How should I burn my non gasser boiler for max efficiency?

[Drewby]

Well I’m gonna try to limp through this winter because I have no other options at this point other than a forced air Yukon furnace that was given to me. I also could install a big wood stove but I honestly thought the wood boiler would be more effiecent with the wood with a hot burn cycle.


When it comes to storage tanks I’m assuming pressurized is better because it eliminates another heat exchanger right?
Would that increase the efficiency of the boiler by letting it run harder and more steady? Or is it always going to be a wood waster to the highest degree.

 

[maple1]

Storage is a big asset for a boiler than has good heat exchange, whether the boiler is a gasser or not. From the looking I did on yours on the net, I don't think it has good heat exchange ability. That most always means heat exchange tubes - I think yours has a direct exit from the firebox to the chimney, no tubes. From what I could see. Although what I could see was scant on info or boiler diagrams, including the user manual. So without good heat exchange ability designed into the boiler, burning hotter will most likely just send even more heat up the chimney. Just the way it is. Lots of guys use boilers like this, but they also are putting up a crap ton of wood every year.

 

[Drewby]

Storage is a big asset for a boiler than has good heat exchange, whether the boiler is a gasser or not. From the looking I did on yours on the net, I don't think it has good heat exchange ability. That most always means heat exchange tubes - I think yours has a direct exit from the firebox to the chimney, no tubes. From what I could see. Although what I could see was scant on info or boiler diagrams, including the user manual. So without good heat exchange ability designed into the boiler, burning hotter will most likely just send even more heat up the chimney. Just the way it is. Lots of guys use boilers like this, but they also are putting up a crap ton of wood every year.

I just looked at mine and it says that it has 39 sq ft of heat exchange area....not sure if it’s good or bad.

 

[peakbagger]

Pressurized versus non pressurized is ford/chevy discussion both have pros and cons. Yes you will have higher efficiency with storage as the air damper should rarely if ever close. The trade off is you are going to have to relight the boiler far more often as properly sized storage is going to mean long stints where the boiler is off line. Note running the boilet flat out is heck of lot more efficient than throttled but if the boiler lacks adequate heat transfer area its still not going to be very efficient unless you add an economizer to the stack which can get really tricky and potentially a creosote producer.

 

[E Yoder]

I think (just my rambles here ) using a couple of thermostats and relays to control the amount of heat going into the rads and slab might be your biggest efficiency gain for the buck you could do for starters. Any time you open the windows it's a waste of wood.
No it's not the most efficient boiler but it'll make heat and you can usually do a changout without wasting a lot of the install parts. You already have it.
We're doing a fair amount of swapping older updrafters for gassers now, with all of what I do being outdoor boilers it's an easy swap.

 

[maple1]

Another conundrum with the slab storage aspect is that the basic theory of storage is your boiler makes more heat than the load needs for a period of time. So storage stores the heat for when the loads can use it. But the slab is a load itself, so there is only so much it needs or can hold before your load space is overloaded with heat. As long as it is taking heat it will always be emitting it. At this point if everything is in place I would just try it and see what happens this winter. Then at least you should be able to firm things up for winters to come. If no design work was done on the rest of the system there will likely be kinks to work through there too.

 

[Drewby]

Another conundrum with the slab storage aspect is that the basic theory of storage is your boiler makes more heat than the load needs for a period of time. So storage stores the heat for when the loads can use it. But the slab is a load itself, so there is only so much it needs or can hold before your load space is overloaded with heat. As long as it is taking heat it will always be emitting it. At this point if everything is in place I would just try it and see what happens this winter. Then at least you should be able to firm things up for winters to come. If no design work was done on the rest of the system there will likely be kinks to work through there too.

That was kinda my thinking also.
The plan was to load the boiler with enough wood for the day....1/2 load, full load or two loads ext. and let it run on full without it getting choked. The pump will put he heat in the slab and radiators as it’s getting made and the boiler will be at optimum burn the whole time. My wall thermostat (or window) will fine tune the room needs.
I always want this boiler running at peak efficiency so it smokes the least. My structure is essentially a large house/shop combo built inside four walls.
I was having a hard time with the idea that these old style boilers CANNOT be setup to obtain anything acceptable for economy. A 40% max efficiency seems way low if conditions are ideal. I’m gonna find out I guess.

I do believe without a doubt that I can get this combo to work just fine for the time being. I know it’s not a modern gasser but instead an old fashioned tank that will be used until I can afford something else. One problem I had with some of the new gassers is that they don’t “look” like they will be trouble free for a few decades. Lots of parts and electronics IMO.
If a $15,000 system only lasts 15 years then it doesn’t offer me any savings over propane....at least right now.
However a garn seems to last forever judging by all the old ones still in service. They cost more though.

 

[salecker]

Just for information...
Econoburns have a 25 year warranty on their firebox's.Simple controls that can be worked around to run without if you have storage and the controls go down.I had to run mine manually for almost 2 weeks due to a control issue and limited time to replace the control.
A garn was my first choice,but the cost to get one where i am wasn't in my budget ever.
I got 4 500 gallon decommissioned propane tanks for free and never looked back.

 

[Drewby]

Just for information...
Econoburns have a 25 year warranty on their firebox's.Simple controls that can be worked around to run without if you have storage and the controls go down.I had to run mine manually for almost 2 weeks due to a control issue and limited time to replace the control.
A garn was my first choice,but the cost to get one where i am wasn't in my budget ever.
I got 4 500 gallon decommissioned propane tanks for free and never looked back.

Sounds like a nice setup!
I am a little sceptical about boilers because of all the used ones that need repair on Craigslist. Lots of them are only 5 years old and getting scrapped.

 

[brenndatomu]

Well I’m gonna try to limp through this winter because I have no other options at this point other than a forced air Yukon furnace that was given to me. I also could install a big wood stove but I honestly thought the wood boiler would be more effiecent with the wood with a hot burn cycle.

Install that Yukon...you'll be much better off than trying to do what you propose with the boiler. Yukons work great if you let 'em stretch their legs! Mine is too big for this house.
IMO installing that boiler is gonna lead to a winter of "school of hard knocks" education for you...listen to these guys, you have decades worth of experience trying to help you here.
With wood heat, every time I have tried to do something that went against what knowledgable experienced burners have told me, I got to find out why they told me it was a bad idea

 

[Drewby]

Install that Yukon...you'll be much better off than trying to do what you propose with the boiler. Yukons work great if you let 'em stretch their legs! Mine is too big for this house.
IMO installing that boiler is gonna lead to a winter of "school of hard knocks" education for you...listen to these guys, you have decades worth of experience trying to help you here.
With wood heat, every time I have tried to do something that went against what knowledgable experienced burners have told me, I got to find out why they told me it was a bad idea

Why do you think it’s a bad idea? I think it’s a great idea EXCEPT I might not get the efficiency that I’m looking for or I won’t get the cleanest burn. That’s why I’m trying to operate it at optimum burn rates. I’ve lived with the Yukon’s before and they work great except they still are forced air and always seemed to cook you out.
I just can’t imagine an air cooled firebox pulling more heat off of a fast burning pile of wood than a water cooled one. And if that’s the case then the indoor boiler will trump the Yukon as far as economical wood usage IMO.

 

[brenndatomu]

Why do you think it’s a bad idea?

Just that I agree with these guys...its just not going to work well...not only to the point of not getting the efficiency you are after, but also not even providing the heat to the building that you plan on having...I hope I'm wrong, but my gut feeling is that you will be disappointed. And no way I'd risk damaging my new concrete slab either!

I just can’t imagine an air cooled firebox pulling more heat off of a fast burning pile of wood than a water cooled one. And if that’s the case then the indoor boiler will trump the Yukon as far as economical wood usage IMO.

Well, the problem here is that the old school "boilers" pull too much heat from the fire (water cooled firebox)...so its hard to get a proper fire going without running WFO...and then they don't have the ability to capture all that "waste" heat going up the stack when running WFO.
The key with those Yukons is all the heat exchanger area that they have...its huge...I'm saying your actually going to capture more BTUs to the building with the Yukon...now if you were going to install a heat storage tank...that might equal things out...or even swing the efficiency numbers back toward the boiler. 1 mans opinion...the others that have commented earlier know the boiler side of things better than me...I prefer scorched air heat here...

 

[Drewby]

Just that I agree with these guys...its just not going to work well...not only to the point of not getting the efficiency you are after, but also not even providing the heat to the building that you plan on having...I hope I'm wrong, but my gut feeling is that you will be disappointed. And no way I'd risk damaging my new concrete slab either!


Well, the problem here is that the old school "boilers" pull too much heat from the fire (water cooled firebox)...so its hard to get a proper fire going without running WFO...and then they don't have the ability to capture all that "waste" heat going up the stack when running WFO.
The key with those Yukons is all the heat exchanger area that they have...its huge...I'm saying your actually going to capture more BTUs to the building with the Yukon...now if you were going to install a heat storage tank...that might equal things out...or even swing the efficiency numbers back toward the boiler. 1 mans opinion...the others that have commented earlier know the boiler side of things better than me...I prefer scorched air heat here...

It’s going to be a experiment I guess.
As far as the slab goes the water will be mixed to the right temp before it’s pumped into it. The boiler is going to provide the lions share of the heat to the bldg and the propane furnace will supplement as needed.
I am going to run the unit WFO hopefully all the time. I will adjust my fuel load to the heat needs so the fire will be done when the slab is close to the temp I want it. And just like you probably do with your Yukon I probably get a good idea of what pieces of wood to throw in and when. And of course the unit will still have an aquastat to shut it down in the event that everything is getting too warm.
I do also realize that I might end up making a fire everyday or so and have some temps swings in the shop area which is Ok.

 

[salecker]

.
I do also realize that I might end up making a fire everyday or so and have some temps swings in the shop area which is Ok.

I read that a lot.I am not sure what the big deal is about starting a fire.When i tell people that i start a fire everyday with my boiler system and let it burn out,they always comment on what a pain it would be to have to start a fire every day.But these are people that are slaves to the fire box and have to keep a fire going or no heat.
Starting a fire in my Econoburn is too simple.Even a caveman could do it.In 8 years i have never had a failed start to a burn,and neither has my wife.She probably starts as many fires as i do.
I think the way you are going to try and use the smoke dragon you will be starting multiple fires a day,and will be waking up to a cold water heater in the mornings.

 

[gfirkus]

My dad had a hs tarm he ran for 30 years without storage. It was still working when he sold. It was in the bsmt and had baseboard heat upstairs. I remember large temp swings. He would load up before bed , in the morning berfore work, fire would usually die out by late afternoon. Definitely needs dry wood to cut down on creosote. He would burn around 5 cord a year . I ended up getting a Switzer boiler because the garns were a little too much and an open system . The boiler Gary built me takes up a 14’ x 12’ area. Maybe you could integrate something like that into your shop space and save you the cost of another building.

 

[brenndatomu]

The boiler Gary built me takes up a 14’ x 12’ area. Maybe you could integrate something like that into your shop space and save you the cost of another building.

Yeah 5600 ft is like 75' x 75'...you'd think there would be some way of squeaking a lil ole boiler in there...sure save a lot of moolah building another!

 

[Drewby]

Yeah 5600 ft is like 75' x 75'...you'd think there would be some way of squeaking a lil ole boiler in there...sure save a lot of moolah building another!

Yeah I did design it to fit a garn but ended up not going with that plan because of where the smoke would exit the bldg was right where a man door to the apartment ended up. The apartment was an after though that was incorporated into the 18x72 room-in-attic that was otherwise just going to be wasted space.
I’m gonna make this smoke dragon burn clean and hot for about 500,000-700,000 btus while it is getting dumped into the slab and the radiators. Then it will probably go offline until I light it again for another round.
The propane will even the lows out.
A dragons breath in the shop will fire up if the boiler gets too hot for a heat dump. Nothing like having a shop at 80 degrees in January because my wife fired the boiler one too many times lol

 

[jebatty]

Looks like you are set on the Royall and your plan is for a hot burn at 500,000 to 750,000 btuh. Have you given thought to 1) what your flow rate will be and how big your main pipe needs to be to move this quantity of btus?; 2) what your temperature drop will be across boiler supply and boiler return?; 3) what your pump head will be and what size main circulator you will need; 4) what the flow rate will be through your in floor pex and through your radiators; 5) what size your distribution piping will need to be? 6) what the necessary sizing of your other planned emitters need to be? And likely a lot of other questions to address.

Careful planning is in order. Many people on this forum have made serious and very expensive mistakes in planning their systems. Unless you are knowledgeable in hydronic design, you might consider employing a professional before going too far down the road in building out your system.

 

[maple1]

Looks like you are set on the Royall and your plan is for a hot burn at 500,000 to 750,000 btuh. Have you given thought to 1) what your flow rate will be and how big your main pipe needs to be to move this quantity of btus?; 2) what your temperature drop will be across boiler supply and boiler return?; 3) what your pump head will be and what size main circulator you will need; 4) what the flow rate will be through your in floor pex and through your radiators; 5) what size your distribution piping will need to be? 6) what the necessary sizing of your other planned emitters need to be? And likely a lot of other questions to address.

Careful planning is in order. Many people on this forum have made serious and very expensive mistakes in planning their systems. Unless you are knowledgeable in hydronic design, you might consider employing a professional before going too far down the road in building out your system.

I don't think he meant that many BTUs per hour. But rather that many total BTUs over the course of a burn. The way I read at least.

EDIT: But all the things you mentioned should still be considered. And would likely have come out in the system design wash if one had been done.

 

[jebatty]

I see the first post rates the boiler at 250,000 btuh, which I will assume is output. Maple 1, you are correct: the same questions still apply.

 

[Drewby]

Looks like you are set on the Royall and your plan is for a hot burn at 500,000 to 750,000 btuh. Have you given thought to 1) what your flow rate will be and how big your main pipe needs to be to move this quantity of btus?; 2) what your temperature drop will be across boiler supply and boiler return?; 3) what your pump head will be and what size main circulator you will need; 4) what the flow rate will be through your in floor pex and through your radiators; 5) what size your distribution piping will need to be? 6) what the necessary sizing of your other planned emitters need to be? And likely a lot of other questions to address.

Careful planning is in order. Many people on this forum have made serious and very expensive mistakes in planning their systems. Unless you are knowledgeable in hydronic design, you might consider employing a professional before going too far down the road in building out your system.

Yes I definitely have thought of those things. I am not hooking this unit up myself. I have a professional that is going to do it with plenty of experience and he says it will work great. The btus that I’m estimating is for the entire burn over the course of a few hours. I’m am trying to find the best burn rate for this unit and extract the heat as efficiently as possible.

 

[maple1]

The best burn rate will likely be right at whatever the system (slab and other emitters) can pull away from it, in BTU/hr. Design work can come up with a decent ballpark number, but overall it will still probably come down to running it and seeing what that happens to be in real world conditions.

There is someone on here who has been running I think a gasser for a while now with no storage and a slab for a flywheel so to speak. He seemed happy with how it was working but I forget who it was & what they had for a boiler.

 

[Drewby]

The best burn rate will likely be right at whatever the system (slab and other emitters) can pull away from it, in BTU/hr. Design work can come up with a decent ballpark number, but overall it will still probably come down to running it and seeing what that happens to be in real world conditions.

There is someone on here who has been running I think a gasser for a while now with no storage and a slab for a flywheel so to speak. He seemed happy with how it was working but I forget who it was & what they had for a boiler.

The purpose of this thread was to hopefully get some advice on the best burning patterns for an older style boiler to get a clean and somewhat efficient burn. I have a great deal of flexibility in my system design due to the nature of this bldg and the backup heat sources. I was having a hard time understanding why a sweet spot cannot be achieved.

Some people said that this unit will smoke and waste energy when it’s choked down due to lack of heat requirements.
The solution would be to keep pulling heat off it and store it or simply avoid putting the extra fuel in the firebox so it doesn’t happen next time.

Others said that it will never get up to optimum burning temp because the firebox stays too cold and it’ll smoke all the time.
The solution to that is keep the pumps off a little longer or have them shut off if the water temp gets too low. Keep the combustion temps up for a clean burn.

I also heard that if it runs with a huge fire wide open then it looses too much heat up the stack.
To prevent some of this I will try to have a smaller fire to leave more room to exchange the heat in the firebox.

This is an experiment until I can afford a gasser down the road. I will probably just burn a batch of wood at a time until I get the approx load requirements right. How I split the wood will probably have a big effect on the peak efficiency also.....but maybe not either.
Thanks for all the advice and keep it coming if anybody has any tips or experience in this kind of situation.

 

[BoiledOver]

This response does not address the purpose of this thread but it might be of interest to you anyway. There has been a Garn posted for sale here in the classified section. Quite a drive but ya never know since there is not an asking price.
https://www.hearth.com/talk/threads/garn-whs-2000.169418/

Ok, it is listed on craigslist too for $12,000 asking price.
(broken link removed to https://pittsburgh.craigslist.org/bfs/d/garn-wood-fired-hydronic/6670668581.html)