NG Condensing Boilers for closed loop radiant floor

[bloomingtonmike]

I have been racking my brain over the past few days looking at NG HE condensing boilers for a closed loop setup. I am scared of electric bills for a large pole barn.

Here is my build.
I have a 40X64X16 polebarn in Central IL - it is 100% double bubbble wrapped and taped and will have R19 fiberglass in walls. No ceiling other than doublebubble for now but it will get a 3/4 marine grade ply ceiling and most likely blown in R30 or better but that wont be for awhile. Walls are getting two layers of 3/4 ply as well in a slatwall design.

Floors are 5" concrete with 1.5" insulated foamular under and permimiter, and vapor barrier, with about 2600' of 1/2" pex in 9 loops one zone.

What HE boilers are people using for closed loop setup in a building this size?

I have a quote on a Hydro Smart Boiler and Panel but still getting details. I was spec'd a HS120CON-NG boiler but not sure if the panel was their one with bigger pumps or not.

A buddy had a local shop put in a Navien 240 but he also has DHW needs as well.

What do you folks like and where did you get them?

Anyone bought a NG setup from BlueRidgeCompany? They seem nice and sold me my pole barn pex kit at this sites recommendation.

Also do I need a stainless collector - I will be running water from my well.

Man its easy to get lost in this research.

Badger recommended a heat loss calc done but i may have to go to his company for that help (thank bro for the offer). Folks at the home show this weekend looked at me like I was crazy and everyone kept saying we install WellsMclain.

 

[Jackfre]

Well, Weil McLain is a Michigan Company and the largest American boiler manuf and they know their stuff. To me, your issue, is going to be trying to heat without a ceiling. I would size the boiler as though the whole insulation package is installed. Otherwise you will end up with way to much boiler.

Navien, Lochinvar, Buderus, Triangle Tube, Rinnai, WM and a bunch of others, but that is enough to make your head spin.

I have to say that whenever I've looked at insulation I think I can do it for cheap. I go to the local insulation company and they are doing the installed job for less than I can buy the material. You try to heat that space without an insulated ceiling and you will rapidly pay in fuel what the insulation will cost.

 

[theoldwizard1]

To me, your issue, is going to be trying to heat without a ceiling.
.
.
.
You try to heat that space without an insulated ceiling and you will rapidly pay in fuel what the insulation will cost.

I agree 100% !

 

[koditten]

Are you set on using a condensing boiler? The difference in efficiency for a shop is hard to justify the extra expense of a condensing boiler.

I did the math on my shop, I figured it would be close to 30 years to break even.

Less to go wrong with a conventional boilers as well. Cheaper boiler, more reliable because of less electronics and not have to deal with the ******** of a condensation neutralizing system. The only drawback I could see would be that you can't vent with PVC with a conventional boiler.

 

[jonjon1]

I wouldn't put a high efficiency boiler, and would NEVER put a Navian.

To stay away from a huge long wall of text here I will give you what I would recomend you install..


First have a heat loss performed so you know exactly the amount of BTU's you need.

I would do this with a mutli boiler setup, I would guess you are around 165K BTU
I would install a
http://www.weil-mclain.com/en/weil-mclain/pd-cgi-gas-boiler/
and this boiler http://www.weil-mclain.com/en/weil-mclain/pd-cgt-gas-boiler/
run them with this control http://www.weil-mclain.com/en/weil-mclain/pd-bcp3-boiler-control-panels/

Set the system up for multi stage boilers controlled by outdoor temperature. With a flat plate heat exchanger for the floor circuits. Pipe it primary secondary with delta t circs. The system would work very very well, i have done it a handful of times for commercial garages.

Much better option than a wall hung mod con.

If you are serious about a mod con and don't want conventional CI boilers, then go with the prestige solo boilers, I would again multi stage this because you are going to need a large boiler and want a low minimum fire rate for 90% of the heating season...

If you want to be talked out of a high efficiency boiler, just ask, I will give you more info than you will want to comprehend on the matter, but after year in this business I can tell you that some people don't care about what makes sense, they just want what they want. This can be proven by the $340K of wall hung boilers I installed last year...

 

[pseudorealityx]

I wouldn't put a high efficiency boiler, and would NEVER put a Navian.

To stay away from a huge long wall of text here I will give you what I would recomend you install..


First have a heat loss performed so you know exactly the amount of BTU's you need.

I would do this with a mutli boiler setup, I would guess you are around 165K BTU
I would install a
http://www.weil-mclain.com/en/weil-mclain/pd-cgi-gas-boiler/
and this boiler http://www.weil-mclain.com/en/weil-mclain/pd-cgt-gas-boiler/
run them with this control http://www.weil-mclain.com/en/weil-mclain/pd-bcp3-boiler-control-panels/

Set the system up for multi stage boilers controlled by outdoor temperature. With a flat plate heat exchanger for the floor circuits. Pipe it primary secondary with delta t circs. The system would work very very well, i have done it a handful of times for commercial garages.

Much better option than a wall hung mod con.

If you are serious about a mod con and don't want conventional CI boilers, then go with the prestige solo boilers, I would again multi stage this because you are going to need a large boiler and want a low minimum fire rate for 90% of the heating season...

If you want to be talked out of a high efficiency boiler, just ask, I will give you more info than you will want to comprehend on the matter, but after year in this business I can tell you that some people don't care about what makes sense, they just want what they want. This can be proven by the $340K of wall hung boilers I installed last year...

Ok, so given that a floor circuit is always going to return cold'ish water to the boiler, which means a condensing boiler is always condensing...which means the boiler is 10-30% more efficient ALL THE TIME, why do you recommend a non-condensing boiler?

Not to mention that venting is easier and less expensive with the condensing boiler.

 

[mygarageone]

I see a multi boiler set up was recommended at what 165 btu. For one thing multi boiler is over kill as is the btu's should he ever insulate the ceiling and I wouldn't do anything without that first.
Insulate the ceiling and watch your heat loss drop by a bunch , go with a modulation condensing boiler with out door controller .
There is no way a set of boiler is better than one , unless one break down or you can't get enough btu's out of a single boiler.
Triangle tube makes a nice pc of equipment and they have a good reputation when proper installed and maintained. The key is proper installation
And over all not much cost diff anymore between a condensing and a non unit.

 

[pseudorealityx]

I see a multi boiler set up was recommended at what 165 btu. For one thing multi boiler is over kill as is the btu's should he ever insulate the ceiling and I wouldn't do anything without that first.
Insulate the ceiling and watch your heat loss drop by a bunch , go with a modulation condensing boiler with out door controller .
There is no way a set of boiler is better than one , unless one break down or you can't get enough btu's out of a single boiler.
Triangle tube makes a nice pc of equipment and they have a good reputation when proper installed and maintained. The key is proper installation
And over all not much cost diff anymore between a condensing and a non unit.

Multiple boilers can be more efficient than a single boiler. Look at the efficiency curve for high efficiency condensing boilers. They run substantially more efficient at part load than full load.

 

[jonjon1]

Ok, so given that a floor circuit is always going to return cold'ish water to the boiler, which means a condensing boiler is always condensing...which means the boiler is 10-30% more efficient ALL THE TIME, why do you recommend a non-condensing boiler?

Not to mention that venting is easier and less expensive with the condensing boiler.

OK, so first I would like to see where 10-30% more efficient comes from?
If were are talking about combustion efficiency, they are at most 10%, where a ci boiler is under rated at 82-86% mod cons are over rated at 94-95%. but for arguments sake lets say they are the full 10% more efficient 100% of the time, lets try to make them make sense.
You spend $2000 per year for energy/fuel. This boiler saves you 10% which is $200. That is absolutely wonderful.

But now consider a few things-
1- they are expensive to install
2- they will not last as long as a std ci boiler {to the tune of half life if you are lucky, show me a couple 20 year old mod cons, I have seen thousands of 40 year old ci boilers.
3-They need annual service, I have seen ci boilers go 30 years with out a scheduled service
4-cost of repairs when something does fail on average mod con repairs are around 25 times more expensive than ci boilers, a honeywell aqua stat costs $185 to replace a lockinvar knight board or fan are around $1000 each!!! {and don't last long, I have replaced them before 5 years on many units}...

So what do you save? NOTHING, its the opposite, they will cost you 5 times more to run, lol..

Now take my advice or don't, its hard to convince someone of something, I know that. I installed over $300K in wall hung boilers in 2013 and I am not an advocate of the units.

 

[jonjon1]

I see a multi boiler set up was recommended at what 165 btu. For one thing multi boiler is over kill as is the btu's should he ever insulate the ceiling and I wouldn't do anything without that first.
Insulate the ceiling and watch your heat loss drop by a bunch , go with a modulation condensing boiler with out door controller .
There is no way a set of boiler is better than one , unless one break down or you can't get enough btu's out of a single boiler.
Triangle tube makes a nice pc of equipment and they have a good reputation when proper installed and maintained. The key is proper installation
And over all not much cost diff anymore between a condensing and a non unit.

Now as far as 165K BTU goes, that will have to be figured with a heat loss, I don't even know where in the country this is, I was using an example..

As far as 2 boilers, there is no such thing as them being overkill, radiant systems love mass, the more water the better they work and more constant they are, allowing you to set temps lower when possible. the 2 boilers will give modulation to the system, as well as back up heat incase one boiler goes down.

Multi boilers are very popular with high end installations, I have replaced many wall hung mod cons with them.

I specialize in the TT prestige boilers, I know them well I have a solo 175 in my own home, but having had installed many of them, I can tell you no matter how perfect you install them they have their faults, I have replaced boards {many of the previous generation}, heat exchangers, and venturi gas valves. Also we had a lot of issues with the ignition systems and new lp installs.... granted they have less issues than weil mod cons and some other units, but they are not perfect.

I can promise you, you install a system I design with multi cast iron units and your neighbor installs a wall hung, in 30 years compare costs, lol...

 

[pseudorealityx]

OK, so first I would like to see where 10-30% more efficient comes from?
If were are talking about combustion efficiency, they are at most 10%, where a ci boiler is under rated at 82-86% mod cons are over rated at 94-95%. but for arguments sake lets say they are the full 10% more efficient 100% of the time, lets try to make them make sense.
You spend $2000 per year for energy/fuel. This boiler saves you 10% which is $200. That is absolutely wonderful.

But now consider a few things-
1- they are expensive to install
2- they will not last as long as a std ci boiler {to the tune of half life if you are lucky, show me a couple 20 year old mod cons, I have seen thousands of 40 year old ci boilers.
3-They need annual service, I have seen ci boilers go 30 years with out a scheduled service
4-cost of repairs when something does fail on average mod con repairs are around 25 times more expensive than ci boilers, a honeywell aqua stat costs $185 to replace a lockinvar knight board or fan are around $1000 each!!! {and don't last long, I have replaced them before 5 years on many units}...

So what do you save? NOTHING, its the opposite, they will cost you 5 times more to run, lol..

Now take my advice or don't, its hard to convince someone of something, I know that. I installed over $300K in wall hung boilers in 2013 and I am not an advocate of the units.

Part load is where the condensing boilers can really kill the standard 84-85% boiler. At those same 30% fire or 50% fire rates is where the condensing boilers are peaking out at 96,97, up to 99% efficient. That's where my 30% comes from. I'm guessing your comment about them being overrated is because you're looking at peak 100% fire situations. At 100%, they do fall into the low-mid 90's, depending on style.

As far as longevity, condensing boilers haven't been available for 20 years here in the States, so that point is kinda moot.

Your maintenance experience is worthwhile, I'm not going to argue it. I don't know the costs for replacement parts. Thanks for adding.

 

[jonjon1]

Part load is where the condensing boilers can really kill the standard 84-85% boiler. At those same 30% fire or 50% fire rates is where the condensing boilers are peaking out at 96,97, up to 99% efficient. That's where my 30% comes from. I'm guessing your comment about them being overrated is because you're looking at peak 100% fire situations. At 100%, they do fall into the low-mid 90's, depending on style.

As far as longevity, condensing boilers haven't been available for 20 years here in the States, so that point is kinda moot.

Your maintenance experience is worthwhile, I'm not going to argue it. I don't know the costs for replacement parts. Thanks for adding.

OK, first lets start with this chart...
That is system efficiency, not combustion, and you are comparing it to combustion efficiency of a mod con, for that to be accurate you would need the same company to do the same chart for a mod con boiler. Does that make sense? In other words, sure that chart makes conventional boilers look bad, thats what it was designed to do, but if you had a fuel fired boiler running in the 40%'s the stack temp would be 1250 degrees, lets be serious here, lol...

So that chart is useless, also most likely designed to represent high mass commercial systems...

So lets kind of start over, as far as mod cons, you are correct, in the US, they are under 20 years {but getting close} and I have already seen so many failures it is alarming. When I brought this up years ago at a Buderus live fire routine I was told by one of the german engineers "americans have it backwards, they keep their cars for 3 years and boilers for 30, it should be the other way around", so if that makes sense to you, go ahead and spend $10K on a mod con, to save you money, lol...

I will give you a real world comparison.

june of 2010 I personally go to a sales call {the son of a good customer of mine bought a 2 family, side by side}. Foreclosed house, boilers stripped, no copper in the house, good sized job. They want a price for a conventional boiler for the rental side and a high efficiency for the side they will be living in.

I tried to talk them into 2 ci boilers but they wanted what they wanted. So I install a Triangle tube prestige on their side and a gas weil mclain ci on the rental side. Both installs are done by me and as good as you are going to get, basic stuff, both have 2 zones and pretty much identical heat loads, the rental side had a heat loss just 800 btus over the owner occupied side.
I broke down the cost for them into 2 bills {for tax reasons} Conventional boiler was $3400 mod con was $6900.

So the first heating season goes by everything works perfect, but I get a phone call, their gas bill is the same as their tenants! I explained that I would come out and take a look, everything was running perfect, all looked good.

A little time goes by and they mail me copies of their bill and the tenants bill {at my request}, sure enough the bills reflect they are saving $85 per year and he tells me the tenant sets their heat higher then he does and doesnt use the programmable thermostat, so they are convinced something is wrong with the system...

I send the TT rep their, he was interested also, he goes through everything gives it a clean bill of health and said their bills are perfect and what they should be!!!

WHAT I KNEW THE EnTiRe TiMe!!! So now that is fine fast forward to 2013 the prestige gen 1 board unflashes for some reason, the unit wont work, it was the first month of the year and COLD, I call up to get a board, guess what? 2 weeks out!!!!!! Yes 2 weeks because A LOT of them had issues and they were back ordered, wanna guess what happened next????????

I ripped the TT out, bought it back off of them for $800 {which I didnt want to but to keep relations good I did } and installed another ci boiler for cost..

Now that is just one story, my business does over a million dollars in sales per year, don't even get me started on lochinvar units and HTP, never mind the previous mentioned Navians {5 year boiler in 80% of the cases}. I installed 2 high in lochinvars in one of my rental properties because I was short on space and they mounted in closets, over thepast 3 years I have done 2 fans and a board {$3000 in parts} between the 2 units, SHOW ME WHERE I SAVED MONEY PLEASE DO....

So now, I know this is a lot of info, and if anyone wants to discuss this in real time OM Ill text you my number, I don't mind giving free advice, Ill even draw the system up for you and talk you though installing it yourself, I have no problem with that...

I am sure someday mod cons will be the end all off boilers, but its not going to be for another 10 years minimum, first they need to have a universal control and gas valve system, like ci boilers have a honeywell control that can fit them all so parts availability and cost can be better managed. Next they need to make the units more affordable {this wont happen until the rebates stop, which is coming soon, they are already getting cut in half and then half again}. And last they need to make them more module, where you can change an HX in 30 minutes and have one on the floor next to the unit for $200...

BUT ANYWAY I stand by what I said, ci is the way to go, the chart above in nonsense. Mod cons don't save energy with just the burner, they use a bunch of methods.
1- outdoor air intake, some people say, "well why heat up cold air with the burner" wwell thats why you don't install boilers for a living, lol. The combustion air has to come from somewhere, better outside than inside, you are forcing your envelope to fail, that 30 cfm is being pulled from the outside no matter what, you are not going to get negative pressure in your house from the burner fan, lol... That burner wants cold air, give it to it... This can be done {and should be} to a ci boiler to, I do it to almost everyone I install, I even do it to oil, its just a simple boot kit...

2- Outdoor reset, wonderful invention I agree, BUT ci boilers can have this too and most of the new ones do, it can be setup with the multi boiler control I linked above...

3-modulation, this is a big one, and you can not modulate a ci boiler {yet}, BUT by using multi boilers you can get a turndown, so now when you only have a small load you only light 1 boiler, when the load raises 2 boilers light, more 3 boilers, etc..... PLUS the extra boilers add reliability and they look awesome sitting next to each other...

4-condensation, ok so they are more efficient and vent so cold that the gases arent hot enough to carry the water, I agree, that is cool, BUT with that comes a lot of other issues, condensate pumps that fail, drain pans that rot out, acidic heat exchangers that rot out, etc etc etc They are just not there yet...

DO THE MATH, its easy to pull a chart off the net and put it in the context that suits you, but all I ask is to do the math.

LETS USE 30% {which I promise you wont happen, don't forget I have the most efficient boiler on the market in my own basement heating my 4500 sq ft home, with all the tricks done to is, on hydro air {nothing returns colder water than a hydro air, which mod cons love}, alpha primary pump, bumble bee secondaries, etc etc etc...

So say you have a big house in a cold area and spend $4K a year to heat it, that means you save $1200 a year {never going to happen}, so the boiler to heat a big house is expensive no matter what.
throw $200 of that savings away for annual service and tune. so $1000 per year...
say $4000 for a ci and $11K for a mod con
thats $7K to make up so that is 7 years...

If you go 7 years with out a service call, I would be surprised, not shocked but surprised, so after 7 years you start making $1000 per year, fast forward to 20 years, that boiler will need to be replaced, but you saved $13K over that time, in a perfect world where it needed NOTHING {not going to happen mind you}. So you take your savings and buy another boiler...

Now with a ci boiler, you can expect to never have it cleaned {I have seen them go 40 years never cleaned and still clean when I pull them out} but the boiler lasts you 40 years, you pay once and forget it....

Now when you come back to earth and realize a mod con will save you 5-10% not 30, you only spend $2000 a year not 4, when most likely you will change parts that cost $1000's and wait for them to come in while huddled around an electric heater, and it will last 12 years not 20, you will see its non sense...


Good luck though, and again if anyone needs more info post or pm me, I have no problem talking about this stuff, I have done very well with it, I have 6 years of schooling and been working on boilers since I was 15 and after 18 most of them weeks were 70 plus hours...

If you already bought a mod con, theres nothing to feel bad about, I have them in my properties too, and I know its easy to get defensive about, but thats not my intent, I just think there are not enough guys out there telling the truth, and why should they, they are selling a boiler that cost them $3000 for $11000 that is easier to install and takes less time without breaking their back!!!!! I was just a different kind of company so liked people to be happy with my work, it paid off I am 35 and retired, lol... {granted that is more because of the rental properties I invested in than my business but with out the business I would have never been able to accumulate the property I own...

 

[BigGMC]

jonjon - excellent info, wish you were local..... I've gotten so many conflicting stories from heat contractors on which type of system I should replace my aging oil boiler with (and sticker shock from thier quotes!). Pretty much made up my mind, I'll research it some more and do it myself.

pseudo - Seeing you're from GA, those efficiencies at 30% fire may be meaningful, but up here in the northern climates, I dont forsee these boilers fireing at much less than 80-100% most of the time due to heat demands.
I guess you could oversize the unit so that it runs at that level more often, but that seems counterproductive.

 

[jonjon1]

jonjon - excellent info, wish you were local..... I've gotten so many conflicting stories from heat contractors on which type of system I should replace my aging oil boiler with (and sticker shock from thier quotes!). Pretty much made up my mind, I'll research it some more and do it myself.

pseudo - Seeing you're from GA, those efficiencies at 30% fire may be meaningful, but up here in the northern climates, I dont forsee these boilers fireing at much less than 80-100% most of the time due to heat demands.
I guess you could oversize the unit so that it runs at that level more often, but that seems counterproductive.

Let me know what you are thinking for your oil system, I will stear you the right way. I started out in oil and we still have A LOT of it up here... I can tell you how and what to install where, fitting by fitting... Much better off doing it yourself, I get $5700 for the cheapest oil boiler install I do and the boiler and parts hardly ever break $2000, and the installs average 6 hours...

 

[pseudorealityx]

jonjon - excellent info, wish you were local..... I've gotten so many conflicting stories from heat contractors on which type of system I should replace my aging oil boiler with (and sticker shock from thier quotes!). Pretty much made up my mind, I'll research it some more and do it myself.

pseudo - Seeing you're from GA, those efficiencies at 30% fire may be meaningful, but up here in the northern climates, I dont forsee these boilers fireing at much less than 80-100% most of the time due to heat demands.
I guess you could oversize the unit so that it runs at that level more often, but that seems counterproductive.

No... ANY boiler is going to be at part-load most of the time. It's not going to have as much load during the day as the night. It's not going to have as much load in April as in January, etc.

100% fire is supposed to be at the design point...worst case scenario. And most engineers will add a safety factor in anyway, just in case your assumptions on infiltration, insulation, etc are off a bit.

As Jon said, with a standard boiler, you can't modulate, so either you need to provide 2, or you're constantly cycling on and off. The condensing boiler just sits there and modulates. Like driving your car. You have options between full throttle and full brake.

Our company is licensed in ~40 states, including Alaska.

 

[pseudorealityx]

Here's a better graph...

Full article: http://www.jmpcoblog.com/home/2014/...-water-boiler-plant-design-part-2-golden.html

Another good article about how to pick a heat exchanger material: http://www.jmpcoblog.com/home/2014/...-water-boiler-plant-design-part-3-conden.html

 

[mygarageone]

Let me know what you are thinking for your oil system, I will stear you the right way. I started out in oil and we still have A LOT of it up here... I can tell you how and what to install where, fitting by fitting... Much better off doing it yourself, I get $5700 for the cheapest oil boiler install I do and the boiler and parts hardly ever break $2000, and the installs average 6 hours...

Yea , it's so cheap to be in business . Michigan does not allow home owner DYI to install there own boilers for a dam good reason. There installing a potential bomb and I have seen plenty of them blow the whole dam house off the foundation. Recently one took out a whole school mechanical room surround by concrete block and cement and it was installed by a lic boiler guy , so let's have more DYI boiler installs , especially CI units which are not forgiving when installed wrong.

 

[jonjon1]

Here's a better graph...

Full article: http://www.jmpcoblog.com/home/2014/...-water-boiler-plant-design-part-2-golden.html

Another good article about how to pick a heat exchanger material: http://www.jmpcoblog.com/home/2014/...-water-boiler-plant-design-part-3-conden.html

These commercial sales pitch articles are a joke when comparing them to reality and residential systems. First off we maintained a couple hospitals and that is a different type of system, when we are talking about multiple 2 million BTU boilers, with a monthy heating bill over $20K sure, saving 10% looks very good.

Lets talk residential. A modern properly installed cast iron boiler, lets compare apples to apples, I will give you a system for example.

A 100K BTU natural gas fired, direct vented {no chimney losses}, out door combustion air, with a combustion efficiency of 85.5%, installed with a Hydro level 3200 plus with odr kit http://www.hydrolevel.com/new/index.php?option=com_content&view=article&id=108&Itemid=143 just as good thermal targeting and odr as any mod con. Install the boiler on an insulation/isolation pad, insulate the near boiler piping, install it with delta t circulation control, and pipe it primary secondary with a delta P circulator on the primary side {for multi zones systems}.

This type of system piped correctly will outlast the houses foundation, lol. When you pipe a ci boiler primary secondary style, you don't get thermal shock of any sort, your return is always balanced with your supply, this makes for very long boiler lifes.

Using delta t circulators will 1 save electric costs and 2 insure your not over pumping a circuit, so if you set your delta at 20* that means the pump or control will slow or speed your flow rate to get proper convection.

NOW pay attention here, yes when a mod con runs it can be setup to run for very long cycles, which is great. but what you don't understand is whether you run a flue with 300* gases out of your house for 35 minutes at a time 10 times a day or run a 200* flue for 24 hours a day, you are throwing about the same amount of energy out the flue {with in 8%}.... Does that make sense to you?

So now we know how a mod con will work, the burner turns down to match the load, the outdoor reset turns down the high limit on its curve to make boiler cycles as long as possible. That is great, I agree it is a good theory and will work when they perfect it and get the boilers to go 20 years with no service and last at least 30 years with out expensive boards and fans to fail...

NOW how my ci boiler install would work...

The burner heats the water battery up to the temperature the hydrolevel tells it it needs {using the outdoor temp reference}, the delta t circ runs the pump to a specific gpm to match your desired difference between supply and return, so it will end up pumping very very slow.

The burner kicks on, heats up the water storage to its temp and waits for the energy to be transferred to the living space via your buildings emitter. When the boiler temp lowers to its low limit it will kick the burner back on and start all over.

Now a lot of guys will tell you "stand by losses are greater" this is actually false {and where commercial systems differ from resi systems, since most commercial buildings have there boilers outside the heated area}, if the boiler is in the building you are heating the loss it sheds through its jacket {and good boilers have good insulation so it isnt much} is still heating your building...
Where commercial buildings lose is- the boilers are huge, outside, and not very well insulated {older ones}, this is not the case with a residential boiler, they have dampers to stop air from moving by the hx when the burner is not lit, metal insulated jackets, and normally less than 13 sq feet of jacket!!!

But anyway, I can talk about this until I pass out, the truth of the matter is, the contractor is ALWAYS going to want to sell you what makes sense for him, the reason I was so successful is I was NOT that guy. I talked my customers out of giving me lots of money, lol. BUT I must have done something right, its 20 degrees out and I am not working

I have been to trade conventions where they openly talk about how short life boilers are "good" for the trade, that turns my stomach, I seen charts showing how you need 1800 customers changing water tanks every 5 years boilers ever 12 etc, each customer is worth x amount of dollars, its all crazy insane BS... Install a boiler that makes sense, that is all there is to it, DON'T show commercial data reports and charts to a residential customer to trick them into thinking they are going to save money, thats just bad business for everyone but yourself...

Heres the truth..

A properly installed cast iron wet base direct vented boiler will last you 40 years, will get the rated efficiency the entire time every time it runs, wont cost much to service, and will not need annual service...

Thats it, thats all there is to it... Sure a mod con will get you 5-10% more combustion efficiency, but at what cost???? 2 to 3 times more over the life of a cast iron unit after service and initial costs.

I have had this discussion many times, many many times actually, and the home owners are much easier to convince than the contractors, lol.. wanna guess why? $$$$$$$$$$ and we are not talking about your money, lol...


PS pseudo, you hold 40 state master licences, I pay over $2000 in licence fees a year just for my 3 states!!!! 40 states has to be $30K+ per year, lol....

 

[koditten]

Awesome responses. Glad I opened up with my question.

 

[Jackfre]

Another thing you have to keep in mind when considering heat loss calcs. They are all based on a worst case situation. Your "design condition" is calc'd off a 20 or so year history. It is going to determine the lowest temp you are going to see...well except maybe this year. Once your heat loss is determined you select the heating appliaance(s) to satisfy that load. Then, on that coldest day of the year, IF they are properly matched the equipment will operate continuously at design condition and satisfy your comfort demands.
The thing is, you are at design condition less than 1/2 of 1% of the heating season, so about 99+% of the time you have vast oversizing of the equipment. Thie selection process is generally fudged even more by the contractor who can't bear to add some capacity. Most systems are then oversized by design and then oversized by selection.
The mod-con/cast iron debate is always fun and there are merits to both arguments. I fall on the mod con side myself, primarily due to the technology and adjustability. With a good outdoor reset program you can just make these things sing. But you have to be a hand to get them set up properly. Yes, they MAY require more serice, but I can have the heat exchanger on my boilers on the floor and apart in about 15 minutes. The gas valves are very robust and proven. The ignition systems are about the same CI-MC. Cleaning burners is a push. Sizing is a big issue today. With our building methods today, our heat loads are falling back to us. I just helped a friend install a 13,500-50,000btu mod con combi. You just won't get close to that in CI. So, I'm a mod-con guy, but I loved that enormous Buderus NG boiler I installed in my MA home in 99. Oh, one other thing. Noise, I could tell when that boiler turned on in the basement from anywhere on the first floor. That mod con we installed, I had to grab the pipes to see if they were hot. That is a big deal in the comfort world.

 

[pseudorealityx]

These commercial sales pitch articles are a joke when comparing them to reality and residential systems. First off we maintained a couple hospitals and that is a different type of system, when we are talking about multiple 2 million BTU boilers, with a monthy heating bill over $20K sure, saving 10% looks very good.

Lets talk residential. A modern properly installed cast iron boiler, lets compare apples to apples, I will give you a system for example.

A 100K BTU natural gas fired, direct vented {no chimney losses}, out door combustion air, with a combustion efficiency of 85.5%, installed with a Hydro level 3200 plus with odr kit http://www.hydrolevel.com/new/index.php?option=com_content&view=article&id=108&Itemid=143 just as good thermal targeting and odr as any mod con. Install the boiler on an insulation/isolation pad, insulate the near boiler piping, install it with delta t circulation control, and pipe it primary secondary with a delta P circulator on the primary side {for multi zones systems}.

This type of system piped correctly will outlast the houses foundation, lol. When you pipe a ci boiler primary secondary style, you don't get thermal shock of any sort, your return is always balanced with your supply, this makes for very long boiler lifes.

Using delta t circulators will 1 save electric costs and 2 insure your not over pumping a circuit, so if you set your delta at 20* that means the pump or control will slow or speed your flow rate to get proper convection.

NOW pay attention here, yes when a mod con runs it can be setup to run for very long cycles, which is great. but what you don't understand is whether you run a flue with 300* gases out of your house for 35 minutes at a time 10 times a day or run a 200* flue for 24 hours a day, you are throwing about the same amount of energy out the flue {with in 8%}.... Does that make sense to you?

So now we know how a mod con will work, the burner turns down to match the load, the outdoor reset turns down the high limit on its curve to make boiler cycles as long as possible. That is great, I agree it is a good theory and will work when they perfect it and get the boilers to go 20 years with no service and last at least 30 years with out expensive boards and fans to fail...

NOW how my ci boiler install would work...

The burner heats the water battery up to the temperature the hydrolevel tells it it needs {using the outdoor temp reference}, the delta t circ runs the pump to a specific gpm to match your desired difference between supply and return, so it will end up pumping very very slow.

The burner kicks on, heats up the water storage to its temp and waits for the energy to be transferred to the living space via your buildings emitter. When the boiler temp lowers to its low limit it will kick the burner back on and start all over.

Now a lot of guys will tell you "stand by losses are greater" this is actually false {and where commercial systems differ from resi systems, since most commercial buildings have there boilers outside the heated area}, if the boiler is in the building you are heating the loss it sheds through its jacket {and good boilers have good insulation so it isnt much} is still heating your building...
Where commercial buildings lose is- the boilers are huge, outside, and not very well insulated {older ones}, this is not the case with a residential boiler, they have dampers to stop air from moving by the hx when the burner is not lit, metal insulated jackets, and normally less than 13 sq feet of jacket!!!

But anyway, I can talk about this until I pass out, the truth of the matter is, the contractor is ALWAYS going to want to sell you what makes sense for him, the reason I was so successful is I was NOT that guy. I talked my customers out of giving me lots of money, lol. BUT I must have done something right, its 20 degrees out and I am not working

I have been to trade conventions where they openly talk about how short life boilers are "good" for the trade, that turns my stomach, I seen charts showing how you need 1800 customers changing water tanks every 5 years boilers ever 12 etc, each customer is worth x amount of dollars, its all crazy insane BS... Install a boiler that makes sense, that is all there is to it, DON'T show commercial data reports and charts to a residential customer to trick them into thinking they are going to save money, thats just bad business for everyone but yourself...

Heres the truth..

A properly installed cast iron wet base direct vented boiler will last you 40 years, will get the rated efficiency the entire time every time it runs, wont cost much to service, and will not need annual service...

Thats it, thats all there is to it... Sure a mod con will get you 5-10% more combustion efficiency, but at what cost???? 2 to 3 times more over the life of a cast iron unit after service and initial costs.

I have had this discussion many times, many many times actually, and the home owners are much easier to convince than the contractors, lol.. wanna guess why? $$$$$$$$$$ and we are not talking about your money, lol...


PS pseudo, you hold 40 state master licences, I pay over $2000 in licence fees a year just for my 3 states!!!! 40 states has to be $30K+ per year, lol....

I'm a consulting engineer, not a contractor. We do mostly commercial, institutional, and industrial work. I don't get paid based on what I specify.

 

[pseudorealityx]

PS pseudo, you hold 40 state master licences, I pay over $2000 in licence fees a year just for my 3 states!!!! 40 states has to be $30K+ per year, lol....

The company I work for is licensed in over 40 states. But we aren't contractors. We're consulting engineers in the commercial/industrial/institutional markets.

 

[jonjon1]

Another thing you have to keep in mind when considering heat loss calcs. They are all based on a worst case situation. Your "design condition" is calc'd off a 20 or so year history. It is going to determine the lowest temp you are going to see...well except maybe this year. Once your heat loss is determined you select the heating appliaance(s) to satisfy that load. Then, on that coldest day of the year, IF they are properly matched the equipment will operate continuously at design condition and satisfy your comfort demands.
The thing is, you are at design condition less than 1/2 of 1% of the heating season, so about 99+% of the time you have vast oversizing of the equipment. Thie selection process is generally fudged even more by the contractor who can't bear to add some capacity. Most systems are then oversized by design and then oversized by selection.
The mod-con/cast iron debate is always fun and there are merits to both arguments. I fall on the mod con side myself, primarily due to the technology and adjustability. With a good outdoor reset program you can just make these things sing. But you have to be a hand to get them set up properly. Yes, they MAY require more serice, but I can have the heat exchanger on my boilers on the floor and apart in about 15 minutes. The gas valves are very robust and proven. The ignition systems are about the same CI-MC. Cleaning burners is a push. Sizing is a big issue today. With our building methods today, our heat loads are falling back to us. I just helped a friend install a 13,500-50,000btu mod con combi. You just won't get close to that in CI. So, I'm a mod-con guy, but I loved that enormous Buderus NG boiler I installed in my MA home in 99. Oh, one other thing. Noise, I could tell when that boiler turned on in the basement from anywhere on the first floor. That mod con we installed, I had to grab the pipes to see if they were hot. That is a big deal in the comfort world.

It is always a good debate and there is no right or wrong, who ever is spending the money is left with the decision, I know some people just love to have the latest and best hanging on the wall, they feel good about it, that is all that matter...

You can install outdoor resets on ci boilers too, it is actually very popular, I have done it 100's of times. Like I said above, the only thing a mod con does that a ci can not is modulate and condensate which I agree will save up to 10% {no more than that}. And some would argue with certain types of systems, having no storage is a very bad thing, you get a mod con hunting around for its temp and see how efficient it is, or get it short cycling on a tricked sensor... But the biggest issues are initial investment, longevity, and service costs/availability...

You shouldn't be able to hear gas boilers lighting from all over the house, lol there may have been an issue. You are in the rare camp that will clean a mod con himself, that is 1 in a million, I don't know of 1 home owner I have installed a mod con for that will self service. Most warranties will not support that either.

heres the other issue, who wants to do that, I get $129 an hour to do it and I dread it lol...

Service aside, if you are honest with yourself and like I said earlier know you are not going to save enough to pay for the unit by the time it needs to be changed, then you are an adult and can spend the money you earn or find how ever you want. That is why I still installed the units, lol I did my part, explained the pros and cons and then gave the customer the choice, a lot choose to install mod cons, they are attracted to them fancy lights.

I asked one of the Utica designers why they didn't make a fancy plastic or fiber type insulated jacket for their ci boilers, and then add a crazy touch screen control to it {that could be bypassed when it failed of course}. It would sell like crazy, gloos black jacket, red touch screen lcd on the front... He replied, we don't want to sell ci boilers, we have to... I took that to mean, the ci technology is where it is going to stay, they are running with the mod con stuff.. sad part is, it has a long way to go...

Say you needed 135K BTU's for a building for less than the cost of most mod cons you can install a multi boiler control and 3 cgi3 ci boilers, never worry about service and have plenty of modulation.

What people don't understand is these boilers have to modulate not to turn on and off and on and off and on and off, because they have NO mass, and when you turn them mod cons on they don't come up to efficient running for a while, it has to start cond. before it gets to the mid 90s a ci boiler is at its rated eff. with in 3 seconds of starting.
With a ci storage boiler, you heat up a battery that is stored in the insulated jacket that is held in the space you are trying to heat {so there are no losses}, then when you need the energy you take it when it drops below a certain point it lights back up...

I'm tired, good night guys, I enjoy talking about this stuff..

 

[jonjon1]

The company I work for is licensed in over 40 states. But we aren't contractors. We're consulting engineers in the commercial/industrial/institutional markets.

Well them are 2 VERY different markets, commercial and residential. Sure the high eff. commercial units do make more sense than not. Several reasons, all of which you must be aware of.

1st- commercial properties get heavy incentives for going "green"
2nd- tax write offs, sure spend an extra $100K its a write off
3rd- like I said above, their energy bills can be $40K a month, so if you save 10% of that, your a hero!!! Who cares if you spend $50K extra to do it.. BUT residential is different that 10% translates to $150 a year, that is a joke, especially when you factor in the annual service...

there are many more reasons HE makes sense for large commercial properties.

I am also an engineer and I have designed $450K systems from start to finish then hopped in my service truck with a crew and went and installed it, I owned the drill rig and sat in the crane while we set custom 1 of a kind roof top geothermal/passive solar systems. When it comes to commercial the sky is the limit, but I always knew the difference and I never let it spill over to the resi market, because NO MATTER how you twist the data, Mod cons make no sense for small to medium residential homes...


Anther note on modulating, I am a firm believer in using heatpumps in the shoulder months, so when people talk about modulation and how important it is, keep in mind 60% of the heating season the heat pumps are going to be running, and when the boiler does get pulled in, its close to the design temp, so modulation is a moot point...

 

[koditten]

Over the last 5 years I have suggested conventional boilers as a heat source many times when people would ask what boiler to heat their shops. I believe that you are the only one that agrees with me. Thank you for the ability to put in print what I was unable to. For your info, I am not an engineer or in the business. I just know how to use a pencil and calculator.

The fact that the only maintenance I do is check the pressure gauge, just amazes me. I don't even turn it off in the summer. It just sits there and does exactly what it is supposed to, year after year.

 

[jonjon1]

Over the last 5 years I have suggested conventional boilers as a heat source many times when people would ask what boiler to heat their shops. I believe that you are the only one that agrees with me. Thank you for the ability to put in print what I was unable to. For your info, I am not an engineer or in the business. I just know how to use a pencil and calculator.

The fact that the only maintenance I do is check the pressure gauge, just amazes me. I don't even turn it off in the summer. It just sits there and does exactly what it is supposed to, year after year.

No problem, I try to keep on top of everything in my industry and even the companies that mod cons are keeping the lights on for agree with me on these points, maybe not in public, lol but I have been fortunate enough to have been behind the scenes enough time to get the truth, even though I didn't need to hear it from the horses mouth because my eyes have seen it in the field. I built a 5 million dollar business with my ideas and designs, when it comes to hvac-r I will never bend the truth or pull the wool, I will tell you your best bet with no bias, NOT because I spent the money on a mod con and can't admit there are better ways to go, NOT because I am trying to sell you something, NOT because I like to disagree, NOT because I want to waste my time giving false or biased information for free, BUT BECAUSE I don't mind helping, and doing so honestly. If anyone here needs a drawing or wants to bounce ideas off of me, feel free, PM me, if your local I have no problem swinging by and taking a first person look at what you are trying to accomplish, I have lists of obs I did where we built the units in house and can give you ever size for each piece of pipe to cut and solder in to make the system... Feel free to ask, and is someone thinks they have a better idea, feel free to say it, I am always open to learning something new and seeing other peoples ideas, but if you are looking for someone to make you feel better about spending $12K on a mod con that will cost you more to run and maintain than something you could have spent 6K on just tell yourself you did it for the environment...

There are ways to heat something cheap- use coal. Its cheap to buy, cheap to install, and cheap to run. You want to save energy and go green get geothermal heat pumps. You want a system that makes sense over the long run and is affordable enough to install get cast iron or a high efficiency furnace.

Which I can also touch on, HE furnaces have come a long way when coupled with heat pumps they are by far the best way to heat and cool an area.
I install 98% efficient variable speed furnaces with a steam humidifier, comfort is there, efficiency is second to none, reliability and longevity is 30 + years, and the initial install is much less then a mod con hydronic system... The only way to heat an area for less is solar and geo. These systems work great, they use the heat pumps in the shoulder months and when temps drop below say 35 your gas burner kicks in {your aux to primary switch temp will depend on the equipment ratings and your cost of fuel and electricity, my electricity here is expensive so the switch temps are higher, its easy to figure out, its where your heat pump starts to cost more per btu than your gas burner}.

The scorched air issues are not an issue with a properly installed system, I recommend steak humidifiers, piped into the registers or zoned for each room. I also recommend as many systems as you can get. So for a 2 story house you would want 2 units, I like to do a main living area unit and a bedroom unit for set back purposes. In the houses I have built {most 2500 sw ft plus} I would normally do 3 units 1 in main living 1 for main bedrooms and 1 for bonus rooms with a zone panel for guest bedrooms. Done properly with the right controls and thermostats you can save real money going with furnaces.

Not only can they modulate burner output, but convection speed as well, when done properly, you can get filtration, cooling, humidity control {both ways dehumid and humid}, and heating. Show me the hydro unit that can do that with out duct work Plus heatpumps with their insane efficiency numbers running for 70% of your heat cycle is much more efficient than a boiler of any sort. Now you add a solar system to that you can shave 80% off your energy bills...

 

[jvitez]

Very interesting thread gents, many thanks for all the detailed information. I've learned a lot.

jonjon1: would this be one of the cast iron conventional boilers types you're referencing? It's a Canadian made product available in my area.

http://alliedboilers.com/products/mini-gas-boiler/?PHPSESSID=2dbe7d7315e6438ce171c5c052277a9b

So in a detached shop/garage, how would you bring combustion air to the unit without having a permanently open vent that would defeat the purpose of air sealing? Is there some type of damper venting that would open when the burner lights?

In my previous mid-90's built house I had a wildly oversized NG mid-efficiency furnace that had a continuously open flexible duct run in a J shape that was attached to the side of the furnace. The end was turned up so the opening was horizontal. This was supposed to reduced the continuous infiltration of air as the J formed a small air lock. There was always some air coming in, but when the burner lit I could definitely feel more air being drawn in. The house had a non HRV central exhaust so this also supplied the make-up air for ventilation. Is this type of combustion air supply still used at all, or was that state of the art 1990's technology....

What would you do to supply combustion air to a conventional boiler in a shop/garage setting?

 

[koditten]

Mine gets plenty from the overhead doors. Very hard to completely seal a detached garage.

 

[jonjon1]

Very interesting thread gents, many thanks for all the detailed information. I've learned a lot.

jonjon1: would this be one of the cast iron conventional boilers types you're referencing? It's a Canadian made product available in my area.

http://alliedboilers.com/products/mini-gas-boiler/?PHPSESSID=2dbe7d7315e6438ce171c5c052277a9b

So in a detached shop/garage, how would you bring combustion air to the unit without having a permanently open vent that would defeat the purpose of air sealing? Is there some type of damper venting that would open when the burner lights?


In my previous mid-90's built house I had a wildly oversized NG mid-efficiency furnace that had a continuously open flexible duct run in a J shape that was attached to the side of the furnace. The end was turned up so the opening was horizontal. This was supposed to reduced the continuous infiltration of air as the J formed a small air lock. There was always some air coming in, but when the burner lit I could definitely feel more air being drawn in. The house had a non HRV central exhaust so this also supplied the make-up air for ventilation. Is this type of combustion air supply still used at all, or was that state of the art 1990's technology....

What would you do to supply combustion air to a conventional boiler in a shop/garage setting?

I would not use them allied boilers, you want a boiler that can be direct vented.

williamson GWI series {advertised in the 82% eff. But I always tuned them to 84% with no issues

Weil mclain cgi series {my preference} I tune these to 85.5-86%

And the slant fin vsph series I have gotten vsph-60's to condense, but easily safely gotten them to -86.5% ish

The williamson is the most cost effective and owned by weil mclain, I have installed hundreds of them boilers...

As far as how to plumb in your combustion air, it differes from unit to unit, some want a small draft control mounted in a tee, some want them on a common wall with x-amount of space between it and the vents, some don't care where you put them...

I put them on common walls per local codes. For draft issues it is a sealed chamber so the air coming in is sucked in by the inducer fan and forced out by the same fan, so you should feel no drafts... There should be no impingement issues...

I can get any boiler to its most efficient number pretty easily, I have used a fan speed control {on the inducer}, a modified pressure switch, with primary secondary piping to pretty much dial in my efficiency, sheet metal plates to keep the negative pressure in the combustion chamber up, and you can dial a basic cast iron boiler to any efficiency you wan't lol. Its obviously not worth the risk in something failing and creating a dangerous situation in which I would have liability.

 

[ctfjr]

Granted, I claim to be no expert here (and its great reading such opinionated views), but. . .

Its my understanding that in a slab system you can expect to get between 40-50btus/sq ft output from the system. From what I understand of the OP's original post, his barn is going to be just over 2500 sq ft. The most you can get out of that radiant load would be about 125mbh. I would think the best time spent would be figuring how to drop his heatloss to that number.

As I have no dog in this fight (ci vs hi eff mod boilers) I'll freely throw my 2 cents in fwiw. I don't see anyone here pointing out the difference between 'combustion efficiency' and 'system efficiency' (some like to talk about AFUE, annual fuel utilization efficiency). Until that is addressed the conversation is incomplete.
Also incomplete is the matter of utility or government rebates for high efficiency equipment. I don't know if any are available for your particular application / location but is sure is worth looking into (you may qualify under a residential or commercial program for a barn). I do know that I installed 2 Burnham Alpine 399's (399mbh each) in a commercial building I own and the utility wrote me a check for 20+% of the entire cost of installation.
The last thing you might consider is your civic obligation to consume less fuel.

Best of luck with your project

 

[mygarageone]

Jon jon 1 , I have a question for you . How old are you and how many yrs were you in business ?

 

[jonjon1]

Jon jon 1 , I have a question for you . How old are you and how many yrs were you in business ?

I'm in my mid 30's, been in the business since 16, but was helping my uncle clean boilers since way before that and not once and a while, every weekend and through out my summers. I have been around it for my entire life. I am still "in the business" I installed a boiler last week for a woman from our church, didn't get paid {not in money anyway, I did get a pyrex full of the 2nd best lasagna I have ever tasted though}.

Curious as to why you ask though? Hvac is one of the industries that how "long" someone is in the industry holds very little weight. I worked with guys with 40+ years that were lost when it came to digital combustion analyzers and some of the new wiring techniques. We say it all the time, the guy with 5 years experience is the perfect hire, sure sometimes they don't like to use a level, but thats easy to teach, try to teach a 63 year old with 45 years on the job how to set the negative pressure differential on a triple pass boiler when its not in the instructions and they have been adjusting draft to -4 at the breech for the last 40 years using the draft regulator. I have tried, not fun... Don't even get me started about the day I taught a class on the Buderus Logimatic control!!!! Class of 16 and 4 of them were under 40 years old, they picked it up pretty fast as did a couple of the vets, but the rest tortured me, same thing when I ran the seminar for the old triangle tube prestige control, the older guys were LOST, it was so alien to them...

 

[jonjon1]

Granted, I claim to be no expert here (and its great reading such opinionated views), but. . .

Its my understanding that in a slab system you can expect to get between 40-50btus/sq ft output from the system. From what I understand of the OP's original post, his barn is going to be just over 2500 sq ft. The most you can get out of that radiant load would be about 125mbh. I would think the best time spent would be figuring how to drop his heatloss to that number.

As I have no dog in this fight (ci vs hi eff mod boilers) I'll freely throw my 2 cents in fwiw. I don't see anyone here pointing out the difference between 'combustion efficiency' and 'system efficiency' (some like to talk about AFUE, annual fuel utilization efficiency). Until that is addressed the conversation is incomplete.
Also incomplete is the matter of utility or government rebates for high efficiency equipment. I don't know if any are available for your particular application / location but is sure is worth looking into (you may qualify under a residential or commercial program for a barn). I do know that I installed 2 Burnham Alpine 399's (399mbh each) in a commercial building I own and the utility wrote me a check for 20+% of the entire cost of installation.
The last thing you might consider is your civic obligation to consume less fuel.

Best of luck with your project

I mentioned all of them points in my posts, but I can do it again...
First system efficiency- that is what I am talking about when I say a ci boiler can be setup just as nice as a mod con, so a mod con's always get setup Primary secondary, with outside combustion air, with an outdoor reset, etc, all stuff that can also {and should} be done to a ci boiler... So the only edge {as I said a few times in previous posts} is the modulation {which if he uses the 2 boilers I reco'd he will be 2 stage, which will get him some modulation} and condensation, which gets us back to combustion eff. He wasn't asking a question about insulation or system design which would also play a part in energy costs, but the differences would be seen with both plants, proper sizing, better insulating your building, isolating circuits, etc isnt going to help a mod con more than it is a ci and vice versa..

I also touched on rebates, which have been pretty much pushed down to a few commercial ones left and the ones the utilities offer and they have to be professionally installed {leaves out the diy'er} and in some cases have to use the equipment listed, sometimes bought directly from them. Around here they have been cut in half and in half again, out high seer heatpump rebate is down to $250 {a joke}. And I did the math back when repates were $2000 for residential installs with more from uncle sam in april, and it still didn't change the fact it didn't make sense for residential buildings...

Now lets touch on your system, if you read my posts you will see that I say a few times "commercial buildings with high energy use can benefit", that is kind of my point, with your two 399's you are talking about almost a million BTU's!!! Of course you are going to save money, as I previously mentioned, the rebates are better for commercial, the tax incentives all together are better, in most cases you can write off the entire costs of your system so the more you spend the more you save...

Be sure to stay on top of them alpines, I had a system with 3 daisy chained together that all burnt boards the same day, turned out one had a short and cooked the 3 of them, that was a commercial building {laundry mat} so not as big of a deal for the company to write a check for $2800 in repairs, but a home owner would have a stroke, lol..

The 399's are known for burning up blower motors, that are $850 locally but can be bought online for less http://www.supplyhouse.com/Burnham-101530-01-Blower-for-ALP285-ALP399 and they are now available pretty fast, but last time I needed one I had to get it overnighted, luckily it was summer time..

I am not sure if your are Sage equipped, they now sell a repair module to get I think sage 2.1 BUT thats $350 plus installation, so $500 upgrade for something you already paid for!!!! I can promise that wouldn't happen with a ci boiler. you need parts, they will be a car drive away, you need service any tech with 3 months experience will be able to give it to you, and both will cost much less for a ci boiler...

BUT, you are a business, so it doesn't matter much, you can write it off, and now the 10% them units save you is more because with a million btus you are using them things, but a customer using $1500 a year saving 10% is not too attractive when you figure they are going to give it back every year in annual service. The alpines need annual service with a seal kit, what has that costed you every year, I get $275 to do it, for 2 you would be $500 even, per year!!!!!

Now for the last comment, going green which I also mentioned. That is worth more to others than some. You may use 10% less energy, but make sure you recycle the units when its time to switch back to ci, jk...

When a home owner replaces a $50 fan and $890 board, they don't get to write it off. They just get to write the check. SO comparing business to residential like I said 5-6 times is not going to work, and this is what MOST companies try to do, they bring up commercial graphs and studies, showing HUGE savings that a residential user will never see...

So rebates, our responsibility to the planet, and commercial vs residential have been covered pretty well now..

Again, I am not trying to say anyone is wrong for buying a mod con, I am just saying don't fool yourself into thinking you are going to save enough to pay for the additional costs. An don't just factor the initial, look at the entire picture, annual service, future parts, longevity and you will come to the same conclusion, IF YOU WANT TO, if you already spent the money, or just want a wall hung boiler, then stop reading this post, because no way am I going to say it makes sense... I even tried to figure it out for people who install there own and don't pay labor, it still is hard to make make sense...

 

[mygarageone]

Jon Jon
You weren't around when high eff boilers were in there infancy , you have critizised the
mod con because of repair costs and to some degree justified.
But before all these mod con came to have all this expensive parts .
There was the Glowcore boiler and. Hydrotherm Pulse boiler . Both were designed to last for yrs like in 20 or more , they used pretty much off the shelf parts and it didn't take a degree in electronics to trouble shoot them.
There biggest down fall , was lack of contractor education and that brought both of them down , bad press.
But because the Glowcore in perticular was designed for longevity with off the shelf parts , I sill have one in operation going on 25 yrs old . When the heat exchanger takes a dump it's over They are out of business and have been for several yrs now. I was a dealer so I had parts for repairs.
So your arguments may be valid today but like I said when they first came out , they were made to last.
These boilers need lots of water moving through them or they were toast and most boiler guys 30 yrs ago couldn't grasp that little detail. That is was the problem back then lack of education with the new technoligy .
These new boilers shouldn't even be sold to anyone who isn't trained in them. It's like putting a 6 yr old behind the wheel of a car and say drive.
I was putting this stuff in before you were out of diapers. And carry just about every cert you can name for all of them and a 10 million btu boiler lic. And mod con boilers are here to stay and the CI units will be gone in the near future , watch it happen.

 

[ctfjr]

Jon Jon

But before all these mod con can to have all this expensive parts .
There was the Glowcore boiler and. Hydrothermal Pulse boiler . Both were designed to last for yrs like in 20 or more , they used pretty much off the shelf parts and it didn't take a degree in electronics to trouble shoot them.
There biggest down fall , was lack of contractor education and that brought both of them down , bad press.

Ahh, the good old days (early 80's). The Connecticut Hydrotherm Hydropulse 'school' (sponsored by the CT Rep and myself) was located in my building. It consisted of 4 A100's that were motor valved to either be part of the building heating system or operate independently. Those poor things were taken apart so many times its a miracle they lasted the 18 years they did (part of the program was something was made to fail & the student had to troubleshoot it).
You hit the nail on the head mygarageone, they weren't complicated - just different - but many unqualified installers put them in and worse, tried to service them.

 

[finn]

Well, I guess I'll be the first to say it, but jonjon, your posts sound more like generalized anecdotal rants against technology rather than well thought out scientifically based studies.

I agree with mygarage that modulating boilers are here to stay and the old, inefficient technology will go the way of the dodo bird, hand crank telephones, dial up internet, and the carburetor .

 

[ctfjr]

I hate to get into a ******* contest here but thought I would throw in some supportable 'facts' (verifiable information). First some bona fides. I ran a small (<$3mm) heating distribution company for 25 years. For the last 20 years I have been working for a medium size distributor (~$70mm). We stock & sell several brands of high efficiency boilers including: Burnham, Weil Mclain, Triangle Tube, Peerless, Buderus, Viessman and Lochinvar.

I just checked our sales records for Burnham Alpine boilers for the last 5 years, 323 units. Number of replacement circuit boards sold - 2. Number of motors sold - 1 (actually that one was a warranty).

I also agree with mygarageone, hang onto your beloved ci boilers. They will become collectors items.

 

[mygarageone]

And by the way , my company did millions of dollars in commercial boiler systems.
I can not remember the last job where a CI boiler was specified ? We did how ever install more than a couple Aerco mod con million btu units . No wall hung unit !
factory training and start up was required for them.
One job in perticular I remember , we removed a million btu oil boiler and installed 10 Glow core L.P gas units . They were designed with lead lag , outdoor boiler reset and some other specialty controls . The first yrs fuel saving paid for the new system. This was in 1991 when both fuels were cheap.

Many of us old men have forgotten more about boiler systems than we care to think about.

 

[yeldogt]

I have never done all the math -- but most of the high efficiency boilers/ furnaces have been more of a pain. My first radiant system used a Buderus atmospheric boiler and eccomatic control -- has been running for 20 year now with one $25 sensor replacement and a circulator switchout.

At least mod cons are better then ALL the oil units that need work every year.


I'm going through this now. I only have space for a mod con direct vent. I have had good luck with Buderus products ... but leaning towards the Viessmann with small DHW tank.

If you have NG -- depending on load and location .. I can see the case for a standard boiler. My studio is not occupied all the time and is a somewhat remote location. If I had NG service I don't think I would worry about small efficiency loss to gain simplicity with NG costs and outlook.

 

[jonjon1]

I hate to get into a ******* contest here but thought I would throw in some supportable 'facts' (verifiable information). First some bona fides. I ran a small (<$3mm) heating distribution company for 25 years. For the last 20 years I have been working for a medium size distributor (~$70mm). We stock & sell several brands of high efficiency boilers including: Burnham, Weil Mclain, Triangle Tube, Peerless, Buderus, Viessman and Lochinvar.

I just checked our sales records for Burnham Alpine boilers for the last 5 years, 323 units. Number of replacement circuit boards sold - 2. Number of motors sold - 1 (actually that one was a warranty).

I also agree with mygarageone, hang onto your beloved ci boilers. They will become collectors items.

Which supplier do you work for? I would love to have one open on Sundays around me, all of them around here close at 12 on saturday and dont open until monday.

I can tell you this, I have replaced MANY Alpine Boards and blowers my self, we are in the national grid line and Alpines are their supplied boilers so there are A TON of them things around here.

If you want to think the mod cons of today are not service head aches thats fine, but from what I have seen and charged people to repair, they are expensive to fix, can be hard to find specific parts for {normally not in stock}, not as many techs are confident with them, and prone to needing repair.

There is no ******* contest, this is a conversation among adults, I am just speaking truth from my experience, and my thoughts on the subject, is it gospel, NO... Just trying to share how I look at it and my experiences from my time in the business. I don't want to offend anyone or steer anyone wrong, just giving some info, take it how you like, a smart person making decisions will want all the info they can gather to aid in said decision...

I can tell you FACT- I have changed a ton of expensive mod con parts, and go ahead and check out the warranty on the boards and electronics in them units, they warranty the HX for x amount of years and then the other parts for much less, sometimes 12 months, well most times.

And I don't know what supply house you work for but in a conversation I had with a rep from burnham, they make more money selling parts than they do selling boilers, so something is off, go ahead and google "alpine boiler problem" or "high efficiency boiler broken" and you will be reading for months...

I can not in good faith recommend a mod con boiler at this time knowing what I know and seeing what I have seen... sorry... if you can go ahead and do so...