Hopefully photos attached.
The stream heat exchanger is 3 x 6metre lenghts and gives me about 2.2m2 of area and when on full load , if stream is 17 c i will get water returning at 13c , cool it down 2k to 11c and round it goes. The stream stays at or above 10c in winter so a good source that was to good to go past.
If you would like any more info ,let me know.
Cheers Andy
