herms coil length?

[rknerem]

Is 25', long enough for a germs coil? I planned on buying a 50' coil of 3/8 copper and using half for a counterflow chiller and half for a germs coil. Would this work?

 

[audger]

10-20 feet is probably long enough. use the rest for the chiller.

 

[rknerem]

Also, will the 3/8 OD coil be too restrictive to the flow?

 

[audger]

its definatly on the low end. depends if the rest of your system is 3/8" or not. your flow rate is dependant on the point of most restriction, so if the rest of everything is 1/2", then yes it will reduce flow considerably. most people use 1/2" for heat exchange coils, and 3/8" for wort chillers.

 

[zeus53219]

I'm using 50' x 3/8" with a chugger pump throttled back about 10-20% and I have excellent flow. I have a buddy that has 40' x 1/2" running a march 809 that needs to be restricted 50-80% to slow down his flow to achieve sufficient heat transfer.I am only using my coil to recirculate and maintain heat only, I do not use it to cool. If I did I would have went with 1/2", but to maintain mash temps 3/8" ss is more than sufficient. 25' should work with no problems.

If you are using the coil to cool as well, then for sure I'd go with 1/2". In my set-up I'm only using it to maintain heat, this is why I went with 3/8". I figured why go with 1/2" at a greater cost when all I'm going to do is restrict the flow anyway. All my other plumbing is 1/2"ID so I am not limited in any other aspect.