munchkin boilers

jerry scharf_3

kieth,

I can try to answer some of the questions:

1) Hard to know, at best it would be a wild guess. The modulating range of the munchkin/vision 3 is wide enough that there is virtually no loss in having a pair of 399s.

2) Only HTP knows for sure. The fact that you will be running the units at such low temperature may make a big difference for this.

3) Given the size and the difference in function of the two sides, I would probably not combine them. I am sure you can put someting together or talk to HTP about their DHW dedicated offering.

4)
for the heating side:
If we assume a pair of munchkin 399s, you would then add a vision 3 controller to manage them. Since the control software is set for a 20F delta T goal, this means that the target water temp is 70F and the return water temp is 50F. At 50F return water temperature, I will conjecture that the boilers can run well over 95% efficient. Some people have reported numbers approaching 98% for cold return water like this. With the vision 3 controller, you get a stepless modulation range from 80 to 800 MBH. You also add the lack of start/stop energy loss and not running over capacity and I would put a SWAG of 25-40% decrease in operating cost. It might be more, but I doubt it would be much less.

DHW side:
HTP has the 399DHW unit. They should have all the designs and numbers on what to expect from this. I've never built anything like this, so I can't help you.

yours,
jerry

keith

Munchkin Application

Looking for some feed back from those of you who may have been involved with a project like the one I'm trying to put together.

Looking at a boiler replacement project for a heat pump application in a apartment building and the Munchkin seems to be a good option. I am looking at installing a pair of 399M'S

But I have some questions and tech support is closed for the Holiday weekend.

1- The existing boiler is 800 MBH RayPack, how do I verify this is not oversized? I am familiar with sizing for straight hot water or steam but not in a heat pump application. This unit is currently operates off of a loop temp sensor. The sensor pulls in the primary pump and burner untill the sensor is satisfied.

2- The manual seems to indicate that the boiler is equiped with a 30lb relief valve valve but the boiler is rated to 125PSI. My system runs at 50lbs. Are they telling me I can increase the pressure rating of the relief valve and still be within the pressure rating of the boiler?

3- The domestic hot water heating system is getting tired. They have (2) 500 MBH copper tube boilers feeding (1) 750 gallon storage tank. The tank lining is shot and needs to be replaced. I was thinking of offering a boiler/ indirect for an upgrade. Both systems live in the same mechanical room. None of the Munchkin drawings in the 399M install guide show a low temp and high temp piping detail. The reason why I was leaning towards Munchkin was the low temp application. Am I accomlishing anything by combining the 2 systems heat source?

4- The current boiler is a on-off, non-condensing unit.Any idea what the gas savings %'s might be using the Munchkin with the Vision controller? Either with or without domestic hot water being supplied?

Weezbo

hello. I have questioned the pressure relife twice and was

assured that that a higher pressure relife was not an option. *~/:)

the first time i instigated a question on flow rates the second time it was more of why some systems are run at higher pressure....i belive it is in the fine print...on the operational parameters of the boiler. what this leads too is proper piping practices...the other question you have on removal of the domestic hot water tank leads me to consider the possibility of the pipes and faucet seats throughout the building and any ,point of use, storage tanks.......a new indirect might be cooler than the previous lash up. once again though ,keeping an eye open to fixture units and flow rates and flushing the system first ...might give you more information to steer by .... that would be important on determinig fuel savings also..

i am like so frazzed out lately ,from being on the run.it is summertime and there is like plenty of work every day...

the munchkin vision control class and a third question of pressure and temperature co relations and a forth question on seconday high limits and another on the upper end operational temperatures i think just about covers the reason to leave the 30 psi on the boiler. i got to hop too it today as the stores close early and i am having bankers hours as usual

keith

Relief valve

Thanks for the responce.

Under standard features listed for the 399M it states:

* 30 PSI relief valve
* Boiler rated up to 125psi relief valve

Am I missing something or does it indicate the ability to operate this boiler @ higher pressures than 30psi?


Keith

Weezbo

i am on my tenth cup of coffee...

so yup that is defenitely what that means Use a 30psi relife valve The guy giving the class that i wisked myself to 500 miles away was Chuck Shaw. And may i say he knows this munchkin thing like nobodies bussiness i helped peel piecies off the boiler and put them back together...i am not just your average heckler in the crowd *~/:)

it is a temperature,flow, pressure for the boiler...

one of the tricks on some poorly operating boiler systems is to bang up the temp...there are upper limits on the control of the munchkin that sence that and would shut it off ...Keith i have never nor have i ever wanted to convert a oil fired viessmann to natural gas however a client who wanting the best yet with the option to convert to nat gas in a couple years when its piped into the block asked me this question the other day...i really dont like converting appliances from oil to gas any thoughts or experiences with that(on a viessmann) ?

Chuck Shaw_4

Looking for some feed back from those of you who may have been involved with a project like the one I'm trying to put together.

Looking at a boiler replacement project for a heat pump application in a apartment building and the Munchkin seems to be a good option. I am looking at installing a pair of 399M'S

But I have some questions and tech support is closed for the Holiday weekend.

I was on call untill 11AM EST. The phone never rang, and I had no messages, sorry I missed your call. In saying that, I dont know how much help I could have been as this is most likely a call that is for normal buisness hours, not a no heat emergency, and I dont have the documentation that I have available to me during the week.

1- The existing boiler is 800 MBH RayPack, how do I verify this is not oversized? I am familiar with sizing for straight hot water or steam but not in a heat pump application. This unit is currently operates off of a loop temp sensor. The sensor pulls in the primary pump and burner untill the sensor is satisfied.

I cannot give you valid help there, maybe someone else can chip in.

2- The manual seems to indicate that the boiler is equiped with a 30lb relief valve valve but the boiler is rated to 125PSI. My system runs at 50lbs. Are they telling me I can increase the pressure rating of the relief valve and still be within the pressure rating of the boiler?

The boiler is rated at 125PSI, because we use the same vessel for our VWH model, which is for domestic hot water, the heating boilers (399M) comes with a 30PSI relief valve. You will need to submit, model, serial#, job location, and job specifics, as to why you want to change the relief valve to us, I have never seen it not be approved on the 399

3- The domestic hot water heating system is getting tired. They have (2) 500 MBH copper tube boilers feeding (1) 750 gallon storage tank. The tank lining is shot and needs to be replaced. I was thinking of offering a boiler/ indirect for an upgrade. Both systems live in the same mechanical room. None of the Munchkin drawings in the 399M install guide show a low temp and high temp piping detail. The reason why I was leaning towards Munchkin was the low temp application. Am I accomlishing anything by combining the 2 systems heat source?

I would use a Vision 1 package on 1 boiler to provide DHW with an indirect, then use the Vision 3 to stage and modulate the systems.

4- The current boiler is a on-off, non-condensing unit.Any idea what the gas savings %'s might be using the Munchkin with the Vision controller? Either with or without domestic hot water being supplied?

I have some documentation at the office, that I can fax to you, from one of our rep firms, about the savings they saw on jobs that they bid. The study was on 4 different buildings, and was done by an independent company. It used degree days and therms, then showed the savings.

Hope this helps,

Chuck Shaw

Technical Support Dept

Heat Transfer Products

keith

munchkin

Thanks for the responce Chuck.

I'll call you on Tuesday.

Keith

tim smith

boiler size for water source heatpumps

Need to know tonnage of all connected heat pumps, then you can figure the gpm required at appx 70 degree water temp. Then based upon an appx 10 to 15 degree delta T you can figure how many btus will be required. Good luck, Tim.

Constantin

A mere homeowner here...

If the two services have separate gas meters, you might be in luck. Based on the AFUE of the boiler and the heating degree days over the time period you have data for, you can make a pretty good guess as to the heat loss of the building. This would take the HP out of the equation... Next, size the boilers so as to meet the building demand on a design day and make the DWH production a priority zone. If a lot of DWH is needed, upsize the the boilers.

My suggestion would be one heating system for space heat and hot water that has multiple condensing, modulating boilers. That way you get redundancy, very efficient gas utilization, etc. The savings are site-specific, though one notable installation replaced two 1.25 MMBTU DWH boilers with 800kBTU of Munchkin and an Thermomax, IIRC.

I'd look into the Thermomax and/or Ergomax series of indirect water heaters... very compact units with very high transfer rates that allow you to open up a lot of room in a given utility space. However, I am also partial to the Vitocell 300 series due to its stainless construction, relatively high transfer, and cleanout port.

Like all boilers, the Munchkin can do high and low temp at the same time, either via injection mixing or a 4-way valve. Naturally, the lower the return water temperature, the higher the efficiency of the boiler. Yet another reason to have it all in one system as opposed to two.

Me_8

I am no engineer however A water source heat pump loop is just like domestic water, outdoor reset does not apply. The heat pumps want to see roughly the same 70* water if its below 0 or 50* outside.
I would also think that trying to do the domestic and loop off the same boilers would wind up costing more,have more possible things to break and not save anything in gas consumption anyway.

Ken_8

Perhaps I can help...

We installed W/M Ultra's in an office complex that used water based heat pumps that needed 70° water to function properly and the boilers ran beautifully! Savings were incredible. You must remember, the electric side of the heat pump is also doing "some" of the heating.

Then we used two 399 Munchie's w/Vision 3 at a senior citizens housing project and simple HWBB emitters. Even nicer than the W/M's and heat pumps!

Rather than torment the explainations here, give me a call and I'll share what we learned and know...
(732) 388-1794. I'll be "catching up" in the office much of today and tomorrow morning before the company comes.

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Keith_8

Thanks for the feedback guy's

It seems the right thing to do is keep the 2 temperature systems seperate. I was thinking by combining them they would have redundancy if 1 boiler went down. In this case it seems not to be the way to go.

Ken, I'll call you about 10:00 A:M.

Thanks for sharing!

Keith

hr

If I had an 800,000 low temperature load

I would install 4- 200,000 modulating boilers. Because... Let's say a 199 Munchkin, for example, modulates from 30,300 BTU/ hr up to 199,999. for a 6.6 to one turndown rate.

If you add 4- 199,999 together you increase your turndown rate to 26 to 1, as you now can ramp from the low 30,300 (one boiler at it's lowest firing rate) all the way to 799,996, with 4 at full fire!

This could be a very, very nice efficiency feature for a multiple apartment building with everchanging, and quite possibly very small loads on mild days.

Furthermore if the loads can be handled with low supply temperatures, say below 140F, than the condensing technology really shines.

Pick a stage controller designed for condensing boilers. This controller watches supply temperature and ramps in addition boilers as that temperature hits 140. Instead of allowing the lead boiler to reach high temperature or full output, it brings on additional stages. This exposes more HX surface to those condensing temperatures, and keeps them all running at the very highest efficiency point. Make sense?

Pipe them in a reverse return, with the boilers in parallel. This assures that each boiler sees the same (low as possible) return temperature to again, keep them in the highest efficiency, condensing mode. Check protection is need in this piping method. Use a Grundfos circ (properly sized) with an intergral flow check built in pumping INTO the boiler.

hot rod

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Keith_8

Do you think

That the increased turn down ratio/efficiency offsets the higher maintenance cost associated with 4 boilers instead of 2?

In regards to domestic hot water: In order to keep the return temps low on a indirect HWHTR it would make sense that oversizing the capacity and keep the tank temp to 140* with a mixing valve set @120* would allow the boiler to condense and achieve peak efficiency. Am I on the right track with this thinking?

Chuck Shaw_4

Keith

What will happen with a Vision 3 control, is you will modulate from 30% of the capacity of one boiler, up to your full load. This modulation takes place in percent incriments, not steps. So, with 4 boilers, it would be more like 371 steps of modulation.

You could then hook up the Vision one control to one (or two) boilers, for domestic hot water.

I was in a hotel just outside of Boston's Logan Airport, they were using 1 (ea) SSU119C (dual coil tank) with a 199M on each coil, and with it, they were taking care of all 40 rooms, and a commerical washing machine.

I do not think, that keeping the boilers in a condensing mode, while making domestic hot water, will offset the cost of additional storage. However, that would depend on the amount of DHW the building uses.

Give me a call on Tuesday, and I will give you the best information that I have available to me.

Chuck Shaw

hr

If only I were an engineer

I suppose you could project that savings. Past fuel bills and weather data may indicate how often the building is at partial load, this is where the low turn down rate would be of value. I don't know where you are located, but the building will be at partial load for some, maybe a good portion of the heating season? A load calc, which I would recomend as you proceed, would help answer a lot of questions. At this point we are assuming that load (800K)to be true. What if it is off by 20%? Or more!

In my area we didn't hit design, not even within 7 degrees of, all last winter.

Keep in mind 4 boilers doubles your redundancy should one, or two go down. That may be a selling feature with a commercial application.

Maintenance should not be a big issue. I suspect not anymore than an annual clean and check on oil fired equipment. Really a simple task with these condensors. Remove the front cover and spray a cleaner and flush, check combustion calibration, period. Not even a dirty job. It may be more of a check than an actual cleaning needed if they are breathing clean air and are tuned properly.

As far as DHW, I want to see if the Ergomax folks will run some output numbers based on 140 maybe 150 boiler side temperatures. Wouldn't it be nice to generate that 120 domestic water with condensing temperature boiler operation. I suspect Ergo, or Triangle Tube indirects with large surface area would be able to get you there. Of course you may have to pay for more HX surface, but it may be better than 180° temperature operations?

I feel another importany key to these condensors longevity is the lowest possible temperature operating range. Probably why Viessmann limits theirs to 167°F. Minimize the thermal stress, imposed by operating temperatures from 70°F to 180 or 190 that some go to in DHW production mode, and extend the life of the HX.

Maybe the Ergomax with the additional coil could work out?

I suspect the Ergo style, reverse indirect, will be able to get us there with the massive amount of excellent conductor (copper) and the turbulant flow they get across that HX.

I believe those 30 -50% fuel savings that we have heard repeatedly here, are probably realistic, with the condensing AND modulation features of these new age boilers. There are too many documanted cases to ignore.

hot rod

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Keith_8

An accurate

heat loss is the 1st step once I find out which direction the Board wants to go in. Although It needs to be done regardless of what direction it goes. Unless when we discuss costs it goes nowhere

In my experience, regarding sales of this type, I find it to be helpful to give budget numbers on a couple of options with some features to be the best way to go intially.

Thanks for the suggestions, I'll keep you posted.

keith

Thanks to Everyone

> Looking for some feed back from those of you who

> may have been involved with a project like the

> one I'm trying to put together.

>

> Looking at a

> boiler replacement project for a heat pump

> application in a apartment building and the

> Munchkin seems to be a good option. I am looking

> at installing a pair of 399M'S

>

> But I have some

> questions and tech support is closed for the

> Holiday weekend.

>

> 1- The existing boiler is 800

> MBH RayPack, how do I verify this is not

> oversized? I am familiar with sizing for straight

> hot water or steam but not in a heat pump

> application. This unit is currently operates off

> of a loop temp sensor. The sensor pulls in the

> primary pump and burner untill the sensor is

> satisfied.

>

> 2- The manual seems to indicate

> that the boiler is equiped with a 30lb relief

> valve valve but the boiler is rated to 125PSI. My

> system runs at 50lbs. Are they telling me I can

> increase the pressure rating of the relief valve

> and still be within the pressure rating of the

> boiler?

>

> 3- The domestic hot water heating

> system is getting tired. They have (2) 500 MBH

> copper tube boilers feeding (1) 750 gallon

> storage tank. The tank lining is shot and needs

> to be replaced. I was thinking of offering a

> boiler/ indirect for an upgrade. Both systems

> live in the same mechanical room. None of the

> Munchkin drawings in the 399M install guide show

> a low temp and high temp piping detail. The

> reason why I was leaning towards Munchkin was the

> low temp application. Am I accomlishing anything

> by combining the 2 systems heat source?

>

> 4- The

> current boiler is a on-off, non-condensing

> unit.Any idea what the gas savings %'s might be

> using the Munchkin with the Vision controller?

> Either with or without domestic hot water being

> supplied?

keith

Budget #'s

Thanks for all of your help guy's.

I spoke with one of the guy's from the Board of Directors of the apartment building that I have been discussing with you today with some budget #'s on upgrading his heating system and his domestic hot water system.

There seems to be some genuine interest in moving forward.
Now comes the nitty gritty. Doing the actual legwork and sizing the systems properly for their needs, finalizing the costs and trying to close the deal.

I'll keep you posted.

Thanks for helping out.

Keith

hr

Don't forget

your consulting fee!

hot rod

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Keith_8

I Hear That!

In this case, good customers are hard to find. This is a building/owners group that we have been taking care of for about 1 year.

The building has some history to it,(don't they all)?

The developer converted it into a co/op and neglected to clean up some loose ends. That's how we got involved .

Seems to be working out well for both parties.

Keith

Keith_8

Here we Go!

Got the green light to move forward today on the project.

Looking forward to the installation. A little different from the larger commercial boilers we have been installing.

Time to put on the thinking cap.

Thanks for the input!

Keith

leo g_13

Good Luck

Keith! I think the board will be quite happy when they get their first, second, third, etc. gas bills (G)!

Leo G

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Scott Gregg

Just a thought...

Take a look at these:

www.camus-hydronics.com

You are an application that looks great for the Dynaflame! (Especially your DHW application!)

Some copper-fin boilers suffer because of lower quality products used in construction. look at how these are built and you will like what you see!

Scott Gregg

Just a thought...

Take a look at these:

www.camus-hydronics.com

You are an application that looks great for the Dynaflame! (Especially your DHW application!)

Some copper-fin boilers suffer because of lower quality products used in construction. look at how these are built and you will like what you see!

Keith_8

That was the selling point

The gas savings made it a no-brainer.

I'll keep you posted.

Keith

Keith_8

1st report good

As a follow up to this post.

The installation of the (2)399's went well. We had a couple of initial kinks to work out at set up time. The factory and vender stepped right up and took care of it.


We were able to reduce the fuel consumption while adding (3) pieces of gas fired equipment to the load of the BLDG. (2) gas fired rooftop units that condition the common hallway's and (1) large unit heater that tempers make up air for the domestic copper fin boilers. All 3 units were left off becuase of poor maintenance.

Bob Maderious the rep from Emmerson Swan paid a visit to go over the install. We appreciated his constructive comments about the install and commisioning process. Nice to be able to track the hours of operation and firing rates. Altho it has been a mild winter it suprised the heck out of me how many hours they fired under 50% of capacity.

Thanks to everyone for the input,

Keith