Speed brewing with RIMS? | Practical questions about 120V RIMS

[Polyphaeon]

Hi All,
I've done quite a bit of research on HERMS systems which seem to be much more popular than RIM, so I thought it might be the way to go. It occurs to me that a RIM system could have some great advantages that I have not seen discussed at length. I should clarify that I value time. If I can shave a half hour on each brew day that is great for me.

My questions are:
Is a 120V RIMS tube sufficient for hitting your temp?
Is a 120V RIMS tube sufficient for on demand strike/sparge water?
Do people run their RIMS tubes after mashing out into and out of the BK to shorten the time to boil? (same approach but for HLT?).

My current thinking is a 2 vessel, 2 tier, 1 pump system with a raspberry pie controller. The controller already exists and can only handle 120V so I am interested to know if these ideas are practical with 120V. The HLT/BK will be on a propane burner. Mostly 5G but some 10 Gallon batches.

If this is practical I imagine you could save nearly an hour on brew day.

Thanks!

 

[Bobby_M]

No, 120v elements cannot give you the temp rise needed for on demand water heating. 240v/5500watt is just barely enough to do this.

 

[dyqik]

A 120V RIMS will eventually get your strike water up to temperature, but it will take time. Look for the "electric heat" spreadsheet to work this out, as it depends on your element wattage and losses.

As an example:
Testing my 120V 1500W RIMS tube last week I was able to get my 2.5 gallons of test water up to 168F, recirculating through the 10gal cooler mash tun. I don't know how long that would take running flat out though, as I'm not sure of the losses due to recirculation. Minimum time for 4 gallons (see calculation below) from 50F to 168F is 34 minutes with a 1500W element.

Similarly for sparging, it depends on your starting temperature and the rate you want to supply sparge water at. You want to add at least 48C to your sparge water (50F to 168F), which requires 201 kJ/litre. With a 1500W (=1.5 kJ/second) element, you can heat 0.44 litres (~0.47 qt, 0.11 gal) per minute from 50F to 168F. This means a 4 gallon fly sparge would take a minimum of 34 minutes with no losses, so a 45 minute fly sparge may just about be doable with a 1500W element running on demand. However, you would need to monitor your flow rates and outlet temperatures carefully to make sure you don't flow too fast and lose temperature.

Both times will be shorter using the kettle on a propane burner to preheat the water at least part of the way. A burner will typically be rated to output about 20 kW (e.g. my nominally 75k BTU/hr Camp Chef), of which maybe half is coupled into the kettle when throttled back a bit. I guess I should work out what power I'm actually getting in my kettle some time.

 

[stlbeer]

I would add that a 5500w/240v element running at 120v will likely lengthen your brew day.

I will use my RIMS tube to shorten time to heat strike water. I recirculate strike water anyway to prevent stratification so might as well have it go through the RIMS tube. I then have 6500w heating the strike water and have primed the pump and RIMS tube to boot.

Good idea to use the RIMS tube to assist in heating the wort to near boil. I'll have to give that a try this weekend.

 

[Bobby_M]

I have some data points here: https://www.homebrewtalk.com/f170/demand-sparge-via-rims-461533/

Basically 1375 watts will get you 30F rise at 1 litre per minute.

 

[Owly055]

While the controller may only handle 120vac, there is no reason you can't handle an 240V element using a solid state relay, or some triacs to handle the voltage and current. I don't know what the switching system is, but of course 240 is just 2 120V lines out of phase with each other, so if you need 120V for the controller itself, all you need is a neutral wire, which is present in most 240 volt circuits anyway......... L1 = 120V, L2 = 120V, and you should also have a neutral and a ground, so a 4 wire plug is capable of providing everything you need......... Ground of course is neutral, but we aren't allowed to use it in circuit even though it ties together at the box. An ordinary range plug has all 4..... that means that you can pair L1 or L2 with neutral for a 120V circuit, and at the same time pair them with each other to have 240V. Be sure you are not looking at problems that don't exist.........

H.W.

 

[Polyphaeon]

Bobby_M thanks for the comment and link.
dyqik Thanks for the numbers I think heating the water with both the RIMS tube and a propane burner would probably do the job nicely.
Owly055 I understand that to get 240V from two 120V you need to use two outlets that are on different circuits (you'll have to forgive my poor terminology, I am still learning). Although the currently available controller is a big consideration for me the other is that I want to maintain some mobility. I know I will be teathered to power with a RIMS tube and pumps but it would be nice if it was any power.
stlbeer Thanks for the input. I think I will probably forget about the on demand water (from Bobby_Ms video it seems it might be difficult to dial in the temp anyways) and use the RIMS tube with the propane to heat the water. I can't see how this would do anything but shorten the time.

I should have clarified my first question: Is 120V sufficient to hit/maintain your temp after mashing in. I think the answer is yes based on Bobbys numbers and in fact for my set up (coleman cooler) I don't plan on using it so much to maintain the temp but nail the exact right temp.

So summary of answers (input welcome):
1) Yes
2) No
3) Don't see why not?

 

[stlbeer]

Yes, 120v is sufficient for maintaining mash temp and capable of small steps in reasonable amounts of time for a 10 gallon batch with 1375-1500 watts.

It probably will perform better for a 5Gallon system. i.e. times will be shorter.

 

[dyqik]

Using a 1000W 120V heat stick with my stove certainly speeds up the time to strike temperature and to boil, but it's less noticeable on my propane burner when brewing outside. A 1300-1500W RIMS would be better, not just because of the extra power, but because of the recirculation and stirring.

1000W should be plenty for maintaining temps - again, I lose 4F maximum from a simple static 4 gallon mash over 60 minutes in a 10 gallon cooler, which is a power of ~35W. Obviously the losses go up as you recirculate (all that uninsulated steel and hose to run through), but not that much.