As the many elements like pump, 3-way valve, enlargement vessel, Management unit and electric powered movement and again-up heaters are contained in the indoor device, there is absolutely no want to install these independently using a hydrosplit. Making use of energy, the pump compresses the liquid to raise its temperature. https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/