cast iron significant difference?

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rob bennett

New Member
Hearth Supporter
Feb 19, 2008
147
Lynden, Washington
I know that cast iron isn't soapstone, but is there a significant or noticeable difference from the heat it gives off compared to a steel stove? Anyone used a PE Summit and then the summit size aldera? Just curious.
 
If you pay more for cast iron it feels better. :lol:

I have both. No difference.
 
I haven't had Summit and Alderlea running. You'd have to ask a dealer like Tom about that. I have noticed the difference in heat retention between the Alderlea and the Castine. There's no question that the greater mass is slower to warm up and slower to cool down. That gives a softer heat and I find the stove releasing its warmth longer after the fire has died down. But I don't see any reason why that mass couldn't be steel instead of cast iron.
 
I only have cast iron, so I can't compare, but I'm surprised to hear people saying no difference between the two. I have always heard what Begreen has said. I guess if you're a 24-7 burner, the longer startup and longer retention really don't matter so in that case... ....no difference!
 
I think the mass is the thing. When the 30-NC at 455 lbs. gets hot it stays hot for hours after the fire dies down. It will drop back to three hundred or so pretty soon after the fire dies but it just hangs there for a long time.

Works well with our goofy climate because a lot of days I can get it hot and let it ease down as the outside temps ease up.
 
I had a steel stove (Lopi Answer) and currently burn a cast Jotul now. Both are great. Steel stove made louder clicking and oil-canning type noise when heating up. 'Heated up faster, and cooled more quickly after the fire subsided.

Cast stove is slower to heat but stays warm noticeably longer (after the fire subsides -- it is a bigger stove). I would own either type.

Regards,

Dexter
 
I think Craig is right about the basic heating characteristics of the two metals. I'm not sure where I got this number a couple of decades ago, but my remaining brain cells have somehow retained the knowledge that cast iron and plate steel are both about 86% heat transfer efficient. Nonetheless, there are a couple of differences as to the perception of the heat output from stoves made of the two materials.

In the case of the Pacific Summit and Alderlea T6 models, one of the big perceivable differences is created by thermal mass: both stoves are built around the same firebox, but the thick cast-iron outer shell on the T6 weighs 110 pounds more than the thin steel shell on the Summit. This enables the T6 to store more heat, and continue to radiate longer after the fire dies down. We've burned both models, and definitely noticed this.

The second difference is more subtle.

A plate steel stove will focus the radiant energy from the fire to "hot spots" at the center of each plate, which can be identified by the perfectly centered circle of faded paint that develops after years of use. Radiant energy flows from these hot spots in straight line vectors perpendicular to the flat plane of each plate: owners of old-time Fisher and Schrader single-wall plate steel stoves soon learned to move their favorite chairs around to the corners of the stove, to avoid sitting in the blasting flow of radiant energy straight out from the hot spots. The textures and shapes cast into the plates of cast iron stoves aren't just for ornamentation: they also serve to change the topography and defocus this straight-line flow.

Here's how that works: take a rubber ball, and stick pins into it, so the point of each pin points at the center of the ball. The heads of the pins will form another "ball" surrounding the surface of the rubber ball. If the rubber ball was a source of heat, the shafts of the pins would describe the path the radiant energy would take, radiating in all directions from the source. Every shape incorporated in a cast iron plate radiates heat from its surface in the same fashion: the result is, the energy flow into the room is diffused, and it is more comfortable to sit near the stove. The old pot-belly stoves were a perfect example, as they incorporated the advantages of a round firebox shape, PLUS ornate relief patterns. Diffusion patterns have also been cast in rectangular-shaped stoves over the years, taking many now-familiar forms, notably Morso's high-relief squirrel and Waterford's curved Wenlock's Castle, both located at the center of each side plate.

The outer shells on Pacific Energy stoves reflect radiant energy back at the fireboxes, and harness it in the form of heated air. This "softens the blow" of radiant energy through the outer plates on all models, but the diffusion effect created by the texture, slight curve and ornamentation on the cast iron Alderlea models' outer shells makes them even more comfortable to sit near.

Didn't mean to write the great American novel here, but it's Sunday morning and nobody's up yet around here but me.
 
Fascinating, thanks for taking the time to add that info Tom. I love it when I learn new things here.
 
The only significant difference that I can discern is that many of the cast stoves are really beautiful, while all the plain old plate steel stoves are just so doggone ugly. I can barely approach either of my stoves to load them without gagging. I tried doing it with my eyes shut, but I wasn't really very successful. %-P Rick
 
Don't worry Rick, your stoves will gain beauty in direct proportion to the temperature fall outside. That and some Jack Daniels will cure your problems.
 
BeGreen said:
...That and some Jack Daniels will cure your problems.

Yeah...never went to bed with an ugly stove. :lol: Rick
 
The other significant difference is that with cast iron, chances are at some point the stove will have to be disassembled and the joints recemented or regasketed.
 
BrotherBart said:
I think the mass is the thing. When the 30-NC at 455 lbs. gets hot it stays hot for hours after the fire dies down. It will drop back to three hundred or so pretty soon after the fire dies but it just hangs there for a long time.

Works well with our goofy climate because a lot of days I can get it hot and let it ease down as the outside temps ease up.

The regular summit tips the scale at 425 lbs. with legs 435 lbs. with a pedestal. their is lots of mass in a summit as well
The T-6 tips the scale at 560 lbs. given the extra 135 lbs. I would have to say it should take longer to warm it up and cool it down.

once it gets to temp they should feel the same.
 
BeGreen said:
Don't worry Rick, your stoves will gain beauty in direct proportion to the temperature fall outside. That and some Jack Daniels will cure your problems.


Bingo
 
precaud said:
The other significant difference is that with cast iron, chances are at some point the stove will have to be disassembled and the joints recemented or regasketed.


I do like the idea of being able to rebuild my stove at home then taking it to a welder or paying alot for the welder to come to me.
 
Metallurgy--cast iron is usually recycled, "melted" steel with additives. It is more porous, or less dense than steels or iron plate.
You can try it yourself: drill into a steel plate and then into cast; the cast is softer, difficult to weld or braze. Corrections allowed now. ;-)

Jack Daniels is a lower order drink; real wood heaters stick to the Single Malts you know. Corrections allowed.................now.
 
johnnywarm said:
precaud said:
The other significant difference is that with cast iron, chances are at some point the stove will have to be disassembled and the joints recemented or regasketed.


I do like the idea of being able to rebuild my stove at home then taking it to a welder or paying alot for the welder to come to me.

The Alderlea's are steal fire boxes with cast plates so no rebuilding required :-) so i guess all you need is a welder for the garage and your set.
 
My wife declared steel stove "UGLY".
I wanted a stove.
Need I say more?
:-)
 
She either needs to be educated or replaced. Anyone whose sole criteria for selecting a stove is visual, is forfeiting their vote in other equally important areas.
 
Below are thermal conductivity values (http://hyperphysics.phy-astr.gsu.edu/Hbase/tables/thrcn.html#c1) of commonly known metals and other materials.

THERMAL CONDUCTIVITY (W/mK) - in metal - proportional to electrical conductivity

Silver
406

Copper
385

Aluminum
205

Iron
80

Steel
50


Lead
35

Glass
0.8

Brick, red
0.6

Water @ 20* C
0.6

In a wood stove comparison, one sees a steel stove vs. a cast iron stove would have quite similar thermal conductivity properties, as has been stated, while one made from brick vs. silver would be very different (albeit about the same price...).

Keep in mind, high thermal conductivity in a wood stove is not an ideal or even a desirable quality (fried dust, indoor weather, etc. - www.mha-net.org). Owners of masonry heaters will attest to the superior comfort from the MODERATE thermal conductivity of their masonry (brick, stone, soapstone, ceramics, etc) heater with its healthful consistent radiant heat.

Aye,
Marty
 
Lets be honest, everyone attests to the superiority of their OWN stove most of the time on this forum. Cat non cat, soapstone insert harthstove etc. Got a rumsford fireplace? I bet you think thats the best.

That being said, I'd love to build a masonary heater. I have read throught that entire site that you mentioned and nearly bought the book until I realized it really would't work unless I put it in the basement.
 
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