one pipe steam or two pipe hot water

cgutha

Hi everyone, I'm back. After three years and four attempts, the house is finally mine. (And the banks.) I have had time to get to know the house, what it can and can not do, and most importantly, what it wants to do.
After much consideration, and studying "The Lost Art of Steam Heat", I have decided that keeping the one pipe steam heat is the best option. (I have also scrapped the idea of a second electric boiler because electric is too costly)
I have a small question not answered in the book. When coal boilers are replaced with gas fired boilers, the new boiler has an ideal cycle rate of twenty to thirty minutes. This allows the vents and system to breath. However, the coal burners had a cycle of roughly twenty four hours. or they were on continuously. How did the system breath back then or was something else changed?
ceg

Gsmith

you would be well served to buy the book by Dan Holohan available on this website's store: The Lost Art of Steam Heating. Will provide you a wealth of basic knowledge to assist in your decision making, from which the input you get from the commenters to your post will then make much more sense.

the_donut

Coal fired systems were on more or less continuously. Depended on who built the fire and when. Air impedes steam flow. Coal fired systems had all day to purge air.
Gas and oil cycles can be orders of magnitude shorter and require faster main venting to purge air to allow steam to reach all the radiators and heat evenly. That’s why many oil and gas conversions are under vented.

An ideal system would fill the mains and risers continuously and fill the radiators to the point where heat loss matches heat output. Trvs can help match heat output to loss at the radiator.

The shorter the downtime between cycles, the less time the mains and risers have to cool off. You are paying to take that cold steel and bring it up to temperature to carry good quality steam to the radiators.

Jamie Hall

Good for you! I'm sure you will have fun with the place -- and learn a lot.

On cycling and venting. The comments above are good; gas or oil boilers come up to steam very quickly, and then cycle off when the thermostat is satisfied. Only on the very coldest days will they stay on more or less all the time -- and then only if they are properly sized.

Depending on the sizing of the newer boiler vs. the radiation, you may or may not be significantly oversize. If you are the boiler will need to cycle on its pressure control. You will read here on the wall all kinds of words on that subject, but the bottom line is that it will have to cycle. Not a major problem.

Anyway -- you need good big main vents at the ends of all the steam mains. Get those, and then start fiddling with the radiator vents to get the various spaces heating the way you want them.

You mentioned somewhere up there that the water line of the newer boiler is some 18 inches below that of the original. This may or may not be a problem. It's a problem if some of the piping originally intended as wet return piping, and below the water line, is now above the water line. Otherwise, it's just a thoughtless install. So go around the whole system and take a good look at all the piping and decide whether it was a steam main, a parallel return dry main (likely to be up high) or a wet return from a drip (down low). Only the latter are a concern -- but they must be below the water line.

Eastman

I interpreted @cgutha's question as:

How did coal fired systems maintain balance? Surely they were not fired at the output level necessary to meet EDR for 24 hours a day. How did the steam know where to go?

Jamie Hall

Eastman said:

I interpreted @cgutha's question as:

How did coal fired systems maintain balance? Surely they were not fired at the output level necessary to meet EDR for 24 hours a day. How did the steam know where to go?

No -- in fact, much of the time they operated at a simmer or not much above -- and very very low pressure at the boiler. But... when you went out to a radiator, you discovered that the colder the room was, the more steam the radiator could condense. The more steam that it condensed, the lower the pressure was there (even into a partial vacuum). So the steam went to that radiator preferentially. So that radiator -- and the space it was in -- got more heat and a hotter space got less.

The biggest single trick was to get the radiator(s) properly sized to the spaces, and the dead men were pretty good at that (modern redecorators and upgraders and remodelers aren't, which can be a big problem).

Bottom line: if you are blessed with a steam system which has not been knuckleheaded, and radiators remain in place, the thing will be, to an astonishing extent, self-balancing, provided only that you keep the pressure down and fire only to the load (let's be kind here, and not get into the various ways to do that!).

To give you a concrete example: the main place I care for is just such a place. Unless the wind is blowing, no room is ever more than two or three degrees warmer than any other. There is just one thermostat (a Honeywell mercury T87) and the boiler is controlled by a vapourstat. That's it.

Eastman

Hi Jamie,

One could argue that your system is simply an example of well executed modern techniques and properly sized radiators. And that two to three degrees is not significant enough to be the driving force of any self balancing phenomena.

I would like a concrete example of a coal fired system that maintained balance to modern standards. Self balancing seams more plausible with vacuum systems. (But vacuum isn't the predominate type of system, no?) I don't see why an under fired one pipe system wouldn't just fill the closest radiators to the boiler.

Jamie Hall

Modern? Um... well, the boiler is reasonably so. I'm not sure of the date of the vapourstat or the thermostat; around 1960 I think. And nothing else has been changed since it was installed, in 1930 (actually not quite true; one radiator was removed in about 1950. We still miss it...).

The point about self-balancing, though, is that it is dynamic, and driven by the rate at which steam condenses. The pressure differences are very small, but enough.

the_donut

I am currently working on a one pipe gravity system designed for coal, looks like retrofitted in the 70’s for natural gas. The biggest problem balancing wise I have run in to is single radiator risers that I assume were additions to servant quarters after a remodel. 4 parallel mains run west to east with a south to north main feeding from the southwest corner boiler.

The issue is the western edge where servants quarters were have no main or riser venting. All main venting for the system is done 60’ east of boiler while ear end of main before the drop into the wet return via Hoffman 75 vents. The servant take offs are 10’ west of header. About 5’ is 6” pipe. The only vents are the 3 hoffman 1a’s fed. The steam favors the low pressure from the 75’s to the point of lagging supply to the western apartments by 12 minutes on the northwestern corner.

12 minutes wasn’t a problem with coal, but it is with 1.5 million btu gas on short cycles of 30 minutes or less, especially after warm weather setbacks.

The temporary solution for us was to make sure all tenants were opening radiators valves (50% was closed leading to 15 minute cycles ergo no heat to western corner) and wiring the second stage burner at the lowest cutout we could.

This took cycles as short as 5 minutes due to pressure to 55 minutes on temperature satisfaction on thermostat.

Every system is different, and the cost of adding vents to risers, correcting piping and adding trvs to radiators can be hard to swallow.

Before I got there the wet returns were leaking, pressure cutout was 7 psi, cut in 5. A vent blew off next to a sleeping tenant and water was spurting out of the main vent 60’ due east of the boiler.

You have to ask yourself what result do you need, and what result do you want for what price. We could spend hours fixing a bad install, bust up 20’ of concrete and replace another run of pipe in the courtyard (we replaced 2 buried sections already). We could spend 10 grand on trvs, controls and get everything near perfect, but that’s not what a property owner wants to hear after they spent a ton on a nightmare boiler install.

Jamie Hall

Sounds like a nightmare indeed. And points out that the venting has to be correct on the mains; all bets are off if the steam can't get to the radiator in the first place, after all.

cgutha

WOW! Thanks guys. The Lost Art of Steam Heat is an invaluable book. I have recommended it to several people including the water tester guys at work.
One pipe steam heat is a unique animal. I look forward to getting it online again.
When I worked in the packing house, I was able to control the boiler input to the load. Electronics could never do this. It is a gut feeling coupled with experience.

Back to very low pressure one pipe heat: If the radiator vent closes with the proper amount of air for the load, does the steam continue to feed into the radiator replacing the condensed steam? Is this how the old coal systems worked?
If so, then could a modulated gas fire "replicate" the continuous coal? Would this be advantageous assuming operation at less then 18 oz. with a vaperstat? I plan to abandon the thermostat in favor of running TRVs in every room coupled with vaporstat.
It's just a theory to shoot at.

Of course, there are other problems. I have yet to inspect the boiler. It was not laid up properly when the house was abandoned. I pulled some of the bottom piping long ago and noticed more mud than I would like. However, I have not looked at it these past three years. Very bad.

I am insulating the house which will change 7/8th of the individual room loads. The current boiler is 300k input, the estimated load will be 180k when complete. I assume I can remove radiator sections per the new loads.

Given the cost of replacing the boiler, My hope is to clean and bring the current boiler back to life. Can a 300k boiler work with a load of 120K? or will the cycle be too short. I doubt that modulating or changing the gas valve and burners would be cost effective. I have not priced the cost of a new furnace system even if the boiler is sound.

Oh well, I have all summer to work this one out.

ceg

nicholas bonham-carter

I would ditch the TRV ideas, and just aim for a balanced system, with excellent main venting, running at a constant lower temperature. With insulation, the boiler will fire for less total time. Removing sections of a radiator will be like opening a can of worms.
When the radiator vents are closed with the air out of the radiator, the steam will continue to flow into the radiator, and condense, losing 1600 times it’s volume.
Plug the lower tappings in your boiler, and fill it up as high as the piping will allow, and look for leaks. If it is watertight, you can pressure wash the mud out before putting it back in service.
Yes the boiler is probably oversized, but you can fix that when you finally install a properly sized new boiler in the future.—NBC

leonz

Hello cguntha,

I have read the entire thread about your heating system and I have really enjoyed reading it.
I grew up with a one pipe steam in our apartment above my parents grocery store and my inlaws had a Montgomery Ward kit house with an original hand fed coal fired steam boiler that was changed out with a gas standing pilot boiler when natural gas was brought through the area in the early 1950's.

Don't hate me but I am going to suggest that you perhaps look at making steam with coal heat.

The EFM DF520 Coal Stokers can burn bituminous rice coal in its underfed forced draft pot stokers to make steam and hot water using Honeywell steam boiler controls.

The EFM DF520-S steam has a firing rate from 21,470 to 214,690 BTU per hour with anthracite rice coal.This is 2.5 to 25 pounds per hour in the coal feeding rate.

I do not know what the firing rate(BTU per hour) would be with the Wyodak Seam Sub Bituminous Coal that is mined in North Dakota and Wyoming. The purchase cost of the Wyodak coal per ton is much much much less than anthracite coal per ton here in the east.

I have provided a link to the EFM home page for you below.


www.efmheating.com

the_donut

cgutha said:

Back to very low pressure one pipe heat: If the radiator vent closes with the proper amount of air for the load, does the steam continue to feed into the radiator replacing the condensed steam? Is this how the old coal systems worked?
If so, then could a modulated gas fire "replicate" the continuous coal? Would this be advantageous assuming operation at less then 18 oz. with a vaperstat? I plan to abandon the thermostat in favor of running TRVs in every room coupled with vaporstat.
It's just a theory to shoot at.

Trvs will close when temperature has been satisfied. As long as there is air still partially filling the radiator, and the trv has vacuum breaker to stop steam from being pulled in by a vacuum from condensing steam, the steam flow will slow to a crawl.

There is a lot at play and air vent trvs can still allow steam in because steam flows from high pressure to low. If the pressure in the radiator is lower than other radiators on that riser, that radiator will preferentially pull steam into it. This is where proper vent sizing is critical.

The trv body is a temperature controlled valve. The controller can be wall mount or on the knob. The body still needs a straight vent matched to the size of the radiator. If the radiator vent is too fast, air will be evacuated completely and steam will fill all sections, temperature will overshoot target, and other radiators further down the line may be starved of steam. The radiator valve style trv will not work on one pipe because condensate will be trapped.

Modulating the burner would require a staged gas valve and control of combustion air. The system I worked on recently had a two staged gas valve and two pressuretrols, one was wired, the other the installer told me was a “backup” even though there was a manual restart pressuretrol wired in line with the controlling pressuretrol. After I wired the second stage, the cycles increased in length but decreased in overshoot and fuel consumption because the system was running in the 1/2 psi range at 300,000 btu instead of up to 1.5 psi at 1,500,000, off for a few minutes, then back on at 1/2 psi.

To get that kind of result on your boiler would require a gas valve replacement. CO and insufficient flue flow gas (read not enough buoyancy to clear chimney and possible condensation of flue gas) may be a problem at lower fires.

I would not abandon the thermostat if you keep the 1 stage gas valve. Place it in the coldest room of the building. When that room is satisfied, all other rooms will be. If you run the system on pressure, rooms may overshoot temperature setting or overheat.

I would follow the Gill and Pajek vent charts and size mains by 1 oz column, risers by 2 oz column, and radiators by 3 oz column. This way air venting is balanced at main and riser level before hitting radiators. Then radiators will draw steam portional to size, which, if you remove sections (which is a lot of work) to size rooms by heat loss, will result in even heating. The trv will assist in balancing heat loss and steam supply.

cgutha said:

I am insulating the house which will change 7/8th of the individual room loads. The current boiler is 300k input, the estimated load will be 180k when complete. I assume I can remove radiator sections per the new loads.

Given the cost of replacing the boiler, My hope is to clean and bring the current boiler back to life. Can a 300k boiler work with a load of 120K? or will the cycle be too short. I doubt that modulating or changing the gas valve and burners would be cost effective. I have not priced the cost of a new furnace system even if the boiler is sound.

Oh well, I have all summer to work this one out.

ceg

My main concern with the old boiler is the corrosion on the right side of burners. It may be moisture from a damp basement, or it may be leaking between sections. If this is the case, a boiler replacement would be a great opportunity to correct the near boiler piping and get a boiler that has a two stage valve. Gas valve replacement isn’t difficult, and is about as expensive as a vapor stat, and the burners just set in the manifold and run in the $20-$30 range depending on type.

One other thing I noticed, your edr calculation didn’t account for the aluminum finish on the radiators. This will bring the edr per section from 3 to about 2.7 reducing your total edr to 1037. This brings your load with 33% pickup to around 330000 btu/hr.

I would install vents, service the boiler, replace the pressuretrol with a vaporstat and run the system to see where you are at. If possible I would see if natural gas is available as this would be much more economical than Lp.

cgutha

Wow. Lots of good advice.
If I dump the TRV idea, that saves a small cost as I have twenty risers and I think thirty eight or more radiators. I did neglect the paint on the radiators. (32 inch two column = 4 EDR each)
You must have looked at a picture of the boiler. Filling it with water before I do anything else is a good idea. Pressurizing it to check for leaks will save time if it has enough leaks that I do not need to bother with cleaning it.
I did a quick search on line, but did not locate any modulating gas valves, a two stage would make great sense and would be easy to install.

Leonz: The old coal boiler is still here. I was gong to keep it as a museum piece. The Velva coal mine has petered out. I have not priced the cost of coal. I doubt my wife would appreciate coal dust. She complains when I bump a wall and the coal dust still trickles to the floor and everywhere else.

We do not have the option of Natural gas. I asked my representative about it and he said the issue came up last year but he does not remember why it failed. He never did get back to me. I think there is small town politics involved.

I forgot that TRVs have a vapor relief valve. This would require breathing.

Painting the radiators to reduce the efficiency is a lot easier than breaking radiators apart and putting them back together.

Keep talking guys, soon I won't have to spend anything to get this back on line!

ceg

leonz

Hello ceguntha,

The EFM underfed burn pot stokers burn very clean and they use an ash tub to collect the ashes under the burn pot.

You will not have issues with fly ash like you would with a hand fed coal boiler. I used a wood and coal fired hand fed until I switched over to a flat grate coal stoker.

You can purchase lids for the ash tubs to eliminate the ash flying around when changing the ash baskets.

Gsmith

Do not break up the radiators because you think they are oversize, nothing but trouble will come of it. And, almost all steam system radiators are oversized for all but the coldest day of the year, after all, they were sized to heat the house on the design day (coldest day) sometimes with the windows open. On milder days, or if oversized because you insulated the house more than was done originally, they will simply only heat part way across. No harm done. Most of us don't complain that we can't drive 120 mph everywhere even though our cars are capable of it. The thermostat if appropriately places will control the temperature. If good main venting and balanced radiator venting is installed the boiler will not short cycle and will only run at very low pressure even if the radiators are oversized.

From your posts it seems you are taking most of the house down to the bare studs and will insulate and then reinstall new walls. And, you seem a little like the adventurous type. You might want to consider converting your one pipe steam system to a vacuum system--search this site for posts on vacuum systems and read the chapter in Dan's book LAOSH on vacuum (chapter 12), and on page 330 of that book begins a description of Igor Zhadanovsky's vacuum conversion, which might interest you. And a few others have posted here with their results using similar but slightly different conversions. You can achieve a vacuum conversion by running small diameter tubing from where the radiator valves normally go to the basement and control the vacuum and system from a common point. I have not tried it myself, but from reading DAn's book and the various posts here there are potentially some significant efficiency benefits to a vacuum system. I mention this because if you have the walls open in an existing house it is way easier to make such changes than if new piping (even very small diameter pipiing) has to be installed in existing finished spaces. Just a thought while you are considering options.

@Jamie Hall has posted a lot about his two pipe system which operates at very low pressure and vacuum a lot of the time as well.

cgutha

First: a report on the windows (from way back). I glazed and painted the windows last summer. Although the top sashes are mostly stationary now (screws or whatnot) the windows and sashes are in great condition with very little dry rot. Some widows are missing a few pieces, but all in all they are in remarkably good repair. I did make the mistake of not opening a few widows after painting so now they do not open. But we'll fix that when I get to that room.
I do not envision a centralized thermostat. With forty rooms spread across four floors, where would I place it? This is why I was leaning toward TRV's in every room.
ooh. if I do not change the column number, then the boiler I have is the correct size. Again, splitting the burner into a duel burner makes sense and cents.
I took a quick look at the "corrosion" rust on the boiler. It may have been repaired in the past. Again a hydrotest will reveal all.
"Down to the studs" Almost. This is a brick building. (See Hotel Berry, Velva ND) I will go down to the brick, add studs, and insulate. My hope is that the temperature change between the hot and cold outside brick will not cause problems with the new inside walls at steady temperature of 68.5 degrees. (tongue in cheek on the temperature.) This question, however, is for a different site of old guys and old houses.
That leaves the question of coal and vacuum. The coal dust I was talking of comes from filling the coal room, and subsequent handling of the stuff. I am also not convinced that I can convince my wife to shovel the hopper full of coal every night before she comes to bed.
I started reading part of the chapter on vacuum, but I do not have the system in place so need to go back to study it in earnest.
Actually, the one pipe system as is fascinates me. Back in my early days of learning steam, I thought there must be a way to use all that energy of latent heat in a steam engine. Otherwise it is wasted. Here is a system that does exactly what I was trying to imagine. Saturated water goes into the boiler at 212, comes out as saturated steam at 212 (dry steam at 215) only that great unused area of the Mollier chart is used. Wow!
Lots to learn, Lots to do.
ceg

Jamie Hall

Oh ho! So that's where you are. I've heard of the Hotel Berry, and I am very interested in what you are trying to do with it -- and absolutely delighted with your efforts. (And yes, I am an historic building freak).

I'd wondered when I read it was up for sale who might end up with it -- and hoped and prayed that it would be someone who really cared about the fantastic detailing and overall condition.

On the insulation -- if you haven't thought of it already, and since you are going to so much effort, be sure and put a really tight, well installed vapour barrier on the inside face. This is going to be a bit of a pain for you -- you will have to ride herd on people pretty hard, especially electricians, but it is well worth the effort that will go into it.

On coal. Coal is cool. Coal is also dusty. It's not the fly ash, but just simply from handling the stuff. It might be fun to use it -- but I'd suggest not. You have your hands full of other things to do, and constantly wiping surfaces (vacuuming doesn't do it) to get rid of coal dust does not have to be one of them. I'd go with either oil or natural gas, depending on availability and price.

On the heating system. I'd stick with the one pipe system, unless it has really been hammered. It has the virtue of real simplicity (the only moving parts are the main and radiator vents, after all) and remarkably low maintenance. It is also, as you note, intriguing from the engineering point of view! That said, however, I'm not sure just how I would control it. I would start out by making sure that the boiler was the right size for the system, however, and making sure that I had the right size radiation in each space (you probably do, or close -- but no harm to checking). Then I would ensure that the steam mains were generous in size -- no sense losing pressure there -- and that they really were adequately vented. I think in your building I would also vent the tops of the risers. It's not usually necessary, but it does no harm. I don't think I'd use thermostatic vents. They are wonderful, if they are only a fraction of the radiation in a system, but if you had them on everything you run a real risk of having wildly varying heating loads as they open and close, which makes controlling the boiler much harder. Then I rather think that I would control the boiler with a timer (use a pressuretrol as a backstop!), but with the timer driven by the apparent outdoor temperature (taking into account wind loads) and running so that the on time was constant, and long enough to ensure that all the radiators got warm as intended, varying the off time to keep the heat input, on average, what was needed to satisfy the heat loss. I would have backup thermostats -- probably just two -- most likely in one of the main rooms, one to turn the boiler on and keep it there if the temperature dropped too low, and the other to turn the boiler off and keep it off if the temperature got unbearably high.

Then some patient fiddling with radiator vents and tweaking of the boiler off time vs. temperature and you should be able to keep all your spaces within a degree or two of where you want them.

Have fun!

cgutha

Seems to me you are up the road a piece, near Crosby. Yes, she is a beautiful building, but fell on hard times recently. Nevertheless, her bones are still intact and her beauty goes deep. Vapor-barriers are to be installed continuously from floor to ceiling and over the ceiling. any seam must have a two foot overlap. I have a background in architecture.
Without the vapor-barrier, moisture will seep into the wall and freeze. not good. freezing water will break brick on a brick house and remove paint on a wood house. (That's why a freshly insulated house requires paint every year, someone skipped over that inexpensive VB.)
I've been studying the TRVs, given that I must first get the boiler up and running, then add one room at a time as I remodel and restore, those are a long way off.
I have been considering vents on every riser. Makes balancing easier. The main is three inch. I need to recalculate now that I have been talked out of downsizing the radiators.
ceg

cgutha

I have a thought that I would like to kick around. After all, I only have book learning and theories when it comes to one pipe. Several sets of eyes would help explain why it would or would not work.
The original one pipe system was coal boiler located midway along the north wall. The boiler is still there. A single 4" pipe came out of the boiler, deadheaded into a Tee, splitting into a 3" main covering the east half of the house and a 2" looping through the west half. Each of these mains traveled three or four feet from the perimeter of the basement until they met midway along the south side of the house where they combined into the return pipe. The two inch main has a five foot loop. The three inch has a gate valve leading into the 2.25 return: First dry, then wet under the floor. Each main is about 100' long with two 90' elbows.
The replacement boiler is piped into the 3" header, the two inch main now tees off the 3" main then doubles back to the west. it also has a condensate tank and pump for the return.
My idea (before I was talked out of resizing the radiators to match the individual room loads) was to change the west half so a single main travels the entire perimeter. That is leaving the 3" as is, eccentrically reducing from 3 to 2", change the slope of the 2" main so the main would end near the boiler. Only 4 risers are affected with the new slope. everything else comes off the 3" main.
The advantage is removing from the system the wet heatsink now under the concrete floor, (allowing the condensate to remain near 212 degrees) The main vent would be near the boiler, only one main to vent. I have enough distance for the 23 inches to the water line.
Without changing the radiators, the velocity in the parallel flow 3" main approaches 29 ft / second. I think that is okay as the main is parallel with a slope of 1" in ten feet. That is seven seconds to travel the main.
The risers will remain the same as they were sized correctly long ago. (Another second or two if vented.)
What do you think? Suddenly, I wonder if two inch will handle the condensate.

the_donut

It could work as long as you vent that air in 7 seconds and no steam goes up to the risers. But, steam will go into the risers and then get pulled by vacuum from collapsing steam ahead of it up and away from the main.

Coal had all day to vent so it mattered little if it took 20 extra minutes to get all the way around the perimeter main. But gas and oil cycles more frequently, even when load matched (1 hour compared to 24 is a big change, and that is a fairly long gas cycle). This is why converted setups use multiple mains to distribute steam. This broke up the loop and allow more even circulation.

The one pipe I have been working is broken into 4x65’ mains separated 30’ apart. Somebody removed insulation from the 3rd main from the boiler. Steam prefers this main ahead of the 4th naturally and even more so now because of lost insulation. It takes 14 minutes after steam hits the header to get enough steam to warm the 4th main.

In addition to this kind of imbalance, on each main, there are 7 risers. The riser closest to the vent, at the. End of 65’ run gets steam first. The riser closest to the tee from the main gets steam last and barely heats until 15 minutes into cycle. Both have the same venting on the radiators, no riser venting. The radiators at the end of 65’ are 4x larger than the ones near the tee. Steam hits the larger radiator and pulls more steam than the little radiators, which starves the other risers.

The longer the main, the harder it will be to get steam to each riser with it taking off into the riser and starving the main. Venting can help this by guiding steam to the end of main. Then risers vents, sized so they vent the correct amount at higher pressure will fill. Then radiator vents sized the correct amount for their size will fill, in theory, assuming insulated lines and low frictional lost.

Eastman

@cgutha

If your interested in advanced control techniques or vacuum conversions, I recommend reviewing the work of @MarkS, @PMJ, and @AMservices. PMJ just started a new discussion.

leonz

Hello cguntha,

I have to disagree with Jamie about burning coal for heat. I have been doing it for 36 years now and going into my 37 year and I am glad I have coal heat as it costs me about six dollars a day on average to heat my very old leaky house that used to be a one room school house up until 1953. I would much rather have radiators for more thermal mass but I am stuck with 3/4 inch finned hot water baseboard for heat using hot water

As far as the coal dust goes I just sweep up the coal dust and toss it back in the hopper with no issues. All you need to do is wear a good dust mask like the 3M model 93 dust masks.

If you have time in your busy life I would you to become a member of the coal heating forum www.coalpail.com
Richard S. (the forum owner and admistrator) has an extensive section on bituminous coal burning and we have a huge amount of information there for anyone to look at.
Becoming a member is also free of charge and there are a lot of folks that use coal to make steam heat on the forum.

The folks on the forum would love to see pictures of your home and the old boiler and piping and they can help you a huge amount as well even though we are on the east side of the Mississippi River. We have a lot of folks that have one pipe steam systems that burn rice, buckwheat and Pea coal.

With the sub bituminous Wyodak Coal Seam you have in the neighborhood you will save a huge and I mean HUGE amount of money to heat the place.

Don't give up on your soft coal just yet.

cgutha

If I were to do that, I would plan on an exterior building to house the coal and the boiler. Coal is not my first choice however, I do still have many of the parts scattered here and there.
My objective is to restore the building while bringing it up to code. The building was built before electrical and water came to town.
At one time it hosted a fine railroad restraint where people would ride the train, just to eat and spend the night.
The horse, buggy steam locomotives and coal heat must have had a unique smell that modern day customers would not recognize. Although the town does still have it's yearly rodeo.
The additional cost of a coal system, is not figured in my calculations.
My current objective is to bring it up to code, make the building efficient while staying true to its original intent.
I will look at the site. it suddenly sounds intriguing. but there is many reasons why the building was converted from coal.
ceg

cgutha

I had some people look the house over yesterday. One suggested something I had thought of before but rejected.
I have twelve foot ceilings in the lobby and dinning room. These two rooms cover half the first floor. They both have metal ceilings which are irreplaceable, Therefore, I was going to not insulate those walls.
But, he suggested, I could insulate the lower ten feet and leave the upper wall as it. that would reduce the heat loss of these two large rooms.
Taking a second look at this idea, I saw how it is possible: except for the vapor barrier. it is not possible to place the vapor barrier where I do not disturb the wall.
I wonder if it is possible to go behind the wall from above...
Lots to consider, it is always that one forgotten detail that breaks the chain.
ceg

cgutha

Well, winter has let up enough that I have started working on the project again. I hope to achieve three things before fall:
1) Complete the room where my wife and I will call home,
2) Complete the exterior, including tucking and painting (last year I borrowed a 30' boom truck. I got the windows caulked and painted, but that was a stretch. This year I have a 40' lift coming in. I hope to get to the soffit.)
3) The heating system. This has been discussed above. I want to thank everyone for your input. I hope I get the details right.
If I accomplish these, I will do good.
ceg

cgutha

to Leonz: If I were to return to coal, I think the boiler would be outside. most of the coal in the area, (I suspect) is owned by the power company. I do not know if there is any private sale of coal in the area.
ceg

leonz

About sub bituminous coal burning,

The three coal dealers near you are Baranko Brothers Dickenson, ND, Center Coal Company Dickenson, ND, BNI coal Bismark, ND.

The testing for the use of sub bituminous coal in the EFM DF520 coal stoker boiler was a success in 2016.

It can make steam with soft coal so you should be able to install it in your system easily by putting it in a concrete walled and floored pit with a Bilco Door as it comes in 2 pieces; the base ash pit and the steam chest and the cladding. You can always add insulation to the boiler too to hold in more heat.
It would not be hard to simply build a coal bin with a coal feeder dog house in the wooden wall of the pit for the feed auger to convey the soft coal from the storage pit to the stoker.

You could install a new dry steam header on the EFM DF520 and pipe the dry steam from the header to the steam lines in the basement through a hole cut in the foundation wall from the concrete pit that the new boiler is set in.

Its something to think about anyway as you have low cost coal for heating so close to you.

leonz

About sub bituminous coal burning,

The three coal dealers near you are Baranko Brothers Dickenson, ND, Center Coal Company Dickenson, ND, BNI coal Bismark, ND.

The testing for the use of sub bituminous coal in the EFM DF520 coal stoker boiler was a success in 2016.

It can make steam with soft coal so you should be able to install it in your system easily by putting it in a concrete walled and floored pit with a Bilco Door as it comes in 2 pieces; the base ash pit and the steam chest and the cladding. You can always add insulation to the boiler too to hold in more heat.
It would not be hard to simply build a coal bin with a coal feeder dog house in the wooden wall of the pit for the feed auger to convey the soft coal from the storage pit to the stoker.

You could install a new dry steam header on the EFM DF520 and pipe the dry steam from the header to the steam lines in the basement through a hole cut in the foundation wall from the concrete pit that the new boiler is set in.

Its something to think about anyway as you have low cost coal for heating so close to you and the all canadian coal heater would be much more expensive to install and you could not make steam with it.

cgutha

Spring has finally arrived and, like a farmer who plans all winter then hits it hard when the weather breaks, I am busy. Today I have time between meetings.
The building was originally coal. There is a coal bin, If I were to look hard, I have old pieces of equipment for handling coal. the old boiler is still there.
but
as we have discussed before, and I know it is still on paper, time to make it reality, the heating system involves the entire house, including and starting with the heat loss of the building.
I have started on one room and notice that the process is time consuming. There may be better and quicker ways to insulate a brick building.
I started repainting my mural, it is going to take weeks. tuck pointing is going to take weeks and is 50 years overdue. and each window, I am still waiting for the estimate on those.
If it were easy, anyone could do it.
With the advise of many, it might even get done correctly. thanks all.
Now for the tricky part.

the_donut

Keep us updated and please add pictures of the renovation. I love to see a work in progress.

leonz

Eastman said:

Hi Jamie,

One could argue that your system is simply an example of well executed modern techniques and properly sized radiators. And that two to three degrees is not significant enough to be the driving force of any self balancing phenomena.

I would like a concrete example of a coal fired system that maintained balance to modern standards. Self balancing seams more plausible with vacuum systems. (But vacuum isn't the predominate type of system, no?) I don't see why an under fired one pipe system wouldn't just fill the closest radiators to the boiler.

===============================================================================================================================================================


If you visit www.coalpail.com and then wander over to the steam heating page you will see a large number of one pipe steam boiler owners that make steam with EFM underfed pot stokers and the sled type burning grate coal stokers being Axeman Anderson boilers.

JUGHNE

Cgutha, I would be passing thru your town next week.
Going to relatives in Crosby, ND.
Steam engine show etc.
Will you be around?
I sent you a PM also.

cgutha

Hi Everyone,
To insulate the brick building, I installed an interior wall reducing the dimensions of each room by four inches. This interferes with the riser placement.
I get to move a lot of piping. -- oh boy.

The rooms in the old hotel were originally 10x10, or 10x14.
This is too small for today's standards so I removed a few walls. Now, I have half the rooms but they are twice the size.
I am recalculating the heat loads.
The problem of oversized radiators is reduced by removing a number of radiators, after all, I do not need two radiators in most rooms.

Originally, the main split, running a loop to the west and to the east (parallel flow). These then looped around the building to meet, first as a dry return, then it dipped under the floor and back up to a condensate tank with return pump. I have removed this huge heat sink.

With the lower load, the three inch main can now accommodate the entire building. At the point where the two mains met, I now join the pipes reversing the flow through the second, two and half inch main. Now, the main continues around the entire building.

Vent the main! Slow vents on the radiators. I hear that. The main will end very close to the boiler. Plans are now to have only sixteen risers. I will try to reuse the originals as much as possible.

I still have not tested the existing replacement boiler. I have done nothing with it. It still sits in the middle of the floor not laid up properly.

My goal is to restore the Berry while bringing it up to code. There was a lot of restoration required through abuse and neglect. Someone tried to install a 4" drain across ten feet of 2x13 (actual) floor joists. They did this by cutting ten inches out of the middle of these joists. I had to repair things like this before the building collapsed.

100% of the electrical is replaced, now in conduit. (I left a sample of gas lighting pipes and knob and tube for the museum display.)

The plumbing also is up to code. The new bathrooms are almost complete. The hot water is looped with a gravity feed return.

The bats were evicted last year, (They do not like vinegar). I am hoping I plugged all their entrances.

The project demands attention to detail in every regard. I thank you for your help, I will be needing more.

Maybe it will be ready to open next summer.

cgutha

Hi Everyone,
Here it is, 2020. We are completing the west half of the second floor. Today, a primed the walls and ceilings. (Ok, it is a week long task.) I still hope to open around June 1. Those of you interested in seeing the progress, I bought HistoricHotelBerry.com which goes to my link.

This summer will be dedicated to working on the pipes and boilers.
I do have one question. Where do I find the venting specs for air vents? Obviously, I need to calculate the volume of the main and each riser then vent them to allow steam to fill the risers at the same rate: quickly. Is this calculated to a certain time, (say 10 to 15 seconds) or just over-vent and call it good?

Thanks,
ceg

Jamie Hall

I'm glad you are keeping going on this -- any sort of careful restoration is a terrific job! On the venting -- Gerry Gill has a useful chart which is somewhere on the Wall. Somewhere... which gives the capacity of various vents at various pressure differentials. That said, it's almost impossible to overvent a steam main, even a small one, and in my humble opinion about the last thing you want to do is slow down a main. Even insulated, the actual velocity of the steam front in a main is much more how long it takes to heat up the pipe. That said, a couple of Gorton #2s on each main should be quite ample. Probably more than enough. The individual radiators are another story. There you may -- probably will -- have to fiddle a little bit to get a good balance.

Ah -- here's that chart. I'd actually been bright enough to download it to my computer!

JUGHNE

Ceg, sounds like you have come a long ways.
I stopped there for a tour in the summer of 2018, we were on the way to Crosby ND.

Would you have to reslope the other 2 1/2" main to maintain parallel flow?

There is a lot of venting info in TLAOSH-revisited, Dan's 2 nd book.
Assuming you will be redoing a lot of riser piping, on page 201 of that edition, (perhaps in the first also) there is a method shown of venting 2nd & 3rd floor risers.
Simple use of a tee rather a 90 and then a straight thru valve.

Or, if you wanted to reuse the existing supply valves, you could also put a tee at the ceiling just below the rad and then with a nipple and 90 pipe up to an air vent for the riser next to the rad.

If the steam mains ends near the boiler you could add 1 or 2 3/4"
risers for main venting.
If you put valves on these risers and opened them as the boiler fires, then time how long it takes to get steam there with one open pipe......then try it with 2 open pipes.
IIRC, a 3/4" nipple will handle 4 gorton #2 air vents.
That number or more might be in the neighborhood of what you need. You could also consider the B&J "Big Mouth" which do more than twice the G2's.......but no float for water....you would want them as high above the main as possible.

Joe_Dunham

Older steam boilers held as much as 4x the water as the cast iron sectional boiler in the pic. So don't be so fast to get rid of the condensate pump. if the tank is big enough, it can be used as a boiler feed unit which will keep a much tighter water level in the boiler. Cast iron boilers tend to prime and surge a lot so there's a lot of carry over and that causes noise and distribution issues. In fact, a lot of grief can be avoided if a Boiler Feed/F&T configuration is added at the time the boiler was replaced. You can install a float only trap (plug the thermostatic potion of an F&T) at each point of drip like ends of mains or any other drip point (you still need air vents) , and possibly eliminate the buried return and run it to the tank. It is much easier for condensate to get back into the boiler if you don' have to deal with the "A" dimension. And you wont have to raise the boiler. And if there's a common location where all drips meet before dropping below grade, you can put a large float only trap there (but you must still use atmospheric vents at end of mains) and dump it into the tank. You'll need to use the float switch on the tank to operate a make-up valve, and install a pump control on the boiler to signal the feed unit to come on (the auto feeder comes off) and a little re-wiring. Or even invest in a new duplex BFU. There not too much for a small one. This will give you a much quieter system even if the pressure is higher than it should be.

nicholas bonham-carter

I think that the cast iron sectional boilers of today have been designed to hold enough water in their operating levels to supply enough steam to fill all the pipes and radiators in the system. An exception might be had for a system with unusually long supplies, and dry returns, or some Weil-McClain boilers.
If you can do without a condensate tank, and go with gravity return, then you have eliminated one potential mechanical element which may fail in the future, usually on a Saturday afternoon, with subzero temperatures.
Some vanishing water levels, while steaming, may be due to over-pressure (over 1.5 psi), pushing excessive water back into the wet returns. You only need a few ounces to get steam quickly up to the radiators, as long as you have generous main venting, (or vacuum).
I have 55 rads on a 1,050,000 Peerless 211 A, and once the wet/dry returns were repiped, the water level is adequately steady, with only gravity return.—NBC