Propane warmth pumps for indoor use in single-family properties at the moment are one step nearer to commercialization. Fraunhofer ISE in Germany has efficiently developed a mannequin of a warmth pump refrigeration circuit utilizing lower than 150 g of propane.
“Many warmth pump producers supply propane warmth pumps however often for out of doors set up solely, as a result of the refrigerant is topic to many security rules for in-door use as a result of its flammability,” stated Fraunhofer ISE in a press release. “If a warmth pump in a single-family dwelling with a typical 5 kW to 10 kW energy exceeds the prescribed most 150 gram refrigerant cost, then it could solely be put in by making of extra security measures.”
Among the finest outcomes of the Low Cost 150 g (LC150) venture is a brine warmth pump with a heating capability of 11.4 kW utilizing solely 146 g of propane, making it appropriate for indoor use with out -through many security precautions. The unit’s refrigerant cost is 12.8 g/kW, which is about one-fifth of the propane cost in commercially out there methods, in response to the German analysis institute.
“The purpose of the venture is to create an almost market-ready warmth pump module that makes use of the climate-friendly refrigerant propane, doesn’t exceed the 150-gram restrict for indoor use, and nonetheless offers adequate warmth for single-family properties,” stated. dr. Lena Schnabel, head of the heating and cooling division at Fraunhofer ISE. “We’ve achieved this purpose in cooperation with our industrial companions and supplied them with the instruments to create a ready-made warmth pump.”
The analysis consortium has constructed, measured, evaluated, and optimized greater than 20 completely different mixtures of warmth exchangers and compressors. One of many key elements in lowering the required quantity of propane is the usage of an asymmetrical plate warmth exchanger. Different causes embody utilizing much less oil within the compressor and shortening the size of the pipes.
In October 2022, Fraunhofer ISE developed a warmth pump with a heating capability of 12.8 kW utilizing solely 124 grams of propane. Nonetheless, its refrigeration circuit just isn’t appropriate for commercialization as a result of it makes use of a semi-hermeneutic automated compressor that can’t function for lengthy sufficient.
The analysis institute now needs to develop low-charge propane warmth pumps to be used in multi-family properties, as a part of the LC290 venture that runs till June 30, 2025. The consortium goals to develop warmth pump options for flooring heating methods, indoor central heating. methods, and high-performance, out of doors, warmth pumps.
The tasks are funded by the German Federal Ministry for Financial Affairs and Local weather Motion.
