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TGTimm
08-30-2017, 02:53 PM
Is anyone doing this? We recently purchased a beautiful new SS, insulated and jacketed 40 bbl HLT from La Breck Stainless.

We are using three Rinnai C199 199,000 btu/hr tankless heaters to heat the tank via a recirculation loop. The HLT is not pressurized, but vented to ambient air pressure. We're shooting for 185*F.

The performance is miserable. We're not getting anything like the projected 8-9 gpm per unit throughput. To heat 20 bbl of 60F water to 185 takes hours, when it should take about 1/2 hour or less.

Anyone with experience with these things--any brand or make? I'm beating my head against the wall.

Rooh
08-30-2017, 04:10 PM
Hi Tim,

I use 2 x 199,000Btu Navien on demand heaters to heat water for our electric hot liquor tank, no recirc loop. Together they make about 6gpm 182 degree water from 55-60 degree incoming water.

As the incoming and outgoing water get closer in temp, the units probably get less efficient. I suspect it has something to due with the recirc flow rate and the temperature differential through the on demands.

Cheers,

Rich DeLano
rich@thebrewinglair.com

TonyT
08-31-2017, 05:11 AM
We use a tankless heater for our HLT, we had to overcome some issues to make it work but now that we've got it going I love it.

The heaters most likely have a factory pre-set temperature differential that will allow the heater to fire the burner or not. For instance, if the inlet water is less than 15 degrees cooler than the set point, the burner won't fire. There is also most likely a factory pre-set maximum inlet temperature, on ours the burner won't fire if the inlet temperature is over 165, period, even if the set point is 185. This makes getting to 185 in the tank impossible.

We plumbed our system with temperature controllers and actuated ball valves so that the outlet of the the HLT into the brewhouse actually runs inline with the heater, and we keep our tank set point at 145-150. Basically a Johnson controller monitors the recirculation loop on the HLT and when it drops below 145F it actuates valves that divert flow through the tankless heater (which is set at 185F) and back into the tank. When the tank reaches the set point on the johnson controller, it closes the valves and bypasses the heater in the recirculation loop.

When we call for hot liquor at the brewhouse, the same thing happens...valves open to divert the 145F HLT water through the tankless heater, set at 185, but instead of recirculating back into the HLT it it diverted (via manual ball valves) out to our point of use at the brewhouse. Works like a champ, the tankless heater has no issues bringing 145 water up to 185 inline to the brewhouse.

As far as the heaters being able to get 60F water up to 185 in a half hour, I'm not sure why they aren't working as quickly as anticipated. Are they stalling out as the tank approaches 185 or is it a long and slow steady process? Are your three heaters running in series or in parallel? Are you controlling the overall temperature set point using an independent temperature controller to cycle valves to feed the heaters or are you recircing through the heaters 100% and using their internal thermostat as your temperature controller?

TGTimm
08-31-2017, 09:17 AM
Thanks for the replies.

Rich--that's a handy data point. Unfortunately for the way we run our brewhouse, we need a lot of water over a short period of time, so we heat the HLT rather than the water going to the brewhouse. We need about 30 gpm for our mash-in, which would be a huge bank of heaters, if you're getting 6 gpm from two--which is making ours look better.

Tony--which brand of tankless heater are you using?

I control the temp via a pump feeding the Rinnais, using a Johnson 429 controller to run the pump. The 429 is just a new version of the 419--a little easier to use, a little harder to understand.

The system you're using is something our consultant is leaning towards. Unfortunately, as stated above, we need a large throughput going to the mash tun--at least, the way we do it.

I've been talking to management about altering our mash-in protocol. It seems we do it differently from most folks, who don't need that 30 gpm at mash-in. Any advice here would be appreciated, too.

I'd like to spend more time on this discussion right now, but I have brushfires in the pub and brewery to tend to....

wailingguitar
08-31-2017, 09:23 AM
Not sure about your system, but our tankless supplier said that they were not designed to heat water that was already hot (i.e. in a recirculating system) and strongly advised against setting it up that way. Instead, I let the water from the tankless trickle in to the HLT once I start my mash in, and let it go until I have sufficient left for spare after mash in, or if I am double brewing, I take it all the way back to full.

Does your HLT not have a heat source?

TonyT
08-31-2017, 10:30 AM
Tony--which brand of tankless heater are you using?


Takagi T-M50 for our main hot water supply and Takagi T-H3-DV for the HLT. I would have gone with another T-M50, it's badass, but the T-H3-DV was significantly less expensive and it gets the job done. We mill directly into the grist hydrator, there isn't a grist case that we're unloading at a rapid pace, so our mash-in is fairly slow and we get plenty of flow from the Takagi


Not sure about your system, but our tankless supplier said that they were not designed to heat water that was already hot (i.e. in a recirculating system) and strongly advised against setting it up that way.

Depends on the unit, the Takagi's that we use are designed for residential or industrial applications, including recirculation systems. You have to change some of the factory settings and use stainless vent pipe to operate above 140F but they work just fine.

TGTimm
08-31-2017, 02:39 PM
Wailing--We recover our castback water, which will be 100-160F, so we need to be able to heat that to 185, also. This seems to be one of the problems we're having with our Rinnai units--heatng hot water.

Tony--Is your HLT pressurized, or is it at ambient air pressure? Our tech is saying the Rinnais aren't designed for a low-pressure output when recirculating. I'll be adding some restriction to the output line Saturday to see what happens.

Those Takagi T-M50s do seem like like kick-ass units, and probably what we should have bought first off. Do you have a contact for a tech I could speak with?

TonyT
09-01-2017, 03:39 AM
Our HLT is not pressurized, it's open to ambient. I've got a couple factory tech contacts, I'll dig them up and PM them to you. I think our biggest hurdle in setting the thing up was getting out of the mindset of "I'll have a big tank of 185F water" and into the mindset of "I'll have a big tank of water that my heaters can get up to 185 as I need it"

Whitewall
09-06-2017, 10:07 AM
Tony,
Do you have a diagram for this setup you can put together? Were attempting to something similar because we want to utilize our knock out water using a HLT and we like to blast our tanks with 30 gpm of hot water when cleaning and sanitizing. Ive been told A/O smith makes a setup designed to do this specifically but iam having a hard time sourcing it. We also mill straight to a hydrator so the gpm your using should be sufficient for us as well. One question though are you filtering your liquor at all coming in to the building or the cast off from knock out?
Thanks

Sean Wallner
Whitewall Brewing Co.

TGTimm
09-06-2017, 12:30 PM
Sean--take any predictions of throughput from a tankless heater with a very large grain of salt. The only ones I've seen that give a realistic estimate of throughput are the Takagis, which claim 4-5 gpm @ 185F from 50-70F incoming water.

I've been tuning the heck out of our system this weekend, and finally got the Rinnais producing ~6 gpm taking 130 water to 185. At idle, when not heating at all, they seem to pass 7-8 gpm--well belos the claimed 8-9 gpm at a delta T of 50.

Starcat
09-06-2017, 05:16 PM
Is anyone doing this? We recently purchased a beautiful new SS, insulated and jacketed 40 bbl HLT from La Breck Stainless.

We are using three Rinnai C199 199,000 btu/hr tankless heaters to heat the tank via a recirculation loop. The HLT is not pressurized, but vented to ambient air pressure. We're shooting for 185*F.

The performance is miserable. We're not getting anything like the projected 8-9 gpm per unit throughput. To heat 20 bbl of 60F water to 185 takes hours, when it should take about 1/2 hour or less.

Anyone with experience with these things--any brand or make? I'm beating my head against the wall.


Timm, although I do not like Tankless Tek, I did install a system that we are using and it works.
Your idea to use it for HLT is a better way to go IMO than using the array to run sparge which we are doing, again quite successfully, but high maintenance.
The Model I chose was because it was the highest BTU I could locate and also supposedly a tougher more industrial grade unit.
With the optional remote digital control, you can gang them up and it will read usefuly things like GPM and more information that can be imagined.

The model is the Takagi TM50N-ASME and we have a twin array.
I built in a cleaning manifold that allows easy patch in of outboard pumps in 5 gal buckets.
We are using an inhibited Sulfamic powder, and cleaning has to be done on 30 day interval.
The inhibitor is a must to protect the Copper HX.
They use a high temp single wall flue that is pricey. The concentric vent kits are the way to go if you can do wall through.
I have photos and a PDF library on all experience I have to date which I can share if you hit me up on email.
So to get an idea of capacity we are running sparge on a 15 BBL system and it will perform in the winter when the inlet water temp drops into the 50s.
You can make it work, but I would prefer a steam system to these any day. We are still running steam, but the addition had to do with timings, available HLT space etc. You know how the limits always come up against time.
If you want my archive let me know.

Sincerely

Warren

TonyT
09-07-2017, 05:12 AM
Tony,
Do you have a diagram for this setup you can put together? Were attempting to something similar because we want to utilize our knock out water using a HLT and we like to blast our tanks with 30 gpm of hot water when cleaning and sanitizing. Ive been told A/O smith makes a setup designed to do this specifically but iam having a hard time sourcing it. We also mill straight to a hydrator so the gpm your using should be sufficient for us as well. One question though are you filtering your liquor at all coming in to the building or the cast off from knock out?
Thanks

Sean Wallner
Whitewall Brewing Co.

All water coming into our building goes through carbon filtration, that gets it to a point where I'm happy with it.

The HLT system is pretty simple, output port from the tank feeds a small 1hp pump that runs all the time. That pump has a T at the outlet with a thermowell for a johnson controller, then another T that splits the output of the pump into two paths. The first path has a normally open actuated ball valve and leads to a return port at the top of the hlt, the other side of the T has a normally closed actuated ball valve and leads to the input of the on demand heater, which also feeds to a return port on the HLT. The output side of the on demand heater, however, ALSO has a T that splits it off so that we can manually close the return to the HLT and open the feed to the brewhouse when we are mashing in, using hand ball valves.

The johnson controller monitors the recirculation temp and when it drops below 140 it closes one valve while opening the other to divert the flow through the heater. When we get above 150, it turns off and goes back into pure recirculation mode. If the HLT is sitting at 155 and not feeding the heater and we need to mash in, we just raise the set point on the johnson controller so that it activates the heater and we get 185 degree water into our blending station at the grist hydrator.

BlackH2O
11-21-2017, 07:12 AM
Not sure about your system, but our tankless supplier said that they were not designed to heat water that was already hot (i.e. in a recirculating system) and strongly advised against setting it up that way. Instead, I let the water from the tankless trickle in to the HLT once I start my mash in, and let it go until I have sufficient left for spare after mash in, or if I am double brewing, I take it all the way back to full.

Does your HLT not have a heat source?

Generally only a few tank less brands can handle heating even mildly hot (100F) water. This was a big issue when I was working with integrating solar hw with my tank less heater. Currently we have a pair of tank less units both capable of outputting 185F water at 6-7 gpm. By design GPM is an issue with tankless. We currently can mash in completely from the tap, but use a HLT for sparging. But again I suspect our needs are somewhat lower as we wait to install our new 15bbl system. I suspect then we will still use our tankless setup and then adjust the temp in our hlt as necessary.

TGTimm
11-21-2017, 09:18 AM
Blackwater: What brand are your units? Our Rinnai C199s can heat hot water and have a max. of 185F, but we're only getting around 6 gpm through them using an over-sized pump. The Rinnai reps think this will eventually damage the units, and recommend using a smaller pump the would get us a throughput of only 4 gpm--not acceptable for our needs.

The sales rep who sold us these claimed they would do 8-10 gpm in our system. Not, unfortunately, in writing.

I'm pretty disappointed by this very expensive experiment.

Mtnmann
11-24-2017, 11:05 AM
I use a Navien NPE-240S to heat a bath pasteurizer, works well but i've noticed a couple of differences from a Rheem 95 that i've used previously. The Navien has an internal valve that restricts outflow to guarantee the set point temp. So if I start out with cold water, the valve restricts to 2-3 gpm so that the max (182 F) output temp is achieved. As the bath warms up, the gpm increases until i'm at max throughput which is 12 gpm or so (3/4 in. copper internals). I have a 1hp circ. pump. The Rheem had no internal restrictor valve and would just pump it's maximum delta T into whatever was running through it, but it seemed to be naturally restricted to about 6 gpm (1/2 in. copper internals).
Timm, what temp are you keeping your HLT at?

mtn

TGTimm
11-27-2017, 08:11 AM
Mt: We keep the HLT at 185, the max for our Rinnais--or I should say we try to.

The Rinnai C199 also has the internal restriction valve.

pc2cr
02-13-2018, 06:54 PM
Our HLT is not pressurized, it's open to ambient. I've got a couple factory tech contacts, I'll dig them up and PM them to you. I think our biggest hurdle in setting the thing up was getting out of the mindset of "I'll have a big tank of 185F water" and into the mindset of "I'll have a big tank of water that my heaters can get up to 185 as I need it"

We use Takagi in our brewhoue and have grown to love them. This comment really resonated with me. Once we entered this state of mind, the heater found a new place on the brew day.

TGTimm
03-06-2018, 09:00 AM
Revisiting this post:

Due to our mash-in procedure, we need a lot of hot liquor at mash-in. Using the Rinnais to heat the water going into the mash tun didn't work, as the max. flow possible is less than 10 gpm each, going down as the delta T goes up, with a flow of only ~2 gpm when heating 45F tap water to 180F.

I re-plumbed the HLT so that we can either heat the entire contents of the HLT by recirc through the three Rinnai C199s, or heat the make-up water through the Rinnais as it goes into the HLT. When we're warming up our cast-back water from the HX (about 160F), it's reasonable fast to heat it by recirc, and when we need make-up water, we have enough time for the Rinnais to keep up. The night before a brewday, we fill the entire 1,200 gal HLT with cold water and have all night to heat it up. After the first castback, we're just heating the castback water.

Our hard water is still a major issue. I clean the strainers on the Rinnais a couple of times a day, and acid-wash the units every two weeks. I expect this frequent cleaning regime to significantly shorten the lifespan of the HXs in the Rinnais. I'm using inhibited sulfomic acid @ ~pH 2-3 for the acid wash, as it seems, based on the color of the cleaning solution afterwards, to erode the copper elements of the system less than phos acid or the recommended distilled vinegar--which is also very expensive.

Thanks for all the feedback and discussion.

gitchegumee
03-07-2018, 07:19 AM
Why wouldn't you use your steam utility? Would be superior technique and likely cheaper to operate.

Bez
03-13-2018, 02:03 PM
This all feels very familiar. We're in the process of starting up. The last roadblock in this process has turned out to be the exact Rinnais you seem to have purchased for your brewery. The sales rep promised that it could deliver 10gpm, which is pretty much all i'm seeing through our city 1'' cold line anyways. We purchased 2 units to do this job. Upon turning them on we are seeing more of a flow rate of ~5gpm, which is so slow that I cannot blend cold water slow enough to hit any sort of adequate strike temp. When I set the units to their lowest setting they run about 9-10gpm, so I know they are capable of pushing water through at the flow rate I need. We had purchased a water tank with the idea that it was going to be a recaptured water from knock out tank, water that could be redirected back to the Rinnais. Unfortunately it now looks as if this water tank is going to be turned into our permanent HLT, installed with a float, using one of the Rinnais to keep it at 150F and the other Rinnai to pass through on the way to heating said water up to 185F. I'm a little skeptical how this plan is going to work out as the initial plan backfired on us a bit.

TGTimm, you mentioned how often you have to clean these things, which makes me even more worried. The sales rep did mention to us that distilled vinegar should be recirculated through them quarterly at most, but it sound like you've needed to do that much more. Nothing was even mentioned to me about a strainer, maybe I need to get on a ladder and figure out where that would be and how often I should expect to deal with cleaning it out. Is it essentially a filter for the units? We also have fairly hard water where I'm located.

mmussen
04-03-2018, 07:14 AM
Question for you guys recirculating into the HLT - What kind of pumps are you using to move the water? I'm guessing something around 3/4 - 1 HP, but am more curious if you're using a full on sanitary grade pump, or something a little bit cheaper since its just being used for hot water.

Cheers

TGTimm
04-03-2018, 02:35 PM
Had some trouble posting a bit ago.

Bez--Your sales rep is selling you a line of bull. Our sales rep told us the same, and I designed the system around this number, much to my chagrin. Consult the delta T/throughput chart in the Rinnai C199 instructions. 10 gpm is possible if not heating the water. Going from our line temp of ~50F to 185, we get about 2-2.5 gpm. Recircing our castback water at ~160 going to 185, we get around 6 gpm. This is with everything perfectly clean.

Mounting the units where you need a ladder to access them is a mistake. There is a little bitty thimble-sized strainer just below the cold in port, on the valve manifold. We clean ours at least daily, and I need to do ours right now--again. Our water is about 130ppm carbonate hardness.

Manuel--We're currently T'ing off our main HL pump for the recirc. IIRC, a C100 pump with 1.5 hp would pretty well meet the needs of a Rinnai C199, but we get better throughput with the over size pump--and likely accelerated erosion of the internal HXs.