ilmalämpö

Ilmalämpö, commonly referred to as ilmalämpöpumppu (air-source heat pump), is a heating technology widely used in Finland. It extracts heat from outdoor air and transfers it inside to heat spaces or domestic hot water. The system can be implemented as an air-to-water solution, which heats a building through water-based radiators or underfloor heating, or as an air-to-air solution, which blows warm air directly into rooms. In Finnish construction and renovation, ilmalämpö is valued for its efficiency and ability to operate with electricity rather than fossil fuels.

How it works: A outdoor unit collects low-grade heat from outside air using a refrigerant cycle. The refrigerant is compressed to higher temperatures and then transferred to the indoor system, where the heat is used by the building’s heating distribution or domestic hot water. The efficiency is described by the coefficient of performance (COP); typical COP values for moderate outdoor temperatures range from about 2.5 to 4.5, but performance declines as outdoor temperatures fall. In very cold weather, supplemental heating may be needed.

Applications and types: Air-to-water systems (ilma-vesilämpöpumppu) heat water for radiators or underfloor systems and can also provide domestic hot water. Air-to-air systems (ilmalämpöpumppu) heat indoor air directly. Hybrid configurations with backup electric or fossil-fuel heating are common in areas with harsh winters.

Considerations: Proper sizing, installation, and insulation are crucial for optimal performance. Outdoor unit placement, noise, and maintenance of the refrigerant circuit are factors to plan for. Ilmalämpö is most beneficial in well-insulated homes and as part of a broader energy-efficient building strategy, especially when paired with clean electricity.