Hi there Mad , ive been thinking over your design idea and agree it will give best performance. Do you have any external hx in mind ? Ive been talking to Vaportec in Napier about ground source hx , the plan is 50mm spiralled stainless steel , 3 x 5m lenghts which will give me 2.35 m2 surface area so i should get 10kw at 5k according to
http://www.engineeringtoolbox.com/ov...ent-d_434.html
Forced liquid (flowing) water - Forced liquid (flowing) water : 900 - 2500 W/m
2K (heat exchanger water/water)
Would you agree with this calculation?