Did I Make a Mistake on a Hitzer 30-95

I was just trying to point out leaving a central heating system off for very long periods causes more expense than it saves. A boiler can be zoned to only help with cold areas and warm air will recirculate and redistribute the heat to even things out. In my mind it is easier to size the stove to cover 90% of the time and let central heat pick up the load for very cold days or in the very beginning and end.

My mental problem with long periods of idling you still have to send BTU up the chimney to keep some draft and it would seem the warming it is outside the more you have to waste to keep the draft going. It seems like the least efficient way to run the stove if you compare BTU to house vs. BTU to chimney. If the stove top is 450 seems like much larger percentage goes to house rather than wasted.

I could be all wrong here but logic tells me it has to work this way. Relighting my stove only takes 45 minutes and turned way down for a week feels like coal burned for no value. 10 gallons of fuel oil seems like a better idea and give me time to do a little stove and stack pipe inspection.

Bob, does your house have central heat? If you mentioned it already I missed it.

What do you have for a chimney?

ddahlgren wrote:I could be all wrong here but logic tells me it has to work this way. Relighting my stove only takes 45 minutes and turned way down for a week feels like coal burned for no value. 10 gallons of fuel oil seems like a better idea and give me time to do a little stove and stack pipe inspection.

You are right in the sense that a low fire is an inefficient fire that generates a much higher percentage of CO and less heat per pound of coal. There is a point where adding a little more air results in more heat for the same amount of coal added.

Where that point is depends on the design of stove with those stoves that retain heat in the fire pot best, being most efficient at low burn.

rberq wrote:I agree that a 50-93 sounds like overkill for 1300 sf. However, the OP said his 65K BTU wood stove does not even maintain adequate heat in the room where it is installed.

My guess would be that the rating on the wood stove assumes very frequent refilling of what apparently is a small firebox.

Mike

Thanks for the ramble, BunkerdCaddis. We started with smaller stoves but didn't take long to conclude that heating the whole house works best with central heat.

Mike

bob15 wrote:When burning the stove on the bitter cold spells (high temp in low teens), I must keep the stove door cracked to get the hotter draft in the stove. the catch with running a stove like that is that you won't get a complete burn of the wood. Instead of all ashes, you will also get charcoal as well. I was told at the one stove place that when you get a stove near it's max output, you can also get similar results (incomplete burn).

I'll defer to the hand-fired guys, but from my limited experience you could expect to get a better burn with coal when running the unit fairly hard. At low output you may tend to have more unburned. At very high output you might encounter clinkering issues, depending on the coal.

Mike

Pacowy wrote:I'll defer to the hand-fired guys, but from my limited experience you could expect to get a better burn with coal when running the unit fairly hard. At low output you may tend to have more unburned.

Nope. Just the opposite. At low output my stove produces a fine powdery ash, much fewer chunks and unburned fuel in the ash pan. When running hard there are more clinkers and much coarser ash.

ddahlgren wrote:In my mind it is easier to size the stove to cover 90% of the time and let central heat pick up the load for very cold days or in the very beginning and end.

I made that mistake with my first coal stove because, you're right, it seemed to make sense. However, then I was constantly pushing the stove to run hotter, which put it into the less-efficient range and required more frequent tending and reloading. Might as well burn wood as do that. When I bought a new stove, I went with more capacity and have been much happier.

rberq wrote:

Pacowy wrote:I'll defer to the hand-fired guys, but from my limited experience you could expect to get a better burn with coal when running the unit fairly hard. At low output you may tend to have more unburned.

Nope. Just the opposite. At low output my stove produces a fine powdery ash, much fewer chunks and unburned fuel in the ash pan. When running hard there are more clinkers and much coarser ash. ..........................

Same happens with my 112 year old range.

Similar to box stoves, it has a rectangular, only 6 inch deep firebox. Run slow and it gets much more complete burning of coal with more white powder ash.

Run hard and there's more beginnings of clinker type chunky ash. And it gets some unburned coal in the corners of the firebed. My guess is the corners don't get to breath as well because the stronger draft pulls the primary air faster so that incoming air takes a more direct path of least resistance to the center of the firebed ?

Paul

Sunny Boy wrote:n't get to breath as well because the stronger draft pulls the primary air faster so that incoming air takes a more direct path of least resistance to the center of the firebed ?

I like your line of thinking here Paul. My belief is that the draft remains the same and instead there is more volume (since the primaries are more open) of combustion air thru the fuel bed.

The uneven burn could also be because the edges of the fuel bed are loosing their heat faster as compared to the center, by way of radiation.

Lightning wrote:

Sunny Boy wrote:n't get to breath as well because the stronger draft pulls the primary air faster so that incoming air takes a more direct path of least resistance to the center of the firebed ?

I like your line of thinking here Paul. My belief is that the draft remains the same and instead there is more volume (since the primaries are more open) of combustion air thru the fuel bed.

The uneven burn could also be because the edges of the fuel bed are loosing their heat faster as compared to the center, by way of radiation.

Lee,
My theory is based on,... I think the corners start to starve a bit for air as the primary air velocity increases through the dampers, the ash drawer area then turn up into coal bed.

Air does funny things as it gets forced to go faster through varying sized cross section areas such as intakes and plenums of various shapes, while being forced from high pressure to low pressure zones and having to turn roughly 90 degrees, too.

In other words, air is lazy. It hates to move well in corners as it has to go faster ! One of the reasons why round firepots burn so evenly.

Kinda like round barns,..... there's no corners for the devil to hide in !

Working on aircooled engines I get to see and analyze why and how air is channeled to inside and outside engine surfaces for fuel/air distribution and heat exchange. Ya start to see what air does by the solutions engineers have come up with over many decades in how better to direct air flow (or other gases).

Paul

Rob R. wrote:Bob, does your house have central heat? If you mentioned it already I missed it.

What do you have for a chimney?

Baseboard heat that I haven't used in 8 years.

Chimney for the coal stove would/will be the same Class A pipe I am currently using with my wood stove.

Base board electric? Or do you have a fuel driven boiler in the basement?

Baseboard water, propane boiler. Not needed for domestic hot water, so it sits off.

I assume you wish to avoid using propane entirely?

Having a system to help out the stove a few days per year can change the stove-sizing game a little.

I would also hook up a zone in the basement and get rid of the meat locker feel.

Rob R. wrote:I assume you wish to avoid using propane entirely?

Having a system to help out the stove a few days per year can change the stove-sizing game a little.

I would also hook up a zone in the basement and get rid of the meat locker feel.

I suspect a little so called wasted heat in the basement not actually wasted heat. Freeze 1 pipe and log that into checkbook and work from there.