My Koker Experience (So Far)

From the "for what it's worth dept." I thought I would share the experience I've had with my Keystoker Koker. First fired up Oct 3,2008.
1) I installed a Dwyer manometer and can't imagine burning coal efficiently without one.
2) I installed a plug in the power cord to the DV motor.
3) I've been doing some searching for a replacement DV blower. It appears to me I can pick one up from Grainger for about $30-$35. With the plug in cord I will be able to quickly swap out the DV blower whenever it shows signs of clogging. I'll then be able to clean and lubricate the assembly and have it ready to go back in when needed. First I have to get over to Grainger and see if they have a blower for me.
4) I adjusted the feedrate on the stoker back about 3 turns. This has reduced the skin temperature on the front door about 50 deg. during idle.
Since doing this, my draft, which had been running at .02-.03 ahs worked it's way up to .05. I disconnected the manometer and checked zero this morning and everything looked good. However, it is still running at .05. I'm just puzzled at how or why the draft would change on a DV furnace. I'm anxious to see what happens when we get cold weather again.
5) I've purchased a rheostat and plan to install it in the DV motor circuit so I can adjust the draft.

Installation review:
The installer and I had a serious discussion about how the Koker should be connected to the existing furnace. He got frustrated with me to the point of saying "I don't care, I'll do it however you want me to". I backed off and we went with his suggestion of connecting the heat output to the cold air return on my propane furnace. This works well when the Koker is churning out heat and both blowers are running. My wife had the house up to 76 deg in no time.
However, when the Koker is idling, heat wants to continuously drift up the cold air return. This is not good for two reasons in my home:
a) when the blowers do come on, the heat ducts are cold and blow cold air for awhile. They haven't been getting any heat. One of the positive features of the coal furnace was supposed to be the continous presence of warm air in the heat ducts. It isn't that way.
b) the main cold air vent in the center of our house (directly over the Koker) happens to be in the family room and is about 5 feet from our thermostat. We've had to cover this vent up in the attempt to balance out the temperature in the house. When we were just drawing cold air through this vent it was fine. Allowing the idle heat to drift up through it makes the family room very warm and the rest of the house goes cold.
My opinion at this point is the "heat into the cold air return" is a real compromise and my intent is to redesign the connection during the summer next year so that the heat, both forced and idle, will go into the heat ducts as it should. I haven't got it completely figured out yet but I think there should be a way to do it.

Anyhow, for what it's all worth; especially for beginners like me. This is where I'm at.
-Len

Thank for your info CoaLen. And the pictures you've sent me I've been looking at my duct work which is not too different from yours. I'm still planning.

I was wondering (what do I know - just kicking ideas) if a duct bridging the high spot between the hot side of the Koker's duct (11x17) and hot trunk/ p-furnace plenum will allow the hot "idle" air to drift/gravity over to the hot air side. If it works, it would create a draft that might retard the warm air from moving up the cold return trunk ar at least split the difference. When the main blower kicks on, it will overcome the volume of the bridge or a damper could be installed that's normally open and will close when the blower kicks in. It would keep some if not all the "idle heat" going in the right direction by gravity if pitched right.

The thermostat in the warm room .... a friend of mine said he hooked up two thermostats one always in a warm spot and the other in the cold spot (this see-sawed depending on heat or central AC was on). He'd set them at the temp he wanted and let them fight it out. I don't know if it was series or parallel and haven't given it any thought ...yet. Never saw it, but that's what he stated

Is that a clean-out T on the dv line peaking over the L in the 11x17?

Dave,
There is a tee at the 90 deg turn in the vent line, and it's got a removable cap to give me access for cleaning the vent line.
Here's a better photo:

Good looking set up. Thanks for sharing your info.

CoaLen wrote:Dave,
There is a tee at the 90 deg turn in the vent line, and it's got a removable cap to give me access for cleaning the vent line.
Here's a better photo:

That makes sense and gives you easy access to get the brush down he pipe to the outside. How long is the pipe from the T to the outlet?

Looks like you have enough room to run two 8" rounds or something out of the upper Koker plenum over to the hot air propane/main plenum. You could run some booster fans in them so they run when the main squirrel cage is off. This should get a lot of warm air into the hot air plenum and alleviate the problem you're having with a hot cold air return trunk. http://www.smarthome.com/3012/8-Inch-110VAC-500CF ... 208/p.aspx When the main fan kicks on, the 8" fans will turn off and all will work as it does now. I've got a bridge between my hot and cold air trunks for my humidifier; positive pressure on one side and negative on the other.

They make some fans that you could control with X-10 or wireless that should be easy enough to hook up. http://www.smarthome.com/2250/Leviton-Fixture-Rel ... 375/p.aspx I use x-10 lighting controlled by x-10 plus there's some newer technology that works as well or better. With this tech, you could wire it for automatic operation, control the 8" fans with either a table top wired box or get something that works totally on radio frequency.

See, now you've got me excited ... I'm starting to see a Koker in my basement

I had the same issue with hot air coming out of my ducts I drilled coal furnace plenum and added a second fan limit and hooked the second fan limit up to the oil furnace fan so I can sense the heat in the coal furnace and tell the oil furnace fan when to come on.

jimbo wrote:I had the same issue with hot air coming out of my ducts I drilled coal furnace plenum and added a second fan limit and hooked the second fan limit up to the oil furnace fan so I can sense the heat in the coal furnace and tell the oil furnace fan when to come on.

Not knowing too much about this (yet!), how does the Koker's plenum limit switch "override" the one in the main furnace?

it don't I just ran a wire back to oil furnace fan so I can control it independtly from the coal appliance. I had to play around with the settings on the new fan limit I installed in coal appliance but got it where the fans come on at the same time based on the temp in coal appliance.

Coalen - Maybe you could get a relay to run the blower full time but on a very low speed. Your propane furnace may even have that ability. Is your propane furnace blower a variable speed? Oh, by the way, Ravens beat Browns! (sorry)

Hey Terry,
I am giving some thought to the snap switch in the plenum. The blower is a variable speed setup so it may be something that will satisfy the idle heat issue.
By the way, if Anderson hadn't decided to throw a screen pass to Suggs that might have been a close game. Or if Braylon Edwards could catch a pass when it hits him in the hands.....aaaggghhh!!

My install is very much like yours, maybe even from the same place in Kingsville , Ohio. I`ve only been burning coal for a short while & haven`t really noticed much cold air coming thru the heat ducts when the furnace fan kicks on but do feel the heat drifting thru the cold air returns. I wanted to stay away from the furnace plemum to keep the constant heat off the A-coil. I`ll pay closer attention once I start back up & possibly make modifications if needed. I probably live fairly close, in Pa. but on the line between Andover & Pierpoint. I do believe the steelers beat the browns also, oh well maybe next year. NOT