CO₂ HVAC heat pump on show at ISH 2019

Stiebel, a German manufacture of heating products, uses a CO₂ heat pump from Japanese HVAC&R manufacturer Denso in conjunction with its LWZ 604 air system to heat buildings.

The ventilation system was on show during ISH – the Bathroom Experience, Building, Energy, Air-Conditioning Technology, and Renewable Energies tradeshow (11-15 March in Frankfurt, Germany) – and has found some success in the Swiss market.

“We are having quite a lot of success in Switzerland,” Hans Dolfeyn, managing director of Stiebel Eltron Belgium, told R744.com. “Due to the low-noise emission regulations.”

Switzerland, Austria and some parts of Germany, according to Dolfeyn, have noise regulations that have prevented the installation outdoors of heat pumps that are deemed too noisy – resulting in some heat pumps being removed from houses.

The air ventilation system emits 56 dB (A) and can be installed inside.

Mitsubishi Electric also showcased its CO₂ heat pump for hot water production at the show, which attracted attention. “Sales are slow. We are selling but not much,” said Germar Helbig, manager export sales – living environment systems, Mitsubishi Electric Europe BV. 

Stiebel Eltron highlighted the cost-saving elements of the air-to-air system when it originally launched the product in 2017.

“We give builders the opportunity to completely dispense with the water-based distribution system of conventional heating systems,” said Dr. Kai Schiefelbein, managing director of Stiebel Eltron Group at the time. “The elimination of this system saves several thousand euros in the planning and construction of new homes.” 

The heat pump system has a 4 kW heat output and a coefficient of performance (COP) of 4.52. It can work in conjunction with photovoltaic panels.

Mitsubishi Electric's R744 heat pump