10,000 gals of 180 degree water would keep the house warm for a long time

[SolarAndWood]

(broken link removed to http://syracuse.craigslist.org/zip/1216259312.html)

Its a little overkill for my needs but the price is right if it works for yours.

 

[stee6043]

I can't imagine this being used for residential hydronics! Man...the heat loss from this tank alone would be enough to heat my house! Not to mention the fact that I'd have to burn my EKO 40 for five days straight just to get it up to temp....ha.

If it were mine I'd cut it in half and make two wood sheds out of it....

 

[SolarAndWood]

I considered cutting an end of it and using it on end. Decided that a little patience in my tank search was better than another project of that magnitude.

I like your wood shed idea. I think I would stand it on end and put a silo roof on it. My wood shed is going to be 10 feet below where my first year drying pile is anyway, wouldn't even need to lift the wood and wouldn't ever need to stack it. Wonder what the wife would think.

 

[muleman51]

My neighbor has a Recycling business (junk yard), he has several tanks that he has cut open for wood storage. They work very well for that! He actually can pick them up with his large payloader and put them close to his OWB when he needs them, real handy.

 

[Nofossil]

If I were designing a new house, I'd consider designing in storage on this scale. That would give you many days between burns - weeks, even. You could build a fire on the weekend and not worry about it until the next weekend.

 

[stee6043]

This would be quite a setup - figure your usable temps for storage are 140-180 degrees. That's roughly 3,600,000 usable btu's per fully loaded tank (in a perfect world of course). I believe an EKO 80 has 275,000 btu/hr output. Assuming you were only charging the tank with the EKO (no other heat loads) it would take a 13 hour burn at peak efficiency to bring the tank back up to temp.

That's actually not as bad as I would have guessed. You could burn your boiler all day Saturday and potentially heat off of it for the better part of a week. Assuming a constant demand of 30,000btu/hr you could get five (5) full days of heat from this tank (assuming no heat loss from the tank).

Sadly...for my humble EKO 40 it would take pratically three days of burning twelve hours a day to get this tank back up to temp. Probably more like five days since I'd have to heat the house at the same time. Obviously with a big enough boiler this thing could be useful - but I think I'd still make a woodshed out of it!

 

[SolarAndWood]

If I were designing a new house, I'd consider designing in storage on this scale. That would give you many days between burns - weeks, even. You could build a fire on the weekend and not worry about it until the next weekend.

Kind of what I was thinking. At the end of the heating season, you would have enough DHW through the 4th of July. I could still integrate something this size into my renovation/rebuild. I could probably build a building adjacent to my boiler room for close to the same price as a big commercial tank.

Also adjacent to my boiler room is a 12 x 12 block room with a 8 foot masonry ceiling. What do you think about blocking in the small doorway, insulating the inside of the walls and putting a liner in it? I always thought it was too big but maybe its worth considering.

 

[SolarAndWood]

Obviously with a big enough boiler this thing could be useful - but I think I'd still make a woodshed out of it!

With ya, but the zoning guys have gone easy on my rehab to this point and that might push them over the edge. I'm not sure you need that big of a boiler for it to be useful. I burn 24/7 now and have no intention of changing that with the boiler as I prefer to put the heat directly into the house anyway. So, when peak load isnt required, the heat store gets built up and we can disappear for a few days without running on backup. BTW, your humble EKO 40 is my dream machine.

 

[Hansson]

(broken link removed to http://translate.google.se/translate?prev=hp&hl=sv&js=n&u=http://www.baxi.se/visa_kunder_detalj.asp?id=51&sl=sv&tl=en&history;_state0=)

50 000 liters

 

[SolarAndWood]

http://translate.google.se/translate?prev=hp&hl=sv&js=n&u=http://www.baxi.se/visa_kunder_detalj.asp?id=51&sl=sv&tl=en&history;_state0=

50 000 liters

That is a beautiful display. If I had such a system up and running, I would probably have a smile on my face though.

 

[Hansson]

yeah but he had to burn a long time to get the hole tank warm. The boiler is a 50KW baxi innova

 

[SolarAndWood]

yeah but he had to burn a long time to get the hole tank warm. The boiler is a 50KW baxi innova

I'm OK with that as long as the boiler keeps my house warm before it heats the tank. I usually have a 7-8 month burn anyway.

 

[karl]

If you insulated it, you could lower the heat loss alot. Plus is doesn't have to be full of water. I would build a wood shead around it. So all that heat I had left over would dry the wood for next year.

Here's an idea. Get 10 or 12 of these and insulate them. Then use solar to heat them up all summer and get two to three months of free heat.

 

[jebatty]

Just for fun, occasionally I do a "pressure tank" search on e-bay, and multi-thousand gallon tanks frequently are listed. Typical prices (plus shipping) are around the $1/gal level. If I built a new home or even a new shop building, I definitely would consider a large pressure tank(s). The 1000 gal (3784 liter) I have is very good; the Tarm Solo 40 heats that very easily into the 180F+ range; and a larger tank with a gasifier definitely has its advantages.

 

[SolarAndWood]

Then use solar to heat them up all summer and get two to three months of free heat.

Any idea what kind of collector area it would take to accomplish this during the summer? My new roof has a 1000 sq ft solar south face pitched for year round production which for me is obviously biased towards summer. It is 7/12. It is planned to be covered with PV but they could be mounted on poles. Does 1000 sq ft even get me in the game? If I do solar water, I want a super simple system that just compliments the boiler. I don't see the payback in an evacuated tube system especially when the boilers do an amazing job generating heat and wood seems to be a better way to store the BTUs.

 

[SolarAndWood]

Just for fun, occasionally I do a "pressure tank" search on e-bay, and multi-thousand gallon tanks frequently are listed. Typical prices (plus shipping) are around the $1/gal level. If I built a new home or even a new shop building, I definitely would consider a large pressure tank(s). The 1000 gal (3784 liter) I have is very good; the Tarm Solo 40 heats that very easily into the 180F+ range; and a larger tank with a gasifier definitely has its advantages.

I have been shopping for one in the 1500-3000 gallon range. I have a lot of flexibilty at this stage of construction but that window is probably going to close by Fall.

 

[DaveBP]

If I had it to do over, knowing what I know now, I would frame my house and pour basement support for a big propane tank standing on end. Drop it in with a crane. 2000 gallons would be something like 4' dia. X 22' long.
Make a central chase right up to the attic and have room at the top for a Hansson-style open expansion tank at the top. I saw a diagram for something like this on a German eco-energy site. A couple years ago I would have thought, "Those crazy Germans!". Now I'm jealous.

 

[SolarAndWood]

Like that. I could probably still do that. While I have the trusses up over the section where I would locate the tank, I could slide it in horizontally on the second floor and rotate it down to the basement. The house originally had a flat roof with 14" I-Beams supporting it. So, slide it in, set up the block and tackle and lower it down.

I don't know a whole lot about tank science other than more water holds more btus. What is the benefit of having it vertical as opposed to horizontal?

Is that a common tank? Or is it a horizontal tank I build a base for?

 

[DaveBP]

What is the benefit of having it vertical as opposed to horizontal?

Beside taking up less floor space the only advantage of vertical tanks for pressurized storage that comes to mind is that they are easier to keep well stratified. Since seeing the result of some of Jebatty's tests I'm not sure that is a deal breaker. As long as you introduce the water into the top of the tank without a lot of turbulence (larger pipe is better) it seems to stay separated well enough.

In my case, the basement is my workshop and I wouldn't want to give up the room for a horizontal installation there but giving up a closet upstairs would be acceptable to me. I'm using two 500 gallon propane tanks horizontally but stacking them on top of one another to fit up under the stairs and take the least usable floor area. A number of others on this forum have done something similar.

There are a few standard propane tank sizes for reference here:

http://propanetanks.us/

 

[SolarAndWood]

Does it make a difference for unpressurized?

 

[Gooserider]

Does it make a difference for unpressurized?

Within limits, theory says you can get better stratification out of a tall skinny tank than you can out of a short fat one, regardless of whether it is pressurised or not, thus in theory the vertical tank would be better either way. However one problem that does come up with a non-pressured tank is that the taller it is, the higher the water pressure exerted on the tank walls near the bottom, due to the combination of increased water pressure and the fact that the weight of the water is distributed over a smaller area - this can rapidly develop into a strength problem for materials commonly used by home builders... It is also an issue for pressurised tanks, but they are typically built strong enough that it isn't a problem.

One issue that also needs to be kept in mind if designing a house around a big tank is that sooner or later you WILL need to replace the tank, just like the boiler, etc... It is important to design the structure in such a way as to allow for replacement without needing to do major demolition / reconstruction... I.e. if doing a vertical skinny tank, design a removable roof section so that it can be removed and replaced w/o needing to replace the entire roof. Alternatively make the outside wall non-structural / removeable... (Note that the ability to replace things is also a code reqirement, though not all inspectors will catch that one...)

Gooserider

 

[pybyr]

As much as I am intrigued with wood gasification boilers/ storage (and happy with my Econoburn) if I were designing and building a home from scratch, I'd strongly consider doing something similar to what some friends of mine just did-- open floorplan house, with lots of south facing windows, and a well-designed (but not super-fancy) masonry heater going up through the center of the dwelling, with extremely good insulation and air sealing in the outside walls. The beauty being-- no pipes or pumps (and associated power requirements/ maintenance). Their house is astonishingly warm whenever I've visited, and it takes them astonishingly little wood or effort to get and keep it that way. They have in-floor radiant in the first floor floor, but it apparently rarely needs to run.

 

[jebatty]

I’d strongly consider doing something similar to what some friends of mine just did-- open floorplan house, with lots of south facing windows, and a well-designed (but not super-fancy) masonry heater going up through the center of the dwelling, with extremely good insulation and air sealing in the outside walls.

Could not agree more, exception being I would not fully endorse the masonry heater, mostly because it does not generate the high temps of gasification boilers and therefore is less efficient from a combustion perspective, and because of the extreme efficiency related to low temp radiant systems.

Although the shop is heated with the Tarm, our house meets most of the criteria listed, and is heated (1500 sq ft main floor) only with a small wood stove we installed in 1990. SW facing windows, open floor plan, as well insulated and sealed as our house can be, given its vintage. New construction, and even remodels to extent possible, needs to focus first on energy conservation through these techniques. Then, the heating system to supply only what Mother Nature does not offer for free.

 

[kuribo]

Could not agree more, exception being I would not fully endorse the masonry heater, mostly because it does not generate the high temps of gasification boilers and therefore is less efficient from a combustion perspective, and because of the extreme efficiency related to low temp radiant systems.

Why do you think that? A properly designed and built masonry heater combusts wood using gasification as well and generates the same high temps....Additionally, masonry heaters have efficiency levels at least as high as gasification boilers, some even higher. In a systems context, they have even better efficiencies as there are no pump losses, frictional losses, idling inefficiencies, storage losses, etc....

 

[jebatty]

A properly designed and built masonry heater combusts wood using gasification as well and generates the same high temps....Additionally, masonry heaters have efficiency levels at least as high as gasification boilers, some even higher.

I can be convinced. Point me to the info or data that shows this and you will have me converted.