Flow rates thru Seton or similar stoves ...

[patch53]

Hello gents, this is my first post here. This is a great site with lots of people who have a lot of valuable knowledge about woodburners.

Me and a friend of mine who runs a small fabrication shop built me a Seton 130, just got it going about 2 weeks ago. What kind of flow rate are you guys running thru yours? I know every situation is different, but it seems to me that the only way to get these units to function properly is to have a pretty snappy flow rate thru them. I am running a Taco 0011, don't have any idea what my GPM's are, but it would shut down in less than 5 minutes with an 008 on it. Seems to be working much better now, getting hot water into my inside (propane) boiler a lot quicker and will keep that water temp steady and even climbing a bit even with all 3 zones running in the house.

Thx, Pat

 

[stee6043]

How long of a run and what size is your piping from the wood boiler to the inside boiler connection? A Taco 0011 is a big pump so I suspect you have quite a long run? Or perhaps you used 3/4" tubing?

Without getting all scientific on head, pressure drop and the like I think the best way to know if you're pumping properly is to look at your supply and return temps. I believe most outdoor units run 180-190 or so on the supply side and should see somewhere in the 160 degree range return. No matter what you shouldn't be seeing less than 140 on your return.

Hope this helps a little...

 

[ISeeDeadBTUs]

I have thought for some time that flow should be variable based on demand and vary the rate so that the GW would maintain open damper without overtemping.

None of that answers yer question, sorry.

BTW, welcome aboard!

Jimbo

 

[patch53]

How long of a run and what size is your piping from the wood boiler to the inside boiler connection? A Taco 0011 is a big pump so I suspect you have quite a long run? Or perhaps you used 3/4" tubing?

Without getting all scientific on head, pressure drop and the like I think the best way to know if you're pumping properly is to look at your supply and return temps. I believe most outdoor units run 180-190 or so on the supply side and should see somewhere in the 160 degree range return. No matter what you shouldn't be seeing less than 140 on your return.

Hope this helps a little...

Hi, I have a run of about 50 feet from my basement to my Seton. The vertical head is about 12 feet, and I have about 6 elbows and about 3 45's in the return to the Seton and about the same on the supply from the Seton. I have 1" Kitec and Copper, but my inside boiler has 3/4" connectors.

I currently have my Seton set at 180 w/ a 15 degree differential between start up and shut down. When I got home from work today the Seton was at almost 200 with barely any wood left in it from this morning. It was about 25F here this afternoon. The dump zone had been going for a long time and just barely keeping from popping the safety valve. I probably put too much wood in it this morning.

 

[patch53]

[quote author="ISeeDeadBTUs" date="1260676683"]I have thought for some time that flow should be variable based on demand and vary the rate so that the GW would maintain open damper without overtemping.

None of that answers yer question, sorry.

BTW, welcome aboard!

Jimbo[/quote

Hi Jim, thanks. I have a feeling that this stove is going to take some time to tweak and understand just how it works the best and what to do and what NOT to do. LOL

After reading some of the bountiful info on this site, I should seriously think about adding a storage tank next year, especially with a gasification stove?

 

[2.beans]

i run a 011 and my seton is 250 feet from my house. i have 1000 gallons of storage and also can run without it and it works fine. ive tried different pumps and the 11 seems best. i like the idea of pumping to the heat heat demand, id like to try that.

 

[mole]

quote]

Hi, I have a run of about 50 feet from my basement to my Seton. The vertical head is about 12 feet, and I have about 6 elbows and about 3 45's in the return to the Seton and about the same on the supply from the Seton. I have 1" Kitec and Copper, but my inside boiler has 3/4" connectors.

I currently have my Seton set at 180 w/ a 15 degree differential between start up and shut down. When I got home from work today the Seton was at almost 200 with barely any wood left in it from this morning. It was about 25F here this afternoon. The dump zone had been going for a long time and just barely keeping from popping the safety valve. I probably put too much wood in it this morning.[/quote]


Pat,
When the water temp reaches 180 and the draft door closes, the temp should drop back to 165 in maybe 3-5 min, depending on boiler temp and load. The fact that the temperature is rising to 200deg during idle suggests that there is some air leakage somewhere. If you open the door after it's been in idle mode for a few minutes and take a quick (nasty!) peek in, there shouldn't be any flames. I had a problem with mine when I first installed it. The temp would rise gradually when it was idling instead of dropping...it turned out that the ash pan had warped and the boiler was sucking a lot of air in around the ash pan seal. The clue was the small flames above the dropout where the ashes go. But you could be leaking in any of a number of places as I'm sure you know. There's been some good threads in the past on how to seal up a Seton. You could probably search it.

JR








2) consume the heat.

 

[patch53]

Hi mole, yeah I've checked that, and the fire is basically doing nothing. No flames and just a faint glow on the logs. After a while, the logs don't even produce much smoke when you open the door. I don't have an ash drawer on my unit so that is not a factor. My air damper seems to close nice and tight. I'm very confident that all my joints are well sealed with no air leakage. besdies, if there was a major air leak the fire would never really stop burning.

What I have noticed is that when you reload the boiler it doesn't give off as much residual heat, but after your fire is about 1/2 way or more burned, and there is a lot of hot coals, it will slowly rise if there is no load, which is probably normal. I would imagine the refractory is giving off a lot of heat as well. I am burning very good wood, red oak that seems to be nice and dry and really gives a lot of heat when its cranking.

And yes, when the unit shuts down at 180F it will start to cool down when there is a load, but it takes a bit longer than 5 minutes to drop 15 degrees, once again depending on the load.

My Seton 130 is definitely oversized for my house, but the one thing I did NOT want was an undersized unit, been there , done that, not fun when its -20F.

I'm also probably going to be adding some storage next summer, so it should work out well in the end. As lkong as I have a working dump zone I don't mind a little residual heat.

thx, Pat

 

[sgschwend]

Patch, you can lower your high limit to 160F and that will help too. If you have so much capacity why not run lower, you want to protect against condensation but 160 should do that too.

 

[patch53]

Thanks Steve, good idea. I was running at only 170 last week, it was kinda warm for here. Back up to 180 now tho, supposed to be about -10F tonite.

 

[2.beans]

is your seton one of the next gen units?

 

[Trzebs13]

I would agree I would not have the damper close at 180 deg that is way to high and will possibly overload your dump zone after some time. One my stove it kills the damper at about 165 deg and with no load will climb to 180 in no time flat. The dump zone kicks in at around 180 and takes it down to about 160. There is no need to be running at much over 180. Also do you have a gravity feed dump for a power outage?

 

[2.beans]

if this is an older modle seton you can seal them up and hardly ever hit your dump zone, then you can run at 180 temps or higher. mine shuts down at 200 and my dump is set at 210.

 

[patch53]

is your seton one of the next gen units?

Not sure what you mean, I bought the plans from Fred last year and built it over the summer.

Pat

 

[patch53]

I would agree I would not have the damper close at 180 deg that is way to high and will possibly overload your dump zone after some time. One my stove it kills the damper at about 165 deg and with no load will climb to 180 in no time flat. The dump zone kicks in at around 180 and takes it down to about 160. There is no need to be running at much over 180. Also do you have a gravity feed dump for a power outage?

Well, last week here it was warm (30F) and I had the aqua shutoff at 170. It got up to 200F a few times but the dump zone was able to keep up until there was a load, but it took about an hour or so for it to get that hot after it shut off. I can see right now that watching the weather is going to be something to consider. When its going to be relatively warm I'll keep a much smaller fire and lower the aquastat to 165-170. But generally winter here is pretty cold and I really don't think I'll have to worry too much about the unit overrunning the dump zone.

I want to run as close to 180 as I can to maximize the efficiency of my baseboard heat. My dump zone is my sunroom which has infloor radiant heat, so no gravity fed dump. If the power goes out then it would probably overheat.

 

[2.beans]

is your seton one of the next gen units?

Not sure what you mean, I bought the plans from Fred last year and built it over the summer.

Pat

i didnt know if you bought one of the new blue units. there not supposed to hit the dump zone so often.

 

[Trzebs13]

I want to run as close to 180 as I can to maximize the efficiency of my baseboard heat. My dump zone is my sunroom which has infloor radiant heat, so no gravity fed dump. If the power goes out then it would probably overheat.
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Well exactly my point you really don't ever want to have a a over heat sistuation on your hands. When that happens you risk injury to just about all of your components, pumps, pex, valves, aquastats, ect. These units hold a enormous amout of heat in the refractory that with out a load, will keep water temps up for hours. I really got allot of advice form this forum to put in a saftey dump zone in my system and boy am I glad I did. I sleep better knowing that when I fill her up at night and put my family to bed that I have nothing to worry about. Search "Loading Greenfire" there is some good ideas about this that may have you think again.

 

[Trzebs13]

is your seton one of the next gen units?

Not sure what you mean, I bought the plans from Fred last year and built it over the summer.

Pat

i didnt know if you bought one of the new blue units. there not supposed to hit the dump zone so often.

With any of these units if your damper is not closing until 180 deg its going to be bumping that dump zone continuously.

 

[ISeeDeadBTUs]

With any of these units if your damper is not closing until 180 deg its going to be bumping that dump zone continuously.

FWIW, with the current temps I set the GW back up to 180 last night. My damper closes at 190 and doesn't go higher with the heat loads I have.
With single digits coming tomorow night, I will probably be set at 185. Last year when we went below zero, the aquastat was set about 195.


Jimbo

 

[mole]

I want to run as close to 180 as I can to maximize the efficiency of my baseboard heat. My dump zone is my sunroom which has infloor radiant heat, so no gravity fed dump. If the power goes out then it would probably overheat.
-----------------------------------------------------------------------------------------------------------------

Well exactly my point you really don't ever want to have a a over heat sistuation on your hands. When that happens you risk injury to just about all of your components, pumps, pex, valves, aquastats, ect. These units hold a enormous amout of heat in the refractory that with out a load, will keep water temps up for hours. I really got allot of advice form this forum to put in a saftey dump zone in my system and boy am I glad I did. I sleep better knowing that when I fill her up at night and put my family to bed that I have nothing to worry about. Search "Loading Greenfire" there is some good ideas about this that may have you think again.

Well exactly my point you really don't ever want to have a a over heat sistuation on your hands. When that happens you risk injury to just about all of your components, pumps, pex, valves, aquastats, ect. These units hold a enormous amout of heat in the refractory that with out a load, will keep water temps up for hours. I really got allot of advice form this forum to put in a saftey dump zone in my system and boy am I glad I did. I sleep better knowing that when I fill her up at night and put my family to bed that I have nothing to worry about. Search "Loading Greenfire" there is some good ideas about this that may have you think again.[/quote]

Pat, I agree with Trzbs. Pressure relief valves are the last line of defense against overpressure, but should not be the only line of defense. A thermosyphon type safety dump may be the best type, because it is not reliant on eletricity, batteries, power inverters, or pumps that can fail. But no single system is infallible. A thermosyphon system won't work if the normally open valve sticks in the closed position.... or if the draft door of the boiler fails in the open position (yes, that one has happened to me!) since it won't provide sufficient cooling capacity for a boiler under full fire. Pressure relief valves can fail too. That's why REDUNDANCY is the rule for safety systems and testing of pressure relief valves annually is so important. You really have to think through all the possible failure scenarios that can screw you and make sure you have them all reasonably covered.

I've lost enough sleep over my emergency backup power that I hard-piped the discharge of my relief valves to the outside of the building, aiming it down and discharging close to the ground so the risk of harm from boiling spray is low. I figured sooner or later something would happen. This way it's a non-event if my inverter fails or if my pump fails mechanically. I also built a critter screen into the end of the relief discharge line to prevent mud whasps or other creatures from making it a home and compromising its function. Each fall, before start-up, I test the relief valves (200F relief valve and 30psi pop-off), check the critter screen, and test the drain. Ironically, I was doing some work in the boiler area one day and inadvertently unplugged my inverter, which shut off my cicrculation pump a few hours later when the battery ran low. Of course I was under full fire at the time....Now I know that the relief piping works as designed!... Which brings up "human error" as another good reason for redundant safety systems!!

Sorry if this sounds overly "preachy". I admittedly have a process safety obsession from working in a chemical plant. It's probably treatable.
JR

 

[2.beans]

is your seton one of the next gen units?

Not sure what you mean, I bought the plans from Fred last year and built it over the summer.

Pat

i didnt know if you bought one of the new blue units. there not supposed to hit the dump zone so often.

With any of these units if your damper is not closing until 180 deg its going to be bumping that dump zone continuously.

ive sealed up my draft door, feed door side panels and installed this ( see pics )and i dont hit my dump zone with the draft shutting at 200*.my dump is set at 210 or so. as im sending this my outlet water is at 200 and return temp is at 130. im also not saying that is the right way to run this, but it can be done.( i also dont have the boiler in my house.) with the power outage thing, before i had inverter back i had the boiler unsweat the pipes and burn the paper off the sheet rock. that wasnt good.

 

[Trzebs13]

I do like that Chimney damper idea I remember seeing that before. The only thing I can tell about this tempature debate is it really must matter on how much heat load you have in your particular situation. Mine is set in and insulated room and only have about a 40' loop in the basement. so there is practicly no heat lost in idle mode. So I can see why mine would be bumping the dump alot more. Than if you had lets say 150' of undergound line from a out building to you home. I bet there little to no temp drop in my loop at idle. And my system only has about 40 gallons in it total which could be another big viarible. I guess what I'm saying is that every install is probably different. And in my situation (with a well insulated house) I see absoulty no reason I would have to run at those high temps. Even thou the components say that they will handle it I can't believe that the life expectency wouldn't go down. Was -15 degrees here last night and the house was a toasty 74. Boy I love wood heat cuz I felt no guilt having it 75 in the house....

 

[patch53]

Thanks guys for the advice. Now I just need to figure out what to do.

I have an inverter that I can use to circulate water off the boiler and into my boiler in my basement, but if the power is out I can't send it thru my zones. I purposely didn't hard wire my Taco 0011, so that if I had an outage I could at least keep the circulation going. This would help bleed off a little heat, but probably not enough to keep it from boiling over eventually, depending upon the length of power outage and the type of "burn" in the stove. If its a really hot burn at the time of the outage, I won't have much time to act.

I have one of those plug in power outage alarms that would at least alert me to an outage in the middle of the night. Outages around here are relatively rare, but do occur eventually.

I had an Aquatherm for 7 years before I built the Seton and only had it boil over 2 times from outages, but the Seton is an entirely different animal, needless to say. With a 8 gallon water tube, I would imagine it would only take a few minutes to boil without circulation.

My Seton is outside in a concrete block building I built just for the stove. How do I make a dump zone that will work in a power outage?

TIA, Pat

 

[Trzebs13]

When I asked this same question I got a few different ideas and actually came up with a different one. Some of the better ideas I have seen use some sort of thermosyphon system. Meaning that hot water rises and cool falls. So I you need some sort of valve that will open with out power. Automag valve is an idea or some sort of normaly open valve, I used a zone valve. But then out the top of your boileer you need to plumb it to a device that will dissapate the heat. Some guy's have used cast iron radiators, base board heaters ect. I used a 40 gallon hot water heater tank. then needs to be plumbed back to the intake or back of your boiler. The whole idea is to get rid of allot of heat in a hurry once the power goes out. So in power goes out, valve opens, hot water rises needs to dissapate, and cooler water is replaced in the return of the boiler. I posted a bunch of pics of my system any way you choose the principal is the same.
Clear as mud right?

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