Viessmann help?

Mike T., Swampeast MO

1) The primary (boiler) piping between the boiler and LLH should be 1" minimum as you want as little head loss there as possible. Since your path to the LLH is going to be a bit convoluted, 1 1/4" won't hurt and won't add much material cost.

2) With primary head loss held to a minimum, you'll have about 6 gpm of primary flow in the LLH.

3) Regardless of whether you zone with valves or circulators, you want to keep total (all valves open/all circulators running) secondary flow no more than about 30% higher than primary flow. Presuming essentially zero head loss in the primary piping this means to keep your total secondary flow between about 6-8 gpm. This ensures both the minimum return temperature to the boiler and maximum delta-t across the HX which in turn ensures the most efficient boiler operation.

4) You can use higher (or lower) secondary flow rates, but if you keep the design secondary flow (again--all zone valves or zone circulators operating) within this range, it means you've done the job the way the Viessmann engineers intended the system to function with a LLH.

5) 6-8 gpm of secondary flow might not sound like much and it will exceed the "standard" 1 gpm per 10,000 btu/hr of boiler output (e.g. 20F delta-t) but as long as you don't have "constipated" emitters (e.g. bare-tube staple up radiant) there shouldn't be any problem.

6) Good flow setters for each zone are a nice addition--and nearly a requirement if you're zoning with circulators as you may not be able to find "standard" circulators small enough for some of your zones.

7) It doesn't make much difference if you zone with valves, circulators or both. Just make certain that you calculate your head losses in each zone and size your circulator(s) for the TOTAL secondary flow (6-8 gpm in this case). In the case of multiple secondary circulators each should provide its <I>share</I> of the load as closely as possible. I would avoid five secondary circulators as one or two should be fine. Once you have your zone head losses you can intermingle them (if more than one circulator is desired) so that groups best match common circulators.

8) Remember that the Vitodens 200 has no thermostat connections. It is essentially a load-sensing device. When you add the low-loss header, Vitodens control essentially ends at the LLH. While in some cases the Vitodens can provide secondary circulation electricity it's up to you to turn the secondary circulator(s) on and off as appropriate--the boiler will do the rest.

Jim_127

Viessmann help?

I have a customer who purchased a Viessmann Vitodens 200, with a Vitocell V300 indirect and he wants me to install it. Now I'm no rookie and have installed my share of water as well as steam boilers but I'm really not familiar with condensing boilers and I'm even less familiar with this brand. I'm looking for advice as to the piping layout. The job consists of 5 radiant zones and 1 indirect. The customer had a manufacturer's rep do the heat loss calculation and material takeoff but I must say it is a tad confusing, however I am up for the challenge. The unit was purchased with a Low Loss Header, DHW Production Kit, Vito Boiler Control as well as 32 Wirsbo Thermal actuators ect.
Can anyone provide me with a basic piping arrangement/sketch as would pertain to the installation with this low loss header. Would it be better to use all pumps, or a combination of pumps and ZV's. I'm trying to keep it as simplistic as possible for my own sake.

Help!

Perry_3

First step

The Vitodens manuals are fairly extensive.

Contact the local Viessmann rep - and have him provide the login codes to the Viessmann website so you can download all of the manuals for all of the parts of the system in advance. Alternately, call Viessmann and get the login codes.

Also, ask the local Rep to help you with the job.

I am a homeowner who had a contractor install essentially the same package (Vitotens 200, LLH, Vitocell DHW, Condensate Neutrilizer, etc) and the local rep showed up at the start of the job, mid job, and to help start up the system when all installation work was done.

Where are you located? People on this site may be able to direct you to some very good resources.

By the way - this is an awsome boiler and I think you will like it. Have the rep show you how to dismantle it and clean it as well. My local contractor was very impressed.

Perry

S Ebels

What size Vito?

That will have a bearing on the advice you need as the two smaller models come with an integrated circ and the larger ones do not.

Basically the Vitodens control will run the outdoor reset, control the boiler side circ, monitor supply temp in the Low Loss header (LLH), run the DHW side of things as well as provide WWSD and setback of water temp if you so desire. It also powers the system side circ(s) if you want to go that way although, the supply house or engineer may have spec'd some other system side controls.

I have some of the manuals on PDF files and I'll see if A: I can find them and B: attach them for you here. These are both pretty good size files so I hope you have a high speed connection.

As Perry said, the Vitodens is an awesome piece of equipment. It's the best condensing boiler on the market (IMHO) period. Nothing else even close to it as far as quality of material used, HX design, burner design, ease of service........name anything you want and the Vito does it as good or better than anything else.

If you take the time to understand the methods that Viessmann recommends for the Vito, I think you'll enjoy the project immensely and be as spoiled as anyone else who's had the privilege to work with this equipment.

Ragu_5

Jim...

Good advice from all. The Vito is truly an awesome machine, and you will be pleased. Definietly seek the advice of Viessmann/and or the Rep. Follow their piping diagrams.

Also ask them about installing a Panamax Power Conditioner to protest the electronics; strongly recommended by Viessmann. Good luck.


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Jim_127

Advice

Thanks for the replies. I'll have to contact the rep for these codes for accessing a better detailed layout. The manual basically doesn't really get to involved in the differing piping schemes. The size (model) of this one is the WB2-24C/24/32. It does have an internal circulator. I just made an appearance at the job and got some work done. I've just mounted a 4'x8' sheet of plywood, painted it, mounted the boiler to the board and ran the venting system. I read some of the instructions and it would already appear that I must modify the LLH because I'll be mounting the header to the left of the boiler. My next move is to mount the remote manifolds and start running the piping back towards the appliance.

joel_19

???

Where did your customer buy it direct???? that's pretty scary,sure you can handle it but what if he tried to DIY that puppy??? . There's only a few homeowners out there that could handle that on thier own.

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mif

Vitodens DIY

Very Bad advise to suggest that a HO do their own service on a Vitodens boiler. Cleaning the combustion chamber necessitates removal of the burner, and that in turn requires that the gas train be opened.
Start-up presupposes that you have a combustion analyzer on hand and the wherewithal to use it and to understand what it is telling you.
Make friends with a well known, reliable, trained installer contractor instead.
The simple appearance of the boiler belies the care with which it must be installed and serviced. I have contractors who make a living straightening out less than optimim mechanical rooms.

Paul Pollets

I'd be asking the same ???

How was the homeowner able to purchase the equipment?

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JimH

the times they are a changin'...

This is already happening more and more. Homeowners are
selecting and buying the equipment and then hiring a contractor to install it. Some of us are willing and able
to scour the internet looking for the best price. We have
the luxury of time to go shopping, unlike the busy contractors. We have the luxury of time to read each and
every word in the installation manuals several times.

People in the supply chain need to recognize that while
many HO's are not very smart about this kind of stuff, we
are not universally idiots. Many of us have technical and
engineering educations, and work in industrial settings,
and/or have experience in areas where engineering and safety intersect, like building race cars and flying planes.

People get injured and killed when 2x4's are used to build
bad stairs and decks. The primary use of dimension lumber
is structural, which thus implies safety issues. Do we
attempt to solve this problem by controlling supply?

-JimH

ALH_4

parts and labor

Contractors will increasingly have to make their money on the labor alone in the future. Hopefully the homeowner realizes this and accepts the $150+/hr labor rate. It's really all a shell game, although presumably the contractor can get a better price than the homeowner based on volume alone. The difference between what the contractor can buy it for and what the homeowner could buy it for would go in the contractor's pocket and should reduce the overall price of the job. Homeowners are shooting themselves in the foot by purchasing their own equipment, because it just puts more money in the supply house's pocket.

Larry_40

Understood, but

I have to agree with JimH. Many homeowners have been burnt by bad contractors, either by generally selecting contractors without recommendation or the lack of quality professionals in a given area.

I had the same problem. I have had three different contractors come to our house, and only one even understood what kind of system we had. The closest contractor on this site is over 90 miles away.

So what happens with HO like ourselves is extensively researching before purchasing.

BTW, I cannot tell all of you thank you enough for all of the information on this site. It is the best I have found anywhere on the web.

heatboy

I agree, Andrew.

I can see where it would cost more, and sometimes, substantially more, if a homwowner purchases equipment and tries to hire someone to install it. I need to make my money and profit every week. If it's not from selling equipment, then it is from labor. So, I see no benefit to the homeowner for purchasing his own stuff. What about warranties? If I supply it, it's my problem. If I don't, it's not. Now the end user must pay for replacement, then deal with the warranty issues. I can tell you there is never a cash back warranty, so he will now have a spare, which will probably never be used.

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Ragu_5

Whoa....

I totally missed that the homeowner bought this Vitodens directly from a supply house; am I missing something here?

My experience with Viessmann (and one of my criteria for accepting them as my partner) is that they want all of their installers to be factory trained and that they will not sell direct. Can somebody fill me in here?

These machines are pretty sophisticated and will deliver their calculated efficiencies IF they are installed, piped and wired as per Viessmann spec ONLY. Read: No Knuckleheads Allowed!.

I'm a little warm under the collar right now; any help out there? Thanks, Jack.




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Larry_40

A little more information for you

I did not attempt to purchase a Viessmann (or anything for that matter) at this time. My angle is not to bypass the contractor, its to make sure the job gets done right.

I have 20 years in the construction business and have just recently changed over to home remodeling for less stress. Many of these older homes in my area are gravity systems with converted coal boilers. I just want to make sure I know whats going on when my subs are on the job. Hell, I would get certified if I thought it was in my best interest.

I try not to step on any toes here.

ALH_4

Combi

I also notice you said you purchased a Vitocell and a 6-24C? The 6-24C is for instantaneous DHW production and is not equipped to connect to a Vitocell.

GW

burned

This is a huge issue for most of us... the homeowners you mention that got burned, from who, the high end guy with the best reputation? no no no.

It is the homeowner that hires on price that deserves to get his clock cleaned. Hiring heating guys is not the place to nickel and dime.

As systems get more technical, the jokers will be exposed for the clutses they truly are.

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Perry_3

In my neck of the woods...

There are no factory trained Viessmann contractors.

The Viessmann Rep works with whatever local contractor that a homeowner who wants a Viessmann choses to work with. I suspect in a few cases their may not even be a local contractor willing to work with a homeowner.

My experience in even finding a reasonable contractor was very painfull - and very expensive as they would only work on a T&M+ basis (make that ++) to install a Vitodens (or any other quality mod-con).

I was very very close to doing my own install - and I can get a combustion meter. I do admit that many homeowners do not have my background though.

As far as buying from supply houses... Piece of cake if you know how to do it.

Perry

Uni R_3

Don't forget...

Preferred homeowners also qualify themselves for that Xx% discount that just happens to be the same as the contractor gets. That's the reward we get from our local supply house for knowing the SKU whenever we're buying from them.

Bob Knebel

Make Sure You Don't Have A Combi Unit

Jim,

You said "The size (model) of this one is the WB2-24C/24/32." If the model number indeed has a "C" in the description, you have a Combi unit with an internal SS plate HX for "on-demand" DHW production. This model is not designed to work with a LLH and #5 sensor (controls get confused), a separate DHW production kit, and a separate indirect tank.

Last year we had to travel a couple hundred miles over to Idaho to straighten out a mis-applied Combi unit with LLH, etc. that never worked right. Believe it or not, the original contractor and homeowner were led down the garden path by an actual VM wholesaler (not our company) that gave them a "good deal" on the Combi unit and accessories! Our company had originally quoted the project but I guess we were too expensive! It certainly was expensive when it came time for travel and consulting to straighten things out.

Bob Knebel P.E. / Radiant Engineering, Inc. / Bozeman. MT

Jim_127

VM help?

I've contacted Viessmann for the codes, but it would seem as though the only literature available are the manuals I currently have. I was looking for a more comprehensive layout and a way to condense it into a tighter space.

As far as the homeowner purchasing the equipment.

This customer is the owner of a fairly large commercial/industrial electrical contracting business who does quite a bit of building automation systems work and actually purchases allot more from this supplier than I even do, and last month I did 50 grand with them. I know this doesn't automatically qualify him, nor does it qualify me, seeing as how I've not gone to the factory school (if I could of, I would though). However, I am quite confident in my ability and am quite impressed with his knowledge/research and selection of this equipment. Since reading the posts and before my reply I've contacted Viessmann and the closest factory trained contractor is almost 100 miles away. But I do respect the level of knowledge one must posses before even opening any of the boxes ; )

I am interested in hearing more about this Paramax Power Conditioner. What does it do

To answer the poster who spoke about the model number. I'm not sure. The next time I go back I'll check for the exact model. The only info I have is the part number for the boiler which says Vitodens 200 #7134-407, and the LLH is 7134-230

Thanks to all who have replied.

Perry_3

Some answers

The Paramax Power Conditioner is a surge protector that includes a cut off for undervoltage. In areas that have low voltage problems it is needed and is a relatively cheap solution (or you will need a much more expensiver full power conditioner).

I live in an area that does not have low voltage problems and installed a much more robust surge protector than that.

The Vitodens is a wonderfull boiler. It can be configured in many different ways - and has an assortment of other pieces and parts needed depending on its configuration.

So you have a Vitodens 200 - either the 6-24 or the 8-32 (and possibly the 6-24C which has built in DHW - but doubt if your customer purchased a Vitocell).

You have also mentioned that you have a Vitocell water tank and a Low Loss Header.

So I am going to make some assumptions here - but given those three pieces; you also need:

A DHW production kit: Part # 7134 214 which will enable the solenoid and provide DHW tank temperature back to the control circuit.


An Expansion board: Part # 7134 209 which will power the secondary circulating pump from the vitodens power supply and turn it on and off as appropriate (usually constantly on during heating season - but there are times it will turn it off).

Please note... Unlike many other boilers you do not use a houshold thermostat to turn the secondary circulating pump on and off. In fact, you cannot hook up an ordinary thermostate to the boiler at all. Viessmann makes several room temperature setting and/or temperature feedback units as appropriate to your situation.

You should have a Viessmann Vent Kit; or one of the Viessmann adapter to a SS venting system. If you are venting out the side of a house near the boiler - usually the "Basic Horizontal Vent Kit: Part # 7134 408" has all the parts needed for most applications. Additional vent parts are available as needed.

How is house temperature controlled: Is this a Monoflow T system, ordinary baseboard, have zones, etc. Depending on that you may need a WS or RS control - or other possibilities.

Don't forget the condensate neutralization kit. Part # 7134 231 unless you know how to build an effective one yourself (I admit that this is pricy... but, it is a nice setup and works well).

The LLH has an optional insulation kit: Part # 9560 994 and some people swear by them and others never use them. I have one.

There is even a nice tool kit that makes things convienient for service and future repairs. Part # 9537 070 which I will admit that most service techs have everything in their tool boxes somewhere. This is a nice kit - and I have one by my Vitodens to make things easier for my contractor to find the right tools when he needs them.

I hope that you also find some of those boxes as well. A really good discussion with the local Viessmann rep may help you sort out what is actually needed for your application.

I did not cover all the possibilities for parts that you might need or want - just the basics that you should have - or should ask about.

It pays to be sure you have all the right parts before you start.

Perry

The Wire Nut

Is price an indicator?

I'm not convinced that a high price tag is an indicator for quality... I paid a lot of money for the heating and cooling system here, only to discover supply and return manifolds being switched, bad programming, non-compliance with manufacturer installation manuals, etc.

It's one of the reasons I took the courses at Viessmann. When I find a company that I can trust, I'll let them do the service work. However, with Ed Wallace AWOL, that just leaves me, my manometer, my smoke tester, and my electronic combustion analyzer to do the job. And for some strange reason, the system just plain works... with no smoke, no soot, etc.

Supply House Rick

Times are a changin'

With Viessmann's extremely low market share, they cannot afford to walk away from any sale. There is a V dealer in the Hudson Valley that will sell a V and at a discount because they are slow movers. I think that V expected the masses to bow and pay. This hasn't happened so they, like the other boiler manufacturers are now in the position to sell to anybody who walks in the door. Can you blame them? If marketing fails, flood the market. Don't forget your wallet...

Tom Hopkins

Ask Dr. Z.

When asked why the marriage of Daimler and Chrysler didn't work out,Dr Dieter Zetsche CEO replied 'We severely underestimated the ability and desire of the American consumer to pay for German technology"
That underestimation cost the difference between the $36 billion Daimler paid for Chrysler in 1998 and the $7.4 billion they sold it for last week.An expensive lesson indeed!

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Perry_3

I'm not sure that is all of the answer

As noted in post above I own a Vitodens 200; and am very happy with it in its first year of operation.

However, the question on why it did not sell so well (and other German products) is not nearly as simple as American Consumers not being willing to pay for German Technology (and engineering).

While there is a large section of the population in any country that will only buy the cheapest item regardless of value; there are in fact a good chunk of people who can be sold on paying more for real value.

The problem with European name brands selling in America in recent years is really two fold:

1) The value of the Euro compared to the Dollar - and the cost to US consumers in Dollars has really worked against European products. Within the US these products tend to be "pricy" just because of the shifting value of currancies in the last decade (admittedly, the US Dollar is not worth near what it was on the international market).

2) Other companies producing reasonable - or even very good designed products in the US. German Engineering and design is not necessarily supperior. In some cases it may be - and I still think the burner and boiler in the Vitodens 200 is probably as good as it gets (very good design).

With all that being said - and after looking at what has happened; I wonder if in hindsight that Viessmann is not wondering if they would have been better to set up Mfr plants (or licenses) here in the US. They could have imported the HX and burners from Germany and produced the rest of the boiler assembly to US standard with US (or Canadian) labor. I think they would have been far more competitive and have a larger market share had they done that.

As far as Daimler and Chrysler; I thought at the time that Diamler had paid a lot more for Chrysler than it was worth - and wondered what they thought they could do with it.

Perry

Tom Hopkins

Perry

I'm sure the unfavorable exchange rate doesn't help but the look on a homeowners face when I quote a Vitodens in comparison to the Keyspan $599 CI standing pilot boiler is priceless,sometimes outright laughter.These are all 500K+ (sometimes many times 500K homes on LI)with all the toys.
You might say it's my poor sales skills and you're right I'm a tech not a salesman but in my defense,what's Viessmann's market share?


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radioconnection_2

"QUOTE: Subject: burned

QUOTE: "This is a huge issue for most of us... the homeowners you mention that got burned, from who, the high end guy with the best reputation? no no no. It is the homeowner that hires on price that deserves to get his clock cleaned. Hiring heating guys is not the place to nickel and dime. "


Most homeowners deal with their home heating oil suppliers. Right or wrong, these are the people they know and trust; and perhaps assume are the only ones who provide burner and boiler services! Most (not all) oil companies are behind the curve on the newer triple pass boilers, outdoor resets, etc. and oftens stick with equipment that's worked for them for years. I'm sure there was a lot of latest-and-greatest gimmicks that never should have been on the market in the past that makes them leary now. On the other hand, the last service tech here had never seen a TigerLoop or a Biasi boiler before.

pete

Perry_3

> I'm sure the unfavorable exchange rate doesn't

> help but the look on a homeowners face when I

> quote a Vitodens in comparison to the Keyspan

> $599 CI standing pilot boiler is

> priceless,sometimes outright laughter.These are

> all 500K+ (sometimes many times 500K homes on

> LI)with all the toys. You might say it's my poor

> sales skills and you're right I'm a tech not a

> salesman but in my defense,what's Viessmann's

> market share?

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 313&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

Perry_3

Where is Viessmann's Marketing?

A very major problem... Do any of these people even know who Viessmann is?

Why has not Viessmann been more effective with national (or at least regional) marketing....

If you were selling cars and you offered a Mercedies versus a Ford... They would instantly understand what is being offered (at least the image of what is being offered as I think some of the Ford vehicles these days are built better than a Mercedies).

Going out there alone... It is tough to sell something that people have no clue on.

One of the reasons that many years ago I sold Encylcopeadia Brittanica and not the Encylcopedia Americana.

Perry

Andrew Hagen_2

Marketing

German engineering has nothing over American engineering. Volkswagens are no more reliable than Chevrolets. If fact the converse may be true.

When it comes to boilers, the Europeans are simply ahead of us when it comes to fuel conservation. Part of the issue is that their energy economics are different from ours. However, in recent years we have been attempting to catch up with Europe in terms of energy costs. No doubt the global economy will equalize energy prices to a great extent.

As energy prices hit Americans harder, we will make different choices. A $599 standing pilot cast iron boiler will no longer look like a good investment when fuel doubles in price...and they will. Until then, it is only the forward thinkers who see the value of investing in efficient heating equipment that no one except the heating service guy ever sees.

Obviously, there is far more to it than that, but once the economics change, high-efficiency equipment and SDHW systems will be the default choice and non-condensing cast iron hot water boilers will be a thing of the past. I would love to see more American made condensing boilers on the market. Unfortunately, thus far the choice seems to have been to source Euro technology rather than innovate.

In my opinion, Viessmann has been very successful at selling a product that is far more expensive (and better designed) than the competition's product. Who has a product truly comparable to a Vertomat, Vitodens, or Vitola?

scott markle_2

Vito and Radiant

In some ways the Vitodens and it's comfortrol programing "brain" is not the greatest match for a high end radiant job.

I assume that this design will utilize the actuators to limit output the zones based on pulse width modulated t-stats. Often some loops (perimeter)are left wild. The boiler will modulate water temp based on outdoor reset. This is workable design provided the heat loss is fairly consistent zone to zone. However should the user desire a responsive rise in room temperature the t-stats have no way of communicating to the boiler that a higher water temp. is required to expedite the request.

The vito is equipped with sun/moon temperature dial which is essentially a shift adjustment to the heating curve. When the curve is properly adjusted these dials represent desired day and night room temperatures. Viessmann makes an indoor sensor as well which makes automatic adjustments to the shift, but I believe the literature recommends against use with floor heat because of it's slow response or thermal inertia. Anyway this nice user interface will be basically unused in system like you describe

You will need a expansion board for the power supply box that will control the circulator/s on the heating side of the LLH make sure the relay can handle the amps. required.
You may only need one circulator (sized based on highest head loop and total flow requirements) If actuators are on all loops a differential bypass will be required to prevent dead heading.

Bobby_2

Viessmann Help

Can anyone assist me in a working piping diagram for this installation?

I contacted Viessmann and I explained that I have 5 radiant zones and 1 indirect and I needed advice on how to control them. At first they told me I needed 5 three way valves and 5 HK-1 actuators. After I contacted my distributor and found out the price of these HK-1's I almost fell on the floor. I could buy 5 mid efficiency boilers for the price of these controls.

I contacted them again and they amended their layout to only use 1 three way valve and 1 HK-1 actuator, but it would seem as though I would have little control over these zones individually. Any thoughts?

I would also like to know if I could use 2 or 3 circulators instead of 5 because I having a tough time finding them small enough for the application, and if so, how would you pipe it and control it.


zone 1 = 510 sq. ft 1.06 gpm 4.4 ft. head (using 5 loops of 5/16" Wirsbo tube)

zone 2 = 651.5 sq. ft. 3.24 gpm 10.1 ft. head (7 loops 5/16" Wirsbo tube)

zone 3 = 734 sq. ft. 1.52 gpm 5 ft. head (8 loops 5/16" Wirsbo tube)

zone 4 = 492 sq. ft. .83 gpm 2.7 ft. head (5 loops 5/16" Wirsbo tube)

zone 5 = 590 sq. ft. 2.88 gpm 9.5 ft. head (7 loops 5/16" Wirsbo tube)

Any help would be appreciated.

Thank you!

heatboy

What are the water temperature.....

....... requirements for each zone? I am assuming this is designed around a 20 to 25 degree drop with such small tubing. If they're all close to the same temp, one pump and five zone valves may be your best choice.

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Mike T., Swampeast MO

You've just discovered the EXTREME cost required to allow a Vitodens to most efficiently drive an American-style system with on-off zone control.

With reasonable design you can replace the three-way valves (and associated controllers) with FHVs for any zone with less than about 10,000 btu/hr heat loss. FAR, FAR, FAR, less expensive and even better as the three-way valves and associated controllers can only approximate the action of the FHVs. Danfoss FHVs have a built-in adjustment to balance different heat losses among the zones and as long as no zone exceeds about 10,000 btu/hr and the system is nicely designed you'll need no more than one secondary circulator.

Jed_2

Jim

It seems to me you're customer is in a bit of a pickle. He bought the equipment, had the heat loss done, and a material take-off done. That's a lot of fairly detailed work to not have a SYSTEM STRATEGY AND DESIGN LAYOUT accompanied. He had the basic design work done, not you. What do you know about this boiler?????????? NOTHIN! Not fair!!!!!!!!!!!!

You may be up for the challenge, but it is up to you're customer to provide you with the necessary tools to do the install. He bought the equipment, not you!!!!!!!!!!

You touch it, You OWN IT! Coordinate with your customer and V to get it right.

JED

Jim_144

Viessmann HELP

The max water temperature of 123degrees should be the same at all 5 zones. The drop should be 20 degree for all of the Quik-Track. The total load is only 48,476 Btuh/hr and the radiant load is 35,623Btuh/hr. Any tricks as to the interfacing of the pumps and zv's communicating with the Vitodens?

Thanks!

heatboy

The pump is powered.......

..... from the mixing actuator on the three way mixing valve and runs independently according to outdoor temps. The thermostats will just open and close the zone valves. When doing this, a pressure activated by-pass is needed so the pump (Taco 00R) doesn't dead head if there are no zones open. The Vitodens (8-32?) boiler will adjust it's firing rate according to what it senses is going on.

hb

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scott markle_2

systen design

You need to know what the longest loop you will be running is going to be. Based on the total flow rate for all the loops select a circulator that can provide the head necessary to achieve the flow rate required for the longest likely loop you will be running.

You may be able to use a single circulator. This would be a nice application for a Wilo Stratos, this pump uses variable frequency drive and built in sensors to provide constant head pressure. It eliminates the need for differential bypass and saves a lot of electricity.

If you have 32 manifold valve actuators than these should your zoning valves. Most likely it was the intention of who ever put this material list together that these actuators would be controlled by pulse width modulated t-stats. Pulse width thermostats are important because ordinary thermostats do not perform well with radiant heat because of it's slower response time. Tekmar has some excellent essays online that explain pulse width modulation.

You will need to establish a heating curve on the vitodens that is based on the actual heat loss of the house. In my opinion this is best done in cooperation with the home owner if they are technically inclined.

Under heating conditions set all of the thermostats to max such that the actuators are all open. over the course of a few days monitor actual room temperature and the room temp shown on the comfortrol display, make adjustments to the heating curve such that they are closely matched. If anything the actual room temps may be slightly higher than the comfortrol display. This gives the thermostats a job to do. Personally I would leave some of the outer most loops (closest to exterior walls) wild with no actuators. The H.O should know that the house will only be able to reach as high as the temperature set on the comfortrol. If they desire warmer they will need to raise this. Essentially the room thermostats become high limits, they will prevent overshoot by solar gain or extra occupants but they will not provide upward adjustment above the global setting on the comfortrol.

This is fine system, but it has one weakness. If a zone has been downwardly adjusted below the other zones and it is asked to recover it will do so rather slowly. This is because it will only be receiving the water temp. it needs to match the other zones, But since it's behind this may take a while.

This is probably why viesmann is recommending all those mixing valves. In a setup like that each zone can do what it "needs" to irrespective of the others. A more economical way although hardly cheap way to accomplish this is with the Tekmar TN4 system, read about it online if your interested. Problem is you have wasted a lot of money on the vitodens controls that you wont use and the vito doesen't intreface easily with 3rd. party controls. Beter off with the new vitodens 100 if you were going to go this way

As far as lone mixing valve is considered, I don't believe this is even necessary. My own house is heated (quick track and slab) by a vito with no mix valve and no indoor thermostats and the house is very comfortable never too hot never too cold, Just right. The mix valve does provide some extra accuracy in maintaining target temp but it's just not required the boiler does a good enough job on it's own.

The one thing that a mix valve will provide is an extra measure of protection for the floors in the event of a boiler over temp malfunction. It was pointed out to me that a user could inadvertently flip the chimney sweep switch which puts the boiler in fixed high fire test mode. this could ruin a slab or hardwood floor. The mix valve would prevent this. Yes but so would a $70 Honeywell strap on aquastat set to 130 and wired to the burner cut off contact.

Good luck

heatboy

While floor heating valves are great......

...... they're not applicable to Jim's system. Having multiple loops per room, which with 5/16th tubing will certainly happen, eliminates the possibility of using them.

Jim, didn't mention whether or not domestic hot water is produced by the Vitodens, so not using a mixing valve may lead to floor issues if DHW is produced with the boiler.

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Andrew Hagen_2

Interface

You do not need any mixing valves. The Vitodens can supply radiant floor temperatures directly.

The system pump will interface with the Vitodens, but it is run entirely by the outdoor temperature sensor and th Comfortrol. When the outdoor temperature drops below the setting on the sun and moon dials (depending on the time of day) the pump turns on. The simplest way to control radiant zones from there is to use zone valves and put a differentiap pressure bypass valve across the pump to bypass the residual pump output when fewer than all of the zones are calling for heat. I have not seen FHV's that will handle the flow required for zones much larger than bedrooms. Though, it has been a while since I have looked into this option. There is no communication at all between the zone valves and the Vitodens.

With your heat load, if you can get the head loss down to approx 5ft in all of the zones, I would not use an external pump or low loss header.