Here's a little BTU spreadsheet I made up

[JRHAWK9]

I know it's nothing fancy as I'm not an Excel guru. I decided as of January to start weighing the wood I put in my Kuuma, just to give me a record of what I burn. I then started playing with numbers in a spreadsheet to compute other things.

You basically need to input the following:
BTU's per LB of wood
BTU's per gallon of LP (or whatever fuel you use)
Average monthly cost per gallon of LP (or whatever you use)
Wood furnace efficiency
LP furnace efficiency
LBS per cord of wood (I normalized mine to oak)

Then you just input the lbs of wood you add per loading and it computes the rest. I do three loadings a day.

Any comments on the values I've used? Any suggestions on anything I can change or add?

The dropBox link to it in Excel 2014 is below.
https://www.dropbox.com/s/p5ir7ardu8rhdy8/Wood Consumption.xlsx?dl=0

 

[Deering]

Looks great!

You might want to add in a column for heating degree days. This is a value that captures outside temperature differences from day to day or year to year, relative to some base temperature. For instance, if the base temp is 65F, and the average temp that day was 25F, the HDD for that day would be 65 - 25 = 40 HDD.

With this data you can compare fuel usage based on that period's HDD to account for outside temps. If February has fewer HDDs than January (it's a warmer month), then you'd expect that Feb would see lower fuel usage. If not, then something is going on (boiler efficiency dropping, wood has fewer BTUs, used more domestic hot water, etc.). It lets you compare fuel usage between different timeframes on an apples to apples basis.

You can get historical HDD data for your location from lots of websites. Just Google it up.

(BTW, I grew up in Wisconsin Rapids)

 

[jebatty]

What's the source for 5500 btu/lb? You might take a look at http://mb-soft.com/juca/print/311.html

 

[JRHAWK9]

I found it below:

http://www.mha-net.org/docs/v8n2/docs/WDBASICS.pdf

In talking with another forum member, he actually uses 5,500 to allow for a little less than perfect wood.

I'm open to use whatever value, as I have no idea what real world results are.

 

[JRHAWK9]

Looks great!

You might want to add in a column for heating degree days. This is a value that captures outside temperature differences from day to day or year to year, relative to some base temperature. For instance, if the base temp is 65F, and the average temp that day was 25F, the HDD for that day would be 65 - 25 = 40 HDD.

With this data you can compare fuel usage based on that period's HDD to account for outside temps. If February has fewer HDDs than January (it's a warmer month), then you'd expect that Feb would see lower fuel usage. If not, then something is going on (boiler efficiency dropping, wood has fewer BTUs, used more domestic hot water, etc.). It lets you compare fuel usage between different timeframes on an apples to apples basis.

You can get historical HDD data for your location from lots of websites. Just Google it up.

(BTW, I grew up in Wisconsin Rapids)

That's a good idea, although I don't have a fancy boiler setup.....just a simplistic wood furnace.

Rapids...not very far from here at all. I'm betting the scenery is just a tad bit better where you are now!

 

[Deering]

I'm betting the scenery is just a tad bit better where you are now!

Indeed it is. So is the fishing! But better chance of being mauled by a bear up here.

I don't have a fancy boiler setup.....just a simplistic wood furnace.

Doesn't really matter. You can track HDD by the year, see how it does each year. Or look back to see performance compared to your previous heating system. See the post I just made as an example.

 

[JRHAWK9]

Indeed it is. So is the fishing! But better chance of being mauled by a bear up here.

Not quite the same as you find by you, that's for sure......but this little guy was on our deck this spring! Scared the heck outta my GF when walking out the door to go to work in the morning...lol

 

[JRHAWK9]

Doesn't really matter. You can track HDD by the year, see how it does each year. Or look back to see performance compared to your previous heating system. See the post I just made as an example.

Just added a cumulative monthly HDD column as well as yearly. Thanks for the input! I found the HDD's -HERE-

 

[Deering]

Great pics! Looks like a 2-year old. Nice to see. Don't think I ever saw a single bear growing up there. Here they're a common occurrence - some live right here in town. We have strict ordinances about securing garbage. Otherwise it becomes a real mess.