Anticipated coal consumption vs. Temp. & Degree Days

I will send you the spreadsheet if you want to mess with it.

Rob, send away via PM. Let me know your nominal daily summer burn rate as well.

lsayre wrote:I could predict in advance to within typically +/- 8 lbs. of coal how much was going to be needed in order to fill my hopper. That was for filling it roughly every third day, and every other day for the coldest stretches. I was amazed at how many times my calculation and reality were one and the same.

To quote the 'A Team': I love it when a plan comes together. The fact that you could predict it that closely is awesome!

Guess I'll jump in here, too. Nice work everyone.

I was never that concerned with anticipating coal usage on a daily basis; more so on a seasonal one. I also would start each season and never remember when I had started the year before. I always wondered if I was early or late each year. Or how much coal I burned last November ... and was it colder last November?

I was also curious about the effect of windspeed on coal consumptiom. I don't know if I ever answered that particular question, but I now know when I start up and shut down each year. I was also concerned with maintenence. When did I last clean out the stove, oil the motors, etc. So I threw together a simple database a few years ago and then added things to it as I got the time ... like how many times I refill the humidifiers, which has absolutely no practical application, but it's interesting to know.

I get the weather data from weatherunderground.com that's uploaded by someone's presonal weather station near me.

It's dead-on accurate each year. I run out of coal on the day it calculates, or I have pretty much exactly the amount leftover that it says. It's nice when I think that I'm running short to have the data from previous years to look back on.

Someone on here (can't remember who) rigged a pedometer to their stove to count how many strokes it takes each day. Fantastic idea that I adopted as well. Unfortunately, my batteries went dead over the summer and I have yet to replace them. But I think that that's far more accurate than measuring pounds in. It's not predictive, but interesting. I've found that I can change the timers on my stove so that the T-stat calls for heat far less often, the stove doesn't overrun the setpoint, and, in the long-run, I burn less coal. The last attachment below shows the timers table that I use to set them.

Attachments show some screenshots and reports. Questions and criticisms are always welcome.

Now that is some impressive data and usage of same. It makes my playing around with numbers seem childish by comparison. Well done!!!

lsayre wrote:Now that is some impressive data and usage of same. It makes my playing around with numbers seem childish by comparison. Well done!!!

Thanks! It all started with a spreadsheet and grew from there. If you have or use MS Access, I'll shoot you a copy of it if you want to play with it.

I was just thinking about adding something else to it - number of people in the house. As a divorced dad, my three kids stay here only four or five nights per week. They're young and energetic and put off heat like little blast furnaces. I wonder if there's a correlation there....

Thanks again.

Horace wrote:

lsayre wrote:Now that is some impressive data and usage of same. It makes my playing around with numbers seem childish by comparison. Well done!!!

Thanks! It all started with a spreadsheet and grew from there. If you have or use MS Access, I'll shoot you a copy of it if you want to play with it.

I was just thinking about adding something else to it - number of people in the house. As a divorced dad, my three kids stay here only four or five nights per week. They're young and energetic and put off heat like little blast furnaces. I wonder if there's a correlation there....

Thanks again.

Unfortunately (in this instance) I run Linux, not Windows.

The chart you developed can actually have a very large impact on your fuel bill when done properly.

One of the ways my primary heating system operates so efficiently is due to this type of charting programmed into my propane boilers computer. I use radiant floor heating throughout my house and with several sensors the computer checks the temperature outside, the temperature in my concrete slab, the temperature returning from the floor, and the thermostat set temperature desired, and compares it once per minute with the degree day chart. As the temperature drops outside, the computer calculates what the concrete slab is losing for heat and adjusts it so that the heat in the house is always within a degree of what the thermostat is set for.

Because my concrete slab is such a thermal mass, and is basically a huge radiator, I only have to heat that floor with water in the 75-100 degree range...in essence it really is only warm water. In another thread a person was trying to claim that a 45K stove could heat a 4000 sq ft home which falls short because a btu is a btu. In my case my boiler is actually pretty dumb, it just has a computer system attached to it that ensures only the minimal amount of heat is used to reach the temperature desired.

It does this through a metering pump. The boiler keeps the main boiler loop at 100-150 degrees, yet the metering pump gets its direction from the computer and mixes the returning water from the floor, with that hot water in the main boiler loop. That target temperature is what your degree day chart is. For instance, if the temperature outside drops, the concrete slab loses more heat, so to compensate for that, instead of sending 76 degree water through the radiant floor tubes, it sends 78 degree water through them, if the temperature outside goes up...well it drops the water going through the radiant floor piping because the slab is losing less heat...based entirely on that charting that you have!

Now here is the part where coal comes in.

Currently I use a hand fed coal/wood stove to keep the cost of heating my house down...propane is expensive. BUT since my propane boilers only job is to keep that main loop hot at 100-150 degrees, I can eventually utilize a coal boiler to do that and utilize the rest of my sophisticated radiant floor heating system to put that hot water where it needs to go efficiently.

Others may tease you, but I can tell you first hand that you are on the right track for getting the maximum heat out of your coal appliance.

One thing to keep in mind here is the inherent differences in coal and propane boilers.

In some ways propane has the edge because it has the benefit of being instant on and instant off so that some fuel is not wasted. At the same time propane flame can be adjusted, from 10%-95%, where as coal does not have that same amount of efficiency or control...and neither does oil for that mater due to the jetting of the nozzle, but that is for another discussion.

There is one issue with the system that I have; because the system requires continual cycling, the circulatory pumps are always on during the heating system, and all of my pumps run me about $10 a month in additional electricity. Also, the metering pump...while not essential for propane (the boiler can be programmed to do what it does), IS required to knock down the high temperature water generated by a coal boiler (or pellet boiler, or oil boiler, or wood boiler, etc) to a temperature the radiant floor heating system can use.

You will have some losses as the coal stove goes into idle mode just burning enough coal to stay lit, but your charting is really the basis of the system what I have, and you are well on your way to having a super efficient heating system. Good for you.

Yes, outdoor reset can have a positive impact on coal consumption and comfort. Another forum member has a Tekmar control on his EFM and does just that. In my opinion outdoor reset works best on well insulated and tightly constructed homes, since it has no idea how hard the wind is blowing.

I will soon be installing an EFM in a brand new log home, and I'm planning to use a Hydrolevel control that adjusts the boiler temperature based on thermostat activity.

Horace wrote:So I threw together a simple database a few years ago and then added things to it as I got the time ...

I aspire to your database! I've put together a few myself and am always using them @ work. Yours looks great. Is that MS Access' continuous form? Nice work!

Horace wrote:Someone on here (can't remember who) rigged a pedometer to their stove to count how many strokes it takes each day. Fantastic idea that I adopted as well. Unfortunately, my batteries went dead over the summer and I have yet to replace them. But I think that that's far more accurate than measuring pounds in.

That's an awesome idea! I agree with you that it would be better than measuring pounds in. My system is auger fed. You've already got my wheels turning. I don't think I can use a pedometer but I'm thinking about putting a cam or something on the shaft of the auger that actuates a counter of some sort. That way I could count auger revolutions and correlate that to pounds. Anybody out there already do something like that? How did you do it?

Horace wrote:It's not predictive, but interesting.

Not quite sure what you mean here. How is it not predictive? It would seem to me that paddle motion should be correlateable to the pounds of fuel used which can then be tied to outdoor temp to predict usage. Unless you mean that it's not predictive by itself and needs to have temperature with it to be useful...

Mike

lsayre wrote:Unfortunately (in this instance) I run Linux, not Windows.

Me, too. I run these with VirtualBox and XP. Let me know if you change your mind.

mdrelyea wrote:I aspire to your database! I've put together a few myself and am always using them @ work. Yours looks great. Is that MS Access' continuous form? Nice work!

Thanks! It's a contiuous subform within a form (I think.) Want a copy? I can zero out all my data and shoot you a copy if you want to play with it. Someday I'll figure out how to make it a web application and give everyone who wants it access to it.

mdrelyea wrote:That's an awesome idea! I agree with you that it would be better than measuring pounds in. My system is auger fed. You've already got my wheels turning. I don't think I can use a pedometer but I'm thinking about putting a cam or something on the shaft of the auger that actuates a counter of some sort. That way I could count auger revolutions and correlate that to pounds. Anybody out there already do something like that? How did you do it?

I know you weren't asking me, but mine is a Dollar Store pedometer and some wires with the ends bared that I have zip-tied to the cam. As far as correlating it to pounds - I would load 15 pounds in the hopper and see how many revs it takes to unload it. Wet coal would feed more slowly, dry faster, but it would give you a starting point.

mdrelyea wrote:Not quite sure what you mean here. How is it not predictive? It would seem to me that paddle motion should be correlateable to the pounds of fuel used which can then be tied to outdoor temp to predict usage. Unless you mean that it's not predictive by itself and needs to have temperature with it to be useful...

Exactly. I can't load the Farmer's Almanac into the DB and predict how much I'll use this year. I guess that that's not impossible, but this is Pennsylvania. If you want the forecast to change, just wait 10 minutes.

Let us know how you make out with your next project!

Horace wrote:

mdrelyea wrote:I aspire to your database! I've put together a few myself and am always using them @ work. Yours looks great. Is that MS Access' continuous form? Nice work!

Thanks! It's a contiuous subform within a form (I think.) Want a copy? I can zero out all my data and shoot you a copy if you want to play with it. Someday I'll figure out how to make it a web application and give everyone who wants it access to it.

Sure! Shoot me a copy. It looks pretty customized to your setup - as it should be - but maybe I can learn something from it.

Horace wrote:

mdrelyea wrote:Not quite sure what you mean here. How is it not predictive? It would seem to me that paddle motion should be correlateable to the pounds of fuel used which can then be tied to outdoor temp to predict usage. Unless you mean that it's not predictive by itself and needs to have temperature with it to be useful...

Exactly. I can't load the Farmer's Almanac into the DB and predict how much I'll use this year. I guess that that's not impossible, but this is Pennsylvania. If you want the forecast to change, just wait 10 minutes.

Right. Although you can current data and historic data to predict how much you'll use in the future. You'll have to take variation into account obviously- but that's what statistics are for. When I did that, I took historic data from this site and plugged that information in to the formula I derived from my current consumption data. That gave me a wide range of past usage information. So then I was able to determine that "for the past X years I would have used Y tons on average with a standard deviation of Z" Then when I ordered coal, I ordered Y+Z tons. If I had wanted a bigger safety net I could have ordered Y+2*Z tons.

Horace wrote:Let us know how you make out with your next project!

Just posted the details

Mike:

I haven't forgotten about you. I ordered and received a Raspberry PI for one of my daughters for Christmas and haven't been able to stop playing with it. This thing is like the Tickle-Me-Elmo of the tech world, although they are a little easier to get now. Fully-functioning Linux-based ARM computer for $35. Very cool.



https://en.wikipedia.org/wiki/Raspberry_Pi
http://www.newark.com/jsp/search/produc ... aspi-group If you want to order one.

I said previously that I would zero out my data before sending it to you, but on further thought, do you want me to do so? I can leave it all in there if you want so you can get an idea of how it works with data in it.

On even further thought, I can just as easily do both. I'll do that.