How many cord of wood are you burning?

[maple1]

... Have a Benjamin cc500 oil/wood unit in the basement ... I am using, by my rough calcs, around 8 cords of wood a year (sometimes not the best quality) .... I know now this unit is about the most inefficient unit I could have selected, wood burning wise, so was hoping that a new gasser and storage could cut my wood use by, well, a lot. ....

Don't know anything about your boiler, but IMO it doesn't sound THAT bad, especially if the wood is not top shelf. In planning for a gasser, you're a bit up against it with your present combo unit. You would either need to replace with another combo (Wood Gun, ...); buy a new FB to be used only for backup/Summer DHW; or keep Ben just for oil. And the last 2 would require a bunch of piping and control changes as well. And if you throw in the cost of storage, you're looking at a hefty investment. My guess is that it would take you a long time to pay that back, with the assumption of saving 2 or so cord a year. How about just putting in the storage in order to maximize Ben's efficiency? (and make operation easier as well)

Yes, it doesn't sound that bad, but after 15 years of maintaining & operation - I'm ready for something else. And I think it is almost at the end of its life. I won't go into all the details on issues I've had with it on here, but for this discussion, I'll simplify it to it doesn't burn wood efficiently at all. I have 30ft of chimey, so lots of draft. If I damper it to burn good in the firebox, the heat has a straight path to the outdoors right up that chimney, and I have to fire it every couple of hours. I know I am losing a good deal of my woodpile straight to the outdoors. If I damper it to try to keep more fire in the unit so I get more heat transfer, it pumps out creosote like crazy. I am up on my roof 3 times a winter with the brush, and even then at that am sometimes overdue for brushing when I get there. And no matter how it is dampered, there is a constant increasing build up of hot coals in the firebox, leading to diminishing firebox volume & poor heat transfer and more waste from continual cleaning out and disposing of unburned clinkers. So from all that, I was really thinking that going to a gasser & some storage would cut my wood use in half. I know it won't be cheap - at this point I think I would get rid of the the Ben altogether & replace it with 2 units - actually don't think I would have a choice since I only have one chimney down there. I don't think storage would help this Ben any, it doesn't give me much more heat than the demand is.

Getting a bit off topic I guess, oops...

 

[chuck172]

Don't count on storage to save wood. It adds convenience, but the wood savings is minimal.

 

[Sawyer]

Kid number 4. We built his house in 2005 and used a combination of panel rads and Viega Climate Panel for the whole place. Not a heating duct in sight anywhere. The house is about 5,800 sq ft plus he is keeping a lightly insulated 1,800 sq ft pole barn at 35-45* all winter. (nice place to let the Kubota thaw out.....) His house is R-22 in the walls and averages R-30 in the ceilings. (some areas are ceiling/roof combination) He has a Garn 2000H sitting approximately 220 feet from the house (in the pole barn) He's also doing domestic hot water for a family of 7. The Garn will consistently digest about 10-11 cords per winter while serving that load. He can let the Garn drop all the way down to 110 before firing again and still have plenty of heat available for heating use with his low temperature system.

What brand of panel rad does your son have? I have not yet installed an under-floor, between the joists, hydronic heating system under the hardwood living room floor to replace and/or offset the forced air supply to this room. Panel rads sure look good if you can get heat at 110*, especially with my Garn. I have looked at some information but it seems they are more designed for 140* and up. Are there charts for BTU's/ft at temperature X?

 

[spidy1967]

I have been using 3.5 cord consistantly since 94 using an 1978 hstarm to heat a 1500 sq ft home. Heating the living space only, radiant heat from the boiler keeps the basemnt 60-65 deg. and the house around 72+. This system really saved me during the ice storm of 1998, i ran the system using gravity. When the tarm sprung a leak about 3 yrs ago i really had to search to find a boiler that DID NOT require electricty to run it. I'm not aginst gasification boilers or pellet stoves ect. i just dont want to be tied to electricity for my heat. After the ice storm i was not going to take a chance with a system that required power to run. I settled with a Biasi 3wood5 it was heavy cast iron not plate steel like the tarm and i still burn 3.5 cords per year. I did convert it to coal and this will be the first season trying coal in it, i tried coal the end of last year and was getting 18 to 20 hour burn times on 40 to 50 lbs of coal. I'm sure with some tweaking i can get longer burn times and will hopefully only burn around 2 ton of coal if my calculations are right. I do have 4 ton ready to go. It may be a little more expensive than wood but not tending it every 5 or 6 hours is worth the difference in price and i have more space in my basement. Guess only time will tell if its worth the change, it would only take a few minutes to remove the coal grates if it doesnt work and i have plenty of wood but i'm sure it will work out.

 

[heaterman]

Kid number 4. We built his house in 2005 and used a combination of panel rads and Viega Climate Panel for the whole place. Not a heating duct in sight anywhere. The house is about 5,800 sq ft plus he is keeping a lightly insulated 1,800 sq ft pole barn at 35-45* all winter. (nice place to let the Kubota thaw out.....) His house is R-22 in the walls and averages R-30 in the ceilings. (some areas are ceiling/roof combination) He has a Garn 2000H sitting approximately 220 feet from the house (in the pole barn) He's also doing domestic hot water for a family of 7. The Garn will consistently digest about 10-11 cords per winter while serving that load. He can let the Garn drop all the way down to 110 before firing again and still have plenty of heat available for heating use with his low temperature system.

What brand of panel rad does your son have? I have not yet installed an under-floor, between the joists, hydronic heating system under the hardwood living room floor to replace and/or offset the forced air supply to this room. Panel rads sure look good if you can get heat at 110*, especially with my Garn. I have looked at some information but it seems they are more designed for 140* and up. Are there charts for BTU's/ft at temperature X?

You can find all you need to know here. www.hydronicalternatives.com

or more specifically > (broken link removed to http://www.hydronicalternatives.com/html/radiators.html)
That page will have everything from installation to temperature correction factors. As a rough rule of thumb, I add about 30% capacity for reduced temp operation. In other words if I have a room that requires 6,000btu I will select a rad rated for 7,500-8,000 at normal temps.
If you really want to get scooby doo about it, install a motorized mixing valve that provides outdoor reset of the water temp in front of your panel rad manifold. I love the feel of a 100* rad on a cool April or October morning.

 

[mark123]

4000sf, eastern canada 8 cord of maple and 2 cord of spruce with my woodgun E-180 for 100% of home heating and domestic water year round.

 

[mark123]

Maple1, I replaced my CC500 with the woodgun last year. I agree the benjamin was not very efficient at burning wood, I used it for 4 years and burnt about 12 cord/ year and couple of 300-400 liters of oil and had a cold house. In fairness it was only rated at 80000btu on the wood side so it was undersized for my application.

 

[maple1]

Thanks for the info mark - sounds like you reduced your wood usage quite a bit if the oil you used was factored in too. Makes me feel a bit better.

I'll try to do some measuring & more figuring in the next few days to see how accurate my 'first guess' numbers were.

 

[Sawyer]

You can find all you need to know here. www.hydronicalternatives.com or more specifically > (broken link removed to http://www.hydronicalternatives.com/html/radiators.html)
That page will have everything from installation to temperature correction factors. As a rough rule of thumb, I add about 30% capacity for reduced temp operation. In other words if I have a room that requires 6,000btu I will select a rad rated for 7,500-8,000 at normal temps.
If you really want to get scooby doo about it, install a motorized mixing valve that provides outdoor reset of the water temp in front of your panel rad manifold. I love the feel of a 100* rad on a cool April or October morning.

Thanks Steve

 

[Sawyer]

Maple 1, “how much wood do you use, cords/year?†is a difficult question to answer with information that’s useful to you. The members on the forum range from extreme winter conditions to mild winter conditions. A house in Kentucky will use a lot less fuel than the same one in northern Minnesota. If usage was expressed as cords per year at X heating degree days and X design temperature and heat loss calculations (BTU/hr) you could better compare some of the information. Where I live I use 9078 HDD for heat loss calculations. Design temperature at -22 degrees. I used 10.5 cords of wood to heat last year for a 4438 sq./ft (Main floor and basement) house with high ceilings, lots of windows, and a lot of exposed wall surface as our house is long and narrow as opposed to a perfect square. Slant Fin heat loss calculations are, for my house 91,000BTU/hr, workshop 33,000BTU/hr. We do have excellent insulation in the form of blown cellulose, walls and ceilings, and sill plates. All penetrations were foamed. We have triple pane windows but they are still low in R value.

Hope this helps.

 

[maple1]

Yes, true - that's why I'm watching for situations similar to mine, from the info that is posted. For a rough idea only. My house is the same age as my furnace (15 yrs), and is insulated fairly well. But we're on top of a hill in the wide open also.

Anyway, I measured my woodpile & did a rough guess at what I'll top it up with in December, and went back 5 years on my oil bills. I'm buring close to 9 (real) cords of wood & 180 gallons (Canadian) of oil for the year for heat & hot water - guess my first guess wasn't too far out. There was a heat loss done on the house back when I built, but it has been since then since I've seen it. If I stumble across it, then maybe I'll try to check out more numbers.

Again, good info in here.

 

[eauzonedan]

Heaterman:

Just a clarification on your 30% upsize rule of thumb for low temp use of radiators........ After looking at the correction factors for low temp hydronics @ Hydronic Alternatives....... Assuming I ran my (green submarine) storage down to say...120 degrees......and assumed a 10 degree delta thru a heat exchanger......this would give me a supply temp of 110 degrees to the radiator.....if I plug in a 68 degree room temp - the table gives me a correction factor of 4.2 (assuming a 100 degree return temp).......which I think says that to get 5k btu I would need to find an emitter with 4.2x5k = 21k btu rated output at their standard conditions to pull 5k btu from it...... are you saying that in the "real world" 1.3 x 5k btu = 6500 btu is workable?..... I'm trying to rough out some budget numbers for emitters and see a 3x spread from what I thought I needed to budget...... just a silly survey guy dabbling in heat stuff.....which is always a bit scarey.... Is there maybe enough thermal mass in a building to make just a 30% upsize work thru a short period of low temp supply that is common with the storage approach?

Eauzone Dan

 

[Sawyer]

As I had this same question minutes ago after I ran their calculations. In an effort to make this topic more searchable and to not hijack maple1's thread I am posting this topic on panel radiators separately.

 

[heaterman]

Heaterman:

Just a clarification on your 30% upsize rule of thumb for low temp use of radiators........ After looking at the correction factors for low temp hydronics @ Hydronic Alternatives....... Assuming I ran my (green submarine) storage down to say...120 degrees......and assumed a 10 degree delta thru a heat exchanger......this would give me a supply temp of 110 degrees to the radiator.....if I plug in a 68 degree room temp - the table gives me a correction factor of 4.2 (assuming a 100 degree return temp).......which I think says that to get 5k btu I would need to find an emitter with 4.2x5k = 21k btu rated output at their standard conditions to pull 5k btu from it...... are you saying that in the "real world" 1.3 x 5k btu = 6500 btu is workable?..... I'm trying to rough out some budget numbers for emitters and see a 3x spread from what I thought I needed to budget...... just a silly survey guy dabbling in heat stuff.....which is always a bit scarey.... Is there maybe enough thermal mass in a building to make just a 30% upsize work thru a short period of low temp supply that is common with the storage approach?

Eauzone Dan

"rule of thumb" = speaking generally or a rough estimate or guideline for going about a given task. (taken from the heaterman dictionary of "Ooops I shouldn't have said that")

Explanation. My usual "Modus Oporendae" is to design around 130-140 temps because those supply temps will keep my gas equipment in condensing mode. I also use ASHRAE table for design conditions which in a lot of cases are less severe than people think. Ours here are -6*F even though the temp can get as low as -30 once in a blue moon.

Use the charts Paul has on his website. They are accurate and will leave you a little wiggle room (there I go again) for extreme situations.

 

[Gasifier]

4000sf, eastern canada 8 cord of maple and 2 cord of spruce with my woodgun E-180 for 100% of home heating and domestic water year round.

Mark123, Do you use storage with the E180? If so, how much. Thanks.

 

[Nofossil]

3500 sf set to 72 °F, dhw, and 550 gallon hot tub in Vermont - just under 4.5 full cords per year average. Wood is about half hardwood and half 'junk' - red cedar, poplar, pine. Some people do better but I'm still learning ;-)

 

[willworkforwood]

3500 sf set to 72 °F, dhw, and 550 gallon hot tub in Vermont - just under 4.5 full cords per year average. Wood is about half hardwood and half 'junk' - red cedar, poplar, pine. Some people do better but I'm still learning ;-)

"still learning" - well, that made me just LOL - soon Nofo will announce that he no longer needs wood at all, and just uses the excess heat his brain is producing :lol:

 

[mwk1000]

7000 sq ft, 3500 up / 3500 down. Heat only at 72 ( no DHW)

One full tent does it for the season. Ash & Oak. 8x10x20.

 

[stee6043]

7000 sq ft, 3500 up / 3500 down. Heat only at 72 ( no DHW)

One full tent does it for the season. Ash & Oak. 8x10x20.

Beatiful home there, MWK. I think I'd stroke out if I had to process 13 cord of wood every year. No way I could keep up.

I heat 3200 sq.ft. with 3.0-3.5 cord of wood per year. I keep the house at 70, no DHW. I hope to someday install radiant in-floor to expand my wood heating season. Currently I heat from late October through mid March (whenever the wood runs out). I'd like to get into April eventually on my bigger pile which is 3.5 cord.

 

[Mushroom Man]

This will be season 3 for wood burning with the EKO. First year I used approximately 12 cords. The next year was 9.
I credit a little experience to second year savings and maybe the storage tank that reduced idling significantly.

The wood was standing dead trees in year one with no seasoning of the wood. The second year was also standing dead plus fresh cut ash....from field to fire in the same week. You would think I would have learned from year 1. Well I did but made a costly mistake. I had planned to burn spent mushroom substrate but it didn't dry enough. A failed experiment so far.

This year I have split and summer-seasoned the wood. Ash, beech, elm, cherry, maple and a small amount of cedar. My windy hill dries wood fast it seems.

The house has 2700 sq.ft upstairs and 1300 downstairs but the basement (likely) has a high heat requirement because it is 11 ft high and mostly above ground with windows like upstairs. There are 1500 sq.ft in 3 grow rooms within the barn. Heavy DHW requirement: DHW is used for pasteurizing mushroom substrate (70 gallons of 160 degree water per day) plus DHW for a family of 5.

To improve performance this year:
I have increased the insulation in 2 grow rooms so the heat loss will be reduced.
The storage should be better utilized with the lines to the tank insulated and
the wood will be drier

I would consider it a win if I used 8 cords or less and a bigger win if I could dry and burn the spent mushroom substrate instead of wood because it has similar BTU capacity, lower cost and (i think) is easier to process.

 

[mwk1000]

My first year of having all the wood ready. Yea ! Not quite 13 maybe 11 though it's a lot - o - wood for sure but it's good way to exercise outside. We love the house, I am finishing the insulation this fall in the basement and hoping it will cut back on the heat load. There is a LOT of concrete down there with 10' poured walls and NO exterior insulation ( Stupid, stupid,stupid ) so I am getting a barrier on the inside. I hope that finally having seasoned wood will help a lot and the basement with luck my tent will not be empty in the spring.

 

[chuck172]

If I were to load my Tarmsolo 40 once a day during the heating season, I will burn over 5 cords.
That is very conservative.
5 cu. ft. firebox
150 day heating season
One load per day.

Most have a larger firebox. Most heating seasons are longer than 5 months.
Most people load twice a day.
So you have to wonder about claims of less than 5 cords being used.

 

[Tennman]

Third season coming up with the BioMass. Our place is way out of the norm for most of you "nerthoners". Here on the Tennessee/Alabama line our average Nov to March temp is ~38F with brief spells in the teens. Heating a 4800 sf 160 YO house where you can see the curtains moving on windy days thru those old wavy glass windows (to give a sense of efficiency). ~3-3.5 "real" chords to keep our downstairs at 68-70F. Our boiler is an oddity in our area where we're surrounded by Hardy OWBs.

So Heaterman, as one of the most respected contributors here why the heck don't you have one? Get your kids to put one in for you!

 

[Bad Wolf]

I used to burn 1100 gallons fuel oil per year heat and DHW for a 3000 sq ft colonial in CT.
My first two years with the TARM I burned 8+ cords each mostly oak but not the best seasoned.
That includes DHW which probably costs me one of those cords from April to Oct.
My third year I added the hot tub and went up to 9+ cords (that's a 500 gallon tub at 104 degrees) I figure I save around $300 per year on electric. It's kind of hard to keep it at 104 when its 10 outside.

If I can ever get the solar panels hooked up I can probably save a cord.

 

[stee6043]

If I were to load my Tarmsolo 40 once a day during the heating season, I will burn over 5 cords.
That is very conservative.
5 cu. ft. firebox
150 day heating season
One load per day.

Most have a larger firebox. Most heating seasons are longer than 5 months.
Most people load twice a day.
So you have to wonder about claims of less than 5 cords being used.

There are many threads discussing this anomoly. First, a lot of us (most, all?) rarely fill our fireboxes 100% full. Second...a 5 cu. ft. firebox will not hold 5 cu. ft. of wood even full (unless you fill it with sawdust I suppose). If you really want to go nuts on measuring wood consumption you would need to do it in pounds with a known level of moisture.

You can come measure my wood piles and watch me heat late October through March on 3.5 cord of cherry and a little oak if you need proof. Bring beer! It will be a cozy 70 degrees...68 at night. In the interest of full disclosure I will typically heat two or three days in this window with natural gas if I have to travel for work...