Corn Stove update

Three weeks ago we finally received the back-ordered stove pipe for our new corn stove and have been able to run the stove for two weeks now.

 

 

 

 

 

These photos show the installation in our basement. We cored holes in the foundation for the intake and exhaust pipes and painted the pipe ivory on the inside and black on the outside with high temperature paint. The exhaust pipe never gets more than very warm to the touch since it uses a blower and double walled sealed corn pipe. We had to jog the pipe with a 45 degree elbow due to the windows directly above in our den.

My wife set the tiles so that we would have a level base even though we have a concrete floor. The first photo shows a sack (bushel ~ 60 lbs) or corn nearby. The stove holds almost a full bushel in the hopper - the top door is visible in the second photo. You can also see the grate used for wood pellets on the floor. The third photo shows a tin of wood pellets which we use to easily light the corn stove since corn does not easily light or requires starter gel. The stove has electronic controls which work quite well. The 'auto' position self ignites wood pellets only when heat is required. We use the 'auto' setting to start the stove initially by throwing in a handful of wood pellets. We then switch the stove to the 't-stat' position after it has warmed up for burning corn. This position uses a regular wall thermostat to regulate the heat output of the stove. When heat is required the stove runs from level 2 to 5 (medium low to high) as we preset it, when the thermostat determines that the room is warm enough it reduces the burn rate to level 1 (low). We set the run position to level 2 which is more than enough to quickly heat the room. Starting is not difficult but takes a little getting sued to to determine where to set the fresh air adjustment (damper). They key is to adjust the damper so that the flames are lively and not lazy, but not so fast that the fuel runs out faster than the auger feeds it. We do not use the third position which is manual since we have a thermostat.

 

 

 

 

 

We ordered 72 bushels of corn which arrived two weeks ago on two pallets which I carried down into our basement. The corn should last the entire heating season provided we keep it dry and keep any mice out of it (the cats should finally start to earn their keep now). It took me two evenings to haul this into our utility area and takes up a footprint which is 4' x 6' and 5' high. We chose to order the entire load at once rather than smaller orders which would cost more in transportation. Cost for this high quality stove quality shelled corn is about $350 dollars plus $75 shipping. Doing a little calculation reveals that corn will cost us about $10.50 per million BTU after factoring in stove inefficiency. Wood pellets run from this amount to almost double depending upon quality and quantity. We also have a high efficiency natural gas furnace which currently costs $15 per million BTU.

After running the stove for two weeks we are very happy with our choice. The weather hasn't been that cold (no lower than 40 F) so we only run the stove about half of the day and it never runs above low after initial lighting. We have gone through two bushels of corn in two weeks so we are getting a little concerned that we bought too much corn. We clean the firepot daily and once a week vacuum out the few ashes that collect and clean the window of soot. Cleaning is easy and no real bother. We find that when we turn on the furnace fan the heat distributes quite nicely throughout our home.

We are looking forward to some very cold weather to see how the stove performs and whether it can reduce our natural gas bill for heating the house. We are also going to attempt to run the stove continuously for a week without relighting once the temperature gets cold enough. I am not sure if we will buy a sealed type battery (similar to an auto battery) which will allow the stove to run without street power. We have never had a sustained power outage but the ice storms in the spring are not to be taken lightly.

UPDATE:
Penn State has this terrific site for references

Comments

[Joshua]

Can you share a little about the design of the firepot on the Baby Countryside? From Magnum's website, it seems that they don't use the stirrer/agitator that the Countryside does (which I think is a plus), but that it doesn't have the grate/slide bottom system that the St. Croix stoves use, but rather a "tool to flick the clinker into the ash pan." Can you share how this operation is carried out, to drop the clinker from the firepot while keeping the burning corn in the pot so the fire doesn't go out? I'm looking to find a design that's easy enough for our family, and so far leaning toward the St. Croix, but want to know how this design handles it. The web (and the BC manual) is light on info here. Thanks!

[Stu]

Joshua - I posted an answer with pictures to better answer your questions. See: http://bermans.blogs.com/opinion/2006/07/firepot_details.html

You can click on any picture for a larger image.

I have found handling clinkers to be simple by doing this twice a day typically before going to work in the morning and later in the evening. There is really no mess involved although I open the door for a very short few seconds when I need to flick the clinker up and again about 15 minutes later to flip it out of the box.

[Bob]

Hello, Stuart
Can you tell me how much corn you burnrd for last season. Thanks

[Stu]

Bob,

We went through 72 bushels of corn last year (under $300 plus delivery charge) between November 2005 and March 2006. We also went through 6 sacks of wood pellets (wood pellets are better when the weather alternates between cold and warm so that the stove will auto ignite as needed).

[Mark Maxwell]

Are you able to pull your stove out to clean out the exhaust pipe? Does your pipe connection behind the stove allow you to do this?

[Stu]

Mark,

Yes the stove can easily be pulled away from the wall - ours is angled so I can reach the clean out Tee without moving the stove but a few inches.

[Dan Augsburger]

Thank you for the info on your stove. Where do you run the damper on your stove (how open is it, and have you adjusted it much)? I'm amazed that you can go for two weeks on a bushel of corn. How much corn were you burning on cold days? This is my first season with a corn stove and I'm still learning how they work and what to expect. Thanks a bunch. Dan

[Stu]

Dan,

I run the fresh air damper at slightly less than 1/2 open. In my original post I said I went through two bushels in about two weeks when the weather was warm and I run the stove less than 1/2 of the day.

After two seasons I find that I really use the corn during the cold weather only and burn around a bushel every couple days. When the weather turns warm I prefer to use wood pellets so that the stove self ignites and only burns when the room gets too cold.

I found this year that 2 pallets (72 bushels) and 6 sacks of wood pellets is perfect for the season. I am also insulating our concrete walls in the basement to reduce heat loss. I am actually worried that the stove will then generate too much heat unless I add better whole house air ciculation. I am trying to come up with a clever way to do this with convection rather than forced air.

Other mini projects might be to add a second fresh air supply to the stove to supply fresh air to the stove blower that handles room air this would increase the positive pressure in the basement and repiping the exhaust stright up through the inside of the house because I am concerned that it is so cold outside that I get too much soot build up. An internal path would allow the pipe to stay warmer and perhaps provide a little heat into our "sun room".

[Richard Lamb]

I am beginning my second season using the Countryside. This year, it is not burning very efficiently. The pot fills up after a couple of hours and then overflows. Any ideas what's going on and what I can do? I cleaned the exhaust fan and the pipe.

Rich

[Richard Lamb]

I am beginning my second season using the Countryside. This year, it is not burning very efficiently. The pot fills up after a couple of hours and then overflows. Any ideas what's going on and what I can do? I cleaned the exhaust fan and the pipe.

Rich

[Stu]

Rich,

Can't say that I have a good answer for you.

I found that I had the same problem last season so I bought a tool to clean out the exhaust pipe and then I took the exhaust fan cage apart and cleaned it thoroughly and found that the stove runs like new. I assume you checked that you made sure that all of the exhaust passages are not clogged - I can't believe how much crud came out of the exhaust after two years.

Your problem sounds like the fire is starving for oxygen and that you either don't get enough fresh air because of negative air pressure in the room (I installed a fresh air intake from the outside of the house) or the exhaust is partially blocked. (I also assume you have opened the fresh air butterfly enough to give plenty of fresh air.) I have also heard about a condition where the fuel gets underneath the firepot and falls into the ventilation slots although I haven't seen this myself. I also take care to use the correct firepot depending upon fuel type. (Corn firepot has more holes small at bottom and larger at top whereas the pellet firepot has fewer hols mostly at the bottom.)

This season we tried cherry pits but I found that the ash built up too quickly so we went with premium wood pellets at $3.60 per 40# bag. They burn well and I am getting spoiled by the auto ignition feature. Last year we had some problems with mice and moldy corn and the restricted exhaust meant that I had a poor burn on the corn so I spent too much time tending the fire. I do miss the pleasant corn smell but we'll see if it makes more sense to do the whole year with pellets. Also with pellets it is easy to buy just a dozen bags as needed rather than deliver a whole ton for the season.

[Cathy]

We've been heating with corn for about 8 years now. The first year we had no problem burning straight corn but since then we have mixed a 70/30 blend of corn and pellets. Our biggest problem is the amount of ash that builds up daily and have found we need to shut the stove down weekly to clean the exhaust chimney. Do you have this problem with ash build up? I've been told that stoves without a pot stirrer don't have as much fine ash and would therefore require less chimney cleaning.