From OWB to EFM520 Installed in Truck Box

Tonite I set the stoker back to 5 teeth/5 air, we were very pleased with the results this week with so much wind (up to 40 mph) lowest a/m temp this a/m was 10*,we had several mornings with 14-18*,some days did not reach 30* for the high & combined with the wind made for a lot of heat calls from the 3 buildings.Last nite we added 190# of coal,the most we have added so far,tonite we added 160#. Scott.. if you are still watching,we seem to be averaging 1 tub of ash for 150# of coal added,so can't complain about the ash level. This week was a perfect "test run" for us to be able to gage it's abilities during January's usual bitter cold temps. So with the lower limit set on 180*,6teeth/6air it looks like this unit may be able to handle the worst stuff that we normally see here. For the ridiculously brutally bitter, windy ,below zero temps that we have seen on occasion (minus 35* in Jan.1994) we still have a few teeth more to go. Not sure how far it can be set to... 7/7 ,8/8 ? ,9/9 ?? 10/10?????? . Todays high with partly sunny sky was 40* & when I walked into the boiler room at 7 p/m it was 70* inside even with the coal bin door open allowing the coal bin vent to let air into the boiler room. What a contrast to tending the OWB in the outdoor temps like this a/m @10*. Have I mentioned yet that we are

Some of the old S-20 stokers could run a maximum of 8 teeth, the newer ones can run 10...but they run best at 4, 5, or 6 teeth. Proper ash ring is critical for maximum economy.

150 lbs of coal : 1 tub of ash is common.

Rob,i was thinking that you had posted b4 that 150#/coal = avg of 1 tub ash,so we are good to go with that,the fines are still a bit much although not as bad as they were with the 4/4 setting,maybe they do not get enough time to settle at higher feed rate ? I should get a timer hooked to the stoker so I can tell how much of the day it is running at each setting. You posted that you have a timer on yours,is there a certain amount of hrs running time per 24 hr period that you will then switch to a higher feed & air ? I only switched to the 6/6 because of the very low temps & high winds that were forecast & as I said in an earlier post,we are very happy with the results of this COLD/WINDY test run.Hopefully we never need to test the 7/7 or higher settings.We can also run the crane a bit harder,we are only running it in the 450 -500 * range avg.

My suggestion would be to test the 7/7 (or whatever air setting turns out to be needed) before you need it, so you aren't trying to experiment with live ammunition. If you find, for example, that you need coal that is sized better to achieve an orderly burn at higher feed rates, that would give you time to acquire a stash and get it dialed in.

I'm not a hydronics guy, but my knee-jerk would be to not go to a higher feed rate until the boiler can't hold the set temp at a lower feed rate.

Mike

I had set it up to the 6/6 because it seemed to be taking a considerable time to get up to the shut-off point.I don't like to think it is sitting at 150-160* for hours trying to get up to 180* which means that all our heat exchanger fans will have to run longer with the lower temp.With the results we experienced thru this cold/windy spell we just came thru I feel pretty confident with the 520's abilities. I was curious when I set it up from the 5/5 to the 6/6 as to what is the difference. I could hear an increase in the feed,but the force of the air was the most noticeable.

Well,it looks like we averaged 100# per day in Oct, 130# per day in Nov. (it was a cold month with lots of high wind),so far 140# per day in Dec, the reason I decided to do these figures is that I was a bit confused/concerned about the usage this month. We have had higher temps than the preceding days in Nov. so why the higher usage ? NO SUN except a little bit on the 1st,early am & then that changed to rain & wind after noon. We have estimated a total usage of 6200# so far leaving us with about 10,000# in the bin. 55 total days usage averages @ 110# per day. We will probably be needing to get an additional 4 tons to get us to the end of May. That is not calculated with Isayre's type of calculator ,just a cheap one that I have. Time will tell if these figures are close to right,hopefully we have figured on the high side of usage. We are very happy with the results so far.Tending the boiler in the box tonite with moderate rainfall & cold outside,my wife & I reflected on what it would have been like with tending the OWB in the same weather condition,it was not a reflection that gave us good memories !! It did give us a very good feeling knowing that those hideous tending times are past .

Windy,
I find that wind speed and direction have a bigger effect than temp alone. Now if its cold and wind is blowin out of the north...... Might help explain some of your observations or it might make ya laugh, either way .

best,
waldo

I just looked up Jonestown, PA and for November the daily average Heating Degree Days per day were 26, and so far in early December the daily average for Heating Degree Days has been 30, so it is not the case that on average to date November has been colder than December. That you burned on average roughly 130 lbs. per day in November and so far roughly 140 lbs. per day in December seems to be consistent with HDD's.

If we can initially guess that on average you burn 10 lbs per day to provide for the homes hot water (DHW) needs, then your home heating needs break down as follow:

November:

130 lbs. - 10 lbs. = 120 lbs. burned per day to heat the home.
120 lbs. / 26 HDD's = 4.62. lbs. burned per HDD

December:

140 lbs. - 10 lbs. - 130 lbs. burned per day to heat the home.
130 lbs. / 30 HDD's = 4.33 lbs. burned per HDD

If anything your December coal burning efficiency has (to date) been roughly 6.5% better than your November efficiency.

waldo lemieux wrote:Windy,
I find that wind speed and direction have a bigger effect than temp alone. Now if its cold and wind is blowin out of the north...... Might help explain some of your observations or it might make ya laugh, either way .

best,
waldo

Same here. -30 and calm is no problem, but 0 with a 25 mpg NW wind really makes the EFM go to work.

David has mentioned on several occasions that the wind roars at his place, plus the buildings are less air-tight than he would like. I'm sure the wind speed and direction has a huge impact on the amount of coal burned.

Waldo,you are correct about the wind direction,especially with our shop.The 3 overhead doors on our shop face to the NNE & we see a lot more heat calls when the wind is from that direction rather than the WNW. How often since we bought this place have I wished that the OH doors faced to the south ? I've lost count .

Isayre, you are correct about the avg temp,but I was going by the days in November that were similar temp to the temps in Dec so far. I wasn't looking at our record breaking low of 10* on 11/22 nor the temps above 60* we had on 11/4,11/5,11/10,11/11,11/24, for Dec so far we have had 12/1 @ 30*low to 50* hi,but the rest of Dec our low was 27* on 12/5 with the high of 38* on 12/3,4, no solar gain with heavy overcast,rain much of the time.We also have had no wind speed in Dec. to compare to the crazy winds we had in Nov.. Now with those #/day figures which look to avg @ 4.5 # I only need to find the avg HDD for the next few months & I should be able to better calculate our future usage.Thanks.

Rob, the rental trailer is the least affected by the wind direction, our house would be next with its ability to shrug off winds from the south or southwest ,both of which happen rarely. East to NE probably are the worst for both our house & the shop, the shop can shrug off the westerly winds pretty decently,but our house is affected only slightly less from the Westerly winds than it is from the NNE. All in all we are very pleased with the #/day coal used. I have been quietly watching other members post their consumption for heating 1 house & the DHW & if I were to use their figures x3 we come out better in several cases.

windyhill4.2 wrote:Isayre, you are correct about the avg temp,but I was going by the days in November that were similar temp to the temps in Dec so far. I wasn't looking at our record breaking low of 10* on 11/22 nor the temps above 60* we had on 11/4,11/5,11/10,11/11,11/24, for Dec so far we have had 12/1 @ 30*low to 50* hi,but the rest of Dec our low was 27* on 12/5 with the high of 38* on 12/3,4, no solar gain with heavy overcast,rain much of the time.We also have had no wind speed in Dec. to compare to the crazy winds we had in Nov.. Now with those #/day figures which look to avg @ 4.5 # I only need to find the avg HDD for the next few months & I should be able to better calculate our future usage.Thanks.

I agree that 4.5 lbs. per HDD is a safe initial bet for calculating your future consumption. Add 10 lbs. per day to it for the homes hot water needs. Here are the historical average monthly HDD's for zip code 15905.

Jan 1111.0
Feb 925.0
Mar 762.0
Apr 401.0
May 172.0
Oct 375.0
Nov 643.0
Dec 974.0

Looks like about 13 tons as a first guess. How many cords of wood did you previously go through? The reliability of this depends a lot on how close you are to zip code 15905. Some of the hilly areas around Johnstown have appreciably more HDD's.

Start here to get a better local HDD picture: http://www.huduser.org/resources/utilitymodel/sou ... graphy.odb

Isayre, did you actually use Johnstown ? We live in Jonestown,HDD days are most likely different for the 2 towns. But,even with that,i had roughly figured about 12 tons for Oct - May. We used about 30 cords of wood +/- for the year. Zip code here is 17038 & we are close to Indiantown Gap Military Reservation .

windyhill4.2 wrote:Isayre, did you actually use Johnstown ? We live in Jonestown,HDD days are most likely different for the 2 towns. But,even with that,i had roughly figured about 12 tons for Oct - May. We used about 30 cords of wood +/- for the year. Zip code here is 17038 & we are close to Indiantown Gap Military Reservation .

Yes, it appears I got the city wrong and that could well make a big difference. Sorry about that! Go to the web link I provided in my amended post above and you will be able to get closer to your local area for the monthly average HDD's. For data from a weather station in Lebanon I get the following:

HDD Jan 1169.0
HDD Feb 984.0
HDD Mar 806.0
HDD Apr 474.0
HDD May 208.0
HDD Oct 427.0
HDD Nov 712.0
HDD Dec 1017.0