The aroTHERM plus uses the natural refrigerant R290 with a global warming potential of just 3 to achieve higher flow temperatures of up to 75�C. Suitable for all applications, this air source heat pump has been designed to deliver the very best performance with low running costs, making it suitable for radiators as well as underfloor heating. With a number of indoor units available to choose from the aroTHERM plus is adaptable for many different types of properties. The ultra quiet operation with a Sound power as low as 54 dB(A) delivers easier planning and siting solutions, making it suitable for use in densely built-up terraced housing estates.