### Will an Air-Source Pump Freeze? The main fear of buyers is the pump's inability to work in hard frost. Modern Termojet air-to-water heat pumps are designed to operate down to -25°C, and some models down to -30°C.
### Technologies for Cold Weather
**EVI (Enhanced Vapor Injection):** Steam injection technology that allows the compressor to operate efficiently even at critically low temperatures.
**Inverter control:** Allows capacity to be smoothly ramped up, avoiding overloads during cold starts.
**Smart defrost:** Automatic defrosting of the outdoor unit as needed — prevents ice formation without stopping operation.
### The Role of the Backup Heater Most systems have a built-in electric heating element. It activates only in peak frosts (below -15°C) when the compressor capacity becomes insufficient. This is the bivalent point.
### Practical Advice When choosing a pump for the Ukrainian climate, pay attention to heat output at -15°C, not at +7°C. A quality pump will retain 60–70% of its rated capacity even in frost. Proper home insulation is critical: the smaller the heat loss, the easier it is for the pump to maintain comfort in January.