A fresh air register perhaps. I have seen houses from the 1880-1900 period that had ventilation systems for bringing in outside air in ducts through the basement. Running it through the celler would warm it a bit in the winter, but cool it a bit in the summer, like a passive partial geothermal.
Casey

Since you said the patches were next to the fireplaces, it might have been an upgrade for disposing of ash after cleaning the fireplace. You would usually find the coal storage in the basement too...like I said, just a guess.

Those holes in your floors are about the size of the old coal furnace hot air runs. If these holes go between the walls and are hidden, is there a chance that they were runs to registers on the second floor? Registers come off the runs, and not all registers are floor registers. I had an old house with a wall register from a coal furnace in just about the same position, near the floor. Lovely old iron wall register.

What calliope said. My little ca. 1900 house had a coal furnace once upon a time (which we didn't know until we discovered the coal chute under the porch, which had been bricked up inside - it explained SO many things!) and the original registers upstairs are in the wall rather than in the floor. They're pretty iron grilles about the same size as the hole you've got in the wall. The bottoms of mine are about a foot above the floor but I've seen gorgeous registers that continue all the way down to the floor, including slanted ones that actually stuck out from the wall a few inches at the bottom, which may account for your patched baseboard. We also have similar holes in our floors on the first floor, although the patches are visible from above. :-( At some point someone changed out the wall registers on the first floor with their accompanying big ducts for little modern floor ones with much smaller ducts.

I read somewhere that forced hot air heating was the "big new thing" once upon a time but many people found it dusty and drafty and went back to the steam/hydronic heat with those wonderful iron radiators. :-)

The old coal furnaces of that era were not forced air. They were often called gravity heat. The hot air just rose up the ducts and into the rooms. We had that kind of heat when I was a kid. No electric required at all. There was a set of chains mounted on our living room wall, they ran through the floor down to the furnace below, and that's how one adjusted the flue on the furnace to let 'er rip and heat up, or to dampen the fire down for overnight.

The heat ducts were larger diameter than modern ones and I had the old ones ripped out in a house I sold last year and modern ducting put in. But left the heavy iron registers.

Long about the sixties people would put modern guts in those huge old coal vehemoths to burn gas. They were referred to as conversion burners. Getting an old coal furnace out of a cellar was a gargantuan project. We removed one from the house in which I am living now. Some fellows did it for scrap and had to torch it apart to do it. So going to conversion burners was quite common and the easy way out. I had a conversion burner in an old coal furnace in the first house I bought when I moved here. Did the job well, but not efficient.

Thanks to all of you for your comments!

calliope, I was excited to read your first comment, because your description made me picture an iron grille register, and that would fit with making that fine line around the patched hole.

After reading calliope's first comment, I went down to the basement to look at the area around the other chimney that's on the other side of the house. The house is pretty much a 'four square' layout: central staircases, one of top of the other (basement, 1st-to-2nd floor, 2nd-to-3rd), and two front rooms and two rear rooms. There are 2 chimneys: both run up through the center between each front-back room pair.

And when I looked at the other chimney in the basement, it also had a "large hole" next to it, similar to the one in the pics. I had not even thought to look for a "twin" there until reading your comments. :-)

calliope and johnmari, from what you describe, it seems to match. While I am aiming to search for more info on the web, now that I know what terms to use, do you mind if I ask a few more questions?

- Would the builders have built both chimneys with hearths into the rooms plus these hot air ducts right next to them? I mean, was that a standard practice? Or would these ducts have been added as a renovation some years later?

Originally, I had pictured each room having a coal-burning oven inside the hearth space at the point where the chimney when through the wall of that room. In most of the rooms, I can faintly see differences in the walls at the points where the chimney passes behind them. So, it seems overkill that they would have two methods to heat the rooms: one from the hearth spaces and one from these hot air registers (but anything's possible!).

- Was it the case that a single coal furnace fed one duct run? I mean, since I seem to have two of these, one on either side of the house, would each have had its own coal furnace?

- Did these coal furnaces not produce smoky air that would pass up into the rooms?
(Though I guess if it isn't forced air, it would be cleaner. Like calliope describes, the warm air rises.

calliope, in the old house you worked on, what were the ducts made of and shaped like? Were the holes the same diameter around, going straight through to the attic? And how did the ducting run "end"? Did it just end at a particular register in a room?

Thanks! I just love learning more about the life of my old house. :-)

Lee

I doubt coal burnt in those fireplaces, but it could have happened. I am not a chimney expert, but your sweep may have found evidence of coal dust in your chimney, and made that statement. I'm sure he did. But the only way to find out what that fireplace actually burnt is to open it and look.

Those are old radiators, and the boiler may have been coal fired. May have also been gas fired. Is it still in your home? I have a hard time believing that anyone would have built a mantel over a radiator, however. Likewise they are seldom placed in front of chimneys.

No, one coal furnace usually heated a whole house. They were absolutely huge. Google one. Above it sat a plenum where all the heat rose. A plenum is a big box affair usually mounted to the joists of the floor above the furnace or directly on top of the furnace, depending on the cellar height. Out of the plenum were cut holes where the ducts were attached. They ran like octopus tendrils to various parts of the house areas and may have branched off at any point. Each of those branching points usually had little keys on them so you could direct the warm air to any particular run. As the ducts went up through the wall cavities, they often had an opening on one floor and then continued on up to the second floor. At the openings another box was fashioned out of sheet metal and a grate put over it. So one run may feed two or three different rooms.

Yes, coal furnaces produce smoke, but that goes up the chimney. That's what plenums are for, they are heat exchangers. That air is not mixed with the heated air. Just like the gas from a modern forced air furnace doesn't mix with the fumes. That also goes up a chimney or is forced through a wall via pipe.

Most houses of that era often had fireplaces too. They would have used the same chimneys. They could have been gas or coal grates or wood. A chimney isn't a straight chute up. It can be multifunctioned and that is what modern codes are all about. It can be multifunctioned to the point of danger.

The old house I live in now was first heated by fireplaces only. Sometime after the civil war and before the 20th century they opened a coal bank on the property and put in one of those old coal furnaces. The walls are 19 inches thick and ducts weren't run to the second floor. They simply cut holes in the upstairs floors and put registers over them to let the heat rise. That was pretty common.

Sometime after 1950, one owner stopped using the coal furnace and went to pot belly stoves. Then they added an electric baseboard heater. This is a huge house. When my husband bought it, he put one in every room and when a gas line came through, we put in a gas fired boiler and went to hot water heat. So yeah............one home can see many types of heating systems in its life.

Old fashioned heating men were simply called tinners. Ductwork wasn't standard and were fashioned on site from sheets of tin. ...

My bad for saying forced hot air. I knew better and said it anyway. :-)

We still have the "octopus" now even though the old furnace has been replaced. The original upstairs run (the only one remaining completely intact, other ones are a pastiche of new and old and others are completely new) ends in sort of a T-shape with each of the top "arms" feeding one of the two bedrooms.

Coal furnaces and boilers were also converted to oil. That's what was in our house before PO put in the cheapie crappy oil furnace that's there now - he said something about taking the old iron furnace out with a sledgehammer - and I've lived with a couple of them before. We know an "afterthought" fan to force hot air was added at some point, it's still in the cellar because it's too durn heavy to move and harder to break up. An elderly furnace man identified it for us. :-) (There are still coal-fired furnaces and heating stoves around though, and quite a few coal dealers. I live in southeastern NH which is SO not coal country! Natural gas is actually not that common around here except in the really built-up areas and even then it's not in every house the way it is in other areas.) One of those houses had just one huge floor register about 3' square in the middle of the downstairs and holes in the floor upstairs - the bedrooms were freezing! Furnace repairmen were NOT happy with those, and yes, they're inefficient as all get-out. LOL It's interesting how pretty they were though compared to the extremely utilitarian heating systems of today - raised patterns molded into the cast iron, I remember one even had traces of gilded paint on the curlicues and molded text (I spent a lot of time down cellar in that particular house in the summer). I guess they were very proud of their "modern" heating!

Aren't most hot water/steam radiators placed near windows or on exterior walls (or shared walls with unheated spaces) to take best advantage of natural convection, rather than on interior walls? If OP hadn't shown a photo of the piping I'd have wondered if the chimney chase had been used to run the pipes for the HW/S radiators. I gotta say I LOVE those old iron rads and miss them, nothing in the world better than those for drying wet mittens and boots and warming towels... I remember having teakettles sitting on top of the rads for wintertime humidity. Even with a pricey whole-house humidifier on our hot-air heating system, in winter our house is so dry that the dog gets so dandruffy he looks like he's been snowed on and we humans are itching like mad.

Wow, calliope and johnmari, you are awesome! :-) I never would have thought to include the word "octopus" in a Google search on this, and when I did, I found an image that depicts how these furnaces operated:
http://www.historichomesofminnesota.com/2008/03/monster-in-your-basement-gravity.html

I'm still trying to piece together the relationship the octopus furnace would have had to the brick+mortar chimney that's on the other side of the house (the other chimney than the one in my above photos). The large hole in the basement ceiling is clearly offset from that chimney, and yet in that room there is an actual 'fireplace' like opening in the chimney and hearth. (As soon as I get the digital photo uploaded, I will post it so you can see what I'm talking about).

your sweep may have found evidence of coal dust in your chimney, and made that statement.
I honestly cannot recall if he said whether he found evidence of coal dust. What he said was that that fireplace (the one open one in our living room) and chimney were too small to be a wood-burning system. That it was "sized for coal".

The gravity furnace isn't still there. The current boiler is oil-fed (oil tank in the basement, common here in Massachusetts), and it was replaced by the previous owner in the year before we bought the house, so I have no idea what was there before that most recent replacement.

19 inches thick walls!! Gosh, those are thick.

Hey johnmari, it sounds like your house might have a similar background, especially since it's in southeastern NH and I'm in northeastern MA. Our current heating system is oil-fired boiler for hot water radiators. And yes, I just adore the cast iron radiators in our house. While a few of them are just squared edges, most of them have flowery patterns in the cast iron. And after shoveling snow, I love that I can set my snowy mittens and hat on top of one to dry out. My dad replaced all of the cast iron radiators in his house when I was little with baseboard radiators and those just don't have enough shelf space to set one's mittens on. ;-)

Aren't most hot water/steam radiators placed near windows or on exterior walls (or shared walls with unheated spaces) to take best advantage of natural convection, rather than on interior walls? If OP hadn't shown a photo of the piping I'd have wondered if the chimney chase had been used to run the pipes for the HW/S radiators.

I originally thought the 'holes' in the basement ceiling were simply for running the hot water rad pipes, but the pipes are not even centered in the larger hole. I agree that white radiator under the mantel is oddly placed. Most of the other radiators in the house are by windows, as you describe.

I have a hard time believing that anyone would have built a mantel over a radiator, however. Likewise they are seldom placed in front of chimneys.

Yes, isn't that "mantel over the radiator" an odd sight? I have never seen it before. And I've got that in two...

OK, this pic doesn't have the best detail, but maybe you can tell if it really used to be a fancy hot air register. (My spouse is off with the digital camera, so this Christmas pic is the best I can find on the computer).

Just inside the green tiles is what appears to be cast iron work painted black. Then the tiny opening in which I have my candle holder and green candles.

The candles rest on a piece of metal which is just loose and lying on the floor part of that opening (is the right term the "hearth" for that area in which you'd build the fire?), under which is a rectangular framed opening. When I stick my head into the fireplace, I can look down and see down into the chimney. The space is tight (and I suppose that I have a large head!), so when I shine the flashlight down, I can only see the back half of the chimney.

When I get my hands on the digital camera, I'm going to take some pictures of the inside of that chimney. :-)

Yeah, we have that dadratted oil tank in the cellar too. A matter of weeks after we moved in the tank was condemned and we had to have it replaced - $$$$$! We don't have a bulkhead to the cellar so the old tank had to be cut apart to get it up the narrow stairs (there was oil-soaked kitty litter everywhere!) and the new one brought down in pieces and welded together on-site because there wasn't enough room for two little ones. But, outdoor ones are a huge PITA in our climate and buried ones are illegal here now.

That fireplace tile is a beaut! I can't say anything about the coal vs. wood dilemma, I think it looks like a coal firebox but I just don't know enough about that specifically to say for sure. I don't know if yours did but the nicest examples of the cast-iron fireboxes often had beautifully detailed front pieces called "summer covers" - try digging around in the manky recesses of your cellar or attic to see if you have one. If you have natural gas lines to the house those can be retrofitted to a gas log relatively easily if you're interested. It doesn't seem strange to me to have both fireplaces and central heating though - after all, we do that nowadays too, don't we? A fireplace is also not unreasonable if you only need to take the chill off one room but don't need to fire up the main heating system and waste all that coal.

My house is WAY more modest than yours - it's in an old mill town. There are thousands upon thousands of these here. We bought it from a flipper in 2007. Originally it was less than 900sf, an addition in 2006 brought it up to not quite 1250. No fireplaces :-( and it didn't even have a full bathroom until 2007! *shudder*

DH grew up in a rambling Queen Anne near Gloucester and we spent a few years in the metro-North (1920s apartment building, in a bad neighborhood so sadly deteriorated) and Cape Ann (ugly 1970s apartment building) areas while he was working in Boston. Second Empire three-flat in South Boston, too - that was an adventure even as a renter, lemmetellya!

I think Caliope has nailed it. There are similar patches in my Mother's 1903 Queen Anne where the original gravity air heating system was removed around WW I and replaced with a gravity hot water system.

Apparently (my Grandparents bought the house in 1943 from the son of the original builders/owners) the gravity air system simply wouldn't heat the house, so after suffering for a couple of years the system was replaced.

As for the fireplaces, I would bet hard money that yes, those fireplaces WERE designed primarily as coal burners.

Coal boilers and furnaces were, once lit, kept burning the entire heating season if at all possible.

But, they didn't want to light them off too early and waste fuel and drive themselves out of the home with the heat.

So, until the temperature dropped consistently into the high 50s or low 60s during the day, it was very common for homes to be spot heated with fireplaces until the true heating season kicked in.

These fireplaces invariably burned coal, which was plentiful in the coal bin.

This is the coal-burning fireplace in my Mom's house. Unfortunately, it is no longer usable because of chimney problems, and it couldn't be used with coal anymore because over time the grates in the bottom burned through, but in years past my Grandparents occasionally used it with wood.

That's a prefabricated cast iron unit.

Koala, no your fireplace did not used to be a fancy register. It has always been a fireplace. No attempt was ever made to make hot air registers, or cold air returns, to look like fireplaces with mantles. Likewise when your old radiator was installed, nobody built a mantle over it. That mantel was hung over a fireplace. It is simply closed over.

Kframe, what a beautiful, beautiful unit that is. It just screams the ornate and rich era of the turn of the century.

My parents didn't keep our coal furnace burning the whole season. My mother took over the job as the stoker/damper/fire starter for furnaces. She would arise early before even my father was up and stoke it up and feed it coal so that the house would be toasty before anyone else was up. She could also dampen the fires just right to keep them burning through the night. You had to let the fires expire to carry out the 'clinkers' and ash. Coal leaves hard, sharp residue you must remove from the furnaces regularly to keep them running right. It builds up quickly. When I was a child, every alley in town was lined with the cinders from coal burning furnaces. I have clinkers embedded in my knees yet, from playing softball and sliding in them.

Everyone dumped their clinkers in the public alleys and I believe even the city used industrial cinders instead of salt in heavy snows.

We live in the country, but like said, there is a coal bank on our property one of the farmers used to mine himself and sell. I guess when the EPA came into being, they made him shut it down. LOL. Anyhows, we have a hillside we eventually turned into a rock garden, and it's comprised of coal cinders. Now covered with soil and planted.

Calliope,

Generally, a coal furnace or boiler would be shut down maybe once or twice during the heating season to clean the shaker grates, but only if it was necessary and, if at all possible, on a mild day.

As long as you had a good supply of relatively slate/stone free coal and you kept shaking the ashes and clinkers into the ash pit regularly, your grates generally wouldn't clinker up too badly.

Pennsylvania (where my family came from) has some of the best anthricite coal in the world, and is known for low clinker formation. Even the soft coal was relatively low in clinker formation.

Removing the ashes and clinkers also didn't require shutting the system down, if you had a system that had a drop shaker grate.

It sounds, though, like the system in your home had a fire pot design, or maybe one of the early stokers. If that's the case, then you might well have had to have let the fire go out to remove the clinker and ash.

Where did you grow up? The type and quality of coal generally available in your market may well have dictated the type of systems installed in your area.

Where I grew up, though? Shaker grates and ash pits. The boiler in the house I grew up in was a coal boiler converted to oil. The oil burner gun was mounted in the old ash pit door.

Furnaces with an ash pit have its own door. You'd adjust the stack and main draft accordingly, open the ash door, shovel the ashes out into a metal ash can or wash tub, close the door, and reset your main and stack drafts.

Then you'd generally wait until the ashes cooled down so you could carry them up stairs and out to the curb.

If you did get a clinker that froze the grates, you'd use the rake and poker to try to break it loose. If that didn't work, the next step was to fire the system really hot for a few minutes to soften the clinker and then try to knock it loose.

Nope, our coal is high sulfur bituminous, higher BTU value than your anthracite, but dirtier. I live in South Eastern Ohio. Probably lived in at least five or six houses with coal furnaces, when I lived in the U.S. The last time I remember we actually used a working coal system (not converted) would have been in the early sixties. There were a pretty wide range of modernity (is that a word?) in the furnaces. I remember my father and my uncle installing one in our basement when I was maybe four or five. He built the coal room under an existing chute and poured cement on the dirt floor. It was an awesome and fascinating job. The other homes had furnaces already in, and some did have ash doors. I remember opening the feed door of them when I was older to watch it burn. If my folks knew I'd done that, I would have been in deep doo. LOL.

It surely was a good heat. No forced air to make drafts, and totally silent. I can remember dressing for school in winter, standing over the heat rising from a register. God, I feel slightly younger than God and older than dirt. LOLOL.

Generally, the higher the sulfur content in the coal, the higher the other non-combustible mineral content as well, and the higher the clinker formation rate.

Your furnace was very likely one with a firepot design. As you note, no ash door, no shaker grates. This was a somewhat later design that was quite a bit simpler to manufacture. IIRC many of the Sears homes came with a firepot type furnace.

In those, the fire was allowed to die down, or nearly out, to let the clinker solidify so it could be removed with a clinker fork and the ashes raked out of the firepot.

My Mother grew up in a house with the big heating grate in the front hall. She said it was a great play to lay in the winter to do homework.

I grew up in a house with steam heat. Very comforting to hear the boiler timer kick in on a winter morning and hear the steam coming up in the pipes.

Koala, that fireplace with the beautiful tilework definately burned coal. You can find examples of the ornamental coal scuttles which stood by them in antique stores in the coal burning country (including NY). Combined with the gravity air furnace, you had zoned heating! BUT aren't you curious about the fire place (and there surely was one) behind the radiator? Could it have tile and iron work as lovely as the one you now have exposed? Now that you are working on that room in the summer (or what should be summer here in the northeast), couldn't you remove the radiator and have a look? I suspect we'd all love to see the pictures :). Many thanks for starting this thread, it does bring back memories.

You know, it didn't dawn on me before, but those large, round patched holes in the basement ceiling/first floor flooring?

Just big enough for an old octapus style heating pipe.

After reading this, I remember that I saw what was probably an octopus furnace in an old house in Atlanta; it was huge. I don't think it was used anymore (the house was used as an antique/salvege business) but the furnace was easily the size of a small room (& the house wasn't immense). No way it could be removed without cutting it up.

Here's a link to a good picture of an Octopus furnace...

http://sarafoltz.files.wordpress.com/2009/05/gravity-002.jpg

Hi all! Thanks for the additional info and comments. And thanks for the compliments on our tiled fireplace--that was one of the first things we fell in love with when we saw the house.

kframe19, that fireplace picture with the curly details is so lovely. They really put a lot of thought into how all of the details work together.

And thanks for mentioning how the rooms were spot heated with fireplaces before they'd turn on the air furnace for the cold season. That answered one question that I had about why the room would have both a fireplace and a hot air register.

tzmaryg wrote:
BUT aren't you curious about the fire place (and there surely was one) behind the radiator? Could it have tile and iron work as lovely as the one you now have exposed?

YES! I am very curious about what's behind that radiator. When I take a close look at the panel that's behind it, it seems flimsier than dry wall. It almost looks like a piece of poster board covered with plain wallpaper that they slid behind the radiator and nailed with little nails into place. While it is summertime, I'm not so sure that I want to take on moving the whole radiator though. :-) When my husband gets home from his trip, I'm going to remove the little nails and get him to help me see if we can simply slide the board out from behind the radiator. (I could probably attempt it myself, except if something goes wrong, then I'd be stuck trying to explain to him what I did!)

--Lee

Keep us posted!

Hi La Koala,

Just a thought on your living room fireplace. It's hard to judge size in an image, but the bricks inside your fireplace appear larger than I would expect for "vintage" brick. More like modern firebrick which is sometimes done to make the fireplace safer for wood burning by today's standards. Do you have any idea if that fireplace and or chimney has been worked on/altered? The cast iron may have been added later to a wood burning fireplace. Paul

I too grew up in an old house in Detroit with one of those very large coal burning furnaces. We had two fireplaces, one on the first floor and the 2nd above the first in the upstairs room that had been converted to a living room. I'm assuming it was probably a bedroom first. We burned coal in them but had blocks of coal that we put in the fireplace. You would get rid of the ashes for the fireplace by putting them through a hole in the fireplace and opening a door near the ground outside.

Sitting on the registers getting warm was the thing to do. Gosh how I miss those days.

Shirl

Hi all,

I first want to thank you all so much for your comments and observations. The insight and knowledge on the GardenWeb forums is tremendous and I learn so much.

Before I forget, Paul (paul4x4), you commented on the size of the bricks in the living room fireplace. I don't have any idea if the fireplace or chimney was altered. I do know that my chimney guy said that the fireplace/chimney is not large enough to be safe for wood burning--and that it is unlined, so that we should not burn wood in it without having a liner put it. Something about the fact that burning wood would send flames too high into that chimney.

I have an update to respond to tzmaryg's comments about what's behind the radiator. Due to a leak in another part of the hot water heating system, the system had to be drained and I took the opportunity to have the plumbers also disconnect the radiator and move it out so I could get behind there.

First, there was a plywood-like panel covered with the light color wallpaper that I had removed from the rest of the wall. This panel was just nailed into the white wood of the mantle surround on one side with small nails, so I took those out and pulled the panel away. Here are photos of what I found behind it:

Long view--see that dark round-ish patch in the center of the peeling wallpaper? That's a 5" hole going into the chimney!:

Close up of hole:

Looking through the hole into the chimney:

Needless to say, seeing an empty hole going into the chimney sort of freaked me out--even if it has been there for quite a number of years. This chimney takes the gases from the boiler. I had the chimney guy out today to seal it up.

If it was a stovepipe for smoke going into the chimney, is it weird that the wallpaper looks like it would have been tucked up right against the pipe at the time?
In the close up pic, you can see how the wallpaper goes right up to the edge of the hole.

tzmaryg, I was *so* hoping to see some decorative tile behind the plywood panel. :-)

Thanks again to all for your input!

My guess is you uncovered a closed over fireplace, later retroverted to accept a pipe from another free standing stove, possibly an oil burner. You just hit the cement they dummied the fireplace opening with.

We have a fireplace in every room of our house. Most of them had been covered over in much the same manner. Our house was built when cooking was still being done in the hearth and heating was in every room via fireplace. It was terribly inefficient but then again wood and elbow grease were plentiful.