high effiency- natural gas boiler
cic317
| Posted in Energy, Heating & Insulation on
Finally got aroung to Renovating my own house, installing radiant heat on in main floor due to concrete slab, 2nd fl its a toss up on forced air/ added to A/C system or base board. My plumber is pushing Burnham boilers. Any feed back good or bad.Also planning on a hot water storage tank run off the boiler to feed two baths & 1 power room Family of 6.
Replies
The best would be a viessmann and second a buderus (spelling), they will both certainly be much more than a burnham but if you'll be staying there then it will pay for itself. Also, look into an on demand water heater, it heats the water as you need it, no need for a storage tank.
"..best would be a viessmann and second a buderus..."
I'm curious on what you base this statement. Personal experience? Do you own or install the products? Warranty? Performance? Efficiency? Dependability?
I hear and read similar statements from many, based on my reasearch, these products are good, but not superior by any means. Enlighten me.
Edited 9/20/2005 11:57 am ET by Tim
"My plumber is pushing Burnham boilers.." Always cringe at the thought of plumbers involved in heating systems. May want to fing a heating contractor to do your heating work.
Nothing wrong with Burnham, though I prefer Weil-McLain boilers. Personally, I wouldn't waste the money on the imports, though they are suitable products, nowhere near as good as their marketing.
The Ultra from Weil-McLain is one of the best values on the market, very similar in form, function & cost to the new Lochinvar Knight boiler, also and excellent product. Both of these are sealed-combustion (i.e. two pvc pipes for combustion air and flue product exhaust), condensing (in the middle to high 90% efficiency range) have built-in controls including domestic hot water priority and outdoor reset and pump relays.
... and I always cringe whenever I see lines like "I wouldn't waste the money on the imports, though they are suitable products, nowhere near as good as their marketing". Your biases are telling indeed.
It's funny to keep reading about how the alleged higher price-points for the EU brands are justified by marketing, rather than performance. My Vitola offers features not found on any other oil boiler in the US... I wanted those features and thus I chose the Viessmann over the other domestic and international choices. Thus, it is arrogant to assume that every purchase decision is driven by marketing. Besides, how is it that the Ci boilers from Buderus cost about as much to the installer as the equivalent WM and Burnham competition. Marketing, right.
I agree that the WM Ultra is sold at a good price point, though I find the HTP Munchkin or NTI Trinity a more compelling design.
The French HX found in the Munchkin and the Trinity series is made of stainless steel, has a 20-year track record, and is likely to survive abusive water conditions much longer than the aluminum blocks found in the Buderus GB142 or the WM Ultra. Yes, you can monitor the water conditions to ensure the pH doesn't kill the Al, but how many service personell or homeowners think to do that?
The gas valve found in the Trinity 400 allows a 16:1 turndown, for a output range of 25-400kBTU/hr (!!!). Thus, a Trinity 400 coupled with a small indirect with a large HX surface (like a Phase III from triangle-tube, for example) could offer a complete, economical heating package for the home and the domestic hot water, with minimal mass and hence minimal standby losses.
The other condensing boilers have been on the market much longer than the WM Ultra. Some teething issues like the lockouts due to electrical interference/brownouts have been addressed by now. However, as a homeowner I prefer a proven boiler if I'm not getting paid to beta-test it (one of my reasons to reject the Burnham Opus O1, for example).
Other interesting designs out there include the new Triangle-Tube Prestige, which may have a more clog-resistant HX than the other designs out there. The HX found in the Viessmann Vitodens is not only much thicker than the other stainless choices on the NA market, but it also is made of a higher quality steel (316Ti vs. 316). The Vitodens also has the lowest electrical energy consumption of any boiler tested by the ACEEE, 8x lower than the WM Ultra, for example.
So, is a Viessmann Vitodens worth the premium over the WM Ultra? I think it largely depends mostly on the quality of the installer, the quality of the maintenance, and the local availability of spare parts.
thanks for your reply, from the reply I would guess your a sale rep for import boilers. with that aside, how about availability of replacement parts or qualified installers. Even though my plumber does a great job on our plumbing installs, I don't need additional headaches due to a lousy install. I've gone thru that on import appliances already.
Why would you think he is a sales rep for a european boiler? He gave you very sound advice, if your going to have an attitude about it then why even bother asking for advice.
Since you don't think Viessmann are worthy enough for your house, then put in a Utica boiler and be done with it.
That's too funny... I work in the medical device area, not anywhere near home heating systems... though they interest me a great deal.
I have done some research in this area due to my own home renovation. So much so, that I ended up taking 5 classes with Viessmann to fully understand the capabilities, service issues, etc. of the Viessmann equipment in my home. I could do this because the Viessmann HQ is close to me and because Viessmann graciously allowed me to take their classes.
As for your nationalistic tendencies, name some boilers on the US market that contain only US-made components. Just like cars, the stuff that goes into boilers these days comes from around the world. For example, the HTP Munchkin has a French HX, a German gas valve, a German blower, and a US exterior body/chassis to mount it all in.
As I have stated before, the quality of a system is largely determined by those who install it, those who maintain it, and those that supply parts. From my reading on the Wall, installers and maintainers have been very happy with the responsiveness of Viessmann whenever installation, service, and replacement issues have come up. My personal experience has been the same, as two evacuated tubes for the solar system that were broken out of the box, were replaced promptly, for example.
That is not to say that you couldn't get excellent support from domestic manufacturers. For example, several luminaries from HTP and Burnham regularly offer their advice for free on the Wall. And when HTP discovered a defect in the blower motor of their Munchkin series, they stepped up to the plate, offered free replacement motors, and extended the warranty of same retroactively (!!!). Burnham has also done it's fair share of credits for casting issues in the V-7 series of boilers, for example.
If you want to find a quality installer, I suggest you start by checking out the Find a Pro services that Dan Holohan provides on the Wall. Perhaps you can find a great installer, regardless of what brand you end up installing in your home.
Edited 9/21/2005 5:26 am ET by Constantin
>>The gas valve found in the Trinity 400 allows a 16:1 turndown, for a output range of 25-400kBTU/hr (!!!). Thus, a Trinity 400 coupled with a small indirect with a large HX surface (like a Phase III from triangle-tube, for example) could offer a complete, economical heating package for the home and the domestic hot water, with minimal mass and hence minimal standby losses.I'm not sure if this holds true for boilers, but with forced air furnaces,if you turn the gas down too much, you lose a lot of efficiency as the flame gets further away from the walls of the heat exchanger and there is less area close to the flame.I base that assertion on combustion analyses I've done with several furnaces.You can approximate the same test using, say, 4" cast iron pipes of differing diameters. Light a candle, stick and hold the different sections of pipe vertically over the candle, centered above the flame.You can literally feel the differences in temperature, or you can measure the temps. As the diameter goes up (e.g., the inverse of turning the flame down) the heat transfer goes down significantly.And the flue gas temps go up, as the amount of heat transfer diminishes.So that "feature," like the two stage burners in some forced air furnaces, is a negative when it comes to combustion efficiency.
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Furnaces and boilers are very different animals due to their very different HX designs. Every furnace HX I've seen has very large passages for the flue gases. By contrast, the gaps for flue gases found in the HX's for condensing gas boilers are on the order of a milimeter. Therefore, a condensing boiler can tolerate much lower turndown ratios than a furnace and increase in efficiency as the available surface area for the HX grows in size relative to the input rate.
Repeat your pipe/candle experiment with a 4" and a 1/8" dia pipe and you'll see what I mean. Simply center the flame of the candle inline with the axis of the pipe and arrange the pipe vertically over the candle. The flue gases from a candle will not warm a 4" pipe one bit. However, it'll rapidly increase the surface temperature of a 1/8" dia pipe because the flue gases will come much closer to the surface of the HX.
"My Vitola offers features not found on any other oil boiler in the US... "
Such as...? You failed to list any of these. It is simply an observation that purchases are based on marketing. It is naive to believe otherwise.
I have no biases or nationalistic tendencies. I design heating system and sell hydronics (and other HVAC) equipment. I have examined as much of the published data on these boilers as I have been able to locate. I sell all of the products you mention except the triangle tube line. I have no preferences in this matter. I do not see "unavailable features" that help to sell Viessman boilers in this market.
BTW, the HX used in the WM Ultra has a 20 year track record in the country of manufacture.
"So, is a Viessmann Vitodens worth the premium over the WM Ultra? I think it largely depends mostly on the quality of the installer, the quality of the maintenance, and the local availability of spare parts."
If it depends "largely" on factors other than the actual products; intallation maintenance and parts availability, then why would any prctical individual pay a premium for a product that is not clearly better? I assert that it is based on the "feeling" that it is a better product, instilled in customers through marketing.
IF a Buderus ci boiler costs the same as a WM (which I doubt is true) and offers no greater efficiency or any superb performance or features, them the ONLY reason one would choose it over an equal product would be marketing.
Edited 9/21/2005 11:18 am ET by Tim
Timbo,
I find it highly entertaining that you consider imports a waste of money, yet didn't offer any proof why this ought to be the case, now chide me for not stating why I consider the Vitola to be the best choice for my application. Last time I checked, that was not the thread topic.
Be that as it may, here are some of the reasons why I chose the Vitola over the competition consisting of Burnhams Opus O1-90, the Burnham V8, the Buderus G115, the QHT Biasi SG3, the Dunkirk DPFO-4, etc.
To the best of my knowledge, the Vitola is the only oil-fired, non-condensing boiler on the US market that is inherently thermally shock-proof in our size (~100kBTU output).
The Vitola also has NO lower limit on the internal boiler temperature - flue gas condensation inside the boiler is NOT an issue. Given our RFH emitters and the insulation we have retrofit, our heating supply temperatures only have to range from 90°F to 110°F. The only reason for the boiler to go above 110°F is to heat the indirect hot water tank. That lowers standby losses significantly.
The Vitola is a very-well-insulated 3-pass boiler that is very easy to clean and maintain. Until recently, no US manufacturer offered a true 3-pass boiler design that could be cleaned with a simple clean-out door in the front. The MPO from Burnham and the coming oil-fired Ultra from WM have changed that, finally. However, neither Burnhams nor WM's new boilers were available a year ago and cleaning them is still not as easy as cleaning a Vitola.
The Vitola also offers an integrated flue gas temperature sensor. Not only is this useful to prevent flue gas condensation in the flue system (a real concern with a system as efficient as the Vitola) but it also ensures that the HX is clean, as rising flue temps would most likely indicate a covering of soot. It's one way to keep the Vitola running at peak efficiency. If the flue gases start to rise in temperature, it sends an error signal.
The integration of the Vitotronic control with the 4-way valve and other bits and pieces is seamless. Our Tekmar 369 deals with the zones, the Vitotronic controls the rest. It can even talk to a LON/etc. system if you want it to. I also find programming the Vitotronic more intuitive than a Tekmar controller, but that's probably just me.
All the electrical connections have numbered and color-coded connectors that make setup, maintenance, etc. virtually foolproof. As the boiler has virtually no internal hydraulic resistance and no lower supply limit, it doesn't have to be installed pri-sec which obviates the need for two pumps.
I could go on and on about the many details that make the Vitola the perfect oil boiler for our application. With its high mass and low standby losses, it offers peak seasonal efficiency while fired with a single-input oil burner. If low-sulfur oil ever gets popular/mandated, a lower-mass condensing boiler like the Monitor FCX could have made even better sense. However, the low-mass, condensing, and modulating boilers so popular on the gas side of the business will only become a reality on the oil side if the oil suppliers decide to defend their dwindling home heating market share and make low-sulfur fuel a voluntary requirement.
As for whether a Viessmann Vitodens is better for an application than a WM Ultra, I have made some points previously that you have failed to address. In a field filled with many different fine gas-fired condensing boiler choices, it boils down to specific features that sell one boiler over another. Whether or not the customers want to pay for these features is up to them.
My experience with Viessmann to date has been very, very positive and hence I had no reservation paying the premium to ensure I got a very robust, well-engineered system with top-notch support. Considering that you specify HVAC equipment, it may be a great idea to take the two-day introductory class at Viessmann to better understand the scope of their product line as well as the capabilities of their equipment.
As for why installers prefer a similarly-priced oil-fired Buderus over a WM, it probably boils down to personal preference. The Logomatic controls have many adherants, the Buderus boilers are considered easier to clean than their WM equivalents (to date, the new oil-fired Ultra may change that), Buderus offers a better-integrated package than WM, etc. Like Viessmann, they offer mixing stations, etc. that talk to the controller in ways that would require a string of Tekmar controllers on a "dumb" boiler. So, once again, there may be tangible reasons for people to select Buderus over WM even at the same price point. After all, it's not just price or marketing that people base their buying decisions on.
Edited 9/23/2005 5:21 am ET by Constantin
>> but it also ensures that the HX is clean, as rising flue temps would indicate a covering of soot.
Isn't it "Could indicate a covering of soot."
So if the tech comes in and doesn't find soot, is he going to assume its a bad sensor and replace it? Or is he going to know to check for scale buildup inside the boiler? Or misadjustment of the burners? Or any other possible cause of lowered efficiency?
I don't know a lot about boilers because I don't see them often, but I know that within the HVAC community there is a lot of misinformation and conclusion jumping being spread.
E.g. "The high levels of CO were caused by the dead bird in the chimney."
Usually, the dead bird is caused by the high CO, cleaning the chimney doesn't cure the CO problem.
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E.g. "The high levels of CO were caused by the dead bird in the chimney."
Usually, the dead bird is caused by the high CO, cleaning the chimney doesn't cure the CO problem.
But if the bird was blocking the chimney, then it could well be the cause of CO in the house, even on a clean burning appliance.
BTW, Happy Birthday.
Edited 9/21/2005 10:28 pm ET by rich1
Yes, that bird could have caused the spillage into the house, but there are fairly low limits on the levels of CO which may be produced byn appliance.If its killing birds, it is probably screwed up big time.My point mainly is that removing the bird from the flue doesn't fix the CO problem.
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A furnace can be producing low, "safe levels" of CO, but once the chimney is blocked, the levels of CO will probably climb to dangerous levels. The only difference is the chimney. How it became blocked is irrelevant. I've seen lots of dead birds in chimneys where the CO was low.
What the tech knows when he/she is called to the home is that something is causing the flue temps to be higher than a high-limit set by the installer. This is where the troubleshooting begins. Opening the Vitola is very, very easy thanks to the captive bolts, wiring harnesses with connectors, etc. Then hang the burner assembly on the built-in hook and have a look inside. This would be my first response, knowing that US home heating fuel can still be legally contaminated with up to 1700 PPM sulfur, etc. Those contaminants are largely responsible for the soot that even a well-adjusted boiler produces, according to the researchers I talked to at BNL.If the combustion chamber and the flue passages are coated with soot and the unit enjoyed regular cleanings, then an obvious question is to ask why there is the build-up. Is the nozzle clogged? Is the nozzle even right? Has the draft been adjusted to perfection, Etc. Only a trained expert armed with a combustion analyzer / smoke meter can tell if the boiler is in the zone or not.If the inside is clean, then scale may be one culprit, though the shape of the Vitola HX makes it more difficult for scale to get a foothold. Besides, what quality contractor leaves a water-feeding valve in the open position on a closed system? Either the hydronic system leaks or it doesn't. Scale usually only becomes a problem on leaking systems with make-up water feeding systems. And, if you don't know the local water conditions (i.e. extreme hardness) then a water test is a very simple and inexpensive way to ensure you won't have any unscheduled visits to the boiler.Now as for the birds and other critters that find their way into flue pipes, I'll only retort that I've seen a less-than-pretty picture of a rather dead and rotten racoon stuck in a 8" flue pipe. Luckily this was on an outbuilding, as the CO inside the building was reading off the scale. The CO problem did not exist before the racoon decided to enter the outbuilding that way. Similarly, I have heard of birds warming themselves on flue gasses and then falling backwards into the flue as even minute CO levels overcome such small animals much quicker than humans. Canaries in the coal mines, and all that.
Edited 9/22/2005 8:29 am ET by Constantin
>>The CO problem did not exist before the racoon decided to enter the outbuilding that way.Oh?Do you know that? I haven't tested many furnaces and water heaters after such situiations are "fixed", but the ones I have tested still had significant CO problems even after being "fixed" by a licensed contractor who believed the animal in the flue was the cause, and not just another symptom.
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I can only report that which was posted. The racoon story was a first-hand account that was posted on the net. Considering that
The flue pipe was horizontal
The racoon had plugged it 100%
There was no CO issue after the racoon was removed
I'd assume that the racoon was the reason that the outbuilding had off-the-scale CO levels.
"There was no co problem after ....I'd want to knoow who did the testing and what protocol they followed.I've tested plenty of furnaces that had major CO, and then a heating contractor has come in, tested the ambient air in the house or the ducts, and pronounced there was no CO.And I did not say never, the point I was making was that a dead animal in a flue is usually the result of a CO problem, not he cause.
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Bob,Like I said, I wasn't there. From what I remember, the flue gases had CO levels in the normal range once the half-rotten carcass was removed. However, IIRC, initially even the ambient air had deadly CO levels due to the recirculation of flue gases out of the draft hood and back into the appliance. That is, the space had to be aired out before the contractor could enter it safely. Tim McElwain always wears his CO meter and it has saved him several times - once in the lobby of a hotel that had a badly-adjusted gas fireplace, IIRC.As you point out, just testing duct air or ambient air is not enough. The flue gas exhaust should also be tested at the commissioning of every combustion appliance, regardless of fuel, and adjusted as necessary to minimize CO and other pollutants while maximizing economy safely. You won't know what the appliance is producing unless you test.Trouble is, I have heard from an engineer who designs condensing boilers that he has analyzed samples of natural gas in his lab that have ranged from 60kBTU to 160kBTU per ccf, depending on the utility, the time of year, and the source of the gas. Under said circumstances, I imagine it's a bit tricky to maintain prefect combustion year-round unless the combustion appliance senses the deviation and accounts for it.
Edited 9/25/2005 7:48 am ET by Constantin
And why would a plumber be bad at hydronics?
I've seen and heard lots, if not most "heating guys" that don't really know hydronics.
Edited 9/20/2005 10:33 pm ET by rich1
>>And why would a plumber be bad at hydronics? >>I've seen and heard lots, if not most "heating guys" that don't really know hydronics.Good point.Of course, the plumbers I have run into who work with combustion equipment are generally clueless when it comes to combustion and venting.The trick is to get someone who is good at all of it.Based on what I've read here, I'll go with Tim; the guy knows his ship, even if he is an engineer <G,D&R>
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"...his ship, even if he is an engineer .."
Trains vs boats...never really looked at it that way before!
Talk abou mixed metaphores <G>
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A plumber would not necessarily be good or bad at hydronics, but simply because it is a water based and plumbers deal with water systems does not always make a good match. Domestic water systems and hydronic systems have different design features and components. I work with plumbers alot because they buy hydronics heating supplies from me. Some are very sharp and know heating systems well and some do not. In my direct experience, more plumbers don't know enough to do hydronic systems right than do.
You have a good about the average forced-air hack trying do a hydronic system, also bad juju. So I'll revise my recommendation: Find a good hydronics installer, not a plumber.
I like that, "find a good hydronics installer".
Dan doesn't call them the Deadmen just for fun.
FWIW, I think the vitola is probably the best boiler in its class. No minimum return temp and you won't void the warranty if the pump is not running.
We have one in a snowmelt for a carwash, gas fired. 180 to the slab when it is -40, the inside looks new. Piece of cake to service. You can clean the inside in less than 10 minutes,open to close. They even supply the flue brush.
The new KN-10(?) looks interesting, but it ain't cheap.
Filling an old system today,"mister, is there supposed to be water coming out of the ceiling?" I love old rads.
180 to a -40 slab for snowmelt, seems to be in range that would cause cracking. In snowmelt applications in which I design for -10, I use a supply temp of 140. You've had no problems with cracking?
I questioned the engineer but he insisted. Three years later, no problems.
When I was having my RF Heating system installed, I asked the contractor about having a Munchkin boiler installed, since it is about 97% efficient.
He said, no, it has to be vented through the roof (25 feet up) and he likes Weil-McClain boilers. Said it was abut 87% efficient.
Not knowing about code for such boilers, I said, OK.
The system is in, and the exhaust from the boiler heats my basement, and pours HOT air out the exhaust.
Incredible waste of energy. At $1.65 per gallon in the spring,(Am afraid to find out how much it is now) for propane, I am shooting 260 gallons of propane into the atmosphere per heating season. Figure for yourself how much that is in dollars.
Come to find out, I could have vented the Munchkin through the plate log and out the side of the house, and 10% improvement in efficiency would have been a lot.
Next year I will install a Munchkin, and sell the Weil-McClain for what I can get for it.
BTW, the two boilers cost about the same.
I was screwed, because I listened to a "Heating Contractor" instead of what I had researched.
Stef
Oh, and lets not put down plumbers. There are ABS guys, and there are those who are academically trained in Radiant Floor Heating an boilers.
You've hit the nail on the head. Relying on steady-state combustion results like the AFUE is ignoring the reality of real-life results like those of a fellow Wallie who observed a 43.6% fuel usage reduction (on a degree-day adjusted basis) when he switched from a 80% AFUE atmospheric boiler to a 94% AFUE Viessmann Vitodens.Thus, I would be surprised if your fuel usage didn't drop closer to 20% or more, as the Munchkin will be much better suited to your type of emitters than most non-condensing boilers are.Don't think you're alone though. I recently stopped by a basement in which there was a brand-new heating system consisting of a Vitola being fired with gas, sporting a ginormous hydraulic separator, and using two fixed 3-way mixing valves to get all the temperatures right. This is an engineered solution, designed by someone who obviously has never taken a class at Viessmann nor understood the cabilities of the Vitola and/or Vitodens.The Vitodens would have been a better choice, fuel and emitter-wise, the hydraulic separator is not needed for the Vitola, and a Dekamatik or a Vitotronic 300 controller would have done a much better job controlling the different temperature zones than fixed-setting 3-way valves. I still can't believe an HVAC engineer specified this mess. What a waste of resources and equipment cabilities.Naturally, the heating contractor's advice (who has taken classes at Viessmann and who has installed lots of Viessmann, Buderus, etc. boilers) was duely ignored. At least the installation is a beautiful display of pro-press work.
Edited 9/21/2005 10:13 pm ET by Constantin
cic317,
Look at radiantec for underfloor radiant heat rather than baseboard heaters. The comfort of a nice warm floor has to be experianced to believe it. Plus if the floor is warm you'll find that you can comfortably set the heat at a lower temp since your feet are the coolist part of your body and if they feel warm you'll feel warm.. If the thermostat is lower you'll save energy without feeling colder! win win situation..
No you don't need to pour gypcrete to get that benefit.
Have a look at http://www.htproducts.com/
Modulating condensing boilers with exceptional thermal efficiency.
Output temperature can be adjusted based upon outdoor temps ("outdoor reset") right at the boiler (with no downstream mixing controls).
(Yes, I have one.)
Our builder / timber-framer and his HVAC plumber installer a Buderus oil-fired boiler with a Carlin burner. We received EnergyStar certification for the house and the technician noted he has never seen a higher efficiency output. Our house features radiant heat (nice even distribution) and Buderus reportedly caters to that market with being quite flexible.
However, the nozzle that was provided in the Carlin module wasn't the correct/ optimally compatible per Buderus. So I'd consult your service / maintenance provider first about the setup - experience fixing others' problems is a wonderful attribute.