2500 watt floating heater

I just put my 2500 watt floating heater into service the first time this AM. This was built to supplement the heat provided by my kitchen stove, and is used in brewing 2.5 gallon batches. My full volume was 3.5 gallons.

From tap water temp to 150 deg, the stove and 2500 watt heater together took 3 min

From 160 deg at the end of mash to full rolling boil the time was 2 minutes!!

Heating and cooling times were the bottle neck in brewing for me until I built my immersion chiller which along with ice tubes, will drop my temp from boil to pitch in just 7 minutes, and now the heater that reduces total heat times to a mere 5 minutes. With a half hour mash and an hour boil, I can easily complete a brew day in two hours total without rushing through things. That includes making up a recipe, grinding grain, and clean up.

Note that these photos are of an incomplete project. The ground wire is not yet hooked up. I need to spot weld a tab on to attach it......... which I will do today, and I will insulate the terminals with silicon RTV. Wort is pretty conductive, so I'm worried about splashing wort on the terminals. I used it today exactly like it is in the photos........ very carefully. Total cost of this project was under $50 including wiring in a 220 outlet. Parts were from Ace Hardware.

Element was from: http://www.sourcingmap.com/ac-220v-2500w-alloy-spiral-electric-water-heating-element-tube-heater-p-381203.html?utm_source=google&utm_medium=froogle&utm_campaign=usfroogle&gclid=CMqK0qCQosACFQuOaQodJ04AOA

H.W.

This made me cringe seeing the terminals unprotected like that... I'm glad to see you've got a plan for that!

What a cool idea! I've been thinking about moving to electric brewing so that I can brew indoors instead of outside with propane. I'm not sure if I'm going to be doing this or how I'll go about it... so now I've got another option! Although, I do 5 gallon AG batches, so I'm not sure how this would work...

Thanks for sharing.

max384 said:

This made me cringe seeing the terminals unprotected like that... I'm glad to see you've got a plan for that!

What a cool idea! I've been thinking about moving to electric brewing so that I can brew indoors instead of outside with propane. I'm not sure if I'm going to be doing this or how I'll go about it... so now I've got another option! Although, I do 5 gallon AG batches, so I'm not sure how this would work...

Thanks for sharing.

Click to expand...

Two minutes from 160 to full rollling boil for a 2.5 gallon brew........... I had a burner going under it also. Previously it took about 20 minutes to half an hour with just the burner. The benefit would be significant in a larger brew.

2500 watts = 8530 BTUs per hour

A BTU will raise one pound of water 1 deg
water weights 8.33 pounds per gallon
7 gallons of water ( a typical boil for a 5 gallon brew ) weighs 14.65 pounds
That works out to 582 degrees per hour
or almost 10 deg per minute (9.7)

Thus if you were mashing at 152, and it was your only source of heat, you would have to raise the temp by 60 degrees. In theory it should do that in 6.1 minutes!!

The 2 minutes it took me to reach boil included a burner under the pot (kitchen stove). It obviously is NOT suitable for you only heat source, but it is a huge benefit when raising temp rapidly. I would definitely be dubious about the benefit for a 5 gallon batch...... 6 minutes is a LONG time ;-)

H.W.

The open connections made me cringe also........ and will be protected next brew. I wanted to retain it that way to photograph it. I play with dangerous things all the time. If you saw my capacitor discharge mouse trap with enough power to kill a person, I suspect you'd cringe even more. Short it with an insulated handle screw driver and it sounds like a 22 shot. A simple voltage double circuit provides about 300 volts DC from line voltage to charge the capacitor, and a high resistance in the supply prevents it from being a fire hazard. It would be difficult to get shocked due to safety features built into the design. When you lift the cover, a device flips down, shorting the system, and rendering it harmless. When you set the lid on, it becomes active again. The capacitor discharge voltage is huge! It damn sure knocks em dead!

Owly055 said:

Two minutes from 160 to full rollling boil for a 2.5 gallon brew........... I had a burner going under it also. Previously it took about 20 minutes to half an hour with just the burner. The benefit would be significant in a larger brew.

2500 watts = 8530 BTUs per hour

A BTU will raise one pound of water 1 deg
water weights 8.33 pounds per gallon
7 gallons of water ( a typical boil for a 5 gallon brew ) weighs 14.65 pounds
That works out to 582 degrees per hour
or almost 10 deg per minute (9.7)

Thus if you were mashing at 152, and it was your only source of heat, you would have to raise the temp by 60 degrees. In theory it should do that in 6.1 minutes!!

The 2 minutes it took me to reach boil included a burner under the pot (kitchen stove). It obviously is NOT suitable for you only heat source, but it is a huge benefit when raising temp rapidly. I would definitely be dubious about the benefit for a 5 gallon batch...... 6 minutes is a LONG time ;-)

H.W.

The open connections made me cringe also........ and will be protected next brew. I wanted to retain it that way to photograph it. I play with dangerous things all the time. If you saw my capacitor discharge mouse trap with enough power to kill a person, I suspect you'd cringe even more. Short it with an insulated handle screw driver and it sounds like a 22 shot. A simple voltage double circuit provides about 300 volts DC from line voltage to charge the capacitor, and a high resistance in the supply prevents it from being a fire hazard. It would be difficult to get shocked due to safety features built into the design. When you lift the cover, a device flips down, shorting the system, and rendering it harmless. When you set the lid on, it becomes active again. The capacitor discharge voltage is huge! It damn sure knocks em dead!

Click to expand...

7 gallons of water weighs 58 pounds. Water with dissolved sugars is even heavier. That would turn the six minutes into about 25, and that's assuming even heat distribution and no loss of heat to the outside environment. I'd say 30 minutes to raise the temperature 60 degrees is more likely, probably longer.

Still cool though nonetheless

max384 said:

7 gallons of water weighs 58 pounds. Water with dissolved sugars is even heavier. That would turn the six minutes into about 25, and that's assuming even heat distribution and no loss of heat to the outside environment. I'd say 30 minutes to raise the temperature 60 degrees is more likely, probably longer.

Still cool though nonetheless

Click to expand...

I got all screwed up.......... I wrote the wrong down for weight.... I'm not sure how I arrived at that figure??? Scratching my head on that one. 8530/58 = 147 degrees per hour or 2.45 degrees per minute. I shouldn't do calculations while trying to brew at the same time.... too much going on. 60 degrees from 152-212 divided by 2.45 deg per minute or 24 minutes.............. Sorry I messed up badly!!

The fact remains that with my 3 gallon brew with the burner under it and the floating heater in it, my time to boil was phenomenally better than usual. A mere 2 minutes on the clock. The element should have accounted for only about 10 degrees of that temp increase in that time period. Normally this would take about 20 minutes with just the burner, so obviously the element is putting out more than the calculated BTUs. Perhaps I screwed up somewhere else. My time was written down as I clocked it on the clock right behind my brew kettle.

Considering the 18 minute gain......... something is way out of whack with my numbers still. And this is with wort......not water. I think it is incorrect to assume that wort takes proportionally more energy to boil based on weight.

Not the first time I've screwed up on numbers.

H.W.

Owly055 said:

Considering the 18 minute gain......... something is way out of whack with my numbers still. And this is with wort......not water. I think it is incorrect to assume that wort takes proportionally more energy to boil based on weight.

Click to expand...

When you go back to rework this, don't forget that the specific heat of sugar is different from water - I've looked it up, but can't find it right now - sorry.

I just did a straight water test using only the element. I started with 3 gallons of hot tap water at 137F, and ran the test for 9 minutes, ending at 198 because I really didn't want to go to a boil. 61 degrees in 9 minutes or 6.77 deg per minute for three gallons times 3 gallons 24.8 pounds. So for one pound that would be 167.9 degrees per minute or a little over 10000 BTUs. instead of 8530 as it should be. Considering the casual unscientific nature of the test, I don't feel I missed it by much. I didn't hang the clamp meter on the wire and check actual current. Temp measurements are subject to error, and actual current may be greater than advertised.

In any case it had a dramatic effect in time reduction. It also has the effect of covering a great deal of the wort..... making in effect a lid, which doesn't hurt.

H.W.

Are there elements out there for 110?


Sent from my NSA monitored iPhone.

ncbrewer said:

When you go back to rework this, don't forget that the specific heat of sugar is different from water - I've looked it up, but can't find it right now - sorry.

Click to expand...

The specific heat of a sugar solution with a brix of 12 is 3.92, and the specific heat of pure water is 4.179

That tells me that pound for pound a sugar solution will take less BTUs per degree than water.... which is what I expected, however there is more weight per gallon. The net difference is really trivial in terms of what we are doing.

H.W.

Doesn't seem that they have any 120v, or 1500 watt elements that would work. Or an equivalent 220v 4000watt~ element. Will have to look more into building one of these.

Owly055 said:

I got all screwed up.......... I wrote the wrong down for weight.... I'm not sure how I arrived at that figure??? Scratching my head on that one. 8530/58 = 147 degrees per hour or 2.45 degrees per minute. I shouldn't do calculations while trying to brew at the same time.... too much going on. 60 degrees from 152-212 divided by 2.45 deg per minute or 24 minutes.............. Sorry I messed up badly!!

The fact remains that with my 3 gallon brew with the burner under it and the floating heater in it, my time to boil was phenomenally better than usual. A mere 2 minutes on the clock. The element should have accounted for only about 10 degrees of that temp increase in that time period. Normally this would take about 20 minutes with just the burner, so obviously the element is putting out more than the calculated BTUs. Perhaps I screwed up somewhere else. My time was written down as I clocked it on the clock right behind my brew kettle.

Considering the 18 minute gain......... something is way out of whack with my numbers still. And this is with wort......not water. I think it is incorrect to assume that wort takes proportionally more energy to boil based on weight.

Not the first time I've screwed up on numbers.

H.W.

Click to expand...

No worries! I've hefted 5-6 gallons up and down stairs far too many times not to spot the weight being off right away!

Looking forward to your pictures after waterproofing the terminals.