A few HERMS questions related to my build...

[cantrell00]

First of all, I have a stainless table that is 48 X 24 & intend to build a HERMS brew stand from it...

Here are the particulars...

1) Six gallon batches (7.25 gallon boil volume)

2) Single pump (for now at least)

3) Will run 2X 1650 watt/120 volt ULWD elements on the kettle powered by 1 Auber PID & 2X SSR. (240 volt is not an option for a variety of reasons) But DO have 2 - 20 amp dedicated outlets to work with.

4) HERMS coil is 3/8" X 75', 2000 watt/120 volt HD element, Auber PID & SSR. Already have the HERMS coil.



Now for my questions....

1) From everything I have read, 2X 5500 w/120 v elements should handle a 7.25 gal boil volume well, right?

2) Should the RTD for the HERMS controller be placed at the MLT return, right above the mash?

3) Would you lay things out differently with the stand, given the limitations of only 1 pump?

4) Can you effectively chill by running the wort back through the HERMS kettle submerged in a ice bath?

5) Would 75' of 3/8" line create too much head pressure for the chugger?

May be silly to ask on 4 & 5. I could verify those through experimentation. Thought I would ask in case someone has tried it with favorable results.

 

[cantrell00]

1

 

[cantrell00]

 

[cantrell00]

 

[The Pol]

If you are using a 5500W element on 120VAC, that element becomes a 1375W element. 2750 watts is not enough to boil with, in my experience. I've always needed about 3500W for a 5 gallon batch.

 

[The Pol]

I would control the HERMS temp, with a probe in the HLT. I did this due to possible lag between the hot water in the HLT, and the wort making it to the MLT. If you control the HLT temp, by reading the HLT temp, no overshoot, no undershoot.

Also, it is advisable to have a way to stir the HLT water, temperature variances in the kettle can become quite large, thusly destroying good temp control.

 

[cantrell00]

If you are using a 5500W element on 120VAC, that element becomes a 1375W element. 2750 watts is not enough to boil with, in my experience. I've always needed about 3500W for a 5 gallon batch.

I've changed some things. Running 4500 @ 240v now.

Will alternate a single PID / SSR between two elements. One in the HLT & one in the kettle.

 

[cantrell00]

I would control the HERMS temp, with a probe in the HLT. I did this due to possible lag between the hot water in the HLT, and the wort making it to the MLT. If you control the HLT temp, by reading the HLT temp, no overshoot, no undershoot.

Also, it is advisable to have a way to stir the HLT water, temperature variances in the kettle can become quite large, thusly destroying good temp control.

Do you mean the MLT? It seems like you could more accurately control the mash temp by measuring the temp of the wort as it returns.

I will be recirculating the heating water to prevent stratification of the HERMS heating water.

 

[The Pol]

No, I mean measuring the HLT water temp, and controlling that directly.

I've went down this path 5 years ago, and this worked best.

To each their own.

 

[cantrell00]

No, I mean measuring the HLT water temp, and controlling that directly.

I've went down this path 5 years ago, and this worked best.

To each their own.

Understood.. I will try both and see which works best relative to my setup..

Thanks..

 

[cantrell00]

 

[SleepyCreekBrews]

Really? ...I usually boil 10 gallon batches with 240vac @ 12 amps which is just under 2900 watts (4800 watts to get it up to temp)

If you are using a 5500W element on 120VAC, that element becomes a 1375W element. 2750 watts is not enough to boil with, in my experience. I've always needed about 3500W for a 5 gallon batch.

 

[The Pol]

Yup

Individual results may vary

I hate having less than 9000W in a kettle, I hate waiting.

Etc

Etc

Etc

 

[augiedoggy]

Theres whats needed and what works faster... and advantages to both like boil off rate and such...(plus insulation and room temps matter)
kind of like comparing a 4 cylinder car to a v8 powered one....
I only NEED about 55% duration on my 4500w element to boil 7 gallons but I choose to use between 65-70% depending on room temp and the wort. for one thing a vigouruos boil is better for hop utilization (found this out the hard way from stovetop brewing) and it drives off other less desirable materials from the wort so I've read... BUT too much and your boil off is crazy high plus I would think at a point your more likely to have scorching depending on the setup.

 

[The Pol]

My keggle ran 5500W at 60% to maintain my desired boil.

But, as with most things, nothing is absolute in brewing. The best thing to do is build it and test it.

To boil off one gallon in an hour will require 8340 BTUs. Which amounts to 2660W of energy. That is assuming no losses, and there will be some. So 2700W is on the low end of the spectrum to reach and maintain a normal boil off rate.