Keystoker Koker and Existing Hot Air Furnace

I just joined here, have been reading for awhile now. Going to pull the trigger and order a Koker. What are the best options for hooking this up to my existing hot air furnace. Should it be duct into both the cold air return and the hot air side of existing furnace or should I just duct it into the existing cold air return only? It will be direct vent also.
Where does the Koker draw its air to be heated from?
I assume the direct vent is where the air for combustion is drawn into stove....correct?

Hi Lutz,

The direct vent is for exhaust only. Many members here have installed the equipment necessary to draw in fresh air from outside. You can find the posts detailing the different methods by using the search function.

Have you considered the Hitzer 710 hot air furnace? When I did a comparison between the Hitzer and the Koker, the Hitzer seemed the better of the two.

This is my set up. My system in independent from my oil heat system (baseboard.) I did a seperate hot air sytem with three different cold air returns running throught the rear blower.

EarthWindandFire wrote:Hi Lutz,

The direct vent is for exhaust only. Many members here have installed the equipment necessary to draw in fresh air from outside. You can find the posts detailing the different methods by using the search function.

Have you considered the Hitzer 710 hot air furnace? When I did a comparison between the Hitzer and the Koker, the Hitzer seemed the better of the two.

• Fresh air supply for Koker

When I purchased my Koker, installation was part of the deal. The installer insisted that pushing the Koker hot air into the cold air return on my propane furnace was the best way to do it. He wired it so whenever the Koker blower came on it also turned on the blower in the propane furnace. This system worked but it had some real drawbacks. As I now understand how the Koker works, I realize the installation he made was simply the easiest way for him to get the Koker operational; it certainly wasn't the best way to get heat through the house.
I now have the Koker putting heat into the top of the plenum on the propane furnace and drawing the cold air out of the main cold air return duct. I do not run the propane blower; the Koker blower does the whole job. I would not put heat into the cold air duct. That doesn't work well.
By the way, you'll love your Koker!
-Len

CoaLen, my system is similar to what your describing except my fan for the Koker is drawing from the cold air duct & there is a baffle that directs the warm air into the cold air duct to the filter cage & up thru the warm air furnace & works quite well. This will be my fourth year with good results so far, I think a lot depends on where you have space to put the Koker.

Thanks for the info...i need to read a lot more on this. Reason for asking is I can have the dealer install it but they were talking about just feeding it into my propane furnace cold air return like "Coalen" had talked about. My thinking was this is the easiest way to do it but will it work all that well. Sounds like not the way to go. I also do not want to run my existing furnace blower, seems like waist on energy.
I just moved into my house, its 8 years old I just went down to look at the existing duct more. I thought it was all wrapped with insulation duct wrap but I have found it to be no metal duct at all. Its certainteed duct board. Will this be safe to use with the Koker?

I don't know anything about the Certainteed Ductboard.
-Len

I'm sure someone will reply that knows for sure but I would think that ductwork that isn't directly attached to the Koker would be OK, it's warm air going thru it not flame.

I ducted mine in series with my oil furnace. I only use the oil furnace blower and blow cold air into the Koker and from the Koker into the oil furnace and then out through the house. I did it this way so I don't need to worry about when we go away and the Koker runs out of coal. The oil furnace just picks up. If you look at the bottom of my signature, you'll see my installation threads.

Lutz, use some steel piping before tying into the DuctBoard. I have a similar set up into DuctBoard. You can see my installation photos done by Keystoker in the Pictures of Stoves forum.

Can't see how the 710 is better than the koker.

Koker has a 240 LB hopper, 710 160 LB
Koker has a 1532 CFM blower 710 has a 1000 CFM blower
Koker is 160,000 BTU 710 is 150,000 BTU

What am I missing?

Sorry I havent been on in awhile. I should have pics for you in a week or two. I picked up the Koker last week and got into the basement. Working on getting the rest of the install done and a coal bin built.

I have a question about the stove pipe hole I need to cut. Its a direct vent unit. If im going out through a concrete wall can I just run the 4" pipe out and not add the 6" section like would be needed through a wood wall

from pg 1 of the Koker install manual:

7. It is not necessary to use 6” black pipe if 4” pipe is going through a non-combustible wall, such as concrete or block. No barometric draft control is required

That's what we were able to do with mine. We cut a hole in the top concrete block large enough for the 4" pipe, put the pipe in and cemented around it.
-Len