I didn't think that the flow rate would be effected. I thought the linear flow would obviously change - i.e. the liquid would flow along the pipe at a different speed, but imagined the volume per minute would remain constant? But...
Aleman wrote:...and that is when I discovered that the restriction of the coil turns and the diameter of the tube really slowed my flow rate down . . . to just under 1L per minute . . .
...Obviously not...
Aleman, what flow rate do you achieve without the coil? I wonder if the smaller pump we're talking about will cope better with this...? Bear with me... but if the pump is set to pump at the rate the coil can cope with then will the flow rate be largely unaffected? All very theoretical...
Also, it doesn't have to be a coil. It could be a series of S bends or something in 15 or 22mm with elbows. It doesn't matter (or does it?) what the shape of the thing is, you just need to get one liquid in contact with the other to exchange heat???
Aleman wrote:although If anyone wants a 6mm copper coil HERMS Unit I have one for sale

. . . only been used twice

I might be interested if you can let me have some more details...?