From OWB to EFM520 Installed in Truck Box

I think the run time issue relates primarily to performance rather than efficiency. Your heating and DHW loads generally are not uniform for a 24-hour day, so if you wait until the unit runs continuously to bump up your feed rate you almost certainly will have times within the day when the system falls noticeably behind on the load. Once you get above 16-18 hours of operation during a day I think your likelihood of that gets pretty high. As Sting might say, that's a figment of the public internet; if you're happy with the performance there's nothing I know of that's wrong with letting it run longer.

A lot of factors may affect efficiency. With a 520 I would be comfortable suggesting that you use the lowest feed setting of at least 4 teeth (with air appropriate to maintain a proper ash ring) that carries your load satisfactorily.

Mike

Pacowy, thanks for that info. The heating load in the a/m is heavy with the outdoor temps generally at the lowest, & that is when both households start using DHW which also demands more from the boiler. That does help clarify the issue for us,i will likely set back to 5 teeth Sunday when the temps moderate again.I emptied a full ash pan this a/m,that is the first time it got full in a 13 hr period .The WINDS were FEROCIOUS here last nite,it was actually shaking the walls,we lose a lot of heat when it is blowing like that.Today the forecast is for about 20 mph wind which will seem like nothing when comparing to last nite. We even had 1 cat exclaim out loud last nite about the 1 really strong blast that came thru.

Maybe the cat was suggesting that you leave it at 6 teeth for a while?

Mike

Could be ,but she just bellowed out like when the really strong blast rocked our world.She did get us laughing which was good because the wind blowing so strongly was a bit unsettling .

windyhill4.2 wrote:We were determined to make this our last winter with wood. On Jan. 8,2014 we had -5* in the a/m,it went to 8* with 30-40 mph winds during the day,we went thru a F250 8' bed load of wood in 24 hrs.This work in the cold,wind & snow at 11 p/m,6 a/m takes its toll on us

Ironically, 1 yr later & we had a low of 5* this a/m,high temp today was 17*, WINDS last nite & over nite were horrendous ,today windy at 20 mph.So this yr, this 24 hr period was not quite as brutal as last yr but it did get close.Tonite we added 270# of coal,emptied 1.75 tubs of ash total today. This work was done inside the truck box @ 60*,no wind in there,no snow to blow or walk in while tending the boiler, 1 tub of ash removed at 8 a/m, 3/4 tub of ash removed at 7 p/m & added 270# of coal at that time. No more tending until tomorrow 8 a/m to remove ash. This brutally rigorous work load to tend the .......... WAIT !! that was last yr. Just think, whistlenut asks me if I miss that .. what we did last yr. We are liking this more each day !!!!!!!!!!!!!!!!!

That must have been about 1,000 pounds of wood compared to 270 pounds of coal.

Aren't you glad you got a 520 instead of a 400,000 BTU unit like the OWB "claimed" to be?

Most people are skeptical when I say that an EFM 520 will whip their OWB in an 8 hour run, but the results speak for themselves.

franco b wrote:That must have been about 1,000 pounds of wood compared to 270 pounds of coal.

To be fair, the Crane stove is also shouldering some load.

Rob,you are right ,we burn 40# /24 hrs in the Crane ,so that equals 310 # to 1/2 cord of wood,still looks like an easy choice Our OWB was rated @ 600,000 BTU Yes Rob, we are very happy with the 520,we are amazed daily at the difference from the OWB in all respects.

As the coal in the bin has gone down to nearly all,we decided to buy some coal so it could dry out b4 we need to use it.Thursday evening I went to our local coal dealer & got him to dump coal on our F250SD ,scaled out 1275# of Reading rice. Here at home I then shoveled it into buckets,carried into the bin & dumped it . We are going to have to save more $$ to get several tons delivered instead of doing it this hard way. Just a few more days & our initial coal purchase of 7.85 tons will be used up. While we would be ecstatic if it had lasted longer,we are very pleased that we got this far on less than 8 tons.This has been far less work for us than the amount of wood we had to handle for the OWB. In a few days, maybe Jan 20 or 21 I can figure out what our averages have been for this coal supply,looking to be around 150#/day avg for the overall avg.We also have used in excess of 1 ton,about 1.5 ? ton so far in the handfed in our house,so technically we will need to add coal usage from both coal burners to compare with the wood consumed by the OWB.

We recalculated & found that there is only 500# remaining from our original purchase of 15,700# of rice coal. This should average out at 150#/day burnt in the boiler since October 10,2014. In a few days we will switch over to Reading rice which we have already tested with great results. Less fines,needs less air to burn, fire has less yellow sparkles ,less ash with a lighter color to it.270# is the most coal we added in a 24 hr period so far this winter & that figure is most likely the highest we will see for this winter as it is unlikely that we will have temps colder in Feb & Mar than we have seen so far.

windyhill4.2 wrote:We recalculated & found that there is only 500# remaining from our original purchase of 15,700# of rice coal. This should average out at 150#/day burnt in the boiler since October 10,2014. In a few days we will switch over to Reading rice which we have already tested with great results. Less fines,needs less air to burn, fire has less yellow sparkles ,less ash with a lighter color to it.270# is the most coal we added in a 24 hr period so far this winter & that figure is most likely the highest we will see for this winter as it is unlikely that we will have temps colder in Feb & Mar than we have seen so far.

Is your burn rate still hovering around 4.5 lbs. per HDD?

Isayre, I just did Dec figures,it comes to 4.59,so still close to the 4.5 figure.

Windy, Windy, Windy,,,,

lsayre wrote: that figure is most likely the highest we will see for this winter as it is unlikely that we will have temps colder in Feb & Mar than we have seen so far.

Why'd ya have to go and proclaim that? you know what happens..... Now Ima have to go buy more coal, sheeeit

waldo

Are you trying to say that I have jinxed it ? Sorry,waldo.