mod/con boiler choices (the intangibles)

frozencanuck

Ok lets assume that I am down to these choices (LOL I wish).



Veissmann:

WB1B 10-26

WB1B 10-35

WB2B 26

WB2B 35



All of these will satisfy my heat load/loss on a design day. (I know oversized the other 95% of the year). I dont want to make a simple $ choice, I would rather choose based on all the intangibles that just are not apparent to someone who is not in the biz & lives in an area where 95% of the units are nat gas forced air. Very little to compare to here as far as boilers go. Hoping that some of you can help with a choice based on the intangibles that of course dont appear in any sales/service/install literature. Any thoughts/opinions on the 100 vs 200 are welcome, not saying I will understand but I will read & hopefully learn. Thanks for your input/advice.



James

Robert O'Brien

You can

You can cut the list in half pretty quick,why would you consider a 35Kw boiler when a 26Kw boiler would suffice? The Vitotronic control and lambda pro separate the 100 and 200. They both have the same HX.  My house? I'd use the 200,the extra features are worth the price difference,others may feel differently. Bottom line,you can't go wrong with either!

CMadatMe

The Differences

The Vitodens 200 while as Bob has stated has the same heat exchanger and venting capabilites as the Vitodens 100 it stops there. With Lamda Pro you get a boiler that has intelligent combustion and a control package that offers you great flexibility dependent on you system needs.



I am personally putting a 200 in my house for a few reasons.



1. The comfort of knowing that the boiler conducts a combustion test itself on every fire.



2. The comfort of knowing that the boiler will adjust itself to gas mixture as we head into the heart of the heating season and the gas company begins to add fillers to the gas supply. Meaning optimum combustion at all times.



3. The ability to gain control of the boiler from my living space without having to go to the basement. I am adding a Vitotrol 300 which provides control of the boiler and indoor feedback to the boiler control. This allows the boiler to look at outdoor, indoor and system supply water temperature when calculating my needed water temperature.



4. The ability to limit heating modulation separate from my domestic needs. I am oversizing the boiler. My heat loss is 40,000 btu's but I have a domestic need that I am concerned about. I am going with the WB2B-26 and going to limit the heating side modulation to 50%. I need 140 degree water at zero degrees based on my loss and limiting the modulation to 50% puts me at 95% on my design day. The boiler will only go into high fire on a domestic call.



These are just some of the differences between the Vitodens 100 and Vitodens 200. There are many more but depends on the application we are up against.



The last reason and most important. I have been involved with Viessmann for more than 20 years and have comfort in knowing that I have the most advanced proven boiler on the planet with a support staff that is second to none.

SpeyFitter

First things first....

1) I'd really like to know what your heat loss is on design day.

2) Also, how many bathrooms (tubs & showers is what I'm looking at) and people in your house that use those bathrooms, are in the house?

3) How long do you plan on living in the house?

4) You call yourself a canuck - where in Canada do you live?

5) What type of heat emitter(s) do you have?

frozencanuck

reply to Scott K

OK



1) design day loss = 46,778 btu/hr not including dhw.

2) 2 full baths, tub with shower in each.

2) 5ppl full time in house, guests/relatives often increase that to 10 in house.

3) Until they carry us out. Hopefully 30+ years.

4) North Central Alberta, 2 hour drive north of Edmonton.

5) Currently 2 fan coils that I replaced 2 nat gas furnaces with, they are 2x oversized for the load (my choice) as she likes it to get hot fast, however she (the boss) has said she wants new floors, that will be my opportunity to install the Uponor mats & tubes or similiar product to achieve lower temp usage for area heating. Your thoughts on that are quite welcome.

We have an 80 gal indirect hot water tank, which works like a charm btw.

Hope this helps.

SpeyFitter

Vitodens 100 vs 200

46,778 BTUH heat loss is small for Northern Alberta. You must have a relatively small house (2 small-ish floors or one big rancher?), I'm guessing in the 1500 to 2500 sq. foot range? Because in Vancouver that's the heat loss for a 2500-3000 sq. foot house (19 F design temp) with newer windows with say average insulation (R12-14 in the walls - R28-ish in the attic, etc.). Mind you guys are probably R-20 PLUS in the walls and R40 plus in the attic I would imagine.

If you have an existing indirect DHW tank that you're confident will go the distance (stainless steel) then you're probably set. 80 Gallons should be plenty for the bathrooms & people you mentioned and if it ends up being an issue you can set the tank at 140, mix it down to 120 or less and set the aquastat or controller to be a little more aggressive (i.e. a smaller differential, if possible). I WAS going to suggest considering going with the Vitodens 100 and a Vitocell stainless tank (best tank on the market quality wise in my opinion) versus a Vitodens 200 and a cheaper tank if budget was a concern but read on.

When I was at some Viessmann training in Langley in September, they told us that in Canada, they still have a decent stock of the previous Vitodens 200 WB2A models in the smaller sizes (24 and 32 KW). They will NOT sell the WB2B in similar sizes until the WB2A's are sold (that's what they have told us). They are selling the larger WB2B's however as they now carry 80 and 105 KW's which weren't availble in the WB2A. I know a few guys who have installed lots of these in smaller commercial projects to date. So you're either going to have to wait until the WB2B's come out after the WB2A's are sold out, or go with a Vitodens 100 WB1B (or a WB2A).

Personally, with your heat loss, the WB1B in both sizes is a little on the large side relative to your heat loss; they have a 37,000 BTUH minimum firing rate (input) which at 95% efficiency is around 35,000 BTUH output-ish give or take depending on return temps to the boiler. If you've ever checked out a temperature graph of Edmonton, you'll note that while it does get quite cold where you live, the actual time Edmonton spends near design temperatures is relatively small hours wise in the grand scheme of your entire heating season. This means that your boiler might see some short cycling when it is in heating mode which puts additional wear and tear on heating components. This is where you might want to consider a WB2B which has a slightly reduced minimum firing rate (about 31,000 BTUH input) which should help reduce short cycling slightly. Or consider a WB2A which has a lower minimum firing rate (25,000 input) which should further reduce short cycling (OR consider a Vitodens 100 with a small-ish buffer tank). The Vitodens 100 boiler IS a fairly popular boiler for it's price point and simplicity with quality built in but Viessmann knows that in Vancouver and more moderate climates and for places with smaller heat losses, there are guys who want a smaller Vitodens 100, and there are guys also calling for a larger Vitodens 100 as well in colder climates or for larger applications as well.

I like that you have oversized your fan coils as that gives you the oppurtunity to significantly lower the water temps; this lends itself to nice long (or longer) burning times with a lower air & water temps for increased efficiency; further reinforcing the need for a smaller lower firing rate boiler or a buffer tank (my opinion). 

The only other alternative is an IBC 15-150. This boiler would rock for your application. But some people are set on Viessmann which is fine.

frozencanuck

Reply to Scott K

Wow close on the footage etc.

We have a 1232 sq ft bungalow with a full finished walkout basement.

Building code here is min R20 walls R40 ceiling/attic. I always build above minimum code, never to it. As you can prob guess I dont build production housing.

Windows are all 3 year old triple pane. All exterior doors have a storm door.

DHW tank is 80 gal stianless.

I like the idea of a stainless buffer tank (was thinking it would be wise to decouple the boiler from the load) good way to reduce short cycling or so the boiler geeks I know have said.

Thanks for your thoughts on the Vitocell stainless steel tank, I will have to price that out as I "feel" not know that decoupling the boiler is a good thing, honestly cant see the downside if the install & materials are good.(No cheaping out for me, no thanks).

Do it once do it right on both materials & install & it will pay you back forever.

With what you have told me about availability of the Veissmann here I may have to install a buffer in any event.

I did look into the IBC products only to find that they were 4x the cost of similiar sized Veissmann, couldnt figure out why though.

Thanks, James

SpeyFitter

The 100 is a bit plain jane....

The only thing going against a stainless buffer tank on the Vitodens WB1B 100 is the schematics they require based on their Versatronik controller they offer. They have a very specific flow rate for the 100 requiring between 1.7 GPM (minium roughly to trigger the boilers flow switch) up to I believe it's 6.2 or 6.6 GPM (off of the top of my head) max flow rate for the boiler's heat exchanger.  To use a buffer tank (i.e. heat flow, or the new Lochinvar stainless buffer tanks) for the 3 pump schematic (as a big low loss header) they require would mean when there is a call for indirect heat  you'd be heating an entire buffer tank up to 172 degrees (which is the preset non adjustable temperature that this boiler heats up to when it is in DHW mode). You'll probably be better off by adding mass on the return as a flow through on the return of the secondary loop for the heating by pumping the return water into the top of the tank and come out the bottom. You could buy a steel electric hot water tank for this to save money and just not hook up the power obviously. The stratification of the tank would ensure that the coldest water always comes out the return and back into the primary loop or low loss header which would help reduce short cycling, as well as act as a natural dirt seperator that you could clean out annually or less.

The other alternative is if you go into the Versatronik schematics you could pick the 2 pump option where it has one pump for the heating circuit and one pump for the indirect, effectively pumping through the boiler for the indirect, and then buy a Grundfos Alpha and just plug it in externally/independantly of the boiler/versatronik controller (for the air handler secondary loop) which means it would be on all the time but would only pump when a zone valve opens (you could unplug it in the summer to save 5 watts an hour usage). Pump directly thorugh the boiler for the indirect (one pump) and for the heating you could use a one of the stainless buffer tanks mentioned above as a big low loss header to reduce short cycling and have a 2 pump set up with one pump not tied into the boiler/versatronik control as I just mentioned.

As far as IBC goes - I know the actual prices of each boiler, and I can tell you that by the time you outfit the Vitodens 100 with all the external accessories that would put it anywhere near the IBC's built in control, plus the extra cost of a stainless buffer tank to mitigate for short cycling due to the lack of low fire modulation, you'll be significantly more with the Vitodens 100. And that's not factoring in the deep modulation of the 150 (15,000 BTUH low fire) or the 150,000 BTUH high fire rate (read: If you got 10 people staying at the house, with an 80 gallon tank you should never run out of hot water with this set up).  IBC has a strong presence in Alberta, and according to their president they actually have I believe it's 4 of their 45-225's heating a pool heat exchanger in Edmonton and apparently they were purposely undersized, so they run pretty much flat out for nearly 8000 hours a year and get their heat exchangers cleaned twice in that time.

Viess

Top Choice.

Last fall I had the WB2B-35 installed. It doesn't have the Vitotronic control but the boiler is in the garage so it ain't no big deal when I need to adjust it. It has saved me on average 65% per month on me gas bill. I guess because they are a high end boiler not to many installers are pushing them? Easier to sell a cheaper boiler and the keep profit margins up, IMHO. I bought this boiler online thereby saving right off the top 1400 dollars and had it installed by a licensed professional. I know that's gonna chap some of you guys butts but in this economy it's every man for himself. If I have any questions I just call or email the guys back on the east coast and get answers right away. Even though I'm not a dealer/installer. It's a GREAT product and the Viessmann folks are very accessible. Bottom line you can't go wrong buying a Viessmann!

PS: Since initial install boiler is purring right along!

frozencanuck

Ok Scott K

So looks like my preferred choices would be Veissmann 200 or the IBC 15-150. Was not really big on the Veissmann 100 after further reading. Have to admit I am having a harder time finding info on the IBC products (just a smaller co) I guess. I will keep looking for sellers/installers for the IBC products & searching the www. for more info as well. I probably was just unlucky & found someones site who decided to inflate prices alot on the IBC product.