Help choosing between efficient wood boiler and wood gasification

[Nofossil]

Have you considered a Greenwood boiler?

One of the main reasons that I got one is because it has long burn times and does not require water storage.

Somehow, the increased benefits of storage combined with gasification has gotten convoluted into a misperception about the need for storage. Let me try to be clear about my experience and understanding:

Gasification boilers do not require storage.

All boilers benefit from storage.

Gasifiers can benefit more, which makes storage a better investment if you have a gasifier.

Gasifiers without storage are still vastly more efficient than conventional boilers. My often quoted hard data about a 40% reduction in wood consumption going from a conventional wood boiler to a gasifier was for an installation without storage.

All that having been said, if you have a gasifier and idle it a lot, you stand to gain quite a bit of efficiency by adding storage. The idling gasifier will burn less than a conventional boiler, but you will reduce your consumption even more with storage.

If you don't operate a gasifier so that it idles a lot, you won't realize much savings from storage. Instead, you'll find that you gain comfort and convenience. You'll have to build fewer fires and your house temperature will remain more constant.

 

[Ecky]

Something that seems to be missing in this discussion is what I consider a significant advantage to having large storage - the ability to use that with a solar system in the shoulder seasons and the summer. A huge thermal mass of water is great for storing heat from a solar panel or two for one's domestic hot water. Add the fact, as mentioned by some, that by storing the heat in a large volume of water, one can run their wood burning appliance at maximum burn and maximum efficiency with minimal smoke. Something like a GARN makes sense as the unit, while not pretty, does provide an all-in-one package. It is not a cheap solution, but the high upfront costs will pay off in less wood consumption and all the benefits that go along with that. My two cents. Cheers.

 

[antknee2]

Something that seems to be missing in this discussion is what I consider a significant advantage to having large storage - the ability to use that with a solar system in the shoulder seasons and the summer. A huge thermal mass of water is great for storing heat from a solar panel or two for one's domestic hot water. Add the fact, as mentioned by some, that by storing the heat in a large volume of water, one can run their wood burning appliance at maximum burn and maximum efficiency with minimal smoke. Something like a GARN makes sense as the unit, while not pretty, does provide an all-in-one package. It is not a cheap solution, but the high upfront costs will pay off in less wood consumption and all the benefits that go along with that. My two cents. Cheers.

What I learned over this past summer is that , my solar system had to be limited to one of my 119 gallon Super Store tanks to be most effective for domestic hot water production . When on vacation I let the energy flow through a second tank. Just something to keep in mind when planning your system.
Anthony

 

[BrownianHeatingTech]

What I learned over this past summer is that , my solar system had to be limited to one of my 119 gallon Super Store tanks to be most effective for domestic hot water production . When on vacation I let the energy flow through a second tank. Just something to keep in mind when planning your system.

Personally, when I do solar installs with a large thermal storage tank, I use a priority design: it charges the domestic tank, first, then any excess energy gets dumped into the larger thermal storage tank. Works out nice. Put up a big enough panel, and you can actually get some space heating from the solar, especially if you have radiant heat.

Joe

 

[Willman]

What I learned over this past summer is that , my solar system had to be limited to one of my 119 gallon Super Store tanks to be most effective for domestic hot water production

Anthony.
I gather from your post that the SHW production of your array is only enough for one tank. Is there a rule of thumb for storage versus collector area ? Would it be different for flat plate versus Evac tube? Thanks
Will

 

[antknee2]

What I learned over this past summer is that , my solar system had to be limited to one of my 119 gallon Super Store tanks to be most effective for domestic hot water production

Anthony.
I gather from your post that the SHW production of your array is only enough for one tank. Is there a rule of thumb for storage versus collector area ? Would it be different for flat plate versus Evac tube? Thanks
Will

My feeling on solar home and domestic hot water production , depends on how you set your solar panels mainly tilt angle . My system actually produces more energy in the dead of the winter months because I set the panels on a 83 degrees tilt , almost vertical , snow and ice seem to slide off . My summer output is highly reduced by the massive trees and slope of the mountain . We have total shade by 3:00 pm .
Anthony

 

[Ecky]

Personally, when I do solar installs with a large thermal storage tank, I use a priority design: it charges the domestic tank, first, then any excess energy gets dumped into the larger thermal storage tank. Works out nice. Put up a big enough panel, and you can actually get some space heating from the solar, especially if you have radiant heat.

Joe

That seems like an excellent idea. Thanks for sharing. I am going to implement it!