Choosing a heat pump is an important decision for 15–20 years. Here is what to look for.
**Type of pump:** air-source (most affordable, fast installation), water-source (high efficiency, water source required), ground-source (stable year-round efficiency, higher installation cost).
**Capacity:** calculated based on the building's heat loss. Approximately: 1 kW per 10 m² of a well-insulated house, or 1 kW per 7 m² of older construction.
**Efficiency class:** look for A++ or A+++. COP of 4.0 and above means 1 kW of electricity delivers 4+ kW of heat.
**Refrigerant:** R290 — the most eco-friendly, R32 — optimal balance, R410A — an outdated standard.
Termojet air systems achieve energy savings of up to 70% compared to direct electric heating.