Fresh Air Supply for Koker

Nice all-around job

Just one question, how often do you take the bike out to blow the dust off?

TAMNOZ wrote:pics don't show what happens to the pipe when it gets to the stove

jrn8265 wrote:Can you show a pic of how you mounted the hose to the koker

I can't speak for any particular make/model of stove, but here are some pics of how I connect my outside air to the 50 CFM Dayton blower that I use for combustion air... My stove is a early 80's Alaska Stoker Stove 2, but my feeder assy. is a custom built/modified setup that I put together... Its no longer a tri-burner, but instead looks more like a leisure line feeder... Here's some pics to look at and maybe give you some Ideas on how to make a real good direct hookup to your blower... Also I use a 4" stainless blast gate to regulate airflow to the blower inlet, you'll see that in one of the pictures, so I have complete control of just how much air I want to supply to the grate without speed controlling the blower motor...
I tig welded a 1 1/4 inch stub of 3" 316Lss sanitary pipe to the factory Dayton equipped removable blower inlet flange, then use a short length (approx 3") of 3" aluminum heavy flex to connect the 4"X3" ss reducer to the blower inlet stub and finish it off with a pair of Dixon ss heavy hose clamps... I will be starting a thread shortly to highlight the new improvements to my setup made this year... I am almost done with it and once I am I'll post many pics that should offer many Ideas to those wanting to do some heavy duty mods to their stoves... If anyone has any questions just shoot me a PM...

How long are your runs for the fresh air intake? I would like to put on but the closest place and most conveniont is right next to the chimney and I am thinking that it will draw in the exhaust. If I go to the other side of the house that would be fine but its about 15ft a way and don't want to restrick the air flow. Do you think that would be to far?

Vernoncoaler wrote:How long are your runs for the fresh air intake? I would like to put on but the closest place and most conveniont is right next to the chimney and I am thinking that it will draw in the exhaust. If I go to the other side of the house that would be fine but its about 15ft a way and don't want to restrick the air flow. Do you think that would be to far?

Vernoncoaler, 15' should not be any problem at all... When in doubt just supersize the duct, you can always reduce once you get to the stove!!! I would suggest you use metal duct instead of flex to get it the distance from your thru-wall penetration to your stove, then add flex to make your termination at the blower... It makes for a much cleaner finished product and is easier to secure to joists etc... Not to mention, most flex sold in the big box stores are intended for discharge not intake and while with what little air most of these combustion blowers demand it would likley never become a problem, but truth is the ones I've seen in those stores are mighty flimsy... If you want to add a blast gate to regulate what the blower can pull through the duct and supply to the grate check out McMaster Carr Industrial Supply and search 'blast gate'... I will post up pics of my entire outside air setup maybe later today... I'm workin' on it in real-time today, so if it gets done I'll put it up...

Murdoc

Ha! Thanks and actually, I run a shop vac with a hepa filter when filling the bucket from the bin, and when filling the hopper. There's actually no or extremely little dust. Just got back from a short ride though...

Homesaver and the rest of you guys,
I feel so stupid since I only installed my stove a week ago, I didn't realize there was a fan under there until last nite when I took a flashlite and started looking. But I do have a question about that fan. There is a flap covering part of the inlet Why do they do that? Also my Koker came with a wall mounted thermostat if you turn the therm down during the day does it slow the feed down or will it ultimitely shut down the stove?
Jim

The combustion motor is set as it is because they determined it only needed that much air to properly burn the coal.

No, turning the thermostat down does not cause the fire to go out. The timer causes the feed motor to run at specified intervals in order to keep the fire burning.

The thermostat causes the feed motor to push coal onto the burn grate when the thermostat calls for heat. When the air around the firebox reaches a desired temp, the circulation fan comes on.

When the thermostat no longer calls for heat, the feed motor stops and the fire slows down causing the air around the firebox to get a bit cooler, which turns off the circulation motor. This cycle can be tweaked but be careful when changing factory settings as you can throw the whole machine out of whack and end up with a nice service bill for a tech to come straighten it out.

I have mine tweaked pretty well now. I'm consuming about a 5 gal bucket of coal a day and one tub of ash a week. In the dead of winter, I expect to be at 2 buckets a day which is not bad heating a 2 story, 2025 sq ft house.

TAMNOZ wrote:I didn't realize there was a fan under there until last nite when I took a flashlite and started looking. But I do have a question about that fan. There is a flap covering part of the inlet Why do they do that?

TAMNOZ, homesaver is right in saying

homesaver wrote:The combustion motor is set as it is because they determined it only needed that much air to properly burn the coal.

But I would like to add to that in saying that the flap that is partially covering the combustion blower inlet is also there to allow you adjustment to fine tune your 'over fire draft' aka the draft inside your firebox vs. your chimney draft... For instance, my chimney is marginal at best, especially in warm weather, anything above 50 degrees outside temp forget about it gotta shut down the stove or die from co... So, with my marginal chimney I may need to reduce the amount of air being sucked into the combustion blower and fed to the fire because the amount of air being supplied is more air than my chimney can take away, in other words my firebox is actually positive pressure instead of negative pressure or draft... So, what that flap is there for is to enable you to either feed more air or less depending on your particular setup/chimney... An ideal setup is where your over fire draft reads the same as your chimney draft and your baro is also set to operate properly within that setting... You will find that by opening that flap up more you can get a mean flame goin' in there, and while that is cool and you may think you are maybe somehow getting the most out of your setup/heating dollar, thats is not what its there for... I would suggest you check your over fire draft along with chimney draft and adjust that flap to a point where you have the readings equal and within a reasonable range as per the stove mfg. suggested range of operation... At that point you are now getting the most out of your heating dollar, not putting it up the chimney and not killing everyone in the house, but instead, 'just right'

Hope this helps
Murdoc

Well said. I should have stated that the factory seting is pretty mudh dead on as is for a power vent setup like mine.

homesaver wrote:Well said. I should have stated that the factory seting is pretty mudh dead on as is for a power vent setup like mine.

Just to clarify between the two types of forced venting for any newbies that might eventually read this thread. Yours is a direct vent where the exhaust fan is mounted inside near the top of the stove, venting/pushing into the pipes that must be sealed due to positive pressure in the ...

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  pipes vented to the outside atmosphere

  

... a power vent is when the fan is located outside venting/pulling to the open air (pics thanks to Rick 386's post)...

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  ... and the pipes are under negative pressure from the stove to the power vent...

  

All stoves might benefit from combustion air fed directly from the outside like you've all shown in these examples.

Yes, well said. Thanks for clearing that up!
I always get the two mixed up.

VigIIPeaBurner wrote: ... a power vent is when the fan is located outside venting/pulling to the open air (pics thanks to Rick 386's

No problem. Thanks for the mention. One thing to remember is that when using a direct vent, all pipe connections must be sealed up tight to prevent the pressurized gasses from being released inside the home. A power vent is not so picky as any leak in the pipes will just minimize the draft.

And that, my fellow coal burners, is exactly why we love love pics to be posted here. They are here for all to see and use as they wish.

Rick

How do you know if you need a fresh air supply or not. I have a Keystoker with power vent.
Jim

Let me currect myself. I have a direct vent, my fan is on top of my heater.
Jim

TAMNOZ wrote:How do you know if you need a fresh air supply or not. I have a Keystoker with power vent.
Jim

Here's my stab at answering your question. There's no exact and concise 'one answer' The extreme (I personally had this situation) would be if you lack proper measured draft and see it change to the good when a door or window in the furnace room is opened and supplying all the needed make up air.

On the other end of the spectrum, any air pulled out by the combined fans has to be made up from someplace else. The make up air will filter in through any leak anywhere in the house until the volume of air leaving the furnace is balanced out. In some situations, it might make a drafty house feel even draftier.

The thought behind a designed air supply is the air is supplied directly to the combustion fan. It cuts down on the cold air filtering in through unwanted places (drafty spots). It makes up air pulled out by the power vent and combustion fan.

If you have a baro, make up air for that should not be provided by an outside make up line. It would defeat the purpose of the baro. That's a whole other discussion.