Question about setting up an EHERMS.

Ok so I have some limitations and I am wondering if I can still accomplish what I would like to accomplish.

I only have 20A standard GFCI outlet available to me in the garage. However I don't need to boil anything. I want to continue to use propane for the boil.

I would like to install an element in my HLT and set it up for HERMS with my MLT. I should never need to go above 175F so will this work with the 20A standard outlet with a smaller element? if so what kind of element?

RIght now I have a pump, and 2 10 gallon boilermakers for HLT and MLT. I have been doing direct fired RIMS cirulcation with a PID(using it only to monitor temps at the moment) on a T on my MLT and just manually firing it. I'd like to automate it with HERMS and my HLT.

Will I be able to heat my HLT and MLT with an element that will run on a standard GFCI 3 prong 20A?

 

It should be do able with a 20a 120v outlet.

 

A 20a GFCI will easily handle a single a 5500w PID/SSR controlled camco element

I would run the PID to an SSR, then have the SSR power the outlet in your case

 

Yes, but a 240v, 5500w element will put out less than 1375w at 110v. The OP could use a 120v, 2000w element on the 20a GFCI plug and have much faster heating times.

 

True, I wasn't thinking about 120 vs 240

 

Don't use your HLT for the heat exchanger, pick a smaller volume (2 L or so) to give the PID more control over the temperature. People around here tend to favor electronic kettles, which easily fit 5 m of 8 mm copper coil. Add a T joint to the coil's output, and stuff your temp sensor in there.

Even with a small volume, more wattage is better. You'll want to step mash and so on, not just maintain temps.

 

Putting the coil in a small vessel will get you faster temp changes if you can live with the trouble of plumbing and heating a fourth vessel. I would add though that the temp probe should be placed in the heat exchange tank in contact with the water you are actually heating. Do not place the probe in the wort exiting the herms coil, doing so is a common mistake.

 

Why is it a mistake?

 

It can result in temp oscillations or over shooting. The idea is to measure the temp of the liquid the pid is actually heating via the element (i.e. the hlt). The temp of the wort exiting the coil is a function of the hlt tank (controlled by the pid) and the temp of the wort coming in, and the length of the coil. Those last two factors are things that will impact the reading the pid receives but the pid has no direct control over them. A short coil or extreme difference between the temp of the incoming wort and the temp of the hlt will toy with the pid's calculations.

In practice this mistake is usually not disastrous but it is, IMO, good practice to measure the temp of the vessel the pid is actually heating and the trust that with a long enough coil and/or enough passes through the coil, the mash will come to match the temp in the hlt. In practice it doesn't hurt to stick a dial thermometer in the mash, because some heat is lost through the mash tun itself (a keggle in my brewery) and via the plumbing carrying the wort from the hlt back to the mash. You adjust for this difference by simply setting the hlt target temp a degree or two higher than the target mash temp. the difference is usually static and easy to account for once you know the quirks of your particular system.

 

you have it backwards. you are not trying to control the temperature of the HERMS water, you are trying to control the temperature of the wort/mash, so that is what you should be measuring. it doesnt matter what the temperature of the HLT is as long as the wort exiting the heater is the temperature you want it to be.

the entire point of running a PID algorithm is so that these variations will be accounted for and you do not have to do any math in your head, and do not have do anything but set the desired temperature and walk away. if the temp of the HLT is toying with your PID output, then your PID is misconfigured.