Hooking up Koker Lite

Hi, I am new here. I have enjoyed reading things on this forum for a while. I am ready to make the change from propane to coal. I am looking at the Keystoker Koker lite with a direct vent system to install in our unfinished basement. We live in south central PA and have a 2000 sq ft two story built in 1994. The house is insulated well but has a lot of windows. We have a propane fired forced hot air furnace. I would like to hook up the coal furnace to the existing duct work. The stove dealer says the best way to hook it up is to blow the hot air from the coal stove into the cold air return and have the existing furnace fan circulate the air. If I do that the hot air from the stove will travel through the propane furnace and it will be running two fans. The manufacture shows in the manual not to hook it up this way. What is the best way to accomplish this goal? I have many more questions! Thank you for any response.

I believe you want to be in the plenum after your existing burner. Never into the cold air side. Others will chime in shortly.

I'm guessing that the suggestion for the cold air return is so that the heated air is delivered close to floor level...seems reasonable.

Some members have plumbed into there return duct. I would think the idea there is to use the exsiting furnace blower, not the Koker blower.

My personal feellings are, do you realy want to put 700 degree air through your propane furnace and blower? To me plumbing them in parellel makes more sense.

I just took a look at the Koker manual on the Keystoker site. There are sevral drawings of how to duct it. ALL show it plumbed into the plenum, except two that show it plumbed into the return. The two drawings that plumb into the return duct have a BIG "X" through them.

If your installer is suggesting that you plumb it into the return duct, clearly he hasn't even bothered to look at the installation manual!

Something to think about.

-Don

Thanks for the response. If the hot air from the Koker is hooked up to the plenum do I still need to have both the koker fan and the circulator fans running? Otherwise would the hot air backfeed into the propane furnace? Also the air from the coal stove will be unfiltered air drawn from the basement, it may be dusty. In a system like this with a coal stove using the existing ductwork, what is normally done to get the return air back to the basement?

Why not tap both the supply & return into the existing ductwork ?? Supply to supply after the other units blower & the return to the return.

iamcold wrote:Thanks for the response. If the hot air from the Koker is hooked up to the plenum do I still need to have both the koker fan and the circulator fans running? Otherwise would the hot air backfeed into the propane furnace? Also the air from the coal stove will be unfiltered air drawn from the basement, it may be dusty. In a system like this with a coal stove using the existing ductwork, what is normally done to get the return air back to the basement?

The best way is to do what W.H. says, plenum/plenum return/return. Install a filter inline before the blower in the return to the Koker. Make a block-off plate the size of the filter. When running the Koker, place the block-off plate in place of the filter on the propane furnace. This will keep the air from circulating through it.

You only run the Koker blower, propane blower stays off.

If you have A/C in your propane furnace plenum, you can put the block-off plate in the Koker return so the A/C doesn't run through the Koker in the summer.
That is a simplistic way of getting it done. You could leave the Koker blower draw air out of the basement if you couldn't get around to hooking up the return. But as you say, it may be a little dusty.

There are automated block-offs that run off of a controler that you can buy also. This could allow for an automatic switch-over to the propane furnace in the event of an out-fire.

That's about the extent of my HVAC knowledge.

-Don

Thank you for your input. It seems like the best way to hook up the Koker is a parallel system. The block off plate is a good idea, it is simple and would keep hot air from feeding back into the propane furnace, but I would like to have it set up if the coal system goes off the propane thermostat would be set to come on at a lower temp. I would like to make a balanced damper for the forced air to open for coal heat and close off propane and the other way around but I can't figure out a place in the system to install it. The plenum goes straight up out of the furnace about 14 inches and tees to go to both ends of the house. No good place to block off the supply trunk from the furnace. Thanks again for all your ideas. Mark

When you cut into the existing duct with the coal furnace duct,put a flap in the duct next to the cut-in. The flap will hinge on a vertical pin that goes thru the top & bottom of the duct. When only the coal burner fan is running,the flap will move to close the duct so air cannot flow to the propain furnace,when the propain fan kicks in it will swing the flap towards the coal furnace duct hole & close it off or at least prevent back draft into the coal furnace.If designed right,the 2 fans could run at the same time with some restriction of course.

Thanks windyhill4.2. The flap or damper is just what I would like to do. It is hard for me to explain, but the main supply coming off the propane furnace and A/C unit is a vertical 24X24 that is only 14 inches tall when it reaches the main horizontal trunk. Then the trunk goes both directions to feed both sides of the house, a very short distance one direction, and the length of the house in the other direction. A flap or damper in the horizontal trunk would cut off supply to part of the house and I can't make a flap in the 24X24 vertical because there is no room for it to open or close since it is only 14 inches tall. Maybe this is not the right system for our house, I don't know. Just would like to know what others have done. Unless I can come up with something else I will probably go with the block off plate idea that StokerDon suggested. Again, Thanks for the ideas and comments. Mark

Put the flap in the long end & run new duct along the short end to as close to the register as possible,tie in there ,it is unlikely that there would be back pressure into the propain furnace that way or do 2 flaps,1 on each side of the vertical duct.

My propane furnace (forced air) sits in the middle of my basement and my koker sits at the front wall, where there was an existing chimney. What I did is cut into my existing propane plenum so that I could slide a piece of plywood into it (I.e. baffle), just below the level of the horizontal ducts that ran off the sides of the plenum. This keeps the coal stove's heat moving in the duct work (past the propane furnace) and blocks off any air movement through the propane furnace. Obviously, this renders the propane furnace useless unless I remove the plywood baffle, so the convection blower on my koker is doing all the work. I also removed the existing horizontal supply duct between the propane and coal furnace so I could put a bigger size duct in (traded 8 x 14 for 12 x 12). This way I could get the max amount of koker heated air up to the propane plenum then let my existing supply duct on the other side of my propane furnace take over. I will try to get some pictures tonight and post them to help make my ramblings clearer.

iamcold wrote:Thanks windyhill4.2. The flap or damper is just what I would like to do. It is hard for me to explain, but the main supply coming off the propane furnace and A/C unit is a vertical 24X24 that is only 14 inches tall when it reaches the main horizontal trunk. Then the trunk goes both directions to feed both sides of the house, a very short distance one direction, and the length of the house in the other direction. A flap or damper in the horizontal trunk would cut off supply to part of the house and I can't make a flap in the 24X24 vertical because there is no room for it to open or close since it is only 14 inches tall. Maybe this is not the right system for our house, I don't know. Just would like to know what others have done. Unless I can come up with something else I will probably go with the block off plate idea that StokerDon suggested. Again, Thanks for the ideas and comments. Mark

iamcold wrote:Thanks windyhill4.2. The flap or damper is just what I would like to do. It is hard for me to explain, but the main supply coming off the propane furnace and A/C unit is a vertical 24X24 that is only 14 inches tall when it reaches the main horizontal trunk. Then the trunk goes both directions to feed both sides of the house, a very short distance one direction, and the length of the house in the other direction. A flap or damper in the horizontal trunk would cut off supply to part of the house and I can't make a flap in the 24X24 vertical because there is no room for it to open or close since it is only 14 inches tall. Maybe this is not the right system for our house, I don't know. Just would like to know what others have done. Unless I can come up with something else I will probably go with the block off plate idea that StokerDon suggested. Again, Thanks for the ideas and comments. Mark

Hi Iamcold, based on the size of your home you will probably need your propain blower to move the heated air, I am blowing heated air into my return vents directly with out going through my furnace as I have approx -1100 sq. ft one story home and the air floats out of the furthest vents. I put filter material around the stove blower to knock down the dust and it works pretty good, come April the house is ready for a spring cleaning anyway.
My basement is unfinished cinder block and with the stove down there the temps. are 60 ish, I would recommend wrapping the duct work with insulation to minimize heat loss through the ducts.
If you are doing the venting yourself try the simplest connections first, there are some good suggestions before me. Sheet metal and self tappers are cheap and foil tape and duct insulation will cover any oops as I am testament to that. Don't be afraid to try different set ups and make sure you have c.o. detectors upstairs and down stairs. Welcome you just made a couple hundred friends

Lots of good ideas. Thanks. If I order the Koker Lite it will be near the end of heating season before I get it. That will give me plenty time to figure out the best way to install before next fall. Plenty of measuring, looking, head scratching..... I do have questions about a water coil but I'll start a new thread for that. Mark

You must use the propain fan. The K Lite's fan will not do the job alone.