Fuel consumption log / prediction models

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OverlookEGR

OverlookEGR

Member
Jan 21, 2015
68
Ashford ny
I've been using my pellet stove for less than a full season, but being an engineer, I MUST collect and analyze the data!

Now my specific situation is simple in some ways, but complicated in others.

Simplified:
1. Only have burned one kind of pellets.
2. Have used room temp mode almost exclusively and do not adjust it. The room our stove is in is usually around 68*F

Complicated:
1. The stove does not heat the entire house very well.
2. We have an oil fueled boiler that also would not heat the entire house very well.
3. The heated house area of each respective heating system does not overlap very much.
4. We use the oil heat periodically when we have company over and sometimes just because we are tired of the extremities of the house being cold!

Anyway, I have been burning keystone hardwood pellets that I picked up for $225 per ton, before tax, delivered.

I have discovered the heating degree day concept and find that to be a great way to track fuel heat consumption in relation to the temperature. So here are my data points so far. Reported monthly. (I figure the process is rough enough, reporting monthly gives me a nice average)

September. 108 HDD, 4 bags burned, 1.48 lbs per HDD.
October, 359 HDD, 13 bags burned, 1.45 lbs/HDD
November, 809 HDD, 37 bags, 1.83 lbs/HDD
December, 969 HDD, 44 bags, 1.82 lbs/HDD
January, 1373 HDD, 56 bags, 1.63 lbs/HDD

Don't really know why the consumption was higher in nov and dec, but I'm still interested and will keep tracking.

Incidentally, the previous owner said she burned 5 tons last winter, it was her only source of heat, and she lived by herself and worked out of the home. Summing up all of the HDD for last winter, that works out to about 1.5 lb/HDD.

What do you guys do?
 
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You lost me at engineer

Just kidding I just dump and go. If I am warm its all working for me
 
I would think windy days would increase heating demand, especially if you do not have OAK. But the HDD data would not allow for wind?
 
So i just quickly read how the HDD work and it seems to take into account the temlerature of the day. Im know expert, but i wouldd think things like wind and the amount of sunlight would affect your heating requirements and arent taken into account by the HDD data.
 
There's a sweet serenity in not being obsessive about the data :) how's it go? Ignorance is bliss? No offense. At least you don't have to worry about reconciling your fuel consumption log or worry if you wrote a bag down or not!
 
True, wind is not really accounted for. We are having our big single pane picture window in our living room replaced next week which should help reduce our heat loss.

Sun is not really a factor for us until late January. It is virtually nonexistent until Lake Erie freezes over. That lake produces a lot of clouds (and snow).

But seriously, the wind and sun factors are not really accounted for with HDD.

Edit: I do have an OAK. I'm glad I do. After reading on here, It seems the way to go.
 
Neither is the increase of insulation value of the house when snow covered or with snow banked against it. Lots of nice dead air space in the fluffy stuff.
 
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The window replacement was something my in laws wanted us to do and since they want us to do it so bad they are
Helping pay for it, we will do it.

Having just bought the house this fall, we are still figuring out where it needs insulation. There was an attic space above the kitchen that I discovered the floor was totally uninsulated. We blew in 8 inches of cellulose this fall, giving us around r-22 which I hope makes a big difference.
 
OverlookEGR said:
I've been using my pellet stove for less than a full season, but being an engineer, I MUST collect and analyze the data!

Now my specific situation is simple in some ways, but complicated in others.

Simplified:
1. Only have burned one kind of pellets.
2. Have used room temp mode almost exclusively and do not adjust it. The room our stove is in is usually around 68*F

Complicated:
1. The stove does not heat the entire house very well.
2. We have an oil fueled boiler that also would not heat the entire house very well.
3. The heated house area of each respective heating system does not overlap very much.
4. We use the oil heat periodically when we have company over and sometimes just because we are tired of the extremities of the house being cold!

Anyway, I have been burning keystone hardwood pellets that I picked up for $225 per ton, before tax, delivered.

I have discovered the heating degree day concept and find that to be a great way to track fuel heat consumption in relation to the temperature. So here are my data points so far. Reported monthly. (I figure the process is rough enough, reporting monthly gives me a nice average)

September. 108 HDD, 4 bags burned, 1.48 lbs per HDD.
October, 359 HDD, 13 bags burned, 1.45 lbs/HDD
November, 809 HDD, 37 bags, 1.83 lbs/HDD
December, 969 HDD, 44 bags, 1.82 lbs/HDD
January, 1373 HDD, 56 bags, 1.63 lbs/HDD

Don't really know why the consumption was higher in nov and dec, but I'm still interested and will keep tracking.

Incidentally, the previous owner said she burned 5 tons last winter, it was her only source of heat, and she lived by herself and worked out of the home. Summing up all of the HDD for last winter, that works out to about 1.5 lb/HDD.

What do you guys do?
Click to expand...
Wow, January was much colder for you than December, about 13 degrees colder. Typically here, January is about 5 degrees colder than December.

I tracked Degree Days when I used oil. When I switched to pellets, I just mentally calculated the equivalents, and since they were in the ballpark, I was good to go, and stopped tracking.
 
Hmmmnnn


I am pretty analytical ... BUT

I have been around long enough to know that generally the difference between a "cold" and "warm" winter is at most 12 - 15 percent in fuel consumption.

Therefore ....

I simply track what I buy ,,,, will subtract any left over ,,,,, and purchase accordingly for next year.

Seems the only practical purpose of tracking fuel use data would be for future purchase reference and bag or ton count will suffice for me.

I do understand the "hobby" though.

I'll stick to fishing.
 
Also an engineer. Dunno your boiler situation but sounds like placement of the stove is suspect. As well, it should be obvious that a point - source of heat isn't going to give you even heat throughout your home. A lot also depends on insulation and layout.

You must be an EE. ;):)
 
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F4jock said:
Also an engineer. Dunno your boiler situation but sounds like placement of the stove is suspect. As well, it should be obvious that a point - source of heat isn't going to give you even heat throughout your home. A lot also depends on insulation and layout.

You must be an EE. ;):)
Click to expand...
CE. Been out of school since 2007. Have had my license for three years.

A lot of those recommended r-values are "prescriptive" by the building code for new homes. My firm does prepare house plans and we usually do a building envelope analysis instead of using the prescriptive values.

I could upload a sketch of the stove placement of you are interested.
 
hyfire said:
Your wasting way to too fuel here oil or pellets, insulate the house and it will payback within a year. Some links of interest which can help calculate your btu loss and savings...Its very nice that you logging but you could do this via a wifi T stat, it will tell you the temp outside, inside and your run time for 30 days at a time.

http://www.ccithermal.com/heatlosscalculator/ruffneck/imp/index.php

Here is another link:

www.insulationsmart.com/what_will_i_save.htm
Click to expand...
being from Ontario how many tons have u gone thru. reading what our American friends r going thru in a season is unbelievable.
 
OverlookEGR said:
CE. Been out of school since 2007. Have had my license for three years.

A lot of those recommended r-values are "prescriptive" by the building code for new homes. My firm does prepare house plans and we usually do a building envelope analysis instead of using the prescriptive values.

I could upload a sketch of the stove placement of you are interested.
Click to expand...
Oh God! A Civvie! Sure. Upload 'em. ChemE and ME here.
 
Overlook, any heat source in your home will also affect your burn rate. Use a space heater one day? That affects it. Or your oil burner? How about a day where your wife cooks or bakes more? Any period where you might open doors to go outside more often? How about running a clothes dryer? If any month has more of those anomalies it will affect your usage. Conservation of energy ...

Also, how clean you keep the stove and all the key heat transfer surfaces matter. I recall one pic you posted showed some more cleaning is recommended.

I collected about 4 years of logs. All the primary variables of the stove, plus weather conditions and any other influential data. It did enable me to create the best set up for my home because of that data and experimentation. Secondary variables had a greater affect than I expected.

Today I never run room temp mode but only stove mode, and my entire floor where my stove is located is comfortable with my set up. I found warming and cooling the stove through the transients to be less efficient; the more of those transients I had, the worse my fuel consumption. That happens in my case because I use the furnace blower to move cold air into the stove room with a 70% duty cycle and it drove the room temp mode crazy.

I adjust the stove temp setting a couple of times a day and that is better. Like you, I'm influenced by Lake Erie and the daily temperature swings are fairly small so stove temp works well.

Glad to see other engineers here. Bachelor's & Master's in Engineering Mechanics; thermal engineer by practice.
 
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Here is my rough floorplan. i tried to detail the heat a little as well to give you an idea of where the oil boiler provides heat and where the pellet stove is located. The first floor file has a link to the circulation fan, hover over the callout. I put in the M-6 model.

jp99, yes, there are many other sources of energy consumption in my house. I don't really think it's possible for me to track all those little sources. I am sort of trying to look at it from a bigger picture, of "with normal every day living: cooking, drying cloths, etc, what is my fuel consumption" Also, it would be nice to have a forced air system so i could distribute heated air around.... AND i may be convinced to run the stove on stove temp :) it's just so much easier (in my head) to run it on room temp. OK. Off to a night meeting for work...
 

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the cug said:
being from Ontario how many tons have u gone thru. reading what our American friends r going thru in a season is unbelievable.
Click to expand...

I am at the 2 ton mark, but I estimate 4 tons by end of season, I am in the process of insulation from R 2 to R 19 so I should see some savings.
 
Cab
OverlookEGR said:
Here is my rough floorplan. i tried to detail the heat a little as well to give you an idea of where the oil boiler provides heat and where the pellet stove is located. The first floor file has a link to the circulation fan, hover over the callout. I put in the M-6 model.

jp99, yes, there are many other sources of energy consumption in my house. I don't really think it's possible for me to track all those little sources. I am sort of trying to look at it from a bigger picture, of "with normal every day living: cooking, drying cloths, etc, what is my fuel consumption" Also, it would be nice to have a forced air system so i could distribute heated air around.... AND i may be convinced to run the stove on stove temp :) it's just so much easier (in my head) to run it on room temp. OK. Off to a night meeting for work...
Click to expand...
Can't open the files
 
How well does that fin tube under the kitchen floor work?
 
chken said:
How well does that fin tube under the kitchen floor work?
Click to expand...
It definitely warms the joist space where they are located. My kitchen island is located over top one of those spaces so we don't benefit from that one so much. I plan to do a little re plumbing before next winter to fix that.

I like the warm floor. I'm just a little worried it's too warm. They say tile floor should not get too warm or the grout will start to break down. I considered putting in a true radiant heat system for the kitchen, but with my existing boiler, it's complicated. My boiler system is a 180*F system and most radiant floor systems are only 140*F systems. My boiler is pretty old too, so I might replace it in the next few years, but now, it's a cast iron boiler(non-condensing). So I have to run the whole system at the higher temp, or buy expensive valves to allow there to be two temperature zones.

So for now, I'll keep the fun tubing in. It's mounted near the bottom of the joist space and there is no insulation in it.
 
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