In a home I showed.

Any one think this might be valuable. It was in a home I showed. It is an oil burner currently or always was not sure. with a floor grate above it for central heat. Still in service. Must be expensive as hell to heat the place.

I haven't seen that style oil burner unit since the same one was removed from my parent's basement in the early 80's. Must run a long time to heat that monstrosity! Wouldn't want that oil bill ...

We used to make kick ass wood stoves out of 55 gall drums--I'm befuddled on that oil critter I wish the pix showed more

Possibly an old coal furnace, I've seen them like that in peoples houses. Whatever it is most certainly some type of solid fuel burner. It was common practice to convert them to oil. My understanding is very inefficient.

That is probably a negative on the cash flow unless the old parts are still around in which case I'd suggest you convince them to convert it back to coal.

I have ripped out a gravity furnace or two in my younger days. These units were typically a coverted coal furnace. Usually the spare parts are long gone. The center is a cast iron furnace with a sheet metal jacket. Usually heavy as a dead horse. Watch out for that white insulation stuff.

Worth about as much as the scrap yard will pay.

I remember coming across this website for old Holland coal furnaces. http://hollandfurnacecompany.com/ From what I read on this site, it appears they still supply parts for this old unit. Maybe they might even be interested in purchasing your old Holland furnace? Contact them and see what they have to say. I'm kind of curious too.

There was a Holland furnace exactly like that one in a building at my dad's work. It had an underfeed stoker, and a large circulating fan was added to the return making it a forced air furnace. I can't see the return duct in the photo....it must be on the back side?
Originally, many of these "gravity (hot air) furnaces" were hand fired, then converted to underfeed stoker, then converted to gas/oil. These aren't very efficient with gas/oil.

Here is a photo of a gravity furnace with a stoker. The stoker is in the lower right corner of the photo (Winkler stoker)
http://www.google.com/imgres?imgurl=htt ... 29,r:6,s:0

These furnaces won't break 60% overall efficiency as a gravity furnace. Install a 'modern' ceramic fiber oil combustion chamber and add a squirrel cage fan, a baro set to .02 and keep the stack temp LOW and they become very easily 85%. Most oilmen would rather just throw a new furnace in and charge their markup, but add a fan, combustion chamber, baro, and possibly some ductwork and in a day or so you'll be saving money and keeping a piece of history out of the scrap heap. Don't discount the efficiency of the old, slow-speed oil burners either, they very often had efficiencies matching and occasionally exceeding modern high-speed flame retention burners. They developed a bad reputation for inefficiency and smoke production mostly due to the poorly designed combustion chamber and combustion chamber material of the time, the burner itself was not the culprit; this is why a properly sized ceramic fiber combustion chamber is not to be overlooked when trying to save money with an older oil burner.

I remember back in the mid 80's having an old hand fed steam boiler converted to oil in our house on Long Island, NY. It had a quite new Beckett burner and I remember the service tech being rather surprised at the combustion efficiency (85% sound right???) and zero smoke readings he measured. It did have a ceramic blanket chamber installed, which I'm sure contributed to the numbers.

As far as overall efficiency, I don't think it was all that good. I remember the stack was pretty hot when it was running, and the tech also did mention that there were some hanging baffles that could be installed to improve it. It was a typical cast iron "pancake" boiler so there was a pretty straight shot through it. Nevertheless, the system was in solid shape and worked well, so my father left it alone. It was also before oil prices went through the roof, so there wasn't a lot to justify replacement.

We had a big oil-fired boiler that I suspect was converted from coal. It came with the house, as did the ancient technician who took care of it. He rebuilt the combustion chamber at one point. I believe it was measured at 69 percent efficiency, whatever that means. Our new boiler is only 86 percent. I don't want to calculate the payback period for the new boiler because I'm afraid I would be upset at the answer. Especially since now all it does is heat DHW, and supplement the coal stove two or three nights a year when it's really cold.

There are several types of efficiencies. The efficiency on the yellow "Energy Facts" sticker on new HVAC products is AFUE, Annual Fuel Utilization Efficiency. AFUE Factors in start up and shut down losses, off cycle losses, to give a total percentage of how much heat is provided to the structure versus how much heat the fuel consumed contained in ideal combustion. AFUE is the most useful gauge of fuel use, but does not factor in electrical consumption of fuel burning equipment. Nothing I have seen published accounts for electrical consumption.

The efficiency printed out by my combustion analyzer is combustion efficiency. This has nothing to do with how efficiently the heat exchanger transfers heat to the building. It does not factor in start up and shut down losses, or off cycle losses. We can have 80% combustion efficiency in a gravity furnace that has an AFUE of 55%. It burns cleanly, little soot, just enough excess air, but is still an energy hog. Also, your new 95% AFUE, tax credit condensing furnace tests on my combustion analyzer at around 90% efficient. The reason, the analyzer does not account for condensation. To truly measure efficiency of a condensing furnace we need to measure condensate produced.

Another efficiency you rarely see stated anymore is "Bonnet Efficiency," also called "steady state efficiency." Furnace Data plates list an input capacity and output capacity, some easy math gives you a percentage. Example, a natural draft gas furnace with 100,000 BTUH input, 80,000 BTUH output has a bonnet efficiency of 80%, but an AFUE of only 65%. After it heats up to temperature, and before it shuts down, its 80%, but that natural draft is removing heat all the time, even when the furnace is off.

Generally, gravity boilers and furnaces are 50-60% AFUE.

rockwood wrote:There was a Holland furnace exactly like that one in a building at my dad's work. It had an underfeed stoker, and a large circulating fan was added to the return making it a forced air furnace. I can't see the return duct in the photo....it must be on the back side?
Originally, many of these "gravity (hot air) furnaces" were hand fired, then converted to underfeed stoker, then converted to gas/oil. These aren't very efficient with gas/oil.

Here is a photo of a gravity furnace with a stoker. The stoker is in the lower right corner of the photo (Winkler stoker)
http://www.google.com/imgres?imgurl=htt ... 29,r:6,s:0

Note that the orginal description was for a central floor grille over top of the furnace. These at the really old style that did not have distribution ducts. A plenum on top of the furnace was take directly up to a floor grille. Hot air comes out of the center of the grille over the heat exchanger and cold air returns on the edges of the central grille.

The disadvantage of these is that the heat distribution to the house is uneven, much like a stove in a single room. They rely on a open floor plan. On houses that are mutiple story, typicall floor transfer grilles were cut into the floor and the return air came back down the stairway. But back to the question at hand - Is it worth anything?

In my opinion, It is probably worth little to tear out and sell. It might be worth saving and coverting back to coal to the right person, providing the heat exchanger is still sound and not cracked. To the average homebuyer, it would be a turnoff and a negative selling point.

freetown fred wrote:We used to make kick ass wood stoves out of 55 gall drums--I'm befuddled on that oil critter I wish the pix showed more

I know the post is a few months old but here's a pretty cool theme on the round barrel stove. This guy makes these up in Vermont. They have secondary combustion, side shelves and a piece of soapstone on the top for a kettle.

SteveZee wrote:

freetown fred wrote:We used to make kick ass wood stoves out of 55 gall drums--I'm befuddled on that oil critter I wish the pix showed more

I know the post is a few months old but here's a pretty cool theme on the round barrel stove. This guy makes these up in Vermont. They have secondary combustion, side shelves and a piece of soapstone on the top for a kettle.

Wow! That this is pretty cool. I wonder how much heat it puts out.

Looks like the price tag must be .....uh ..... very wide ...