Help Deciding on K6 or K8 Boiler

if your going to end up spray foaming the ditch any way, here ya go, I believe its the best price you will find, they even offer 2", but do not show a price, just remember, pex ID is not whats labeled, pex-al-pex is, so say 1/1/5 pex, is more like 1/1/4 true ID, where 1/1/5 pex-al-pex is true 1/1/5" ID.

some options..

http://www.badgerinsulatedpipe.com/SPD/e-z-lay-tr ... 556513.jsp

http://www.badgerinsulatedpipe.com/SPD/pexalpex1- ... 717718.jsp

price's per foot.

My K8 had 2" supply, and 1.5"returns.

If I had mine to do over & knowing what I know now, I probably would still use 1". I would likely use 2 pair instead of just one. My reasoning for this is the availability of fittings for the 1" at the local hardware stores & supply places. Bigger than the 1" seem to be much harder to find,you may experience differently in your area. I don't care what is out there on the internet,when you need a fitting RIGHT NOW ,the internet won't help.http://www.freeheat4u.com/5-WRAP-INSULATED-REHAU- ... p_146.html I believe this place has the best price on pex & I have purchased water to water plate exchangers & water to air exchangers from them as well. Never had any issues with anything from them either.

Pacowy wrote:

Scottscoaled wrote:How many have you ran? Personally. Not someone elses B.S. Your personal experience. You tell me that it's reasonable to get less output from the most popular coal boiler made, because it isn't designed to run at that rating. Then in the next breath tell me that it's reasonable to expect more output from a boiler that is rated at a lesser output because it is designed to do that. And that is based on the fact that you can "imagine" it running like that. No. you only have proved that if you spout it long enough someone might believe it.

I think your main fight is with the numbers, not with me. EFM originally spec'd it at 20 lb/hr and at that feed rate found it produced 166.8k btu/hr gross output, pretty close to the 171.8k btu/hr EFM now publishes. Either one of those numbers lets it handle most residential heating applications with ease. I'm not saying anything to disagree with that.

The only way the number goes over 171.8 is if you assume it will burn rice efficiently at feed rates over 20 lb/hr (9-10 teeth), and this is where the problems arise. Every test of every EFM stoker rated to burn both rice and buck I have seen (9 units total) concluded that more air is needed with rice than with buck for any given feed setting, to the point where many of them will not operate properly on rice at the maximum feed setting. My personal experience - which includes about 250 tons burned through several units, mostly 3 EFM's - bears this out. I found burning rice in an S-30 to be a nightmare, because the unit couldn't breathe well enough to produce its spec output. This has been borne out by others on the forum, who have described in detail the problems they have encountered in attempting to get high-end output from an S-20 on rice. All you have described from your experience is burning buck on 3 teeth, and I think you mentioned one person who runs a 520 at 8 teeth. If you don't have personal experience running 520's at 9-10 teeth on rice, or a list of other people who do, on what basis are you arguing about this?

Mike

Mike, I don't have a fight with you. I have an issue with your misrepresentation of published numbers from companies who have been in business for many years and have done the legwork necessary to insure their integrity. You seem to have no problem calling EFM a pack of liars. Based on the fact that you burned 250 tons of coal in three of the biggest coal hogs made. Yes, I am able to burn 3 teeth feed rates to heat my 4000 Square foot house. I bet you would be thrilled to achieve that kind of efficiency. I could get away with a 5 tooth feed also.
What we all do know is that every boiler doesn't work at peak efficiency at the top end. EFM's don't. Keystokers don't. Van Werts don't. Axemans and AHS's do. Why would you insist that the Keystoker wouldn't be pushing coal off the grate at max feed rate when there are so many threads on this forum that refute that? I so far have only read a couple threads that indicate the EFM's have that problem. Most of the time lower grade coal was the culprit. Your experience with the S-30 stoker, that was when you first started running stokers? Can you say it was the stokers fault or can it be blamed on getting that real good deal of "bad coal".Could it have been a 1/8 HP motor on the stoker instead of a 1/6 HP motor? That same stoker passed thru my yard.
The guy burning the 8 teeth, well it wouldn't matter if he did burn all 10 because his piping isn't big enough to transfer that much heat out. He has burned over 550 tons by my figuring. Another friend whose boiler I service, runs 5 teeth feed on a S-30. We just keep adding loads. According to the number crunchers we shouldn't be able to heat what we do with the settings that it is at. He is heating a 4500 square foot shop that isn't very well insulated (putting it mildly), sidewalks, Another 2000 foot well insulated garage with 14' minimum ceiling height, and his poorly insulated 1600 sqare foot house. Still on 5 teeth. The stoker just runs longer. So far it is 6-1" zones. He loads with a front end loader and I'm just about finished installing an ash removal system.
I can do this all day.
I still can't figure out why you won't critique EFM's the same way you critique Keystokers. There is one other thing. I am OUT of boilers to sell. I have no EFM's, Keystokers, or Van Werts.
I think what ever the guy rebuilding the house decides, one of the most important issues to address is the PEX sizing,installation, and layout. Remember, it's pex. There is a temperature limiting factor that comes into play. This is a case where you need as many GPM's as financially possible.

hotblast1357 wrote:if your going to end up spray foaming the ditch any way, here ya go, I believe its the best price you will find, they even offer 2", but do not show a price, just remember, pex ID is not whats labeled, pex-al-pex is, so say 1/1/5 pex, is more like 1/1/4 true ID, where 1/1/5 pex-al-pex is true 1/1/5" ID.

some options..

http://www.badgerinsulatedpipe.com/SPD/e-z-lay-tr ... 556513.jsp

http://www.badgerinsulatedpipe.com/SPD/pexalpex1- ... 717718.jsp

price's per foot.

They have the best price for 1" Pex-al-pex. $.71 a foot. $2.84 per foot if running 2 pair in the ditch.
Don't forget to put a 3/4" pvc conduit or two in the ditch also for controls, cable tv, whatever.

Scottscoaled wrote:Mike, I don't have a fight with you. I have an issue with your misrepresentation of published numbers from companies who have been in business for many years and have done the legwork necessary to insure their integrity. You seem to have no problem calling EFM a pack of liars. Based on the fact that you burned 250 tons of coal in three of the biggest coal hogs made. Yes, I am able to burn 3 teeth feed rates to heat my 4000 Square foot house. I bet you would be thrilled to achieve that kind of efficiency. I could get away with a 5 tooth feed also.
What we all do know is that every boiler doesn't work at peak efficiency at the top end. EFM's don't. Keystokers don't. Van Werts don't. Axemans and AHS's do. Why would you insist that the Keystoker wouldn't be pushing coal off the grate at max feed rate when there are so many threads on this forum that refute that? I so far have only read a couple threads that indicate the EFM's have that problem. Most of the time lower grade coal was the culprit. Your experience with the S-30 stoker, that was when you first started running stokers? Can you say it was the stokers fault or can it be blamed on getting that real good deal of "bad coal".Could it have been a 1/8 HP motor on the stoker instead of a 1/6 HP motor? That same stoker passed thru my yard.
The guy burning the 8 teeth, well it wouldn't matter if he did burn all 10 because his piping isn't big enough to transfer that much heat out. He has burned over 550 tons by my figuring. Another friend whose boiler I service, runs 5 teeth feed on a S-30. We just keep adding loads. According to the number crunchers we shouldn't be able to heat what we do with the settings that it is at. He is heating a 4500 square foot shop that isn't very well insulated (putting it mildly), sidewalks, Another 2000 foot well insulated garage with 14' minimum ceiling height, and his poorly insulated 1600 sqare foot house. Still on 5 teeth. The stoker just runs longer. So far it is 6-1" zones. He loads with a front end loader and I'm just about finished installing an ash removal system.
I can do this all day.
I still can't figure out why you won't critique EFM's the same way you critique Keystokers. There is one other thing. I am OUT of boilers to sell. I have no EFM's, Keystokers, or Van Werts.
I think what ever the guy rebuilding the house decides, one of the most important issues to address is the PEX sizing,installation, and layout. Remember, it's pex. There is a temperature limiting factor that comes into play. This is a case where you need as many GPM's as financially possible.

I agree with you on the piping stuff.

I'll try one last time to clarify my point here, which you steadfastly are avoiding. I don't think a 520 is on equal footing with a K-8 at the high end because the 520 is trying to burn 25 lb/hr of rice in a machine designed to supply air for 20 lb of buck. As a result you don't have any examples of anybody who actually has achieved the performance you are touting. A K-8 maxing its output can breathe easier on buck. Not sure why it seems to be hard for you to accept that.

Instead you seem to prefer cutting into me, other EFM stokers, the coal and anything else you can dream up - without evidence - to distract from this point. I haven't misrepresented anything. It's an S-20 because it was spec'd to burn 20 lb/hr, and it's a 520 because that's the net s.f. of steam radiation (at 1.33 pickup) it was spec'd to carry. It's a fact that more recently EFM has changed those numbers so that despite the current limitation of the unit to rice, its performance appears stronger than when it could use rice or buck. You still don't have a single example of anyone who actually achieves the higher performance, so I'm not planning to advise anyone to rely on the higher numbers.

For the record, the rice coal wasn't cheap (IIRC from Cornwall via Hoosac Valley), I didn't sell you the S-30 and it doesn't matter if it was powered by a squirrel in a cage. The experience I described is the same as the findings from extensive EFM stoker testing back in the day - they tend to max out early on rice due to airflow limits. Especially since you are actually using buck I don't understand why you are fighting this.

Mike

You can compensate on the EFM by using the Highboy which has a water capacity of 54 gallons vs 40. The Highboy also has more heating surface area.

I'm fighting this for the simple fact you can't tell me how many pounds of coal per hour the K-8 burns to get ratings just a little higher (or lower depending on what you believe) than the 520. For all you know it could be burning 5 lbs per hour more which would make your point pointless. A Gentleman Janitor Model 63 is advertised at 200k Btu's. Yet it also has to burn 40lbs per hour to get that. EFM hasn't hid anything. It can and will burn 25lbs/hr. Maybe not efficiently on the higher end. I would think the Keystoker would suffer the same problem. It might burn how ever much coal it takes to get to it's rating but,,,, the top end efficiency suffers the same. Let's keep apples to apples.

Scottscoaled wrote: It can and will burn 25lbs/hr.

If that is the case,why is it considered a 20#/hr stoker ? Is the 20#/hr at the top of a certain efficiency rating ?? I am asking to learn,not to argue .

My experience with buck in my 520 showed that airflow was not the problem...the short dwell time of the burning coal in the pot was what caused problems. I found that a feed rate of 7 or more teeth with buck pushed the fire out of the pot. This happened to me about 5 years ago and I blamed it on the coal, but a few years later I tried if again with some free-burning buck and had the same results. Perhaps this is why the old EFM literature said buck could be used at reduced feed rates?

As for running wide open on rice, Chris at EFM ran 10/10 with Blaschsk rice for months...although I think he also used the larger pot ring. I have never been able to put a large enough load on mine to run it at that level of output.

Keystokers seem to have a unique issue that I call "clinker dams" when running hard. Basically the ash can fuse to the side rails, or the ash can from a long sheet that backs up from the ash tub. This is more of an issue with red ash coal. Two of my neighbors have struggled with this even at the suggested feed rate. I swapped some coal with them and the problem went away...and our EFM happily burned the "clinker coal".

I think we can agree that both units can have issues when pushed to the redline, and it would be unwise to expect that performace all the time.

Until you can come up with solid figures on the Keystoker side, it's all really just your personal opinion.

windyhill4.2 wrote:

Scottscoaled wrote: It can and will burn 25lbs/hr.

If that is the case,why is it considered a 20#/hr stoker ? Is the 20#/hr at the top of a certain efficiency rating ?? I am asking to learn,not to argue .

10 teeth times 2.5 lbs/hr of rice gives a 25 lb/hr rating. 10 teeth times 2lbs/hr of buckwheat gives it a 20 lb/hr rating. The auger fills better with rice to get the extra half pound. It is hard to get it to burn that much of either per hour. It has to have the right coal and it won't burn the coal completely. That is what Mike is saying. I don't disagree with him. I just think the same is true for the Keystoker or others in the same class for that matter.

Rob, thanks for that info. With the debate info & what you have now posted, it looks like my 520 has some reserve capacity,even if that means less efficiency. If we should ever get a brutal front that would drop temps below -10*,i should be able to get more out of my 520 than the 7 teeth/8 air I ran it on with Superior coal last season. I assume from a previous post, that set on 10 teeth the 520 can burn up to 25 #/hr if absolutely needed.~~~~~~~~~~~ Scott, THANKS for that explanation.

windyhill4.2 wrote:Rob, thanks for that info. With the debate info & what you have now posted, it looks like my 520 has some reserve capacity,even if that means less efficiency. If we should ever get a brutal front that would drop temps below -10*,i should be able to get more out of my 520 than the 7 teeth/8 air I ran it on with Superior coal last season. I assume from a previous post, that set on 10 teeth the 520 can burn up to 25 #/hr if absolutely needed.~~~~~~~~~~~ Scott, THANKS for that explanation.

Some coal will burn faster than others. It will give up the heat faster. That's the stuff to save for a coald spell.

Scottscoaled wrote:Until you can come up with solid figures on the Keystoker side, it's all really just your personal opinion.

Keystoker publishes their own ratings, which are neither my opinion nor my responsibility. I'm not aware of any evidence that the gross output they claim is not reasonably attainable. If you are aware of such evidence please present it, because I think this gentleman was advised it's what he needs.

Mike