power! a practical question

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warthog

Well-Known Member
Joined
Sep 18, 2006
Messages
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Location
Park City, Utah
i am planning my own electric brewery. my question refers to power. the place i plan on brewing already has a 30A circuit installed, i plan on using that. i really don't want to go higher, the house is old, it has 150A service, and i find all sorts of scary wiring errors whenever i dig into something.

i am planning a 5 gallon system, but really only because of the 30A number, and i honestly would rather go 10 gallon.

so here's the question for all of yous guys who have built an electric brewery:

how long does it take to boil? my calcs tell me with 6000W max (25A at 240V) it will take 11:15 (about 1 min longer for a 5500W element) to bring my 6 gallons of wort to boil ( dT 80F - i live at 7000' boiling is ~200F and my wort comes out of my m/l tun at ~120-130).

that said, 100% of my power does not go to heating the wort, or does it? what sort of heating efficiency should i expect?

i plan on insulating my hlt, m/lt and kettle, but the tops will be open, so i expect some heavy losses there. any thought?

i guess the next question has to do with the specific heat of wort, but i think i need to assume that its greater than 1.00, i assume it depends somewhat on the o.g. but does anyone know of a formula or rule of thumb?
 
I don't have exact numbers for you, but using a 5500w element for 5 gallon batches will be pretty painless, your temps will rise quickly. People easily brew 10 gallon batches with 5500w elements
 
Effectively 100% of the energy will go into the wort. A bit is lost on in the wiring and SSR, but probably only a percent or two. Of course, you will lose some to ambient depending on insulation.

Here's a plot of a 10g boil with a 5500W element. It took about 45 minutes to go from 70F to boil. Should scale linearly to batch size, so maybe 22 minutes for a 5g batch.

electric_boil_test-38779.jpg
 
thanks! quick number crunching tells me your system is ~85% efficient at transferring electrical power into hot wort. that's actually pretty encouraging, i may scale up. how much insulation does your system use? what was the ambient temperature? i see you are in fla.
 
It was winter when I did that... probably around 65F. That was on my HLT, which has NO insulation. With an electric system, there's no reason not to insulate, but really it would save me only a few minutes and maybe 5 cents, so I don't bother. I even have a whole roll of Reflectix that I did use for my keggle mash tun.

In theory, you should see the result of heat loss as a non-linearity in that line (heat loss to ambient should increase as the temp between the water and the air increaases). It's pretty linear though (hold the straight edge of a piece of paper against the curve). Also, I should look at the voltage going into my element. It's a long run from my breaker box to where I brew (~50') so there might be significant loss in the wire.
 
cool! thanks again. i'm an engineer (not an ee), so i love numbers :), please check that voltage, i can work that into my calcs. my basement is about 65f year round. so those numbers should jive pretty well.
 
The two numbers you really need are voltage and the element resistance. Power (watts) will be V^2 / R. I'll try to measure both of those Friday and post here. (can't measure current because everything I have is fused at 10A - I need a clampon ammeter).
 
i'm assuming i can get figure out the element resistance from its nominal wattage. v^2/w=r so at 240v^2/5500=10.47 ohm or am i missing something here?
 
i'm assuming i can get figure out the element resistance from its nominal wattage. v^2/w=r so at 240v^2/5500=10.47 ohm or am i missing something here?

Reality.

That's the school answer. The school answer also says that it will take 37 minutes 52 seconds to get to boil from 70F with a 5500W element. It took longer. Time to check assumptions.

Because I can't measure the element resistance with much accuracy, I'll put a regulated voltage source across it and measure the current (I can do both at the same time with my benchtop power supply :) )
 
honestly, i was just trying to save you the effort. i figured the number based on nominal would be close enough, and all i would need then is the voltage, to calculate the real efficiency. knowing that you had a long run of xx awg tells me the volts are lower than 240, therefore the watts are actually lower than 5500, which means the total system efficiency is greater than 85%. way better than a gas fired system. so i'm happy with that, and will look into scaling up to a 10 gallon system.

thanks for your help. watch this space, i will be posting progress from the planning stage (now) to completion (hopefully soon).
 
Wart, 5500w works better than a large propane burner for 13 gallons. That's my batch size, and I parked a KB6 in the back of the shed only for decoction duty. Math is cool and all, but real world is much more scaleable.
 
Wart, 5500w works better than a large propane burner for 13 gallons. That's my batch size, and I parked a KB6 in the back of the shed only for decoction duty. Math is cool and all, but real world is much more scaleable.
IME a 5500w kettle will be more than adequate for all but the largest and grandest home breweries. I recently did several 15g batches w/ a measly 4000w, and while admittedly a tad slow, not objectionable given batch size.
 
thanks wilser. i'm a pretty busy guy, part of my motivation behind building an electric brewery, is to speed up my brew day (and get a better boil - i'm an electric turkey fryer/stove top all grain, armstrong brewing system, brewer).

my brew day right now starts at about 8a and finishes up at about 3-4p depending on the recipe.

i start with hauling everything up from the basement, getting mash water heating, cleaning, sanitizing and assembling everything while i wait for that. it takes 45 minutes just to get my mash going, then 45-60 min for mashing, another 30 or so for lauter, then 30 more minutes just to heat up to boil, then 60-90 minutes boil, chill (that's the only quick part of my system - about 5-10 for the 6 gallons i boil), big splashy dump into my conical, pitch; disassemble, clean and sanitize; then drag it all back to the basement and put it back on shelves. it all adds up to 7+ hours of entertainment, that i can only make time for once a month at best.

the other part, is so i don't have to haul everything up and down the stairs, i tore my meniscus skiing last season, and i still haven't gotten it fixed. my knee hurts just thinking about hauling my full conical down the stairs to the basement. i got permission from the boss (wifey) to take a corner of the basement (~300 ft^2) and turn it into a brewery/man cave. i've got water, and electricity, and not a lot of space or $$.

the good news is that i'm an engineer (with degrees in mechanical engineering, computer science, and mathematics), who works for a company that makes precision temperature controlled chambers for semiconductor manufacturing. i can get a lot of cool cast offs: we've got old plcs, pumps, motors, thermoelectric heat exchangers, fans, filters, stainless steel coils....

this will be a total custom system designed and build by me, using some of the great info i've found on this forum, and a lot of advice from those who've tackled this before me too (that's you guys). i know a lot about heat transfer, and controlling air temperature, but not a lot about controlling liquid temperature (the math is the same, but the experience, is not).

so thanks all in advance, as i dive into the design phase...

regards,
n
 
I wanted to chime in on the pot insulation and the capability of a 5500 watt element.

so first I wanted to say I insulate my pots and I notice it really seems to work very well. I used a sheet of insulating closed cell foam, then contact adhesive and outer shell of reflectix. I use the reflectix with velcor so I can take on and take off the the wrap as needed for cleaning. (here is a picture with what I used) - see post 575

I have two 25G megapots that I use in for my hlt herms and BK. Insulated, I can boil a full pot. 5500 is perfect for most every home brew system IMO

I use a full HLT (23 gallons or so) for my herms and it takes a fair amount of time to heat that up. I would say it is about a degree per minute. It is less than that in reality but that is a ball park. Since I have two sides to my rig I can fire two elements. So a lot of the time I will put about half the water in each pot to speed up heating the strike water for the herms.
 
OK....mega smart move setting up the basement brewery! I realized a few years ago that the brewing was the easy part...moving all the equipment and then hauling the finished product is way more work than the actual brewing....electric basement brewing is the easy way to go irregardless of total watts!

Put a simple cheap timer on a low wattage HLT and let it run while you sleep........plenty of hot liquor to start the day before you wakey.... :)
 
OK....mega smart move setting up the basement brewery! I realized a few years ago that the brewing was the easy part...moving all the equipment and then hauling the finished product is way more work than the actual brewing....electric basement brewing is the easy way to go irregardless of total watts!

Put a simple cheap timer on a low wattage HLT and let it run while you sleep........plenty of hot liquor to start the day before you wakey.... :)

now there's an idea!:mug:

i've been eying an obsolete plc, rack and some i/o modules for a while. if i can score those.....
 
now there's an idea!:mug:

i've been eying an obsolete plc, rack and some i/o modules for a while. if i can score those.....

Here ya go again w/ the a/r thinking....my thoughts were a $12 timer from walmart plug and play...

Stop designing and get brewing...stick an element into a kettle and brew a batch, then design you hi-falutin "system" all you want over a cold pint........ :)
 
oh, i've got a keg of stout, and a keg of dunkel. with 6 gal of english brown in secondary. beer flows freely at warthog brewing co.
 
OK, you were right. 10.00V applied, 0.958 amps measured, = 10.4 ohms.

233.5VAC measured with multimeter.

22.01 measured with clamp-on ammeter.

So that's only 5139 Watts of heat from my element. I don't have time to do the math right now (son want's to play ping pong).

[I"m back]

Based on my timed boil, I'm only getting about 4600W of the power to my element. So, I'm losing about (5100-4600)/5100 or 10% to ambient.
 
what size kettles are you using? i've got a line on some 60qt for cheap cheap (local army surplus store). just guessing about your set-up, it looks like insulation would help your boil times quite a bit (not thinking about electricity cost, just thinking about how long the brew day is). assuming a convective heat transfer of 10 w/m^2k (guess, based on high humidity and low altitude), and a surface area of 0.15m^2 you are losing about 120 w out the top and 380w out the sides and bottom.

anyway. i'm thinking of moving from my original 40qt pot system to a 60 qt pot system so that i can make 10 gal batches (i thought about going 80 qt, but i just don't have the space). is 60 going to do it? keggles are 62 qt, so that should work right?
 
what size kettles are you using? i've got a line on some 60qt for cheap cheap (local army surplus store). just guessing about your set-up, it looks like insulation would help your boil times quite a bit (not thinking about electricity cost, just thinking about how long the brew day is). assuming a convective heat transfer of 10 w/m^2k (guess, based on high humidity and low altitude), and a surface area of 0.15m^2 you are losing about 120 w out the top and 380w out the sides and bottom.

anyway. i'm thinking of moving from my original 40qt pot system to a 60 qt pot system so that i can make 10 gal batches (i thought about going 80 qt, but i just don't have the space). is 60 going to do it? keggles are 62 qt, so that should work right?

speaking of saving time. The larger your HLT the better IMO. I thought 25g hlt was going to be too big, man was I wrong. It is great having all that water heated and ready for use. That use could be a back to back batch, or simply cleaning water. More mass in the HLT also means your herms can take a punch if needed.

I know you said space was an issue, but I would go for the 80qt if you can. I can still catch a boil over with my 100qt BK if I am not paying attention. Thanks to the alarms on my system though... that is no longer an issue!
 
cool good advice. i wasn't planning on herms. i've had a few crazy ideas, but i've scaled them back a bit. for my m/l t, my plan is to give it a good thick layer of insulation, mount a sparge nozzle to the lid, and call it good. though maybe i'll get a really big (80-100 qt) hlt, and 60 qt m/l t and bk. that said, i'm planning on plumbing my corner of the basement with hot, cold, and r.o. water, and tying into the sewer line. the whole project is going to cost a lot of $$ i don't have. so i need to try to figure out where to spend and where i can save.
 
Gotcha. For my use in particular (on a well) it helps me bank water early so I have enough for chilling later in the day.

look into the flexible closed cell foam insulation. It works very well for everything but the bottom of the pots. And don't be a knuckle head like me (order all you need in one shot to save on shipping :mug:)

The hot water line is a cool idea, and will help save you time on heating up the HLT. Extending the plumbing to my brew area is something I really want to do, but only after I have my ventilation system in, since that means my rig will be permenantly placed with no movement. Right now I swing it out to pump directly to my fermentors.
 
ha! i hadn't thought of using my hot water heater as an hlt. does anyone know if i can put a filter on that? my hot water tanks collect sludge over time, and often sound like they're percolating coffee. i'm not sure i want to use that water without filtering it first.
 
at least the hot water heater gives you a jump start.

My thoughts on the rest are:

1. Any alc. you consume is way worse than the sludge you might get
2. Any sludge that came through would drop out into the trub in your fermenter

take witha grain of salt, my .02
 
thanks again. i'm really just posting my thought process (or lack thereof) as its happening. you should see what i usually eat ;-) i'm thinking that the minerals will change my water chemistry, leading to beer problems, i already have difficulty with lighter beers (pils etc) due to my very hard water.

so here's the plan as it stands:
60qt hlt w/ 5500w heating element (controlled via ssr and some sort of pwm type modulator)
60qt m/l t with a good thick layer of insulation (probably a rubber type - thickness/r value tbd)
60qt bk w/5500w heating element (controlled by the same method as the hlt)
15 gallon fermenter/inductor
the system will be a multi-level 'brew sculpture' the bk will be able to move to 2 levels, for filling and draining to the fermenter. this will save space overall
the whole system will be on casters so i can store it out of the way

things i am still thinking about:
control methodology - plc or discrete pid controllers
how to ensure that the hlt and bk are not using more than 30a together - 30a is my max, its an older house with 150a service, adding a 50a circuit i think will cause all sorts of new problems
 
thanks again. i'm really just posting my thought process (or lack thereof) as its happening. you should see what i usually eat ;-) i'm thinking that the minerals will change my water chemistry, leading to beer problems, i already have difficulty with lighter beers (pils etc) due to my very hard water.

so here's the plan as it stands:
60qt hlt w/ 5500w heating element (controlled via ssr and some sort of pwm type modulator)
60qt m/l t with a good thick layer of insulation (probably a rubber type - thickness/r value tbd)
60qt bk w/5500w heating element (controlled by the same method as the hlt)
15 gallon fermenter/inductor
the system will be a multi-level 'brew sculpture' the bk will be able to move to 2 levels, for filling and draining to the fermenter. this will save space overall
the whole system will be on casters so i can store it out of the way

things i am still thinking about:
control methodology - plc or discrete pid controllers
how to ensure that the hlt and bk are not using more than 30a together - 30a is my max, its an older house with 150a service, adding a 50a circuit i think will cause all sorts of new problems

Pump. One of the major advantages of an electric system is that the kettles can be at ground level. If I were you, I'd build a very low structure and mount a pump on there. I don't use gravity for anything: my system is space-station ready.

Lots of 30A-limited brewers on here with control boxes that switch between the different elements to make sure only one is lit. In fact, I'm one of them. Never a problem.
 
the shape of my brew space limits my configuration options. i plan on having my hlt directly above my m/lt, with the movable bk mounted to the same mast on the side. i could still use a pump, to transfer to my fermenter, but i have concerns about hot-side aeration. maybe i could put the pump after the chiller....
ah yes, the other thing that's still tbd - wort chilling. my current thoughts there is just to run my immersion chiller from my cold water tap, and into my drain (as i do now) wait till the wort is cool enough, then transfer.
 
bad news update :( due to a mis-understanding with the boss (wifey), i do not get 1/4 of the basement, i get 1/6th of the basement for my brew space (~175 ft^2). i may not even have room for the space saving 10g system i was planning. aaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrgggggggggggghhhhhhhhh. i need to figure out a more compact plan......
 
bad news update :( due to a mis-understanding with the boss (wifey), i do not get 1/4 of the basement, i get 1/6th of the basement for my brew space (~175 ft^2). i may not even have room for the space saving 10g system i was planning. aaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrgggggggggggghhhhhhhhh. i need to figure out a more compact plan......

Hmmm.
 
maybe. i'm not looking forward to winter brewing then. we get some serious snow here. i think i'll see what i can do with my space.

DSC05686.jpg
 
bad news update :( due to a mis-understanding with the boss (wifey), i do not get 1/4 of the basement, i get 1/6th of the basement for my brew space (~175 ft^2). i may not even have room for the space saving 10g system i was planning. aaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrgggggggggggghhhhhhhhh. i need to figure out a more compact plan......

You go back and TELL her that you get exactly what she would get if she were to divorce you--

HALF!!!
 
You go back and TELL her that you get exactly what she would get if she were to divorce you--

HALF!!!

you tell her. i have 3 words that sum up the situation.

1. irish
2. redhead
3. menopause

run, fast, don't leave any tracks, moving water is your friend.....
 
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