Steaming Garn

[Sawyer]

Every time my temperatures approach 185 degrees I start getting steam/condensation coming out of the overflow tube. It is not boiling over. I did not notice this happening till I got a fair seal on the manhole cover, before this it went into the insulation.

I am now stopping at 185-190 degrees. I would like to run up to 200 but am afraid to do so without knowing if others are having this same experience.

This morning's burn start 142 degree supply temp, 2.5 hours later I shut down at 195 degrees supply temperature and steam/condensation out of the overflow tube. The steam is not excessive, boiler room temperature at the end was 95 degrees @ 10% humidity.

 

[bpirger]

Hi George:

I just finished a fire and I'm sitting at 208. I see no steam visually. I climbed up the ladder and felt around the manhole...and while everything is warm, I didn't feel any condensation in the fiberglass. Now, I couldn't reach everywhere...and while the Garn is wrapped in R30 on top, it isn't closed in yet. So I have three walls around the Garn (2x6), the front is still open, and I wrapped R30 around the tank and placed R30 up the back. But on top of this insulation is just open to the air inside my shed. And my shed is also not insulated and not at all tight yet. All the soffits are wide open. So, if I do have any escaping vapor, it might escape before it sits in the fiberglass. The fiberglass also isn't pushed tight against the manhole riser. I just cut around the manhole with a utility knife (cut the fiberglass roll) and it isn't at all crammed in as a tight fit. So it was very easy to slip my fingers in around there. Again, this might help water vapor to escape.....

No steam or condensation coming out of the overflow tube....I did hit this temp previously, so I wouldn't expect an overflow from expansion.

I did get my overhead door installed though...so now my primary air flow through the boiler shed is just the soffits. Before Tuesday, there was a 7'x8' wide open door 24/7....Hopefully this summer I will get the chance to insulate. But it probably isn't high on the list....as I have the addition to insulation, rock, finish, the shop/garage to insulate/rock, etc. I'm not yet heating the adddition and garage/shop. I know what I will be doing this spring/summer! And let's not forget the firewood for the 2012-2013 season!

 

[bpirger]

Repeat...sorry.

 

[bpirger]

Sorry guys...repeat again!

 

[Sawyer]

Bruce, I'm not sure why I am getting the steam/condensation. My water level is fine, in fact I am going to add water as I have 7†between the manhole and water level. The Garn is well insulated, as you can see on the blog, full to the top. The top rafters are covered with ½†OSB. The room is almost too warm but the main heat is coming from the fan and fan housing. I took the IR gun around the enclosure and it is cooler than the opposing partition wall in front of the boiler room.

I thought my temperature gauge might be wrong but after firing and eliminating the stratification the front bung and my supply pipe are within a degree or two and most times the same.

Maybe I should fire to 205 and see what happens, can’t explode.

 

[Kemer]

Hi George
Here's my take.I had what you described happen to me to.I think when the tubes get hot the turbulence causes the water inside to bubble and it goes out the over flow.But Ive been wrong before.

 

[Sawyer]

Hi George
Here's my take.I had what you described happen to me to.I think when the tubes get hot the turbulence causes the water inside to bubble and it goes out the over flow.But Ive been wrong before.

Harry, are you saying it only happened to you when flue temperatures were high. Maybe 400* and above? or was it storage temps were high as well as high flue temps?

 

[RowCropRenegade]

I had to recalibrate my front gauge. It was off at least 10 degrees. I made sure to have inline all Weis temperature gauges. Supply coming into house with pump running at least 20% is over 200. Matches up with front gauge. I still get a drip every now and then from going over 203. No biggie.

Coldest December here since 1970 here they say. Not suprised I sucked down 1.5 cords of black locust.

Not to hijack the thread but I'm struggling burning some 25 year red oak lumber. Been in this barn forever, impossible to work with construction wise. But damn dry. No puffing but more smoke than I like. My air control brick cracked in half. (never dropped) Still learning.

 

[Sawyer]

I had to recalibrate my front gauge. It was off at least 10 degrees. I made sure to have inline all Weis temperature gauges. Supply coming into house with pump running at least 20% is over 200. Matches up with front gauge. I still get a drip every now and then from going over 203. No biggie.

Coldest December here since 1970 here they say. Not suprised I sucked down 1.5 cords of black locust.

Not to hijack the thread but I'm struggling burning some 25 year red oak lumber. Been in this barn forever, impossible to work with construction wise. But damn dry. No puffing but more smoke than I like. My air control brick cracked in half. (never dropped) Still learning.

Pretty normal temps here so far.

Reed, have you had to add water to your Garn yet?

I have not used my brick for a while. I am burning 4 year dry maple. I took Tom's advice and load as far possible to the rear and load full loads. At first I was loading half loads but Ken Oaks, my rep, said they are burning full loads with better efficiency by eliminating the cool times burning twice. perhaps the full chamber has helped me eliminate puffing. I get smoke for about 5-10 minutes, then mainly steam which dissipates within 30 feet, or nothing at all. I am finally able to get up to the 500* temps with this pattern.

 

[Kemer]

George
I equate it with sticking a hot poker in water.I think a quick hot fire will do it .I don't hardly ever get my temps up past 180.Not that I can't but it just seems to last longer going from 180 to 140.I use approx.18 degrees overnight.If I go higher I just use more degrees up.

Harry

 

[Sawyer]

George
I equate it with sticking a hot poker in water.I think a quick hot fire will do it .I don't hardly ever get my temps up past 180.Not that I can't but it just seems to last longer going from 180 to 140.I use approx.18 degrees overnight.If I go higher I just use more degrees up.

Harry

18 degrees on a 2000 for 12 hours should be about 22,000btu/hr. I have been pulling about 12,000/hr on the shop and 50,000hr on the house when we were in the single digits to zero at night and teens during the day. under those conditions I fire twice a day.

When I put the pex below the living room floor so I can use the lower temps for that area I will be better able to use the lower temperatures. Right now the coil likes 140*+ water which means the supply from the Garn has to be at least 150* to the heat exchanger. I am going to buy the pex and parts next week for that project. I am putting in a hardwood floor in that room but I was told by Uphonor that I can still get 24btu/ft with an 8" spacing.

 

[Rick Stanley]

George-
When I first filled mine it did the same thing. The hotter I got it, the more water and steam came out of the overflow as it expanded. I think once you get it up to 200 or whatever for the first time, then the water level in the Garn will be right so it can go up and down as the temps do, without any discharge. I routinely hit 200 now without any discharge.

Rick

 

[Sawyer]

George-
When I first filled mine it did the same thing. The hotter I got it, the more water and steam came out of the overflow as it expanded. I think once you get it up to 200 or whatever for the first time, then the water level in the Garn will be right so it can go up and down as the temps do, without any discharge. I routinely hit 200 now without any discharge.

Rick

I just finished a burn at 197*. The tube was dripping but it was not steaming. I crawled up on the top and checked the manhole cover it was dry as well as the adjacent fiberglass.

I will be more patient and wait for the dripping to stop..

 

[pybyr]

I don't know how much "margin" there is to work with vertically between the level of the overflow port and the top of the top hatch, but could you perhaps rig length of copper tubing pitched very slightly uphill for a distance from the overflow port? That way steam or moisture might have a chance to condense and run back down in.

 

[benjamin]

just a shot in the dark, but is this just the air escaping from the fresh water and carrying some moisture with it?

Maybe you want to bring it right up to a simmer, and then see what happens the next time it gets hot?

 

[Sawyer]

That is an interesting idea Trevor; I will run that idea past the rep. it would not be difficult to create a P trap which may stop the vapor, which will always be there at high temps as it is an open system. I would not want the P trap to cause vapors to escape through the manhole cover or I would be back to where I started.

When I install the in-floor tubing under the living room floor the need for high end temperatures should cease.

 

[bigburner]

I have a 4000 gallon indirect storage with a 24 inch man way in the top, similar to a Garn same temps etc. It's uncovered right now and the evaporation in huge but you don't see visible steam rising from it. How much make up water are you guys using? and there must be tons of condensation on the covers correct!! My guess -- 7 ft diameter vertical tank it losing an inch a day.

 

[RowCropRenegade]

George, no I haven't had to add water to my unit yet.

 

[BHetrick10]

Jim Staufferer with Garn told me I shouldn't have to add water to the Garn during the heating season. He did say to check it periodically though.

My Garn wont show up until February so I dont have any hands on experience in any of this.

 

[Rick Stanley]

No make-up water needed during last years heating season. There is a low-water sensor that will let you know if water is needed, but it hasn't been an issue yet for me.

 

[pybyr]

I have a 4000 gallon indirect storage with a 24 inch man way in the top, .

Holy Cannoli! That sounds like a possible Boiler Room Record!

 

[Sawyer]

I have a 4000 gallon indirect storage with a 24 inch man way in the top, similar to a Garn same temps etc. It's uncovered right now and the evaporation in huge but you don't see visible steam rising from it. How much make up water are you guys using? and there must be tons of condensation on the covers correct!! My guess -- 7 ft diameter vertical tank it losing an inch a day.

As stated below, refilling is not a big requirement. The manhole cover is convex on the underside. The water droplets run to the center and then down the low water sensor rod back into the water.

 

[hedge wood]

I have a 4000 gallon indirect storage with a 24 inch man way in the top, similar to a Garn same temps etc. It's uncovered right now and the evaporation in huge but you don't see visible steam rising from it. How much make up water are you guys using? and there must be tons of condensation on the covers correct!! My guess -- 7 ft diameter vertical tank it losing an inch a day.

I am in the second heating season with my Garn 2000 and added about 200 gallons of water before this heating started but none during the first or so far during the second season and I run mind up to 200 degree plus a lot of the time to get more time between burns.

 

[TCaldwell]

If my water temp is at 190+/- it will steam through the overflow port,, if the combustion output is still high, once the inducer shuts off , the steam stops. With steam coming from the port, usally means the manway cover has a good seal.

 

[bigburner]

Thanks guys- INVERTED cover that sounds like the ticket. I have a make -up water float/valve I plan on sticking in there also. I need to keep my tank 100% full so I don't get the water line rust thing going on, I may extend the manway up a little so the water level change stays in the manway.