vs. gas boiler: 6–10 years (depending on electricity/gas prices and solar PV integration). 12. Conclusion The CTC EcoAir 107 is a well-engineered, mid-efficiency monoblock air-to-water heat pump ideal for smaller, well-insulated homes in temperate or cool climates (e.g., UK, Germany, Southern Scandinavia). Its main strengths are ease of installation (no indoor refrigerant), compatibility with CTC’s hybrid systems, and quiet operation. However, it is not suitable for uninsulated houses or very cold regions without a robust backup heating source.