Rookie looking for some OWB help

[Randy Wiesner]

Here is the background for my situation, sorry if it's a little wordy. We built a 2600 SF 2x6 framed log cabin last year and this is our first full winter in it. Our property is 10 acres of mixed hardwood and our primary heat source is a Sequoyah E3300 gasification OWB with a fire box about 3'x3'x3' and an LP furnace for backup. I built a rack near the boiler that holds 8'x5.5'x18"of wood, or about 1.3 face cord. The garage isn't complelty insulated yet but I have a unit heater in there that keeps it around 35 most of the time. All inside PEX has pipe insulation, all outside PEX is insulated and buried (except last 15' not buried). The return pipe to the boiler is still pretty hot when it leaves the house so I don't think I am wasting heat anywhere.

I fill the firebox at 6 in the morning and 6 at night and barely have enough coals to rekindle a new fire and the water temp is already down to 70 degrees. If I did my math right I have gone through about 16 cords of wood since the last week in October because I am going through about a rack a week, a little more if the outside temp stays below 10 degrees. Needless to say I am out of cut wood already. I now know that my wood hasn't been properly seasoned but it was all downed dead wood to start with.

I have experimented with the set point sensor on the access door. But didn't notice any difference in wood consumption. Just a longer burn time to bring the water back up to 180. I noticed the cheap thermostat that the installer used for the boiler doesn't always cutoff at the desired temp (70). So I will have to see about getting a better t-stat. I have also experimented this week with burning wood but letting the LP t'stat control the house. My hope was if I burn a little gas with the wood I could stretch the rest of my wood some. I am still consuming the same amount of wood so that experiment didn't help much either.

Am I doing something wrong? Are there some adjustments on the boiler thatcan be made? Other suggestions?

Thanks

 

[Como]

I did some quick mental computations and with a lot of assumptions and came to about that level of consumption.

You could get a better idea by doing a heat loss calculation or perhaps heating for a week with propane and seeing how much you use and multiply it by the Boiler efficiency to get your btu load.

 

[Fred61]

You need to get actual data to troubleshoot the problem like actually checking the temperature of your underground run to check for loss. Your description of the return temperature "pretty hot" tells me you checked the temperature by feeling it.

 

[Hunderliggur]

your wood rack holds about 1/2 of a cord so I think you have gone through about 6 cords so far. Have you checked the moisture content with a meter? No all standing dead wood is dry so you may already have been burning wet wood. As has been suggested before on this forum, get yourself some dry wood (e.g. pallets) and burn with that and see if it makes any difference.

I have a 6" Cypress Log house. Is your log cabin log siding over 2x6 or something else?

 

[AOTO]

Sequoyah is out of business... Sucks to be us....

 

[Frozen Canuck]

That kind of wood consumption is not out of line for any OWB. They are very poor at creating usable btu's from wood or any other fuel for that matter. It's just the way they are designed.

Sorry to say that there is likely no problem with the unit or what is tied into it & you are probably getting all the performance you will ever get from it. As with many/all OWB's most of the heat just goes up the stack.

You, I and every other OWB owner in North America (these things don't exist is Europe) basically have two choices.....

(1) chain axe a small forest each & every year to feed to the beast. (2) Buy a quality gasser designed & built by people who know what they are doing (knowing not guessing) there is a difference.

Me; I am getting sick & tired of being married to a chainsaw just to keep the beast fed & seeing 60% minimum of my efforts go straight up the stack.

For you now it's all ooooo ahhhh nice new shiny toy, I like it....why doesnt it work better though? I thought it was supposed to heat my house easily? Isn't that what the salesman said?

In time that will change to WTF did I ever buy this POS. Trust me you just dont have enough chainsaw hours yet.

 

[Duetech]

Hi Weasel. Welcome to the forum. The problem with OWB's is it takes wood to keep the beast idling. I have used a gasser without storage and they use wood whle idling too but just not as much. There is added expense and learning to handle storage but it can really pay off in labor and savings when done right. My gasser uses about 6.5-7 full chord for a year (summer dhw) but around 5 is for the real winter stuff. OWB's do not let a fire reach potential by design. Loading an OWB in different ways can have an impact with wood consumption. I have a ceramic OWB that will burn a full load in 16 hours and a half load in 12 to 14 hours. I load half full but load the front half instead of from the bottom up it's front to back. A partial load heats the wood faster and that heats the boiler faster. Don't just "load the boiler" experiment with loadings. Best to you!

 

[flyingcow]

8x5.5x18inches is about 66cu/ft. 128 cu/ft in a cord. So you're rack holds about 1/2 a cord.

 

[heaterman]

XXXX amount of wood has XXXX amount of btu content. Those btu's are all released in some form or another when the wood is burned and they all go somewhere.

Here's your choices:

Lost out the stack in the form of high flue gas temperature or smoke.
Lost into the ground via poor grade tubing/insulation
Lost through the cabinet of the OWB sitting outside at 10*.....think about it.......
Lost because of moisture content over 20% (two things happen when you burn wet wood)
Lost from the structure through poor sealing, insulation, windows/doors.

You probably have a combination of a 2 or more going on and each are discoverable and "preventable" in some way or another. All you can do is start investigating. First thing i would do is measure your stack temp while burning to see what is going on there. Not much you can do there beside making sure your wood is at 20%MC or less. Second would be to get an accurate measurement of you supply/return temp in the underground loop in operation with no house load on it. Check those right at the back of the wood boiler.
There is nothing you can do about btu's lost caused by a heating appliance sitting outside in the snow....
Get a moisture meter and see where you are at. Take a round log that looks dry, split it and check the MC in the middle of the piece.
Go over your house with a fine toothed comb and tighten up everything.