Big Hitzer 30-95 Mods.

I got brave or foolish. I have complained for some time about the noise from my stove's blower. I also replaced the blower motor after only 3 years. The stove has a double layer top with an air space between the two layers. Duct work on the back carries the air from the blower up the back of the stove to the top, accross the top and blows out the front. That all works just fine with the blower running, but with the blower off the exhaust gas temp rises because the heat is held inside the stove by the double layer top and the ductwork on the back.

With sheet metal nibbler and cutting torch in hand I turned my 30-95 into a radiant heater (I hope). I cut most of the sheet metal duct work off the back with the nibbler. I cut 5, 2" diameter holes in the top in front of the hopper opening. This should greatly improve the escape of heat being produced without the fan.

Next, with the cost of heating oil, I want to get away from running a furnace in the fall and spring when the weather is so variable. I find the coal produces much more heat than I can use at mild temps. So, I want to burn wood in my Hitzer in the evenings during these seasonal transitions.

I am thinking that I will build a heat baffel to be suspended from the same lip that the hopper hangs from. The baffel will be under the flue outlet and not go all the way to the sides of the stove. That should route the heat arround the baffel and keep the flames from going directly up the flue (which they do without any baffel in place). That part should be easy.

Next I need to let in combustion air over the the wood fire. Unless someone has a better idea, what I plan to do is cut a hole in the side of the stove just above the fire bricks and install a spinner vent. Open with wood and closed with coal of course. I will install both baro. and manual dampers, and cap the baro. durring wood burning.

Where can I buy a spinner draft control? Are they different size for wood or coal stoves? Is one spinner enough to maintain a low to medium wood fire in the Hitzer?

Your suggestions and comments would be appreciated. I am not thin skinned so you may be blunt if need be.

Hitzer puts a spinner draft control on some of their stoves. I know my Model 82 had one. Could you mount the spinner in the loading door?

I don't have much time this morning so, I'll give you a quick mod, that would not have caused destruction to your stove. Instead of cutting holes in the top of the heat exchanger, you should have used the heat exchanger to your advantage. What I'm about to tell you would work way better than cutting holes. All you had to do is take the fire brick off the back wall of the firebox. That's it! This would allow the steel to heat up, and would naturally pull air through the fan, and up across the finned heat exchanger, into the room. It would actually be like a little fan. For even better performance, you could have fabricated a slip over the fan adaptor, and extended the air inlet within 1" of the floor. Or, take the fan completely off, and duct the air inlet within 1" of the floor. In the past, I've actually fabricated heat sheilds with this theory. When heated with radiant stove, the air would go in the bottom of the heat sheild, and come out the top with enough force to blow a match out. The wall behind the heat sheild would be cold. The hotter the stove got, the hotter the heat sheild got, and the faster the air would travel up through the tubes. I run my HITZER fans on low anyways. And yes, the 30-95 fan is noisy. I may actually do this with my 30-95, and eliminate the fan noise all together. After all; my 50-93 came from the factory with no fire brick on the front wall of the fire box. Guess I could take it off the back wall of the 30-95. The air following the back chanel would help to keep the steel cool. "A natural air flow fan", so to speak. Thanks for triggering an old idea...... For burning wood, add the over fire air. This would be another simple mod. Drill a round hole in one of the sides, about 1-1/2 " in diameter. Cut a tear drop shaped piece of sheet metal to cover hole. Fasten with spring loaded nut & bolt. The spring would put tension on the tear drop shaped piece of sheet metal, holding it at any position you set it at. No signs of burn through on 50-93. Should be no concerns of burn through on 30-95, as air traveving the chanel would cool steel of stove. Oliver

grizzly2 wrote:Next I need to let in combustion air over the the wood fire. Unless someone has a better idea, what I plan to do is cut a hole in the side of the stove just above the fire bricks and install a spinner vent. Open with wood and closed with coal of course.

Where can I buy a spinner draft control? Are they different size for wood or coal stoves? Is one spinner enough to maintain a low to medium wood fire in the Hitzer?

Grizzly,

About all I know of this is to tell you the set-up on my stove that burns both coal and wood... The over-the-fire air feed is 1/2 the size of the under-the-fire air feed. There are two feeds under and one feed over, all are the same size...

I found this part at Woodsman:

http://www.woodmanspartsplus.com/50276/ ... -Knob.html

You might be able to figure out how to use that....

dj

I would extend the baffle all the way to the sides and put a perforated pipe along the front edge to feed secondary air. This is what is done in modern wood stoves and works very well. Take a look at some stoves in a stove shop. On one side the pipe could extend outside the stove with an adjustable air intake. As long as you are about it you might as well try to make it burn cleaner and more efficiently.

Rob, No can do the vent in the feed door. It has a big glass in a cast iron frame. I would have to replace the glass with a thin plate steel and I am nnot willing to do that.

Oliver, Oops Your idea sounds good. any concerns for burn through of the back

dj, Thanks, good rule of thumb to keep in mind for draft size. Good source for draft knob. I need to look at one to see what configuration of hole(s) it covers. I assumed a spin vent was a complete assembly that fit into one big hole.

franco b, Good idea for the secondary burn. I can build that.

grizzly2, I added to my previous reply. Oliver

More good ideas Oliver. That would make for a simple vent. Thanks.
Grizz

This is a follow up to the above conversation about modifications to my Hitzer 3095. I have 5 two inch holes cut out of the top accross the front just in front of the hopper door. I have the fan duct work on the back removed. I made these mods before Oliverpower gave his very good suggestions.

At stove side temps of 300 degrees, I can hold my hand an inch above the top of the stove where the holes are NOT located without any discomfort. When I hold my hand above any of the holes I cut I cannot keep my had there for any lenth of time due to the heat pouring out of the holes. The area on the back of the stove where I removed the fan ductwork is too hot to lay my hand on.

While it would be more efficient to have the whole top single layer, I know I am now getting more heat out of it than I was. It certainly seems good to be rid of the noisy fan. However I still have to run a small box fan on low when it is below freezing out in order to move the air to the other end of this ranch house. The box fan is quieter than the squirel cage fan that was on the stove.

If I had it to do over, I think I would do the same because now I can heat spring and fall with no fan. If I were only using the stove durring he coldest months I think it would be best to build a duct work from a small box fan to the opening in the original ductwork opening in order to force air thru its intended path, but with a quieter, cheaper to replace small box fan such as I am using now.

I would try Oliverpower's ideas if circulating the heat the lengh of the house were not an issue.

Overall I am satisfied with mods I have made. I am also sure I have hurt the resale value of my stove.

P.S. I have not made any modifications to my stove to accomodate burning wood. Not sure if I will in the future or not.

Please sound off if you have done any of these mods and what problems it has caused // benefits it has brought // how you would have done it differently.

#1) REMOVED REAR FIREBRICKS TO GET MORE HEAT OFF THE STOVE?

I am considering removing the rear firebricks in my 30-95 to see if it will draft naturally w/o having the blower on. This mod was suggested by Grizzly2 (see: Re: Big Hitzer 30-95 Mods.) a while back and someone else chimed in that they had done it on their 50-93 and had seen no indication of burn through.
Some of the folks on the Hearth forum have warned against doing this same mod in the 13-NC wood stove (which I also have and considered MOD-ing) because of possible burn thru.

#2 INSTALLED A BAFFLE FOR WOOD BURNING IN THE SHOULDER SEASON TO KEEP FLAMES OUT OF TUBE?

#3) INSTALLED 2NDARY TUBES ACROSS TOP OF STOVE ?.

As with most hypothetical mods, In theory it seems very doable. Drill matching holes on each side and install a spinner vent (line on Kodiaks or Harmons) those spin controlled holes would feed both ends of a stainless tube with holes in it. When burning coal you just shut em tight - or leave em cracked just till the volatiles are burnt off.

grizzly2 wrote:Where can I buy a spinner draft control?

Go to a Harman dealer and order the spinner for the ash door of a Mark 1 / 2 / 3 coal stove. Take a good look at a stove so you can see how it is mounted -- basically a center hole to hold the bolt that the spinner spins on. Then some circumferal holes around the center one, which are exposed to admit air as the spinner moves out away from the stove body. My guess is that for wood burning you might need two spinners, one on each side. I considered adding one on my Harman Mark 1 to make the secondary air adjustable.

Edit: Oops. I see this is a pretty old thread, and dlj gave you another source for the spinner. Similar principle to the Harman spinner, except the Harman is fancier and is concave so it makes contact only around its outside edge. I think the Harman would be much better for mounting on a flat surface, because being concave it allows for a nut on the bolt holding it.