Guys,That's is about 15m of copper tube isn't it? Bloody long hex. Look up the pressure drop through that length of copper tube with whatever ID your tube is and see if the brown pumps are within the spec required. Factor in the extra head required for pumping from point to point.
I've just done a quick and dirty trial and I'm getting 2L per minute exiting the coil, so going to see how it preforms with gas heating....fingers crossed.The flow is pretty good, 8L per min max i think and the max head is 3.0m, so it would probably be fine but may have some flow restriction, but the units are cheap enough to get one and test. 15m/50' of copper for a HX is probably a bit much though, with copper the thermal conductivity is real good so you can use a much smaller coil.
I used mine in a fairly flow restricted setup yesterday with a Hoprocket and whirlpool chiller and it did quite well.