Garn WHS3200 & Wood Gun E500 – Another Night Out [Part 7]

[jebatty]

See Part 6 for links to Parts 1-6.

I'm lamenting the lack of any real winter this season, cold that is. With the Deep Portage improvements, including the added 4000 gal of pressurized storage, correction of the problem with the return water protection valve for the Wood Gun, and more accurate gpm flow calculations through use of measuring differential pressure on the circulators, the only other thing that's needed is a few really cold days and nights to again put these two fine boilers through some high output paces. That cold weather still is not in the forecast, and may not happen this season.

Observational and anecdotal perspectives:

1) The 4000 gal new storage (plus the 3200 gal of the Garn) has enhanced the combined boiler system performance considerably. The ability to have 7200 gal of 160F+ water has really smoothed out supply temperature and simplified operation of the heating system. With nearly 2 million stored btu's, good for 4 or more hours of heat from storage only, both day but especially night operations have become effortless.

2) It is now all but impossible to overload either boiler to cause the Garn temp to get too high or cause the Wood Gun to idle. Based on general winter cold conditions, the chief operator sets a target temperature for mid-tank of the 4000 gal storage tank, and staff just loads either one, the other, or both boilers to achieve that target during the day and especially for stating the night. Load 100 or so lbs of wood, which is pretty much a full load for either boiler, and walk away.

3) Staff preference and hot water temperature requirements have shifted to more use of the Wood Gun over the Garn, primarily because the Wood Gun puts out 170-185F water consistently when fired without needing to preheat any of the 7200 gal of storage. The 4000 gal storage tank is supplied directly by the Wood Gun and is plumbed as a hydraulic separator, and if storage is down to 130F, for example, firing the Wood Gun delivers that extra hot water to the top of the tank, which flows through to top of tank supply to system, and the heating system has all the hot water it needs. Extra boiler output then can gradually heat the entire tank without shorting or delay in supplying the heating system demand. Also, I don't think the Wood Gun ever has gone into idle this season, which was an unpleasant occurrence (to be avoided) last year.

4) Garn use has been heaviest in two situations. First, in fall and early winter (and probably also this coming spring) when higher temperature water has not been needed. Second, to quickly boost the temperature of the entire 7200 gal of storage. At temperatures seen so far this season, the Wood Gun output normally is sufficient to meet system demand, but at higher demand periods it cannot also build-up reserve storage temperature very quickly. This is where the extra output offered by the Garn is very helpful, as both boilers together have an output to system in the range of 1 million btuH, or around 500,000 btuH for each.

5) Perhaps best of all from an economic perspective, use of LP for space heating from the now backup LP boiler system is 0, and use of LP for DHW has been greatly reduced. No more big payments to the "oil man." Plus, use of local wood has supplied jobs for local loggers and firewood cutters, supported local families, and aided the local economy -- all through use of a local, sustainable, fuel wood source of energy. This is a win - win operation for jobs and the environment.

 

[Singed Eyebrows]

See Part 6 for links to Parts 1-6.

I'm lamenting the lack of any real winter this season, cold that is. With the Deep Portage improvements, including the added 4000 gal of pressurized storage, correction of the problem with the return water protection valve for the Wood Gun, and more accurate gpm flow calculations through use of measuring differential pressure on the circulators, the only other thing that's needed is a few really cold days and nights to again put these two fine boilers through some high output paces. That cold weather still is not in the forecast, and may not happen this season.

Observational and anecdotal perspectives:

1) The 4000 gal new storage (plus the 3200 gal of the Garn) has enhanced the combined boiler system performance considerably. The ability to have 7200 gal of 160F+ water has really smoothed out supply temperature and simplified operation of the heating system. With nearly 2 million stored btu's, good for 4 or more hours of heat from storage only, both day but especially night operations have become effortless.

2) It is now all but impossible to overload either boiler to cause the Garn temp to get too high or cause the Wood Gun to idle. Based on general winter cold conditions, the chief operator sets a target temperature for mid-tank of the 4000 gal storage tank, and staff just loads either one, the other, or both boilers to achieve that target during the day and especially for stating the night. Load 100 or so lbs of wood, which is pretty much a full load for either boiler, and walk away.

3) Staff preference and hot water temperature requirements have shifted to more use of the Wood Gun over the Garn, primarily because the Wood Gun puts out 170-185F water consistently when fired without needing to preheat any of the 7200 gal of storage. The 4000 gal storage tank is supplied directly by the Wood Gun and is plumbed as a hydraulic separator, and if storage is down to 130F, for example, firing the Wood Gun delivers that extra hot water to the top of the tank, which flows through to top of tank supply to system, and the heating system has all the hot water it needs. Extra boiler output then can gradually heat the entire tank without shorting or delay in supplying the heating system demand. Also, I don't think the Wood Gun ever has gone into idle this season, which was an unpleasant occurrence (to be avoided) last year.

4) Garn use has been heaviest in two situations. First, in fall and early winter (and probably also this coming spring) when higher temperature water has not been needed. Second, to quickly boost the temperature of the entire 7200 gal of storage. At temperatures seen so far this season, the Wood Gun output normally is sufficient to meet system demand, but at higher demand periods it cannot also build-up reserve storage temperature very quickly. This is where the extra output offered by the Garn is very helpful, as both boilers together have an output to system in the range of 1 million btuH, or around 500,000 btuH for each.

5) Perhaps best of all from an economic perspective, use of LP for space heating from the now backup LP boiler system is 0, and use of LP for DHW has been greatly reduced. No more big payments to the "oil man." Plus, use of local wood has supplied jobs for local loggers and firewood cutters, supported local families, and aided the local economy -- all through use of a local, sustainable, fuel wood source of energy. This is a win - win operation for jobs and the environment.

Jim, I thought the Garn 3200 could fire at 1 million btu by itself? Randy

 

[jebatty]

The Garn specs show 700,000 btuH maximum output under specific conditions. The test burns last winter indicated on a continuous, not maximum, burn basis sustained output was in the region of 500,000 btuH.

[added] For my Tarm and based on 5 years of operation I use rule of thumb average output over a burn of 75% of maximum rated output, which for the Tarm is 140,000 x 75% = 105,000 btuH. This seems to also be about right for the Garn: 700,000 x 75% = 525,000 btuH.

 

[Singed Eyebrows]

The Garn specs show 700,000 btuH maximum output under specific conditions. The test burns last winter indicated on a continuous, not maximum, burn basis sustained output was in the region of 500,000 btuH.

[added] For my Tarm and based on 5 years of operation I use rule of thumb average output over a burn of 75% of maximum rated output, which for the Tarm is 140,000 x 75% = 105,000 btuH. This seems to also be about right for the Garn: 700,000 x 75% = 525,000 btuH.

The old rating for the 3200 was 350,00 to 950,000 btu. Garn has revised ratings on its revamped website, whats up Heaterman? Randy

 

[Como]

I narrowed my choice down to the Wood Gun and the Garn, having one of each was not an option I considered.

I remember reading the Wood Gun literature and it saying that storage was not required. I As everything I had read suggested otherwise I costed it with storage, but not this much.

 

[jebatty]

I believe the WG design is to totally close off air supply when it goes into idle, which I suppose should eliminate the smouldering/creosote issue, while maintaining sufficient heat to restart the fire as water temperature drops and the WG comes out of idle. Call it what you will, but with the E500 there is quite a moment of excitement when it comes out of idle -- major puffing or more like an explosion. DP found that adding storage so that idling would not occur is a better outcome.

 

[Como]

It is sort of the way OWB's work, which is why I dismissed it.

I am sure this is a much better solution.

 

[muncybob]

Jim, I solved the "explosion" you described by reducing the fesh air intake. The damper is at about 85% closed and no situations since and seems to burn fine. Still, I plan to have storage one day primarily to help in the shoulder seasons. I'm sure the efficiency would be slightly better with storage too since the fire is not instantly defeated when it comes out of a burn so there is a very short period of smoldering.

 

[bpirger]

Jim, sounds like an extremely fine setup there....and one to be proud of. I really like the idea of independence and supporting the local communities. How much wood is burned in a season, say this year and we can extrapolate to normalcy.

I'd think the community would be very happy with the setup, especially the much easier overnight tending. I'd think this system would make a great article in a trade magazine...not sure if Fine Homebuilding would be right, but something along that line.

Efficient, convienient, supporting local folks, and renewable. What more could be asked from the system?

 

[jebatty]

Thank you. The volunteer pay is great, too -- got them to double it this year. Last winter, which may more typical, wood use was in the range of 85-90 cords for 56,000 sq ft. This year would have been less, even with the same winter as last, because of other energy improvements: new exterior doors and most windows.

 

[Como]

That is not much at all.

Sort of gets difficult putting a financial argument for energy improvements when you are saving a few cords.

 

[heaterman]

The Garn specs show 700,000 btuH maximum output under specific conditions. The test burns last winter indicated on a continuous, not maximum, burn basis sustained output was in the region of 500,000 btuH.

[added] For my Tarm and based on 5 years of operation I use rule of thumb average output over a burn of 75% of maximum rated output, which for the Tarm is 140,000 x 75% = 105,000 btuH. This seems to also be about right for the Garn: 700,000 x 75% = 525,000 btuH.

The old rating for the 3200 was 350,00 to 950,000 btu. Garn has revised ratings on its revamped website, whats up Heaterman? Randy

Not a clue. I have never messed with a 3200 or even been around one. There are a couple articles about them on the www but I don't recall if they talk about output.

 

[Gasifier]

It is sort of the way OWB's work, which is why I dismissed it.
I am sure this is a much better solution.

A large Wood Gun with plenty of storage would be nothing like an OWB? A Wood Gun is a gassifier, an OWB is certainly not. Maybe I am not understanding what you meant there. Sorry if I am.

 

[heaterman]

It is sort of the way OWB's work, which is why I dismissed it.
I am sure this is a much better solution.

A large Wood Gun with plenty of storage would be nothing like an OWB? A Wood Gun is a gassifier, an OWB is certainly not. Maybe I am not understanding what you meant there. Sorry if I am.

He's referring to idling, which in any boiler is detrimental to efficiency and emissions.

I recently saw a test document in which several brands of boilers were used including a very high tech Euro model with computer controlled combustion. Emissions were very bad when the unit was operated at low loads of 25% or less. Storage and complete consumption of the fuel load is the only way that one can stay "clean" through the entire fuel load. Idling or shutting down the fire is less than ideal in any type of boiler. This will be proven to be fact if the agencies involved ever get their junk in a hunk.

 

[maple1]

It is sort of the way OWB's work, which is why I dismissed it.
I am sure this is a much better solution.

A large Wood Gun with plenty of storage would be nothing like an OWB? A Wood Gun is a gassifier, an OWB is certainly not. Maybe I am not understanding what you meant there. Sorry if I am.

I think he simply means a Wood Gun is designed or intended to idle, as is an OWB?

I think I would have to admit that, in my mind at least, I would equate a Wood Gun to a gassing OWB in design & operation.

EDIT: typed too slow again & got beat to it...

 

[Gasifier]

He’s referring to idling, which in any boiler is detrimental to efficiency and emissions.

I don't think that is a good comparision. But I understand what you mean Heaterman. I hear ya. I guess I do not understand why he said that and then said that is why I dismissed it. When storage would solve that problem easily.

Maple1. He did not say a Gassing OWB. But, I hear ya. Again. Maybe I am not understanding what he meant.

 

[Como]

I know at least one GOWB that is run flat out. Well most of the time anyway.

I need to look if Wood Gun still promote this method of operation. Just to make it clear when I was doing my comparison is did it on the basis that the Wood Gun would need storage.

My gut feel is that with storage the Wood Gun would produce better figures than a Garn in most cases, without worse. Probably not a lot in it.

I remember speaking to a guy in Telluride who had one and was very happy with its performance.

 

[jebatty]

My hope was that we would hit a spell of -10 to -30F days/nights this year, a week long or so, and I could really push the Garn WHS3200 and Wood Gun E500 in a system that will demand everything these two boilers have to offer. Obviously, that would be an extreme operating scenario, but with data collection and as much objective analysis as I could offer, the results might be interesting, at the least.

 

[Gasifier]

I know at least one GOWB that is run flat out. Well most of the time anyway.

I need to look if Wood Gun still promote this method of operation. Just to make it clear when I was doing my comparison is did it on the basis that the Wood Gun would need storage.

My gut feel is that with storage the Wood Gun would produce better figures than a Garn in most cases, without worse. Probably not a lot in it.

I remember speaking to a guy in Telluride who had one and was very happy with its performance.

I remember seeing, and complimenting your set up with your pictures. Looks like a nice set up Como. I get more curious as I think about it though. And when I read your statement of comparing it to an OWB, it made me think about it even more. I can understand that statement, I guess, if you were thinking of no storage. That it would idle like an outdoor wood boiler. But certainly would not burn like one when back in operating mode.

From a business standpoint anyway. What made you decide on two boilers? It would seem that two Garns and the "stuff" to go with them, would be much more money than the price of one large Wood Gun and adequate storage. And the cost of maintaining them both. I suppose I could see one supplying the heat while the other is warming back up or is down for cleaning/maintenance. Don't get me wrong Como. I am not critisizing your system. I am new to this stuff. I just ask questions out of curiosity. And knowing that when I get the answer I will have learned something. That is always a good thing in my book. If you don't mind, please fill me in on your decision making process. I am interested on how your system will function.

 

[Como]

It was a close call.

I would need to look up the numbers but cost wise there was not much in it. When you add storage. If memory serves me right in this scenario they have staff feeding 24/7 if needed. I like to sleep.

I had also gone through a very nasty winter and had a few issues with equipment failure.

So for me the biggest issue is overnight, you heat during the day then put the last load in and have you enough btu's to get through.

Because of our location we have massive temperature swings at any time, it has been relatively warm, nearly hit 30F today, we could have been -30F, we were last year. We easily can drop 20F as the sun goes down.

Also I will be burning year round so I thought ganging would be better.

A Wood Gun with Storage would I am sure have worked as well, a lot of storage.

But I will never know for certain.

 

[WoodChoppa]

I'd love to see an Econoburn EBW-500 included in this ring, that would be quite the fight!

 

[Gasifier]

I'd love to see an Econoburn EBW-500 included in this ring, that would be quite the fight!

:lol: I would like to see that big of an Econoburn, with storage, at work as well WoodChoppa! Not looking for a fight. Just curious of Como's decision making process.

 

[TCaldwell]

Jim, Is there a night with the froling planned? Would be curious as to the actual performance data vs. brocure info.
tom

 

[Gasifier]

Jim,

I am checking out the Deep Portage website right now. Cool. When I clicked on it there was not much info on the Gassification systems yet? What are you doing there anyway? :lol: Get back to work! :lol: No, seriously. I am going to do some reading on the site. Interesting. Are you going to be making up public information/description for the Gassification system? Hey, looks like you got closer to some of those temperatures you wanted! NOAA says it is -8F there. That was quick. How are those beautiful wood burning boilers humming along now?!!

 

[jebatty]

Oooh - yes - I would like a date night with the Froling. It was installed late, already into the heating season, and there are a few minor things I would like to adjust in the plumbing to bring the Froling up to 100% of the capability I believe it can deliver, and I can't do that during the heating season. I also need to install more sensors to monitor and data log all key locations. Will have to wait until next heating season for a serious and detailed report.

Staff is very satisfied with the Froling in that for a 6000 sq ft structure, forced air heating, not built well regarding insulation, windows and doors, the Froling so far this winter has provided 100% of space heating and DHW. In doing that it has replaced 2 - LP forced air furnaces (remain as backup), have to check on their btuH rating, and an electric DHW heater. Savings have been substantial. The coldest night this winter was -25F, and as installed the Froling met all demand, although at this temp it had no excess output to add to storage. The Froling has met the goal, but I think it can do better.

My current major focus at DP is analyzing the DHW system for the main facility with the goal of the WG/Garn eliminating need for supplemental hot water through an LP hot water heater during high demand periods. A large commercial BoilerMate is being used now to provide DHW during the heating season, along with a 1000 gal DHW storage tank. I don't think much thought was given by the installer to performance capability to meet need, but I think again some plumbing adjustments may result in improving the performance, and/or other recommendations will be made. Analysis is ongoing.

Also on the agenda is debugging the evacuated tube DHW solar system installed late last summer. This may be performing too well during the summer and design changes likely are in order, along with design changes to allow it to perform during freezing weather.

-9F outside right now, will be a bright sunny cold day.