Clear my mind up PEASE !!!!!

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

Joe Rettura

New Member
Dec 15, 2009
7
east of Pittsburgh
Hello all

I have econoburn 150 (150,000 btu) my home is about 3000sq ft well insulated. My set up is in my detached garage 40 ft from my home and feeds under ground into my in home oil boiler. i have 4 zones. The way I am using my econoburn is to fire and get it to temp then my water circulates non stop between the house and garage utilizing the zones to open and pull as needed. It has worked very well and the the econo 150 shuts down once it reaches temp and keep it between 180 and 197. I can get about 6 hours of burn time in winter months when day temps are between 25-32 degrees and nights about 5 hours when it is 16-25 degrees. When temps are above 32 degrees i can get over 8 hours of burn time.

Here is my dilema. I need to get 8-10 hours of burn time so that i do not have to refire. like most people i work and dont get home early enough and when i arrive the temp on the econo is down to 155 and the firebox is empty and even sometimes the coals are cool. I have considerd putting in a storage tank (500-1000 gal) however my concern is : am i going to boost my wood consumption due to the fact i am heating more water?

Most of the info i have read is conflicting. some say water storage is the answer in shoulder months but it doesnt help in cold months. others say it is the only way to get longer burn time. I do not want to go through the hassle or expense to experiment myself. What is the reality of it ? I have called the manufacturer and they were no help.

My next question is if i am circulating non stop between house and boiler location with the thermal storage tank in between, is it going to be effective or is it just going to cool a larger volume of water as the zones pull as needed. then again as a result larger volume of water will it or will it not cause more wood consumption?

Do I make sense to anyone or am i just rambling ? can someone please help me sort this out in my head please


Thanks,

Musclecar Joe
1965 Buick Skylark GS
Econoburn 150
 
Not any help but if your main circ quits running your boiler will overheat. How are you controlling your heat do you utilize a set back T-stat? Or set your daytime temp a little lower if no one is home. What type of wood are you burning? Does your boiler idle much if so insulating all the piping will save on stand by losses, expecilly if the garage is cold and pipes exposed.

I don`t have storage yet I will be putting it in next year.
1 reason keep the boiler running flat out more effecient use of BTU`s in the wood I burn. Idleing means less heat for the wood I burn.
2 I can fire twice in the evening before bed time to heat storage.
3 I can fill the boiler in the morning before leaving to carry the day with storage.
4 Shoulder seasons where storage will save wood..
 
Just a few thoughts based on the way my system is working:

Don't think of storage as being between the boiler and the heating zone. Think of it like the heat zone on one side, storage on the other, and the boiler in the middle. When the house is calling for heat, it takes it from the boiler. When the house is NOT calling for heat, the BTUs produced by the boiler go to storage. The boiler idles little or none, so its efficiency is at its peak. (so in the long run it seems you use less wood for the same amount of heat)
For sake of argument, let's say now you only get a 4hr. burn........less time than before........BUT, you then run the house from the storage for another 4, 5, or 6hrs. or more depending on several factors, most of which you can control.

No storage= no heat unless the fire is burning.
Storage= heat for many hrs. even though the fire is out.
 
I think what you are saying is that the run time with a full load of fuel does not provide the number of Btu(s) you need. Somehow you need to obtain more Btu to use.

Storage will only increase your burn time if the storage is up to temperature before you leave. Then your load will be supported by both the storage and the boiler

This is how I analyzed my system to determine what to build.

I took the type of wood I would be burning and looked up the number of Btu(s) per cubic foot that wood produced. Then determined how much wood I could put into my boiler. That gave me the total number of Btu(s) from the wood source. Then I reduced that number by the efficiency of the boiler and that provided the amount of heat I could use. I did the same type of calculation with the addition of a storage tank and selected a working temperature range. I could then determine the number of Btu(s) available for my use. In my case I only have 500 gallons of storage, but it doubled my output.

It sounds like in your case you need more Btu(s) than your boiler/system can provide.

I am one of those folks that will tell you that a well made storage system helps a boiler under all conditions; and the cost is very low compared to the boiler and the house hot water heat system.

You ask a system design question in the end, I would tell you that there are many ways to make your system work well with storage; the folks here would be happy to review a design and offer suggestions.
 
ohbie1 said:
Just a few thoughts based on the way my system is working:

Don't think of storage as being between the boiler and the heating zone. Think of it like the heat zone on one side, storage on the other, and the boiler in the middle. When the house is calling for heat, it takes it from the boiler. When the house is NOT calling for heat, the BTUs produced by the boiler go to storage. The boiler idles little or none, so its efficiency is at its peak. (so in the long run it seems you use less wood for the same amount of heat)
For sake of argument, let's say now you only get a 4hr. burn........less time than before........BUT, you then run the house from the storage for another 4, 5, or 6hrs. or more depending on several factors, most of which you can control.

No storage= no heat unless the fire is burning.
Storage= heat for many hrs. even though the fire is out.

so are you saying that i can continue to let my pump circulate through the storage tank continuously and i will have the same results ? or do i have to set it up in a way where the tank opens and closes itself as a zone ?

musclecar joe
 
I copied this method from the link below. Note that there are three independent cases of how the heat flows. It is a simple system that I can says works because I implemented it. And I am saying you may need to modify your system implementation, but after doing so it will work for you as it does for me. You can see the diagram by following the link.

Here is one method:

Borrowed from: https://www.hearth.com/econtent/index.php/forums/viewthread/19086/

1) Heating from storage
If there is any heat demand, then the corresponding zone valve(s) are open and their limit switch(es) are closed. This energizes the Load Circulator. If the storage is above 140, and the wood boiler is cold, then the load circulator will draw hot water from the top of the storage and return cool water to the bottom of the storage. At this point, there is a clockwise loop from storage through the zones and back. There is no flow through either boiler.

2) Heating from Wood Boiler
If the wood boiler is fired up, then the wood circulator will come on. If there’s still demand, then the load circulator is still running and the bulk of the flow will be from the wood boiler through the zones and back. Depending on the relative flow rates of the two circulators, there may be some flow into or out of storage.

3) Heating storage from the wood boiler
If the wood boiler is running and there’s no demand, then the load circulator is off and there is no flow through the heating zones. In this case, the flow is from the wood boiler clockwise to the top of the storage and back from the bottom of the storage to the wood boiler.
 
sgschwend said:
I copied this method from the link below. Note that there are three independent cases of how the heat flows. It is a simple system that I can says works because I implemented it. And I am saying you may need to modify your system implementation, but after doing so it will work for you as it does for me. You can see the diagram by following the link.

Here is one method:

Borrowed from: https://www.hearth.com/econtent/index.php/forums/viewthread/19086/

1) Heating from storage
If there is any heat demand, then the corresponding zone valve(s) are open and their limit switch(es) are closed. This energizes the Load Circulator. If the storage is above 140, and the wood boiler is cold, then the load circulator will draw hot water from the top of the storage and return cool water to the bottom of the storage. At this point, there is a clockwise loop from storage through the zones and back. There is no flow through either boiler.

2) Heating from Wood Boiler
If the wood boiler is fired up, then the wood circulator will come on. If there’s still demand, then the load circulator is still running and the bulk of the flow will be from the wood boiler through the zones and back. Depending on the relative flow rates of the two circulators, there may be some flow into or out of storage.

3) Heating storage from the wood boiler
If the wood boiler is running and there’s no demand, then the load circulator is off and there is no flow through the heating zones. In this case, the flow is from the wood boiler clockwise to the top of the storage and back from the bottom of the storage to the wood boiler.

I SEE SAID THE BLIND MAN!!!!!! ok cool, i think i can do this with minor modifications. I am thinking of finding a used 500 or 1000 gallon used propane tank for the storage. Now I need to decide if i am going to install it inside or outside due to limited space. I figure I can get one for about $250 and with a little copper a temp gauge and some fittings, vwala ! i will just need to isulate the heck out of it with a couple of inches of the spray foam they use in hot tubs or maybe build a cabinet around it and fill it with insulation.

Thanks so much and happy holidays !!!!

Musclecar Joe
 
As you see storage will help fix your problem but in the meantime there area few other tricks to try and help the burn time

The wood use the higher btu wood you have like oak locust ash when you need the longer burn.

Use a set back thermo to turn down the house demand while you are gone.

play with the temp setting on the boiler and see if you set it at 175 instead of 190 what happens to the burn times

install a timer you can set to the approx burn time so the boiler does not continue to run when it's out of wood and burn up all the coals so at least you can leave a hot bed of coals for when you get home ( someone here did this a couple of years ago and wrote about it )
 
Muscle car Joe, I am in season one with my Econoburn 100 with no storage . I live just outside of Buffalo, NY so our temps are comparable. I loaded my boiler last nite at 8 pm to just above the door with a 50/50 mix of hardwood and pine and bumped the controller temp down from 175* (where I keep it during the day) to 165* for an all nite burn. Got up at 5 am this morning to a 72 degree warm house with cherry red, big bed of coals in the boiler and it still running at the 165* temp. The outside thermometer showed 22* . My house is not as big as yours at 1700 sq. ft. with a full basement under that, where my boiler is located. I have found that all nite burns are easily achieved with my installation so far down to a 15* overnite low. We'll see what happens at 0* in January, but I think I will be able to get an 8 hour burn at any temp . I have 4 finnned zones and DHW hooked to the Econonburn of which I regularly use 3 of the zones(set at 72*) and DHW. Try lowering your boiler temp to 160-165* to achieve a longer burn time and adjusting your house zone temps to achieve a longer burn until you get your storage up and going. I love my Blue Monster otherwise known as the Econoburn 100. Good luck Bruce
 
I had a similar situation mostly because I was not prepared with good wood for this season. I bag up a small walmart bag of coal and throw in on top of my wood and it will burn for 10-12 hours. Without the coal I was getting 4-5 hrs My boiler is not a gasser and I am guessing the econoburn can not burn coal but worth checking especially considering where you live. Coal is easy to come by and cheap
 
Joe, two things I think you will have picked up here: one, storage will NOT increase the BTU output of your boiler and that seems to be the basis of your problem; two, the only way to increase your burn time is to pack more BTU into the firebox by using more energy dense fuel like oak or Biobricks. Storage is great, but won't give you longer burn times or more BTU output of the boiler.
 
Tony H said:
As you see storage will help fix your problem but in the meantime there area few other tricks to try and help the burn time

The wood use the higher btu wood you have like oak locust ash when you need the longer burn.

Use a set back thermo to turn down the house demand while you are gone.

play with the temp setting on the boiler and see if you set it at 175 instead of 190 what happens to the burn times

install a timer you can set to the approx burn time so the boiler does not continue to run when it's out of wood and burn up all the coals so at least you can leave a hot bed of coals for when you get home ( someone here did this a couple of years ago and wrote about it )

it is set at 180 but i get the point. I will try tonight.
 
airlina said:
Muscle car Joe, I am in season one with my Econoburn 100 with no storage . I live just outside of Buffalo, NY so our temps are comparable. I loaded my boiler last nite at 8 pm to just above the door with a 50/50 mix of hardwood and pine and bumped the controller temp down from 175* (where I keep it during the day) to 165* for an all nite burn. Got up at 5 am this morning to a 72 degree warm house with cherry red, big bed of coals in the boiler and it still running at the 165* temp. The outside thermometer showed 22* . My house is not as big as yours at 1700 sq. ft. with a full basement under that, where my boiler is located. I have found that all nite burns are easily achieved with my installation so far down to a 15* overnite low. We'll see what happens at 0* in January, but I think I will be able to get an 8 hour burn at any temp . I have 4 finnned zones and DHW hooked to the Econonburn of which I regularly use 3 of the zones(set at 72*) and DHW. Try lowering your boiler temp to 160-165* to achieve a longer burn time and adjusting your house zone temps to achieve a longer burn until you get your storage up and going. I love my Blue Monster otherwise known as the Econoburn 100. Good luck Bruce

I'll give it a whirl tonight. thanks.
 
BioHeat Sales Guy said:
Joe, two things I think you will have picked up here: one, storage will NOT increase the BTU output of your boiler and that seems to be the basis of your problem; two, the only way to increase your burn time is to pack more BTU into the firebox by using more energy dense fuel like oak or Biobricks. Storage is great, but won't give you longer burn times or more BTU output of the boiler.

I tend to disagree somewhat BHG - sounds like Joe is getting to the point where his boiler is idling, which means that it is meeting his needs, and that a lot of the time he may well be circulating water without pulling any heat from it... If he adds storage he will get the added BTU's that are currently going up the stack during his idle time (which sounds like it might be as much as a third of his burn cycle...)

Storage won't increase his BURN times, I agree, but why should we worry about burn times? I want to think about the amount of time that he can heat his home from a given burn, which is a subtle but significant difference... Storage will help "even out" his demand, so that he uses the heat produced more efficiently, and allow him to time his burns more effectively.... Obviously it will help during shoulder season when he can live for extended periods off the storage tank... During peak season, he might need to burn three fires - one when he gets home, a second before bed to top off the storage, and a third just before leaving for work to supplement the storage from overnight... Using storage to "time shift" his heat production should work very nicely for him...

Gooserider
 
Gooserider said:
BioHeat Sales Guy said:
Joe, two things I think you will have picked up here: one, storage will NOT increase the BTU output of your boiler and that seems to be the basis of your problem; two, the only way to increase your burn time is to pack more BTU into the firebox by using more energy dense fuel like oak or Biobricks. Storage is great, but won't give you longer burn times or more BTU output of the boiler.

I tend to disagree somewhat BHG - sounds like Joe is getting to the point where his boiler is idling, which means that it is meeting his needs, and that a lot of the time he may well be circulating water without pulling any heat from it... If he adds storage he will get the added BTU's that are currently going up the stack during his idle time (which sounds like it might be as much as a third of his burn cycle...)

Storage won't increase his BURN times, I agree, but why should we worry about burn times? I want to think about the amount of time that he can heat his home from a given burn, which is a subtle but significant difference... Storage will help "even out" his demand, so that he uses the heat produced more efficiently, and allow him to time his burns more effectively.... Obviously it will help during shoulder season when he can live for extended periods off the storage tank... During peak season, he might need to burn three fires - one when he gets home, a second before bed to top off the storage, and a third just before leaving for work to supplement the storage from overnight... Using storage to "time shift" his heat production should work very nicely for him...

Gooserider

Gooserider I think you are absolutely correct. my boiler does idle for quite a bit of time and the heat goes op the stack. the btu output is more than adequate for my needs however the time it heats my home is about 5-6 hours. you are right I am letting the fire manage me and not me managing the fire. heat storage i hope will allow my home to be heated for 8-10 hours to allow me to get home and refire. I have recieved some advice to turn down my aquastat and/or my thermostat. For now I am experimenting with that concept tonight. we will see how it goes. maybe I can get an extra hour or two. my long term plan is definatly to add 500 or 1000 gallon storage. I dont mind lighting a fire if it is on my terms. my biggest concern originally was that I would boost my wood consumption with storage however I have been corrected on that notion. my second concern was that storage would not help in the cold months from some posts I have read. The more I hear from responses to my post I believe that in fact that it will help me and I will have heat being sent throughout my home for a longer period of time. Most important is that my oil back up will not kick on every day and I can regulate my heat usage with the storage.

thanks,
Musclecar Joe
 
There should be cases that when storage is added the boiler burn time does increase. It has to do with the fact that the boiler controller uses hysteresis and that storage improves the run/idle duty cycle efficiency.

Regardless, what is important is that storage makes using a wood fired heating systems easier; with only a small increase in system complexity and cost.
 
airlina said:
Muscle car Joe, I am in season one with my Econoburn 100 with no storage . I live just outside of Buffalo, NY so our temps are comparable. I loaded my boiler last nite at 8 pm to just above the door with a 50/50 mix of hardwood and pine and bumped the controller temp down from 175* (where I keep it during the day) to 165* for an all nite burn. Got up at 5 am this morning to a 72 degree warm house with cherry red, big bed of coals in the boiler and it still running at the 165* temp. The outside thermometer showed 22* . My house is not as big as yours at 1700 sq. ft. with a full basement under that, where my boiler is located. I have found that all nite burns are easily achieved with my installation so far down to a 15* overnite low. We'll see what happens at 0* in January, but I think I will be able to get an 8 hour burn at any temp . I have 4 finnned zones and DHW hooked to the Econonburn of which I regularly use 3 of the zones(set at 72*) and DHW. Try lowering your boiler temp to 160-165* to achieve a longer burn time and adjusting your house zone temps to achieve a longer burn until you get your storage up and going. I love my Blue Monster otherwise known as the Econoburn 100. Good luck Bruce

Eureka !!! I feel so stupid !!! i did as you suggested and as of last night i got 9 1/2 hours with no reserve tank. Not only did I get a longer burn time I did not turn down my thermostats at all. They were set at 72 and have remained there all day. My oil furnace has never kicked on and I am thrilled. I am still going to put a thermal tank on but I think I am only going to put a 250 gallon one on.

Thanks so much

Musclecar Joe
 
So if you turn down your thermostat on the boiler you got a longer burn time? I did this and thought it worked but was not quite sure. I thought maybe it was a few flukes in a row.
 
musclecarjoe said:
airlina said:
Muscle car Joe, I am in season one with my Econoburn 100 with no storage . I live just outside of Buffalo, NY so our temps are comparable. I loaded my boiler last nite at 8 pm to just above the door with a 50/50 mix of hardwood and pine and bumped the controller temp down from 175* (where I keep it during the day) to 165* for an all nite burn. Got up at 5 am this morning to a 72 degree warm house with cherry red, big bed of coals in the boiler and it still running at the 165* temp. The outside thermometer showed 22* . My house is not as big as yours at 1700 sq. ft. with a full basement under that, where my boiler is located. I have found that all nite burns are easily achieved with my installation so far down to a 15* overnite low. We'll see what happens at 0* in January, but I think I will be able to get an 8 hour burn at any temp . I have 4 finnned zones and DHW hooked to the Econonburn of which I regularly use 3 of the zones(set at 72*) and DHW. Try lowering your boiler temp to 160-165* to achieve a longer burn time and adjusting your house zone temps to achieve a longer burn until you get your storage up and going. I love my Blue Monster otherwise known as the Econoburn 100. Good luck Bruce

Eureka !!! I feel so stupid !!! i did as you suggested and as of last night i got 9 1/2 hours with no reserve tank. Not only did I get a longer burn time I did not turn down my thermostats at all. They were set at 72 and have remained there all day. My oil furnace has never kicked on and I am thrilled. I am still going to put a thermal tank on but I think I am only going to put a 250 gallon one on.

Thanks so much

Musclecar Joe

Dropping the boiler temps will reduce transmission loss both from the boiler itself and the underground line. Think of it this way... if your sending 190 degree water through your line, the temperature differential between the line and the ground is about 140*. Drop your boiler and line temp to 160, and your differential is now 110* or 22% less... which should give you about a 22% decrease in heat loss through the line. Depending on what percentage of your overall heat load that the line loss makes up, this could make significant changes in burn times. Couple that with any Btu's that you actually store in the ground or the shed around your boiler, further decreasing the temperature differential between stuff making heat and stuff absorbing heat (heat loss) for a short while after you lower the temperature setting and you've got a good chance to gain some significant length to your burns.

Add to that - the fact that cooler boiler temps will reduce the stack temperatures and also increase overall efficiency.

Don't ever take for granted the amount of heat loss you fight when using underground line... regardless of how good the underground line may be. Plenty of underground line manufacturers make you feel all warm and fuzzy as though heat loss were a non-issue with their line... but consider that even a 2* temperature drop one way (figure about 4* out and back) at say 10 gallons/minute flow rate, your loss is equal to around 4*delta T(8.3Btus/gallon)(10 gallons/minute)(60 minutes) = approx 20,000 Btu's hr... CONSTANTLY!! That is SIGNIFICANT considering the actual AVERAGE Btu load for a 24hr period is probably less than 40,000 btu/hr on an average home on the average winter day.

Another thing to consider, is that while your boiler is rated at 150,000 Btu's/hr... it will probably have to consume an entire load of wood at a full bore burn in about 4 hours to meet that rating given the input/output efficiency of a typical downdraft gasifier and volume of the firebox... and since you can't get a full bore burn for a full 4 hours without tending and adding wood, well, you get the picture. For a 10 hour burn, don't attempt to supply any more than 50,000 Btu's/hour of actual draw(give or take depending on fuel quality), be it from the house or the underground line, and even that is probably pushing it. This presents a two-edged sword, however, as after you start going past 8 hours of burn time on a load of wood, the efficiency of the unit starts to decrease rapidly as creosote will build inside the heat exchanger, thereby reducing thermal transfer and increasing stack temperatures dramatically. Again... this is why thermal storage is so fantastic... it totally removes this issue.

I understand the lifestyle choice to have the fire and all the mess outside. Makes good sense from a hygenic perspective... but if you're going for true high efficiency, the boiler and the piping should be inside the space being heated so that transmission and standby losses are not actually lost, but reclaimed by the structure. And of course, add some thermal storage.

hope this helps
cheers
 
Status
Not open for further replies.