1000 Gallon Propane Tanks stacked storage

[WoodWacker]

I know of two people that 1000 gallons stacked. It works well for them. You would need a minimum of a 80 kw boiler.

henfruit, how come such a large boiler is required?

Spray your tanks with 4 to 6" of closed cell foam first then cover with a foot or so of cellulose or fibreglass.

Thanks more like it... This sounds good. Is the spray foam good with the heat? Does it have to be rated for higher temp?

 

[henfruit]

Chris, If you go smaller you will be doing more than one load of wood to get the tanks back up to the operating temp. The idea is to match the storage load to the boiler. Fill the boiler full, let it charge the tanks. Repeat in x number of hours later depending on heat load and weather conditions.

 

[henfruit]

The two I know of are using a 100 kw Vigas and 75 kw Viadrus.

 

[WoodWacker]

I guess my goal is to start one fire per day. Big storage would allow for that. As for boiler size, that would determine how many times I fill it? I wouldn't mind refilling it during a burn, is there issues with refilling during a burn?

 

[jebatty]

No issues with my Tarm. Some experience smoke roll out if they open the firebox door during a burn. With the damper open and the firebox door open during a burn, temps in the flue can rise very high and rapidly, 1000F and higher.

 

[BoilerMan]

No issues refilling, just that a bigger boiler will charge tanks faster. Think of it as load and walk away till tomorrow.

TS

 

[WoodWacker]

For me, it's more inconvenient to start 2 fires than fill the box twice during a burn. More storage, same boiler.

 

[maple1]

Ideally, you'll be burning to match your heat load, and it won't matter how much storage you have. Main thing is the more storage you have the longer you can go between burns. But the longer you go the more wood you'll have to burn to replace what was drawn from storage. More storage doesn't really mean burning more wood - but you will have to burn more to charge it all up from cold.

 

[flyingcow]

Woodwacker, I might have missed it, but have you figured a heat load for your house?

FWIW- I have a 1800 sq/ft, 2 story house, avg insulation, on a hill in northern Maine. 3 teens. A fair amount of DHW use. I have 820 gals of storage. Nights like tonight, slightly below zero, I start a fire and fill the boiler again, but only half a load. I find it easier to refill than do two fires a day. During the "polar vortex", or what we call january winter, I did do a couple of am and pm fires for a few days.

And i don't have an issue with smoke rollout, fill whenever. Above zero nights and mid 20's during the day, I start a fire and that wll do it. What i'm getting at, do you need 2000 gals of storage? And yes, you can't have too much storage.

One fire box full of wood will fill my storage pretty good. In the summer, i get 4 sometimes 5 days of DHW. Thats on one firebox full of wood. Light it and don't have to go back to the boiler room for 4 days.

I have a boiler rated for 102,000 btu's. I would follow henfruits recommendation on size of boiler for that much storage. I kind of got off topic.

 

[huffdawg]

I have a 1200 gals. of storage and 40kw boiler I definately wouldn't mind having a 60 kw. The 40 works good but the 60 would definitely cut out a few loadings. with 2000 gals I would use a 60kw or you will be loading your boiler a lot.

 

[jebatty]

2000 gallons of storage is not too much for a 60kw boiler. The firebox is large enough to handle a single load of wood and you can walk away and have the storage perform two very important functions.

Storage, aka accumulator, performs two important functions: 1) a buffer to absorb normal burn btu's during so that the boiler does not idle, which improves efficiency and as a side benefit makes it really easy and simple to properly operate the boiler, and 2) storage to accumulate btu's in excess of demand to then supply demand between burn periods.

I believe #1 is nearly an essential function. Being able to load the firebox full and walk away, knowing that the boiler will not idle because the storage has the capacity to take the excess btu's, makes a cord wood boiler operation just about as automatic as it can be, unless you have an automatic wood loader and a modulating boiler. This is the primary function served by 1600 gal of storage for a Froling FHF-L50 boiler at Deep Portage. To make loading to avoid idling as simple as possible, all that is needed is a temp monitor that provides middle of storage temperature, and then with experience or by calculation, knowing that if that temperature is X degrees F or less, you can load the boiler and walk away.

Function #2 adds tremendously to the convenience of a hot water system. As others have said, being able to supply demand without having to be around to keep the boiler fired is a great benefit, and for your size of boiler 2000 gallons of storage will work well to perform this function. I have 1000 gal of storage with a 140,000 btuh rated boiler, normal winter demand around 15,000 btuh, and by burning to load storage to abut 185F I have sufficient btu's available to meet demand for two days, thus allowing burns not more often than every other day during most of winter, and then as outside temps begin to warm burns three and more days apart. Based on your demand you may not be able to burn as little as every other day, but you will have available hours of heat without needing to tend your boiler.

I do find stacked 1000 gal tanks a little daunting, probable full water weight close to 20,000 lbs.

 

[henfruit]

With that much storage, you will want to be able to heat the house and charge the tanks at the same time. If the boiler is to small you will never get the tanks up to temp unless you just keep filling it all day long. If you do not mind filling it twice to get the tanks up to temp. Which will take about 8 hours, you will still need to be there for the second filling. If you size for two fillings once in the am and once in the pm you have accomplished the same thing and not had to baby sit the boiler. As far as restarting the boiler, that is so simple it really should not come into play with the size of the boiler you will need. You will need x number of pounds of wood to heat your home a day, you can do it daily or every day but in the end you have still burned the same amount of wood.

 

[bmblank]

There's nothing saying you can't partially heat the storage and then come back another time and to it off. Maybe you build a fire Monday and aren't there to load it up again. So then you build a fire Tuesday and only need to fill it once. Then Wednesday you live off the tank. Thursday you go back at it.
The tank doesn't need to sit at 180 all the time. If it only gets to 150 you could still live off of that heat for a bit.

 

[maple1]

If the boiler is to small you will never get the tanks up to temp unless you just keep filling it all day long.

You will need x number of pounds of wood to heat your home a day, you can do it daily or every day but in the end you have still burned the same amount of wood.

I'm kind of reading those as two contradictory statements. Once storage is up to temp, say early in the heating season, it shouldn't take any more wood to maintain 2000 gallons that it would 500, all else being equal. If a boiler won't pump out more heat than the house needs, then storage won't accomplish much & shouldn't likely be considered. Myself, I would want a boiler that could pump out twice what my house needs (talking rough averages if there is such a thing) - and I would size my storage to how long I would like to go between burns. With heat capacity of one boiler load of fuel as a minimum.

 

[goosegunner]

I would go with the vertical 500 tanks. much easier to handle. I did not see what type of emitters you are using. If all low radiant in a new house it would change your needs greatly.

As I read through this thread I think about my experience with storage. With my 1000 gallons and my forced air heat exchanger I like to add hot water to the top more frequently than try to stretch the time to the max. Start to finish it takes me 5-10 minutes to have a fire going and walking out the door. These cold days we have been having I do two fires a day. This morning the tank was 165/145. I put in 40 lbs of wood, set the timer for just over an hour. Tonight my tank will most likely be 165 to 170 top. I will have a longer fire to carry through the night time heat demand.

gg

 

[stee6043]

I have a 1200 gals. of storage and 40kw boiler I definately wouldn't mind having a 60 kw. The 40 works good but the 60 would definitely cut out a few loadings. with 2000 gals I would use a 60kw or you will be loading your boiler a lot.

My sentiments exactly. If I were to do it all over again I think I would have gone with the 60 for this exact reason. One less load of wood on most average winter days for me. My 40 works perfectly but on those really, really cold days I do have to stay up an hour past my normal bed time to toss in that last load.

If I were considering 2000 gallons of storage I think I'd be leaning towards an 80kw boiler. In the end this whole storage gig is mostly about convenience. The faster you can charge your storage (and heat your home while charging) the less time you'll spend feeding the boiler.

 

[henfruit]

Maple, you are saying you can raise the 2000 gallons of water from 150 to 185 with the same amount of wood to raise 500 gallons 150 to 185?

 

[maple1]

Maple, you are saying you can raise the 2000 gallons of water from 150 to 185 with the same amount of wood to raise 500 gallons 150 to 185?

No, that's not what I said. What I was trying to say, was once you get storage up to temp, typically in the fall when loads are light, you won't burn any more wood keeping it there. The amount of wood (and the size of the boiler needed) would then depend on your heat load and how much the heat is used, or how fast it gets used up.

Most everything about size of storage & boiler would ultimately come down to how long you want or need to go between burns, and how many re-loads you want to do to re-charge it. Re-loading is easy & only takes a couple minutes. Preferences & personal schedule. But a smaller boiler doesn't mean you burn more wood over a given period keeping your storage warm.

Or maybe that is what I said & I have some magic wood in the basement.

 

[henfruit]

A smaller boiler with a large amount of storage is going to take longer to get up temp.Once you get it up to temp, you then have x amount of usable btus depending on your heat load.

 

[Tennman]

Here's some ideas for your brainstorming. My welder welded nipples that were longer than my planned 4" of foam to the tanks. We welded 2 heavy angles on both sides so the fork lift could handle the tanks vertically with foam inside the 10' ceiling. We set the tanks on the flatbed for the foamer. The forklift carried the foamed tanks into the barn vertical and set in place. Then we cut the handling angles flush with the foam. The day may come when I add another 500 gal for a 1500 total. But gonna start with 1000 gal. I wanted vertical mainly to save floor space but I had a 10' ceiling and a very thick slab in that location. First pic shows the forks supporting the tanks over half way up (kinda dark sorry). Second the final resting place. These things are scary heavy to handle in close spaces. Moving the 500's was plenty a handful. 1000's would be exciting but I wasn't able to move with a sling with the rafters. Lots of ways to skin this cat, this is just how we did it. Hope it helps. Best wishes.

 

[flyingcow]

Woodwacker, you looked at a Garn? Especially if you're looking at having 2000 gals. And there is a dealer in state.

 

[Coal Reaper]

If the boiler is to small you will never get the tanks up to temp unless you just keep filling it all day long.

You will need x number of pounds of wood to heat your home a day, you can do it daily or every day but in the end you have still burned the same amount of wood.

I'm kind of reading those as two contradictory statements. Once storage is up to temp, say early in the heating season, it shouldn't take any more wood to maintain 2000 gallons that it would 500, all else being equal. If a boiler won't pump out more heat than the house needs, then storage won't accomplish much & shouldn't likely be considered. Myself, I would want a boiler that could pump out twice what my house needs (talking rough averages if there is such a thing) - and I would size my storage to how long I would like to go between burns. With heat capacity of one boiler load of fuel as a minimum.

i think henfruit meant "you can do it (have a fire) daily or every OTHER day". whether one load per day or two loads every OTHER day, if the house requires the same BTUs over that period of time, then you still need to feed the boiler just as many pounds of wood to meet that demand from storage. BTUs in = BTUs out ( - standby losses). again, just convienience and what fits your lifestyle. for shoulder season i am learning that i preffer to have more frequent small fires to top things off. in case something comes up and i cant make it home to get a fire going, i know i topped off the day before and can get away with skipping a fire when i need to and the house wont go cold. winter i am firing every day regardless, likely two fires and sometimes a reload in the evening due to polar vortex conditions, haha. now summer i try to go as long as i can because it is a small effort to heat up a cold boiler.
the idea is to try to match storage size to boiler output such that one load of wood brings tanks from min required supply temp back to full charge. take into consideration head demand during your burn time. you can add less wood to a slight undersized boiler for given storage system. a smaller boiler you can only add so much wood to. i wish mine was a bit bigger for the current periods of cold we are expeirencing that NJ is not used to. when heat damand is high it takes a long time to charge the tanks when i a simultaneously heating the house. i read earlier that this january was the coldest in 25+ years for the northeast...

 

[maple1]

I think we're kind of all agreeing on the basics & semantics kind of throws curve balls.

I was reading/interpreting that if you have more storage, then you need a bigger boiler because larger tanks need more heat. Whereas it's not the size of storage that dictates how much heat you need over a given period, but rather heat load/loss. So it comes down to how much you want to reload your boiler over a given period. I know that I would like to have more storage, but have no desire or feel a need to increase my boiler size to match such an increase in storage size. Most times I would likely burn the same way I am now - but if I wanted to streatch my storage to avoid a days burning, I would just reload an extra time when charging. My boiler seems to pump out a lot more heat than my house uses at any given time so it doesn't have much problem charging storage when heating the house. I think even if I were to do it over again with twice the storage I have now, I would likely pick the same boiler. But that's just me with my situations/preferences.

Carry on.

 

[Fred61]

I agree! I was beginning to think that the rule was (( Your boiler must be perfectly matched to storage you must only load up one firebox full to get your storage up to your high setpoint and walk away. If you return to the boiler at the end of the burn you get 10 points taken off your score. If you add more wood at that point you loose 20 points and you must sit out of the game 'til Sunday)). I must confess that I have broken the rules for the reasons Coal and Maple mentioned above.

 

[flyingcow]

I agree! I was beginning to think that the rule was (( Your boiler must be perfectly matched to storage you must only load up one firebox full to get your storage up to your high setpoint and walk away. If you return to the boiler at the end of the burn you get 10 points taken off your score. If you add more wood at that point you loose 20 points and you must sit out of the game 'til Sunday)). I must confess that I have broken the rules for the reasons Coal and Maple mentioned above.

Or you over fill the boiler and it idles for too long.......you're out of here. Isn't that when webbie takes our hearth pass away?