Cold Air Return. Do I Need It?

Both of the coals I tried were right at the mine.

The first I got may have been deep mined.

What I've been getting most is right at the pit.

Right now, I got the house on the upper comfort level.

It's driving me nuts trying to figure out how to get the house warmer.
It doesn't seem like it ought to be the fire because I can get good temps in the fire box.

I'm hoping that it may have something to do with no return.
Before next fall, I'll be changing things around so I can fit a return easier.

But, that doesn't seem to explain why wood heats better than coal

I partially close the secondary after I get a good fire

larryfoster wrote:Both of the coals I tried were right at the mine.

The first I got may have been deep mined.

What I've been getting most is right at the pit.

Right now, I got the house on the upper comfort level.

It's driving me nuts trying to figure out how to get the house warmer.
It doesn't seem like it ought to be the fire because I can get good temps in the fire box.

I'm hoping that it may have something to do with no return.
Before next fall, I'll be changing things around so I can fit a return easier.

But, that doesn't seem to explain why wood heats better than coal

I partially close the secondary after I get a good fire

Don't rule out the coal itself. As I stated earlier, when I used the Waynesburg coal I could get the furnace cherry red, but the house was cold. All I did was switch coal and the house got warm, without a cherry red furnace. I should add that my coal consumption dropped from 12 to 14 tons of the Waynesburg coal, to 7 tons of the Big Vein coal. I seem to be using more of this Pittsburgh coal than I was of the Big Vein, but it's warm in the house.

That's crazy, isn't it?
Hot fire but no heat

My options are somewhat limited for supply.

I could go back a try a little of that first coal again now that I think I know a little more about the furnace.

In theory, I'm paying $100/ton for the coal I'm getting but they don't scale and I get closer to a ton for $50.
The other place is $75 for run of mine but they weigh so I can't leave there with much more than 1/2 ton

Do you have a thermometer on the pipe? it sounds like you are cooling the top of the fire box with too much secondary air when you prop the load door open a half inch.

If you can't get good heat output with the spinner wide open, it sounds like the fuel bed is getting ash bound along with too much secondary air.

And yes, you have variable temperatures of air being pulled into the convection blowers so that is also causing variable heat output. This is adding confusion to your results.

larryfoster wrote:That's crazy, isn't it?
Hot fire but no heat

My options are somewhat limited for supply.

I could go back a try a little of that first coal again now that I think I know a little more about the furnace.

In theory, I'm paying $100/ton for the coal I'm getting but they don't scale and I get closer to a ton for $50.
The other place is $75 for run of mine but they weigh so I can't leave there with much more than 1/2 ton

If you can get nut coal, that furnace will preform a lot better for you. Run of mine is a lot of extra work, with the fines in there.

Another tip is to try and talk to other people that have used both brands of coal to see which they like best.

The first place I went when I started had screened for $125/ton and unscreened for $75.

Where I get now, he implied that it was screened.
I always get mine from a smaller pile separate from the bigger piles

I asked if he sold house coal over the summer.
He told me that if he didn't have any (I think he said) "cleaned", he could het me pretty clean stuff from the outside edges of the big piles
Although I do get fines on my loads, I put mostly lumps.

Most of the lumps are smaller than a softball to golf ball or bigger

Larry, I posted pics of my furnace and my coal in this thread: My Clayton 1600M

Now you can see the size that works best for me.

I'll see if I can get a decent pic of my coal and maybe the fire.

If it eases your mind, I get smoke coming out of my load door also, but usually only after I put fresh coal in. After it burns off the volatiles the smoke stops.

Although I haven't tried it, I would have to agree with 'Berlin' , that the 6 inch flue is what causes this. Just too much smoke from Bit coal for the 6 inch pipe.

8 inch would be better, but I cannot do it.

SWPaDon wrote:If it eases your mind, I get smoke coming out of my load door also, but usually only after I put fresh coal in. After it burns off the volatiles the smoke stops.

Although I haven't tried it, I would have to agree with 'Berlin' , that the 6 inch flue is what causes this. Just too much smoke from Bit coal for the 6 inch pipe.

8 inch would be better, but I cannot do it.

I never disagreed with Berlin and, like you, I can't do it
Just got back up from stirring the coal I put in an hour ago after overnight.

First thing this morning, I only had some hot (warm?) coals.
After poking and breaking up the congealed stuff, I put 3 shovels on and stirred it around to get the hot coals in and more airways.
Got smoke while the fire was trying to catch the new coal.

Went back after 20 minutes and had some flame and stirred some more.
Lots of smoke.

After another 30 minutes, more fire (will post pic in a bit) but still lots of smoke while stirring

When I woke up, mine was like yours. A congealed mass inside at the top of the firebrick.

I shook all the ashes, broke up the barely glowing mass, thru on 1 shovel of nut coal, left the bottom door open and got coffee.
About 30 minutes later, the blower came on. I went back down, shook a little again til it was glowing good underneath, broke it up and added another shovel of coal. I closed the ash door and left the spinner completely open.

Went back down about an hour after that, broke it up and added another shovel. I'll go back down at roughly 11 am and do it again, and i'll close the bottom draft about halfway or so at that time. Depends on what the fire looks like.

Here's some pics of my fire starting at 50 minutes after my morning firing.
Typical lump of my coal.
My coal pile
About 1-1/2 hours from the start this morning.
Ash door was open and secondary was full open.
Temp was about 475.

At this point I closed the ash door and moved secondary slider to medium.

I just added 2 shovels of coal on mine. 1st was the nut coal, as it will light quickly, then a shovel of fine to hold the fire and slow the burn. I also closed my bottom damper to 50%.
Unless it starts cooling off in the house, I won't touch it again for 2 to 4 hours or so.

I'll be heading down to load shortly.

I have trouble with the bottom damper.
I've tried opening it the whole way to see if I could get more fire from the increased air instead of opening the ash door.
I can't notice much effect.

Right now, I keep it open 4 turns and usually never bother with it.

I've tried 3, 5, 3-1/2.

2 turns will slow the burn.

I put mine at 50% right now, because it's warming up outside and my draft will be weakening. If it were below freezing, I would be able to close it more because my draft would be stronger.
I have no control of the 'over the fire air' with my current setup. I will be changing that over the summer.