-heating https://www.fujitsugeneral.com/us/residential/technology/xlth-low-temp-heating.html https://www.fujitsugeneral.com/us/residential/technology/xlt...