Starting the journey...

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Bluelagoon888

Member
May 20, 2006
19
Galiano, BC
Hi

I am newly researching wood gassification boilers, searching for an alternative to propane heat. I have really benefited from reading this forum - thanks so much!

Here is some background on my system at this stage:

- I have an 80 gal insulated DHW tank.
- The DHW tank has two internal heat exchangers, both with glycol in them. One goes to an evacuated tube solar hot water panel. The other goes up to my radiant floor manifold.
- The DHW is heated presently by a sidearm propane fired heater (Takagi TK-3 Pro). When the water in the tank falls below a set level, a pump sends water from the hot water tank to the Takagi and then the heated water goes right back into the hot water tank.
- The radiant floor is divided into two zones, each running a Grundfos Alpha pump set at the very lowest power setting of 5W. I get < 1 gpm on each zone.
- Radiant floor tubing is set in 1.5 inches of concrete that is on top of my subfloor. I have bamboo or carpet on top of the concrete.
- I believe the heat exchangers in the DHW tank are undersized. As a result, I can't get the house hotter than 18 degrees celcius in winter. Too cold for me.
- I have hard well water, so the heat exchangers in my DHW tank do get coated with scale. Every summer we put vinegar in the hot water tank and then empty the tank to try to eliminate the scale buildup. But it still definitely has an effect on heat transfer.

And a bit of background on my home:
- 3500 square feet, two levels, mostly cathedral ceilings and lots of glass.
- Built in 2009 roughly. 2x6 construction with fiberglass batts. No attic.
- I have calculated about 45,000 BTU/hr.
- We are contemplating an addition in the future that would add roughly 1/3 more floor space, and would boost BTU/hr to 65,000. But the addition is mainly my pipe dream and not a huge priority right now.
- I live on a nearly-deserted island in the Gulf Islands in between Vancouver, BC and Victoria, BC. To get propane I have to hire a guy with a modified truck to deliver it. He has to get on a barge to get to me. I have only one supplier so I'm at the mercy of his prices and the barge adds $600 per delivery. If I was home full time, I believe I would spend around $6000-7000 / year on heating with propane. My last propane bill was almost $2 / litre after barging costs are factored in.
- Being remote also means I can't just pay for wood. I have to chop it myself or hire someone to do it.
- I am off grid, so electricity consumption is crazy important to me. A pump running at 50W for several hours is a big deal.
- Due to work commitments, I am not at home consistently. I might be home for a 3-7 days, then away for about the same period, then back for a week, then away for 5 days, etc. Up to now, to save on propane, when I leave home I have been turning off the heat.

So....now for some questions!

1. I am considering the EKO line of stoves, but I'm concerned about power consumption for the fan. The Vedolux 37, for example, only runs the fan at the beginning of the burn and shuts it off after the flue gasses get to a certain temp (per their manual). But the Vedolux is way more expensive than the EKO, so I'm hesitating. Does the EKO stoves run the fan all the time?

2. Is it possible to replace the pump on the EKO stove with a Grundfos Alpha pump?

3. The Vedolux recommends a stand to put the stove on. Does the EKO need a stand?

4. In a system with no storage, is it acceptable to run water from the DHW tank straight into the boiler from a health/safety perspective? I have read some systems do this, but have also read that boiler water is not potable water. While most people don't drink their DHW, you do consume a little bit when showering etc.

6. So far I have looked at the EKO, the Vedolux, the Froeling, the Garn, and the EconoBurn. I discarded the Froeling due to price and the Garn also due to price. I discarded the EconoBurn due to power consumption. The EKOs seem to be pretty popular around here. I like the Vedolux due to power consumption and ease of cleaning but am less impressed with price. Any other stoves I should be looking at?

7. By reading this forum, I definitely understand that a system with heat storage is preferable. Is it possible to set up a system that will send heat first to the hot water tank, and only when the hot water tank is up to temperature does the system direct heat to the storage tank? Is there a smart valve I can buy or something that will do that for me? (I'm not up on plumbing or hvac gear.)

8. Given that I am not home for stretches of time, I wonder if I would be better served by a system with no storage. I could buy a smaller stove (e.g. the EKO 25) and plumb it directly to the hot water tank. I would save money from not having to buy storage...and if I'm only going to be home for 3 days, maybe it doesn't make much sense to heat up a whole storage tank. Does this logic make sense at all? Or is having storage just so important that it is worth getting no matter what? Anyone do a lot of travelling -- what are your experiences?

Thanks for any responses.

Really appreciate it!
 
What a unique situation you have? You may be on the right track with small gasser, no storage for your situation. Is freezing pipes, frost heave of the concret floor not a concern to be able to leave it unheated while you are gone?
 
Random things:

Boiler water & DHW shouldn't mix.

The Varms need storage.

As far as I knew, the Varm fan runs all the time while it is burning.

How tall could your chimney be? Varm does make a natural draft boiler with no fans at all - that's what I have. My chimney is 30' tall (7" insulated stainless), I could get by with one a bit shorter. I suspect 25' would be fine. I would think that would be a big consideration for off-grid use.

I would say the main reason for the Eko popularity is their price/value.
 
If it is going inside the home consider induced draft only, froeling, Varm, tarm solo innova.

If you would be saving 6000-7000 a year the price difference would be payed back quickly.

It has been posted on the site before that the Froeling controller needs consistent clean power. I would research that carefully.

Seems like the Varm natural draft would be a good choice for your situation.

gg
 
What a unique situation you have? You may be on the right track with small gasser, no storage for your situation. Is freezing pipes, frost heave of the concret floor not a concern to be able to leave it unheated while you are gone?

Hi rkusek,

Yeah...it's an adventure for sure. :)

Where I live the temps get down to -5C for about a month. I have glycol in the pipes in the floor so that they don't freeze.

I did have my water pipes freeze this winter - first time in many years that has happened - so whatever I do will need to take that into account.
 
Do you run a generator occasionally? Run the geny for a 3 to 5 hour spell which a properly sized boiler with storage store the heat. Then heat house off of storage?

Hi flyingcow,

That's definitely a possibility, although I don't run the gen every day. I suppose with storage I wouldn't run the boiler every day either. It's a reasonable thought for sure.
 
Random things:

Boiler water & DHW shouldn't mix.

The Varms need storage.

As far as I knew, the Varm fan runs all the time while it is burning.

How tall could your chimney be? Varm does make a natural draft boiler with no fans at all - that's what I have. My chimney is 30' tall (7" insulated stainless), I could get by with one a bit shorter. I suspect 25' would be fine. I would think that would be a big consideration for off-grid use.

I would say the main reason for the Eko popularity is their price/value.

Hi Maple1,

The chimney can be as high as it needs to be. I'll be putting the boiler in an outdoor shed where the wood will also be stored.

So if DHW and boiler water shouldn't mix, does that mean I need some kind of water/water heat exchanger?

The power draw is definitely a big consideration. I'll look into the Varm natural draft ones a bit more. The issue, of course, is the price. :)
 
If it is going inside the home consider induced draft only, froeling, Varm, tarm solo innova.

If you would be saving 6000-7000 a year the price difference would be payed back quickly.

It has been posted on the site before that the Froeling controller needs consistent clean power. I would research that carefully.

Seems like the Varm natural draft would be a good choice for your situation.

gg

Thanks goose gunner. I'll put in more research on the Varm.

I'm not spending $6000 / year now because I don't live in the house full time over the winter. My spend this past year was about $3000 or maybe $4000 for hot water, and another $2000 for propane to run the generator. Still, even at $3000 / year, I can pay back a system pretty quickly.

I'm not a fan of systems that require electronics to function. I prefer very simple systems. My SHW is a great example of a system that is complicated, and has had multiple expensive failures. When you live as far out in the bush as I do, there's no such thing as getting a repairman to come out and look....or they'll come out, but hit you with a $1000 travel charge just to come out and realize they forgot the part they need or something like that.

I think the stove would go in an outdoor wood shed that I will build to hold the stove and cut wood.

Thanks again.
 
If it is going inside the home consider induced draft only, froeling, Varm, tarm solo innova.

If you would be saving 6000-7000 a year the price difference would be payed back quickly.

It has been posted on the site before that the Froeling controller needs consistent clean power. I would research that carefully

Seems like the Varm natural draft would be a good choice for your situation.

gg

no power issues with the froling , had serious power fluctuations, bad enough to shut my wilo pumps down, but the froling controller never even flinched.
btw it is 220v
scott
 
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