HITZER 50-93 W/Fan, & Side Heat Exchangers...

oliver power · Post by **oliver power** » Tue. Jan. 20, 2015 9:21 pm

What do you think? The 50-93 with fan blowing air up around the smoke outlet, across the top finned heat exchanger, and out into room. It is a "Heating Machine". However, during times of power outage / fan off, The stove heats up, causing bi-metallic thermostat to stay closed. The stove sets there, slowly radiating heat. With vertically finned heat exchangers (left & right sides), air can be drawn from floor, up through finned chase for natural circulation. As heat is drawn off the stove, bi-metallic thermostat opens, feeding air to fire. This creates more heat to be drawn off stove via side heat exchangers. The 50-93 would have the best of both worlds. Fan, and natural circulation. I sent this to HITZER. Comments???

freetown fred · Post by **freetown fred** » Tue. Jan. 20, 2015 9:27 pm

Sounds outstanding OP for someone that don't have as many outages as I get on the hill here. Even just the fins would increase heat distribution--but hell, that's been done on another type stove & I believe worked well:)

oliver power · Post by **oliver power** » Tue. Jan. 20, 2015 9:41 pm

freetown fred wrote:Sounds outstanding OP for someone that don't have as many outages as I get on the hill here. Even just the fins would increase heat distribution--but hell, that's been done on another type stove & I believe worked well:)

Yes Fred, Leave the 50-93 w/fan as is. Have vertical fins welded on the left & right sides, and a chase fabricated over the fins, extending from near floor, to top of stove for natural circulation. Side heat exchangers can be another option for the 50-93. Actually, it can be an option for many stoves. Same theory as the D.S. Circulator.

oliver power · Post by **oliver power** » Thu. Jan. 22, 2015 3:07 am

Next time I'm fabricating in the shop, I may whip up a couple modular finned chases from sheet copper / aluminum. Strap them to the stove for testing. I'll keep everyone posted.

freetown fred · Post by **freetown fred** » Thu. Jan. 22, 2015 3:38 am

Nice, don't forget pix

hotblast1357 · Post by **hotblast1357** » Thu. Jan. 22, 2015 8:50 am

I've thought about this for a while with my hot air furnace, I've been looking for heat exchangers and have found they are rather expensive for the size I would need.. My thought was.. Could someone just weld angle iron up the side next too one another? When done it would look just like fins? Or would this not work like a heat exchanger would?

oliver power · Post by **oliver power** » Sat. Jan. 24, 2015 5:16 pm

hotblast1357 wrote:I've thought about this for a while with my hot air furnace, I've been looking for heat exchangers and have found they are rather expensive for the size I would need.. My thought was.. Could someone just weld angle iron up the side next too one another? When done it would look just like fins? Or would this not work like a heat exchanger would?

I don't see why it wouldn't work. Welding actual fins would be less money. A chase (Box) over the top of them would give chimney effect, causing more force, and better air movement / circulation.

hotblast1357 · Post by **hotblast1357** » Sat. Jan. 24, 2015 9:25 pm

Less money? Have you seen the price of those things? Lol I already have a furnace so no need for a chase or box, I already have it.

oliver power · Post by **oliver power** » Sun. Jan. 25, 2015 6:32 am

hotblast1357 wrote:Less money? Have you seen the price of those things? Lol I already have a furnace so no need for a chase or box, I already have it.

Not sure if we're talking the same thing here. Are you talking a new heat exchanger, or simply adding fins. I'm talking a modular finned, clip-on heat exchanger, which fastens on the side of stove. Or, simply weld on fins, and cover with sheet metal chase. Yes, there would be a little labor involved either way. Maybe more than I'm thinking. But, I'd still like to make a couple up. As a rule, Freetown Fred doesn't use his fan. Maybe I'll make one up for Fred.

hotblast1357 · Post by **hotblast1357** » Sun. Jan. 25, 2015 5:46 pm

I'm sorry I mis read what you posted, yes using angle iron to make fins would be cheaper, I would just like too know if it would be as effective as a heat exchanger. I would pull my sheet metal off my furnace and weld angle iron vertical on the sides the. Mount my metal jacket back on.

rberq · Post by **rberq** » Sun. Jan. 25, 2015 6:04 pm

Instead of welding the flat of the angle iron to the flat side of the stove, weld the edges of the angle iron to the stove. That will make multiple triangular convection passages and effectively triple the surface area of the sides (as long as there is very-efficient heat transfer through the welds). Add a sheet-metal outer cover across the points of the angle iron to create a second set of triangular convection passages.

rberq · Post by **rberq** » Sun. Jan. 25, 2015 6:08 pm

oliver power wrote:Maybe I'll make one up for Fred.

Coward. Try it out on your own stove first.

I bought several dozen small (2" X 2" X 1/4") finned aluminum heat sinks and stuck them on the back of my stove by putting strong magnets on the outer ends of the fins. I had three problems:
1) The aluminum was too smooth and slippery, so any vibration (like shaking down ashes) caused them to slide down the stove and fall off.
2) No way to measure whether I was getting MORE radiant heat via the heat sinks, or LESS radiant heat because the aluminum sinks were blocking radiation from the steel.
3) Wife complained that they were ugly, even though she couldn't see them unless she made a conscious effort to look behind the stove.

I think what she really meant was, not ugly, but unconventional, and therefore likely to inspire ridicule from visitors. I wonder if Isaac Newton was married -- probably not or we would still think the sun circles the earth.

SWPaDon · Post by **SWPaDon** » Sun. Jan. 25, 2015 6:13 pm

If you are just trying a 'test run' why not make your sheet metal case, and attach sheet metal "V" shaped pieces with zip screws ?

rberq · Post by **rberq** » Sun. Jan. 25, 2015 6:29 pm

SWPaDon wrote:If you are just trying a 'test run' why not make your sheet metal case, and attach sheet metal "V" shaped pieces with zip screws ?

We need SOLID contact between the fins and the stove body, to allow for conduction of heat from the steel sides of the stove and into the fins.
A problem with angle iron is that only the cross-section (thickness) of the iron conducts heat into a fin, regardless of the surface area in contact with the stove. Thin sheet metal pieces would accomplish even less conduction.

rberq · Post by **rberq** » Sun. Jan. 25, 2015 6:40 pm

hotblast1357 wrote:I've thought about this for a while with my hot air furnace

My neighbor has a Hot Blast furnace with dual convection blowers and the two large ducts coming out the top. He has thermometers mounted in the output ducts, and there is a huge amount of air coming out but at very low temperature, maybe 110 degrees. So I would say those blowers are sucking just about all the available heat off the furnace, and fins would not improve anything.

http://www.tractorsupply.com/en/store/united-stat ... 2500-sq-ft