Viessmann Vitodens 200 or Triangle tube prestige solo

Raggy

Need suggestions, I live in the Seattle Tacoma area and in the process of replacing and old oil burning Wm P268v-w DOE 86 with a natural gas Mod/Con. I have narrowed my choices to the Viessmann Vitodens 200 series or the Triangle Tube Prestige Solo series. My out door design temperature is 25 F and my house is a 1965 2550 sq ft multi level home. Ashrae heat loss calculation came out at ~70000btu and the slant/fin calculator and one other came in at ~62000btu. I originally purchased a TT prestige solo 110 but have been second guessing my choice thinking that the boiler is about 20% over sized. I really like the new viessmann vitodens 200 b2ha with a modulation output between 10.9 and 61kbtus. Yes I realize this boiler this boiler is a little undersized but there is a lot of info out there saying btu losses are over inflated(fudge factor). Triangle tube solo 60 is another option but even more so undersized. My current heating element are fintube base board that will eventually be upgraded to staple up and I floor light gypsum top pore. I will also be adding a TT smart indirect for dwh. What are your thought or suggestions?

Alan (California Radiant) Forbes

How many

zones do you have in the house? Or will you have when the staple-up gets installed.  If multiple zoning, I like the Viessmann for many reasons: modulation (6.5 to 1) and reliability being the most predominant.



The only time it really gets cold in Seattle is when the Seahwaks loose which is not that often.  Good luck in the playoffs................ except when they play SF.

Raggy

Eventually 4

You got that right , about the Hawks.



I currently have 3 zones but will eventually have 4 zones. The existing fintube and fan coils will be remove and replaced with pex throughout. I will be commissioning the new boiler on the old system while a update floor by floor.

unclejohn

I would

Go with the TT 110 especially if your adding the indirect.

Raggy

I worry

About short cycling the 110 with its modulation only coming down to 30kbtus. We have two full bathrooms and have no plans to add a soaking tub. Do you think dhw will be insufficient with the smaller boilers. Recovery so about 1/2 on the smaller boilers.

Alan (California Radiant) Forbes

Then,

I'd consider the TT Excellence combi boiler for heating and DHW and make sure it's installed with primary-secondary piping (compensating for over-sizing).  It's over-sized for your heating load, but just right for DWH as long as you are happy with only two or three fixtures being used at the same time, no more.



You seem to be in a load-boiler continuum (similar to a space-time continuum) that makes choices difficult.  I live in Berkeley, CA; half your heating load, 1 bathroom with a Viessmann 50 gallon indirect, a 50K BTU Munchkin and three people in the house.  We all get along really well.  With double the heating load and another bathroom, either the Excellence or the Solo 110 with indirect seems a marriage made in hydronic heaven.



How many people in your house?

Raggy

We

Have 5 people in our house; 3 young children and 2 adults. I wish they made a TT prestige in the 75kbtu range or more turndown like the viessmann.

Raggy

Your spot on

With the load dilemma. I want to make curtain that I'm not cycling my boiler to death and that the boiler is operation at near max efficiencies during the heating season.

M Lane

Compare heat exchangers

Not a fan of the Giannoni at all. I just put a 110 mbh Prestige in for a 2200 sq. ft. staple up/domestic hot application; couldn't be happier. The one Viessmann I installed (owner-provided and I was a sub to the geothermal guy) was a bit of a fiasco. The vent kit (done by the GT guy's son) looked like hell. The exhaust made an awful odor which was picked up by the clients JennAir intake. Lots of hard feelings, liens, etc. Makes me skittish as hell to try one out when I have no issues with the Prestiges and Knights I use.

Ironman

Both are good boilers

The fire tube HX in the TT is the best design available.



Another consideration is that the Viessmann is limited too 167* max supply temp. That may not be enough if your BB were sized for 180*. Viessmann also does not allow the use of PVC for venting.



The most important component in any hydronic system is not the boiler! It's the installer! He's 98% of the equation.



I'd recommend that you contact Paul Polletts at Advanced Radiant Technology. You can find his info by clicking on the "Find a Contractor" tab above.

CMadatMe

Don't Be Concerned

With the top end of the modulation rate, the boiler will never go there unless you need it. With Vitodens you can limit the modulation rate for heating independent of domestic hot water so dependent on your domestic needs a B2HA-28 may be the better fit. Your giving up a little on a low end of the modulation rate so in lieu of using a low loss header you could do a small Caleffi 25 Gallon Thermocon buffer take to take its place.



As far as HX goes. Viessmann makes their own, its not a gionnoni. Has a limited lifetime warranty, constructed of 316 Ti Staniless and pretty much bullet proof. If your after a combi then look at the Vitodens 222-F. It will out perform that Triangle Excellence and the tank is also constructed of the same 316 Ti as the boiler heat exchanger.

Raggy

Chris

Thanks for your input. From reading other posts on The Wall, I know your a big Viessmann fan. Can't you limit modulation rate of heating independent of domestic hot water on both boilers? TT you can set you curve for low mass high temp or radiant etc and set dhw priority. Isn't this independent control or am is missing something? I realize the upper end of modulation isn't important as long as it's above you heat loss @ designed outdoor temperature and it meets you domestic. Chris, I'm not sure why so many people think the viessmann vitodens has a gionnoni heat exchanger.Did viessmann at one point use this hx?

Raggy

Centrotherm

Polypropylene flex will be used for venting my boiler Ironman , so the use of PVC won't be a concern. Regarding venting, has anyone deadheaded the computation air in the same chase as the venting. I have a tile lined cinder block chimney that was once used with a inefficient oil boiler and I worry about contaminated combustion air form existing black soot and particulate lining the chimney. Maybe I'm over thinking this but I remember this instructor at the TT training class stating fresh clean combustion air is a must or damage to equipment will result. What is you experience?

Raggy

Sounds like TT 110

Thanks For the advice Alan, sounds like a majority recommend the TT solo 110. Since I already have the solo110 and smart 40 in my possession I can start my project now.

Raggy

Good

To hear your experiences MLane. What was the design outdoor temp for your 2200sq ft project and how many zones?

M Lane

Reply

We used -10 as the design temp. I always consult with my favorite heat guy at my primary supplier for load calculations, he is a value-added service for them (plus we then share the liability). Then I add my input, double check the plan, etc. This house is an odd one. I have 2 zones of plateless staple up, one zone of in slab radiant, one zone of baseboard, and domestic hot water. It took an elaborate manifold to do that. We had a -10 to -15 spell a few weeks back, and with the house being fully remodeled we had gaps in the windows and no ceiling/insulation overhead, and we still maintained 70 inside.

As for my Viessmann experience, the problem was far more the cast of characters than the product. I personally never do work for lawyers who specialize in suing people, but that's what the client was in this case. I had to produce GPS records to get paid as he disputed my T&M bill. Commented that it was "worth a try". I based my comment on the Giannonni HX on memory then doing a quick look at the manual before posting that. excuse my mis-information if it was wrong. I'll admit to not knowing enough about Viessmann to accurately comment.

Raggy

I did consult

My local supply house and he performed the ASHRAE heat loss designed for for 24 f DOT and came up with 72500btu loss. Originally he wanted to use 28f assuming I was down town Seattle. He also did all the loop layouts for the new radiant. There will be 3 manifolds with a total of 4 zones one for each floor. Zones will be 12100, 16300,19600 and 24000 btus. All zones are under the TT lowest modulation point. Unless I get a controller that will allow me to stack the zones on a call for heat.

SWEI

Conventional zoning and outdoor reset

do not always play nice together.  Have you considered TRVs?  Can you reduce or eliminate the zoning?

Raggy

Zoning

Will be controlled with thermal actuated valves off the wirsbo ep manifolds.

SWEI

Just remember

that you will need to raise the ODR curve a bit and that room temps will tend to drift up and down a bit.  PWM radiant-capable stats with slab sensors will help.

unclejohn

If your worried

About the TT being oversized add a buffer tank.

DYI

Amen

to buffer tanks.



TT Prestige Excellence 110 Trimax

BB-30 buffer tank

0°F design day

115°F system temp

38,000 BTU/hr heat loss

3 zones

1,875 sq. ft. in floor radiant slab, single story new last year

Got down to -2° two weeks ago. 72° inside temp

Used Loop CAD 2012 for system design

Disclaimer: The general contractor had his plumber do the install. Based on what I've learned on this forum I would have done things a little differently if I could actually do plumbing.

Raggy

Swei

Is the procedure you described the best way to control the up and down swings? Or is there a better way to design the system? Would the viessmann vitodens be better suited for my application? I know the 6.5:1 turndown is a plus. I talked with several installers and they love viessmann and more than one has said it is superior to anything on the market. I know TT is also a fine product but I'm leaning towards a viessmann purchase.

Raggy

Yes

A boiler buddy is an option but at a fairly substantial cost. I do have an old 65 gallon electric hot water tank I could sacrifice as a buffer if that's my only option.

SWEI

Viessmann

has superior controls of both combustion and the system.



My personal belief is that the TT HX is a better fit for most US systems, especially where hard water is present.



The combination of lower minimum modulation rate and indoor feedback might make the Vitodens 200-W B2HA a better fit for you.