HERMS Testing Question

[chudsonvt]

So I am building a very very simple HERMS system with a 10 gallon cooler with a 1500W electric element as my HLT and a 5 gallon cooler as my MLT.

I potted my element to help seal it all up and it should be cured this evening. I should have the rest of assembly complete this evening as well. So I will want to do a leakage test run as well as test temp control (manually turning the element on and off and the pump on and off).

When testing the HERMS response, does anyone know how close an approximation filling the MLT with water is as compared to actually having my mash in there?

I will create a build thread later, in case anyone is interested in what I have created.

 

[chudsonvt]

I may have answered my own question. The heat capacity of malt is lower than that of water (pound for pound). However, the typical ratio of LB of grain to LB of water is not terribly significant. Say 10lb of grain with 4 gallons of water is about 33lb. And the grain hold about 0.38 the heat of water. So if anything, the water test will take a bit more energy to change the temp. So if all other variables are fixed, it will be a little slower to change the temp than the mash, assuming I am using the same flow rate. Water is much thinner than the wart...

Long story short, I think it is a good rough test to run water through the HERMS coil and see how the temp changes. I just want to see how it behaves before using about $40 worth of materials for 5 gallons of beer.