Altherma 4 heat pump propane Existing buildings from Daikin

The discussion about the heat transition in the United Kingdom is often abstract – focusing on laws, subsidy schemes and target figures. At the trade fair in Nuremberg, however, the technical implementation of this transformation is presented in very concrete terms.

The focus is on a new generation of air-to-water heat pumps that have been specifically developed for use in existing buildings and at the same time mark a technological change of direction: the consistent use of the natural refrigerant propane. Daikin is one of the world's largest suppliers of air conditioning, heating and ventilation technology. The Osaka-based group has been active in the market for around a century and employs almost 100,000 people worldwide. In Germany, Daikin Airconditioning Germany, based near Munich, operates as an independent sales company and serves installers, wholesalers, planners, architects and large plant manufacturers. The portfolio is correspondingly broad, ranging from small split units for living spaces to complex air conditioning systems for railway stations or airports. Heating, cooling and fresh air are not understood as separate disciplines, but as an interconnected system.

Altherma as a series product for the heat pump market

The focus of the trade fair presentation is on Altherma, a product name that has been established in the heat pump market for many years. Daikin launched the first Altherma on the German market back in 2006, positioning it as a mass-market air-to-water heat pump. While heat pumps were still considered a niche technology at the time, the series gradually evolved and accompanied the market ramp-up over several generations. With the fourth generation, the series has now reached a decisive point. Altherma 4 is the manufacturer's first air-to-water heat pump to use the natural refrigerant R-290, better known as propane. This is Daikin's response to regulatory requirements and ecological demands, as synthetic refrigerants are coming under increasing pressure. At the same time, the new system is not intended to impose any restrictions on performance or scope of application.

Designed for detached and semi-detached houses

The Altherma 4 is available in several output sizes and is clearly aimed at detached and semi-detached houses. The output range covers typical buildings with a living space of up to around 300 square metres, both in new and existing buildings. However, the focus is particularly clear on renovation. In Germany, there are still numerous buildings equipped with oil or gas boilers that will need to be replaced in the coming years. This is exactly where the new heat pump comes in. A key argument is its ability to provide high flow temperatures. Many existing buildings are heated by radiators and therefore require high temperatures in the heating system. The Altherma 4 is designed to generate flow temperatures of up to 75 degrees – even at low outside temperatures of minus ten degrees. In many cases, this eliminates the need for costly conversion of the heat distribution system, which significantly lowers the threshold for switching.

Natural refrigerant as a technological step forward

The use of propane as a refrigerant is a logical consequence of the current F-gas regulation, but it is technically challenging. Propane is highly efficient but highly flammable. The requirements for the design, transport, storage and installation of the devices are correspondingly high. Daikin therefore emphasises that safety was a top priority in the development of the Altherma 4. Safety does not begin during operation, but already in the supply chain. The heat pump is delivered without a filled refrigerant circuit. The propane is stored in a separate safety container inside the device until commissioning. Only when the installer starts the device in the proper manner is the refrigerant released and introduced into the system. This significantly reduces the risk during transport and storage, for example in high-bay warehouses or during handling on construction sites. In addition, all electronics are designed in such a way that there is no ignition source in the unlikely event of a leak. Sparking, electrical discharges or other potential sources of danger are structurally excluded. This multi-level safety concept distinguishes the Altherma 4 from many other R-290 systems currently available on the market.

Positioning in the current heat pump market

The launch of the Altherma 4 comes at a time when the heat pump market is experiencing significant fluctuations. After strong sales growth in recent years, political debates and uncertainties surrounding the Building Energy Act have led to caution among end customers. At the same time, there is still structural pressure to gradually replace fossil fuel heating systems. With its new generation, Daikin is deliberately focusing on a product that addresses these areas of tension. The combination of natural refrigerant, high flow temperature and a clear focus on existing buildings aims to remove practical hurdles. The heat pump should not only be ecologically convincing, but also function technically and economically in real existing properties.

Classification and outlook

The Altherma 4 is an example of a development that is likely to shape the heat pump market in the coming years. Away from theoretical ideal conditions, towards solutions that work in existing buildings and meet regulatory, ecological and safety requirements in equal measure. Propane as a refrigerant is less of an experiment and more of a necessary step that sets new standards. Whether the Altherma 4 will establish itself as a benchmark in the market will become clear when it becomes available in the autumn and is put into practice. However, it is clear that Daikin is sending a clear signal with this generation: heat pumps are not only the technology of the future for new buildings, but also a realistic replacement for oil and gas heating systems in existing buildings.