Air conditioning as a heating system (heat pump)

Efficient heating with an air-to-air heat pump

Air conditioners are often seen as merely a cooling aid in summer. However, modern split and multi-split systems are true all-rounders . They can not only cool effectively but also heat extremely energy-efficiently . These devices function as air-to-air heat pumps and are a future-proof, environmentally friendly alternative or supplement to traditional heating systems.

Learn how your air conditioner can become an efficient heating system and why this technology is becoming increasingly attractive, especially in light of rising energy costs and climate goals.

What makes an air conditioner a heat pump?

The key lies in the reversibility of the refrigeration cycle.

Normally, the air conditioner extracts heat from the interior and releases it to the outside via the outdoor unit (cooling). In heating mode, this process is simply reversed :

1. Heat absorption: The outdoor unit extracts residual heat even from the cold outside air.

2. Refrigerant: The refrigerant absorbs this heat.

3. Compression: The compressor compresses the refrigerant, causing its temperature to rise sharply.

4. Heat release: The now very hot refrigerant flows through the indoor unit and releases the heat directly into the room air.

This means that the air conditioner does not generate heat through combustion, but rather transports existing heat very efficiently from the outside to the inside.

Why is heating with an air conditioner so efficient?

The main reason for the high efficiency is the efficiency rating , which is expressed by the so-called COP (Coefficient of Performance) or, on an annual average, by the SCOP (Seasonal Coefficient of Performance) .

📈 SCOP – The benchmark for efficiency

The SCOP value indicates how much heat energy the system generates per unit of electricity used.

Example: A SCOP of 4.0 means that the system generates 4 kWh of heat energy with 1 kWh of electrical energy.

Conventional electric heaters have an efficiency of 1:1 (COP of 1.0 ). Modern air-to-air heat pumps (air conditioners) achieve SCOP values ​​of 4.0 to over 5.0 . This allows you to save up to 75% on energy costs for heating compared to conventional systems.

Advantages of air conditioning as a heating system

Limits and conditions

Although heating with an air conditioner offers many advantages, there are also aspects to consider:

• Low outdoor temperatures: Efficiency decreases at very low temperatures (below -10 °C to -15 °C). However, highly efficient brand-name models (often referred to as "cold air conditioners") are optimized for these conditions.

• Air distribution: As an air-to-air system, the air conditioner directly heats the room air. This is ideal for rapid heating, but it should be noted that no radiant heat is produced (as with underfloor heating).

• Maintenance: To ensure the efficiency of the heating operation, the system, especially the outdoor unit, must be regularly cleared of snow and ice in winter.

• Noise level: During heating operation, brief noises may occur when the outdoor unit defrosts.

Conclusion: Is air conditioning the right primary heating system?

Whether an air conditioner can serve as the sole main heating system depends heavily on the insulation of the building and the climatic conditions.

• As an addendum: During the transitional seasons (spring/autumn) and for quickly heating individual rooms, the air conditioning system is unbeatable in its efficiency.

• As the main heating system: In well-insulated new buildings or renovated existing buildings, a correctly dimensioned multi-split system can completely replace the central heating system or at least relieve it for 90% of the time.

The combination of flexible cooling in summer and cost-efficient, environmentally friendly heating in winter makes the modern air conditioner one of the smartest investments in your living comfort.