comparison of propane vs coal usage in a koker

Hello everyone, I was wondering if I could get some opinions on my coal usage vs past propane usage. Going into this coal burning "hobby", I was burning approx 650 gal of propane a heating season for my 1,700 sf house, using forced air with the furnace in the front basement (~600 sf). So based on btu usage, I was burning about 59.4 millon btus of propane. Converting that to coal produced an expected amount to burn at 2.5 tons. The one thing I didn't take into account when figuring this is the btu's being dumped into the basement itself. It is a poured basement with insulated (Styrofoam sheets behind dry wall) and it has easily maintained temperatures in the low to mid 70's while the coal furnace has been running. So heating the basement isn't a bad thing, I now have warm floors above the basement.

I am anticipating using up my entire 7200 #s of coal and maybe more based on what I have used so far this season. That puts my potential coal usage for the year between 3.6 to 4 tons. I guess this isn't too bad, but this will put a bigger dent in my savings over propane and increase my pay back time for the koker.

I was just wondering if some of you past propane users with a similar scenario as me find the additional coal usage reasonable. I am pretty sure I have the koker dialed in so I am not wasting coal (like I did the first few weeks).

Thanks for any help you can offer.

Hey Rob, how warm was the basement when you were only burning propane? Are you keeping the main house the same temperature as before?

You aren't the first person to burn more coal than initially calculated, and more often than not it comes down to heating more square footage (intentionally or not) and a higher average temperature in the home.

Rob R. wrote:Hey Rob, how warm was the basement when you were only burning propane? Are you keeping the main house the same temperature as before?

You aren't the first person to burn more coal than initially calculated, and more often than not it comes down to heating more square footage (intentionally or not) and a higher average temperature in the home.

Yeah, that is what I am slowly figuring out. My basement stayed probably in the mid/upper 60's while burning propane and the main house is a couple degrees warmer most of the time due to the furnace overshooting the thermostat (thermostat is set the same, at 68 F).

It is tough to compare solid fuel consumption to push button fuels.

Not only is combustion efficiency different but also system efficiency is different.
You will probably use 5 to 10% more btu's just based on combustion efficiency. Most fuel cost calculators let you plug this in.
The system efficiency is also usually less. The solid fuel must have a constant fire. This tends to lead to more system losses via ductwork and piping as you are experiencing with a warmer basement. I have a remote boiler that has considerable loss to the shop that it is in. I would not normally heat this shop if I had to burn oil or propane. I also went to great expense to insulate the piping and the boiler to minimize the warming of this shop with the coal.

Also, the psycological effect of thinking the fuel is cheaper tends to lead towards a warmer thermostat setting.

So yes, be prepared to burn more that what a non-adjusted conversion of propane btu to coal btu's would be.

My situation was a bit different.
Rent tank so no choice on contract price getting ripped.
Old slant fin galaxy 170k and not operating efficiently probably 70%.
5700 sqft now heating finished basement and keeping a toasty 72 vs 65.
Now unlimited DHW, additional savings on electric tank.
Also using for 20k pool for summer, use pool another month in the spring and an extra month in the fall.

Consider the following. These numbers will be different for you.
Condensing Modulating Boilers are up to 97% but also 10k + install
Well Mclain Gv90+6 is 3,500 + install, if i had to replace the galaxy probably what i would get.
The S260 was 8500 + install. Coal is 1/4 of price of propane and if you buy bulk or large quant, you can save even more
due to inflation. My payback is 3 to 4 years.

Modulating problems = $$$$$$
Coal problems = $

It's tough to compare "apples to apples" here. When I went from my home's original propane FHA system to the Koker's FHA back in 2007 I found myself burning a LOT more BTUs; because, now keeping warm didn't cost an arm and a leg---plus my basement was now nice and warm too. You've got to factor in the intangible effect of being truely comfortable; versus, freezing 'yer ass off...

My 2 cents.

Some articles about issues with newer condensing boilers.
http://enhancedlivingblog.blogspot.com/ ... their.html
http://robertkyriakides.wordpress.com/2 ... d-weather/
http://www.cisionwire.com/next-step-mar ... s,c9187210
http://www.lettingfocus.com/blogs/index ... en-conned/

We used to burn on average 960 gallons of oil per season. This was with the stat set at 64 when away and nights and 68 when getting up in the morning and evenings. It was chilly in here and we had to wear slippers and sweatshirts most of the time.

Fast forward to last heating season. We put in a used Koker, keep the house at 68 from 10pm to 6am and 70 from 6am to 5pm and 72 from 5pm to 10pm. We now just turn up the stat if it feels chilly when the setpoint is under 72. House is MUCH warmer, We no longer wear slippers or sock and sit around with a t-shirt on and PJ bottoms (nice and comfy). We used 12,980 lbs., over 204 days for a total cost of $1600. Oil would easily have been over $4000 due to the long cold winter we had last year.

Change your thermostat and you'll be more efficient and have more even temps with almost no overshoot. I posted the info in another thread but can post it here if you like.

along with saving the high cost of fuel oil, their is the priceless feeling of security and warmth with a pile of red hot anthracite coals burning in my iron stove in the front room.

An interesting observation: Been running a coal-trol for about a month now and my basement temp has dropped about 3-4 degrees. With the coal-trol running my convection blower almost constantly (probably 90% of the time each day), it is pushing more of the koker's heat into the living space (even the luke warm air produced at low feed rates), keeping the sides of the koker cooler and thus reducing the BTU's being dumped into the basement. Thus, the coal-trol is making my koker more efficient by putting more of the coal's BTU's into the living space.

I second the higher t-stat after switching to coal. After I finally got my KA-4 fired up in the new house the t-stats when from low 60s to 70F. I haven't run the wood stove since

Here is a nice fuel comparison calculator that's built into the forum. I don't know when they added it but I found it doing a Google search: http://nepacrossroads.com/fuel-comparis ... ulator.php

I have a similar story. We used to keep the house at 62-63 degrees, and now its at 68-70 degrees with coal.

For the past 5 winters we heated the home with electricity. During that period we ranged from about 27,000 KWH to 33,000 KWH of annual usage, based on how heavy the winter was, and how many of the kids (now all adults) were still at home and not off at college, or off getting married, etc... My winter months electrical usage generally ranged from 4,500 to 6,500 KWH per month, particularly for Dec, Jan, and Feb, and March.

Now I can already see that I'm down to using only about 550 KWH of electricity per month during the winter months. But it is costing me more in coal usage than I had initially anticipated, perhaps to the tune of about one ton of extra coal annually.

I initially assumed that the AHS Coal Gun would be between 82% and 86% effieicent, but now I know that my overall system efficiency (coal burning efficiency) has in reality been only in the range of perhaps as low as 65-70%. There have obviously been areas where I miscalculated. Things such as inneficient coal consumption on warm days when few to no BTU's are really required have thrown me off, and with this odd winter, we have had our share of such warm days. Also the cost of the extra 6-8 degrees of round the clock warmth was not initially considered, and I'm certain that other efficiency matters related to soild fuel heating were also not considered.

Our coal burning efficiency seems to be great when its grippingly cold, so what is really needed is a more normal winter (or a really nasty one) to see how that affects the system efficiency.

lsayre wrote:Also the cost of the extra 6-8 degrees of round the clock warmth was not initially considered,

That much difference in average temperature is significant.

I'm not all that upset about it, as I'm still saving a bunch.

As much as you want to eek all the btu's out of your coal, don't overlook the fact that you ARE warmer, the envelope you live in is warmer, AND not a dime has to leave this country! PLUS you can keep a supply that will last for years at the price of 2 winters of oil or 1 winter of propane.....alright, i winter and 3 days.

97% efficient condensing boilers.....yah right! You think it is expensive to 'tune up the beemer', well you are about to experience a 'puckering beyond compare' as that boiler ages.

Some folks would not be happy if the damned fuel of whatever derivative were free, so if you don't want to give up your propane for whatever reason, go swiftly to the poor house, and please list your inefficient junk coal burning equipment on the forum so some innocent newbee can have a chance at the dream of keeping his or her family warm affordably without constantly bitching about costs they don't understand.