May have to downsize boiler for new home

May have to downsize boiler for new home

PostBy: Vampiro On: Mon Sep 23, 2013 9:10 pm

Hi all. Well, winter is right around the corner. I am the proud owner of a new home. The great thing about it is it is all brick. The only down side is there is no coal boiler! :P It is attached on one side, and has a nice driveway on the other side. I have my trusty AA 260, but never did install the boiler as the hot water conversion had to wait. It all seemed to have worked out, as the new home is eager to have a stoker boiler installed. The new home is around 3000 sq ft. It has anywhere from 8' to 10' ceilings on the upper levels, and the basement is around 6'8.

The house is all brick construction, with a layer of plaster on the brick which is around 1 1/2 thick in some areas. There also is new sheet rock with insulation in some areas of the house, while others retain the plaster walls. There are new windows all around.....well front and back as the side of the house doesn't have any. The brick is all re-pointed as well.

Currently the house is set up for single pipe steam heat. The current boiler is 200,000 BTUs. I had done a few heat loss calculations, and I require around 80,000-104,000 BTU's with an outside temperature of 0 deg, and an inside temperature of 74 degrees. The extreme would be 120,000 BTU but that would be with downgraded values of insulation. Although it normally doesn't hit 0 deg. F. during the winter, I thought I might include the extreme temp as a buffer.

The current beast puts out 260,000 BTU's. That is very over-sized. With an AA 130, or AHS 130 I would be able to provide heat and hot water comfortably based upon the calculations.

I might be converting to hydronic heat, and the AHS 130 would seem to be a space saver for me, as I am planning on relocating the boilers to the rear of the house. There will be the coal boiler, the gas boiler, and an on demand hot water heater in the future. Being the AHS 130 has a hopper, all I would need is a flex auger from the outside bin to the boiler.

I guess (If I'm correct) the next step would be finding someone to trade with. Either way, I would like to be burning coal this winter :D

I have already purchased my Axeman from here, and my Harman coal stove also. Both experiences were great.

Take care all. :0)
Vampiro
 
Stoker Coal Boiler: Axeman Anderson S260
Hand Fed Coal Boiler: #45 BAD HWH
Hand Fed Coal Stove: Harman Mk1
Coal Size/Type: Anthracite, Pea Coal
Other Heating: POS gas boiler

Re: May have to downsize boiler for new home

PostBy: Rob R. On: Mon Sep 23, 2013 10:09 pm

When it comes to steam, the amount of radiation connected to the boiler is the most important. Measure the radiation if you are worried about it, but if the existing boiler heats the house fine an AA260 should work just fine. Also, I believe the 260,000 figure is gross, not net.

How about some pictures of the existing boiler and piping?
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: May have to downsize boiler for new home

PostBy: agcowvet On: Mon Sep 23, 2013 11:15 pm

Rob R. is correct, in a steam system the boiler must be sized to the connected load--the radiators or convectors--so as to balance its production of steam with the load's capacity to condense the steam. Piping, especially near-boiler piping, is extremely important for proper and efficient system function; venting is the other big often-neglected item. Not all steam systems can be converted to hot water, and you may not want to anyhow: steam at 0.5 to 2 psi vs water at 15+ psi...if there are leaks you'll be finding 'em for sure! (Also, radiators will put out less heat on water than on steam, and might not be able to keep up.)

Best site going to learn more about steam heating is http://www.heatinghelp.com They even have a special section for just steam http://www.heatinghelp.com/forum-catego ... ctly-Steam

Disclaimer: I am not a heating contractor, just something that is naturally interesting to me.
agcowvet
 
Hot Air Coal Stoker Furnace: efm AF150
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Newmac NL-2 (oil)

Visit Lehigh Anthracite

Re: May have to downsize boiler for new home

PostBy: Vampiro On: Tue Sep 24, 2013 12:19 am

OK, just got finished measuring the radiators. I need to go to sleep lol.

They are the fancy radiators with the leaf designs on them.

There are 3, 8 column radiators at 38" high. (around 24" Wide)

2, 5 column radiators 38" high (16" wide)

2, 4 column radiators 38" high (12" W)

1 - 4 tube 24" high radiator (newer radiator) (11" wide)

Widths are approx.

So I believe everything is around 500-510, while the AA 130 is rated at 540. The 260 is rated @ 1060 or 1080. for steam, and I believe the AHS would be the same.


The current boiler is a 200,000 BTU weil-Mclain EG-55 boiler that puts out 200,000 BTU's, with a net output of 167,000 BTU's. The Sq Ft. rating for steam is 521, with a steam BTU hr of 125,000 for the AHRI ratings. So I have a rather large inefficient gas boiler that has a lower EDR rating than the 130. Did the bureau of mined report rate the AA-130 just shy of that number?

The water full is 17.3 gallons and at steaming level is 11.2 gallons. The 130's hold around 27 gallons full, and maybe 20 at steaming level.

Off to sleep. Thanks for the help all.

Oh, and as for the piping, I will be putting in a new drop header, and insulating the near boiler piping. The distribution piping is mostly insulated.
Vampiro
 
Stoker Coal Boiler: Axeman Anderson S260
Hand Fed Coal Boiler: #45 BAD HWH
Hand Fed Coal Stove: Harman Mk1
Coal Size/Type: Anthracite, Pea Coal
Other Heating: POS gas boiler

Re: May have to downsize boiler for new home

PostBy: Pacowy On: Tue Sep 24, 2013 12:45 am

Does the 500-510 figure include an adequate pickup factor? Also, has an adequate allowance been made for the btu load associated with DHW needs? IMO there are plenty of reasons to stick with a boiler that provides a lot of reserve capacity, especially with a steam system.

Mike
Pacowy
 
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite

Re: May have to downsize boiler for new home

PostBy: Vampiro On: Tue Sep 24, 2013 5:57 pm

Well, I overcalculated the EDR. That's what happens when you try to make calculations when your up for days. :D The installed radiation Is actually less.

There is a PDF which has a chart that I've seen elsewhere to calculate the EDR for each radiator. Here: http://www.google.com/url?sa=t&rct=j&q= ... 7864,d.dmg

I mistakenly over calculated. My radiators are two column radiators. I made each section a column of which I was wrong, so the numbers became inflated (was wondering why the chart stopped only at 5 columns lol) So based upon the chart, the height of my 2 column radiators plus the number of sections for the total installed radiation comes to around 199. So let's say 220 for arguments sake. Multiply the 220 sq ft by 1.8 for piping losses and that leaves me with 396 sq ft edr. Even if we multiply by 2 for losses, it would equal 440. So it seems the 130 can handle the load. If we subtract 18% from the total EDR of the 130 (540 sq ft edr steam), we wind up with 442.8.

So I hope I am not in error once again, and I do believe I've nailed it. Let me know. Thanks for the help.
Vampiro
 
Stoker Coal Boiler: Axeman Anderson S260
Hand Fed Coal Boiler: #45 BAD HWH
Hand Fed Coal Stove: Harman Mk1
Coal Size/Type: Anthracite, Pea Coal
Other Heating: POS gas boiler

Re: May have to downsize boiler for new home

PostBy: Rob R. On: Tue Sep 24, 2013 6:52 pm

It is up to you, but if it were me...I would install the 260 and enjoy the steam heat. You can burn buck in the 260 and still have plenty of capacity, plus you already own the boiler.

Converting to hydronic heat is a serious undertaking, and seems like a needless expense. Steam systems tend to overshoot the thermostat in mild weather, but that seems like a small compromise to not repipe the entire house.

:idea: You could add a hydronic zone off the steam boiler to a few key areas to help in the fall/spring.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: May have to downsize boiler for new home

PostBy: Vampiro On: Tue Sep 24, 2013 7:12 pm

Well, the hydronic conversion would be at a later time if I do it at all. I may go ahead and just keep the steam like you pointed out. The only other issue is an oversized boiler. Which it seems I have now, and would have with the 260. The 130 after the calculations (if correct) is more than enough for the installed radiation. So if I could swap my boiler to an ahs 130 or aa 130 then I would have the correct boiler, and wouldn't be wasting fuel.

The benefit of doing it now would save me from switching in the future, when I move the boiler room to a new location.

Could an Aa be operated with a flex auger from an outside bin instead of using the attached auger? That would free up space.

Thanks again for your input and ideas.
Vampiro
 
Stoker Coal Boiler: Axeman Anderson S260
Hand Fed Coal Boiler: #45 BAD HWH
Hand Fed Coal Stove: Harman Mk1
Coal Size/Type: Anthracite, Pea Coal
Other Heating: POS gas boiler

Re: May have to downsize boiler for new home

PostBy: waldo lemieux On: Tue Sep 24, 2013 7:14 pm

Vamp

If the existing boiler is 200k and seems to be a happy fit with the house, then I would stay with the AA260. I know nothing about the AA but for me there is no such thing as a "too big boiler" untill you get to 200% or so . I gotta believe you can dial that thing back if its a little big. The AA crew will be along to set you right soon enough. If youve never rum a stoker boiler your in for a real treat ... :D


Waldo
waldo lemieux
 
Stove/Furnace Make: efm
Stove/Furnace Model: s-20

Re: May have to downsize boiler for new home

PostBy: Vampiro On: Tue Sep 24, 2013 8:53 pm

Thanks for the reply. This is my first heating season in the home. It seems like they oversized the boiler a great deal with the existing radiation. That and the house is well insulated with new windows to boot. If my calculations are verified as correct, I might as well see if someone would swap boilers. But I am open to keeping the aa 260 for this season.

Townsend, if you're out there, I just might need those measurements of the near boiler piping :0)
Vampiro
 
Stoker Coal Boiler: Axeman Anderson S260
Hand Fed Coal Boiler: #45 BAD HWH
Hand Fed Coal Stove: Harman Mk1
Coal Size/Type: Anthracite, Pea Coal
Other Heating: POS gas boiler

Re: May have to downsize boiler for new home

PostBy: mozz On: Tue Sep 24, 2013 9:49 pm

AA's don't like to be dialed back. I have a 130 running steam and 9 radiators. I have never figured out the radiation footage but i heat this 1925 house with hardly any insulation no problem. I think the oil boiler i took out was rated at 165k. I also don't know if you can run the AHS on steam? See if anybody chimes in on running a efm 520 on steam and what radiators and what square footage. The AA runs the asher from the auger tube so if you ran a flex auger you would need to put the doghouse in a barrel or mini bin. Does the current setup work good and heat evenly?
mozz
 
Stoker Coal Boiler: Axeman Anderson 1982 AA-130 Steam

Re: May have to downsize boiler for new home

PostBy: Vampiro On: Tue Sep 24, 2013 11:25 pm

Thanks for the reply Mozz. My house was built around the same period. The link I provided in the other post above should help in determining the total EDR for each radiator.

What is the sq footage of your house? Is it brick, or frame? Do you have high ceilings as well? Based off of everything, I am leaning toward the 130. I have a feeling the 260 will have a bunch of unburned coal. Does your boiler provide DHW as well? How many lbs a day are you going through?

As for the auger tube, what if I cut it shorter, or cut it off and just left a partial tube with the the gear to run the asher? Then set the flex auger to turn on when the boiler is supposed to ash? That would be for the future. If I wind up swapping the boilers, I will install the auger, and make a temporary bin with the dog house as it is supposed to be set up in the beginning unless I find a steam AHS.

They have made AHS's boilers in steam trim. However, I can just stick with the AA-130. I like the setup of the AHS and AA boilers. The better thing with the AHS is it saves a little more space being there is no direct drive auger, saves on the power consumption as well.
Vampiro
 
Stoker Coal Boiler: Axeman Anderson S260
Hand Fed Coal Boiler: #45 BAD HWH
Hand Fed Coal Stove: Harman Mk1
Coal Size/Type: Anthracite, Pea Coal
Other Heating: POS gas boiler

Re: May have to downsize boiler for new home

PostBy: Rob R. On: Wed Sep 25, 2013 6:09 am

mozz wrote:AA's don't like to be dialed back. I have a 130 running steam and 9 radiators. I have never figured out the radiation footage but i heat this 1925 house with hardly any insulation no problem. I think the oil boiler i took out was rated at 165k. I also don't know if you can run the AHS on steam? See if anybody chimes in on running a efm 520 on steam and what radiators and what square footage. The AA runs the asher from the auger tube so if you ran a flex auger you would need to put the doghouse in a barrel or mini bin. Does the current setup work good and heat evenly?


EFM made it simple...a 520 was originally rated for 520 sq. ft of steam radiation.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: May have to downsize boiler for new home

PostBy: Pacowy On: Wed Sep 25, 2013 8:23 am

Yes, and that's sf of actual installed radiation, net of the pickup factor. And EFM was equally informative in naming the 350, 700, 900 and 1300.

Mike
Pacowy
 
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite

Re: May have to downsize boiler for new home

PostBy: Vampiro On: Wed Sep 25, 2013 8:50 am

Efm sure made it simple. Always was wondering what those numbers meant. Thanks.

So, all in all I guess I'm ready for a swap. My calculations seem right. Mozz what is the maximum size for the steam outlet?
Vampiro
 
Stoker Coal Boiler: Axeman Anderson S260
Hand Fed Coal Boiler: #45 BAD HWH
Hand Fed Coal Stove: Harman Mk1
Coal Size/Type: Anthracite, Pea Coal
Other Heating: POS gas boiler

Visit Lehigh Anthracite