Wood consumption - CB Classic vs. Profab 400

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leeallen1

New Member
Mar 9, 2011
22
S Maine
I would like some feedback on a question that involves comparison between a non-gassifier and a gassifier - we are talking outdoor boilers here.

The CB Classic 6048 has a firebox that holds 60 cu ft. of wood - that's a lot! . The Profab 400 gassifier's firebox holds 21.3 cu ft of wood. Now - they both claim they can easily go 12+ hours in the dead of winter when there is a high demand for heat. ( This is with the firebox filled). I can testify to this with the Classic because the I have one.
If we assume the 400 can do the same, can we also assume that the unit will burn 2/3rd's less wood than the Classic?
 
I am burning around 20 cord per season to heat 5000 sq ft (Sept- June) - shut down for approx. 2-3 months - 3 family home w/ heated garage. BTUS are around 150-160
 
I have a CB 6048 Classic....firstly the only time I have ever filled the firebox on this unit is when I went away for 3 days in February...came home and there was still coals in the botom and temp was at 172...house was still warm.

SO, I am in a cooler locale than you....I have a heat load of more than 100kbtu/hr, 4000 sq ft house and shop and DHW, I heat from September to middle of may typically.

In the dead of winter it is -30 degrees here and I am on a cliff overlooking a lake so there is always wind. My boiler is almost 80 feet higher in elevation than my house, and my thermopex run is 135 feet....above ground...yes, above ground, due to bedrock everywhere. (very minimal heat loss from boiler to inside my shop where it goes to HX, maybe 1 degree max.)

I easily get 12 to 14 hour burns, and I do not fill, I would say, maybe 1/4 to 1/3 maximum...few splits and then 24 to 30" rounds. In the dead of winter I stoke it at 5 am , then again around 700pm or so...

Although we still have another 4 to 5 weeks left of burning, (only stoking every 24 hrs now), my estimate is between 9 and 10 full cord for this years heating season.

I burn all hardwood during the worst part of winter...a lot of trash in the shoulders....

Are you burning hardwood? Mostly rounds?

Mike
 
Yikes, 20 cord, my back hurts just thinking about that. I get 12hr and longer burns with my Portage and Main Optimizer 250 with a 11 cubic ft firebox.Actually probablly 8 cubic ft of wood. Not as many sqft as you (3200).
 
Some rough calculations suggest 20% efficiency for the CB so 50% for the Profab, sounds possible.
 
leeallen1 said:
I am burning around 20 cord per season to heat 5000 sq ft (Sept- June) - shut down for approx. 2-3 months - 3 family home w/ heated garage. BTUS are around 150-160

You started a thread similar to this about a month ago. 20 full cord is twice the wood you should be using. Something is wrong with your setup other than your boiler. Were you ever able to isolate the hx(s) to see what you were loosing? All it takes are 3 valves, 2 tee's and 4 foot of pex to tell you what you are loosing to the ground. Even if you do go with a more effecient boiler you may not fix the main culprit. If it was me I would start with the underground pipe since regardless of what type boiler you use (gasser or standard) poor quality underground pipe can rob a lot of btu's.
 
I agree with Kawliga and Pulse. There is no way you should be using 20+ cords. Something is wrong. Now, I have heard that if you fill an OWB to the rim twice a day it will burn that much, but if you only put in enough to get you to your next fill, that is all you need. I have a 6048 and have "never" filled it. I have 5 HX's, heat a 3000 sqft home with 2 forced air heaters, all DHW, 500gal hot tub and keep a 24X32 "lightly" insulated pole barn @ 50 degrees and when it is below freezing I use 2 mason wheel barrel's full of wood a day. Mix in a couple large rounds for overnight.
Are your 20 cords full cords? 128 cuft?
 
Yah, Lee....what did you find out on your analysis....you defintely have some other issue here....and Varna is correct...if you put more wood then you need it WILL burn it....only stoke what you need and your consumption should go down...man...if I had to cut 20 full cord, my cb would be sold yesterday...for my use it is pretty efficient...

Before you make any changes to a new boiler you better assess your current system operational temps/flow rate etc...

Mike
 
Buddy of mine has a 6048. And if it's average winter day, he found the same thing about filling it. Filled it to the rim, burned 90% of it. Filled it 1/3 it burned it all. House stayed just as warm. He has a big heatload, big house not insulated very good.

BUT, I think in you're other post you mentioned the size of your wood rack. You thought it held a cord, but the measurements figured a half a cord. So...you only burn 10 cord?

Biggest variable with people and wood consumption is the tape measure. The buddy i mentioned that has the 6048? He allowed he only used 10 cord a year. In my head, No Way! We measured his wood shed. He said it held 10 cord. Measured out to alittle over 14 cord.

6048 boiler does throw some serious BTU's when needed. But you gotta throw some serious wood at it.
 
Thanks for all the feed back. I just have not had time to address my situation and with the warm weather, my wood consumption has reduced drastically. I think my first move will be to see what I am losing for heat by installing some temp gauges so I can see what my temp loss is between the feed and return. That should tell me if I have an underground heat loss. Thanks, again.
 
pulse said:
leeallen1 said:
I am burning around 20 cord per season to heat 5000 sq ft (Sept- June) - shut down for approx. 2-3 months - 3 family home w/ heated garage. BTUS are around 150-160

You started a thread similar to this about a month ago. 20 full cord is twice the wood you should be using. Something is wrong with your setup other than your boiler. Were you ever able to isolate the hx(s) to see what you were loosing? All it takes are 3 valves, 2 tee's and 4 foot of pex to tell you what you are loosing to the ground. Even if you do go with a more effecient boiler you may not fix the main culprit. If it was me I would start with the underground pipe since regardless of what type boiler you use (gasser or standard) poor quality underground pipe can rob a lot of btu's.

are you suggesting that I just install a loop so the water does not go thru the HX? Get a temp when it leaves the boiler and a temp when it returns to the boiler? Thanks
 
leeallen1 said:
pulse said:
leeallen1 said:
I am burning around 20 cord per season to heat 5000 sq ft (Sept- June) - shut down for approx. 2-3 months - 3 family home w/ heated garage. BTUS are around 150-160

You started a thread similar to this about a month ago. 20 full cord is twice the wood you should be using. Something is wrong with your setup other than your boiler. Were you ever able to isolate the hx(s) to see what you were loosing? All it takes are 3 valves, 2 tee's and 4 foot of pex to tell you what you are loosing to the ground. Even if you do go with a more effecient boiler you may not fix the main culprit. If it was me I would start with the underground pipe since regardless of what type boiler you use (gasser or standard) poor quality underground pipe can rob a lot of btu's.

are you suggesting that I just install a loop so the water does not go thru the HX? Get a temp when it leaves the boiler and a temp when it returns to the boiler? Thanks

Yes that is exactly what I am saying. Load your boiler like you would when heating then see how much wood you use in 12 and 24 hours. Not very scientific but it should give you an idea how much heat you are loosing to the ground. It would have been nice to try this during the winter, but it should still give you an idea. Gauges are great if you can place them for an accurate reading. Good Luck!
 
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