How to Bring in Outside Air to My Kineo Base Burner Stove

Yer welcome partner. From one Coal burning brother to another, good luck with your project..

Lightning wrote:Yer welcome partner. From one Coal burning brother to another, good luck with your project..

Thank You!

Bottom line: if air is leaving the house, by whatever exit point, then air has to be infiltrating the house from someplace.. and this will be usually from various small leaks around the sills, windows, doors. through electric outlet covers from leaking stud spaces behind the electric boxes, etc etc etc..

If you want to control where the infiltrating air comes from: then create your own pathway. I like the idea of a raised hearth that is heated by the radiant from the baseheater's base..

Air can't leave unless air is infiltrating from somewhere.. If it is infiltrating in areas that you would prefer to keep warmer and not be cooled by the infiltration, then bring your outside air source to the stove base.. whatever outside air you provide, there will be that much LESS infiltration.. unless you decide to run the stove with much higher draft.

It's pretty simple physics..

I did the outside air source duct job on my first house.. I had plastic 'storms' over the inside of the cheap windows. The plastic was pulled inside by the negative pressure in the house whenever the gas boiler fired.. The plastic puffed inward like a pillow.
I installed a dryer duct from outdoors to the base of the the boiler, near the burners..
Immediately the windows stopped puffing up, and the rest of the house was perceptively warmer..
IT WORKS..
Simple: air in from a known source or air in from everywhere and cooling down the whole house..

Greg L

LsFarm wrote:Bottom line: if air is leaving the house, by whatever exit point, then air has to be infiltrating the house from someplace.. and this will be usually from various small leaks around the sills, windows, doors. through electric outlet covers from leaking stud spaces behind the electric boxes, etc etc etc..

If you want to control where the infiltrating air comes from: then create your own pathway. I like the idea of a raised hearth that is heated by the radiant from the baseheater's base..

Air can't leave unless air is infiltrating from somewhere.. If it is infiltrating in areas that you would prefer to keep warmer and not be cooled by the infiltration, then bring your outside air source to the stove base.. whatever outside air you provide, there will be that much LESS infiltration.. unless you decide to run the stove with much higher draft.

It's pretty simple physics..

I did the outside air source duct job on my first house.. I had plastic 'storms' over the inside of the cheap windows. The plastic was pulled inside by the negative pressure in the house whenever the gas boiler fired.. The plastic puffed inward like a pillow.
I installed a dryer duct from outdoors to the base of the the boiler, near the burners..
Immediately the windows stopped puffing up, and the rest of the house was perceptively warmer..
IT WORKS..
Simple: air in from a known source or air in from everywhere and cooling down the whole house..

Greg L

These were my thoughts exactly...another confirmation that I am not crazy!
Randy

LsFarm wrote: I like the idea of a raised hearth that is heated by the radiant from the baseheater's base..
Greg L

Greg,

I completely agree with everything you said - except the above sentence. I tried the raised hearth in a house I owned in France a number of years ago, and it simply didn't work. It was visually very attractive but not functional. I found that there was a temperature stratification with the region below the raised hearth colder than above it. Made for cold feet. In retrospect, I always thought that it would have been awesome to make a sunken hearth, but I've never tried it, yet anyway...

dj

dlj wrote:

LsFarm wrote: I like the idea of a raised hearth that is heated by the radiant from the baseheater's base..
Greg L

Greg,

I completely agree with everything you said - except the above sentence. I tried the raised hearth in a house I owned in France a number of years ago, and it simply didn't work. It was visually very attractive but not functional. I found that there was a temperature stratification with the region below the raised hearth colder than above it. Made for cold feet. In retrospect, I always thought that it would have been awesome to make a sunken hearth, but I've never tried it, yet anyway...

dj

I was not planning on making the whole hearth area raised. It would just be a platform made out of steel 6" high for a heat chamber to warm the incoming air.

Randy

is your stove on the first floor ? do you have a basement under it, even unheated ? can you bring air in along a floor joist space to the hearth area and then up thru the floor into the raised area ?

it isn't going to take much of a temp. diff. to be useful. you can even make an off set serpentine path under the raised deck to enhance the temp. rise.

the biggest bene. will be controlling the location of infiltration. in the houses I have used this same set up on it has been very positive because the neg. pressure is moved away from the MANY places to a more productive ONE.

i would however consider making the rise just 3.5" plus the deck material. keeping the volume under there smaller will help with draw AND temp. rise.

Photog200 wrote: I was not planning on making the whole hearth area raised. It would just be a platform made out of steel 6" high for a heat chamber to warm the incoming air.

Randy

In that case you could make it easier, by just using some 3-1/4 x10 inch sheet metal duct that comes up through the floor behind the stove, (or through the wall behind the stove), then using a 90 degree corner duct, leads under the stove and stops with a 3-1/4 x 10 register grill right under the front of the stove base. Even if you only have a crawl space under the stove, that size duct can be run between floor joists to the house sill and out with another grill on the outer face.

Since the ductwork is mostly hidden under the stove, it would be the least seen option. And it would be easier than building something that has to take the weight of the stove when the floor already does that. No need to even move the stove. And if you paint it black, most folks would think it's part of the stove ?

Plus, the exposed sheet metal of the duct's top surface, being closer up under the stove base, would preheat the incoming air even more than if the stove was on any kind of a raised hearth. If you get the grill register that has shutters, you could easily shut off the duct at the grill when you don't need it.

You can buy all that duct work at Home Depot, or Lowes.

Paul

As KC said,use a floor joist space as a cold air duct,cut round vent in floor or raised hearth under the stove ,(round vent for round stove),cold air drops so the draft from the stove would pull fresh air to the stove without cold air trying to rise up into house. Just my simple way to explain as I see it ,maybe i'm off kilter on that,looking for others input on how that works. Not to argue with Paul ,but if cold air is brought in at say 6" above the floor level,could the cold air then infiltrate the entire floor area up to that 6" level ?? If cold air is brought up thru the floor from the joist spacing under the floor,then in theory cold would not rise any higher than the top of the duct vent unless it was drawn in. I could be totally off on this idea & am waiting for the more educated, scientific among us to explain that better.

I'm thinking that bringing cold air into the house would result in it being sucked in by the stack effect of the house itself. There exists a low pressure system in a heated structure resulting from the warm air trying to rise out of the house. It does so, to a greater or lesser degree, no matter how tight the house is constructed. It would be best to supply the combustion air directly into the burn chamber. I think. Especially if the stove is in a heated living area.

Any part of those sheet metal ducts not needed to absorb heat can be insulated with off-the-shelf materials.

By heating the top of the duct as it runs under the stove, you create a natural stack affect within the duct. Like with the draft of your chimney, the hotter the duct gets the more that duct will draft.

Controlling how much air the duct drafts in under the stove can be done with the type register grills that have movable shutters built in (think long skinny MPD's. ).

By experimenting with shutter opening, such as closing it down and watching a mano until you see it drop, then open the shutters until the mano doesn't rise anymore, you can find the sweet spot to get the register sized to feed only the air that the stove requires, without over-feeding the house stack affect.

Paul

Is stack effect different for a 1 story vs 2 story house or no difference ?

I see it the same as Carbon 12. There is much more going on than meets the eye when it comes to air infiltration. I agree with him that the dedicated air source will result in additional infiltration instead of just relocating the infiltration.

When dealing with infiltration, stack effect of the house and location of the neutral pressure plane, yes it is all simple physics BUT the dynamics of the big picture get somewhat complicated.

Lets not over think this with unknowns. As Greg said, it's really very simple. Air in = air out. The fewer places air can leak out, the better the air to the stove can be controlled and be more affective.

I doubt the house's stack affect is strong enough to mean much when the air inlet would be so close to the stove inlet, plus that air inlet can be sized to only what the stove requires by using a register with shutters. Like I've said, air is lazy and if the outlet is close to the stove's primary air inlet, guess which pathway wins.

Keep in mind that if the house stack affect was so strong as to make that air inlet useless to the stove, Randy would never get his stove started in the first place.

And in this instance, with Randy's house being so tight that just opening a window near the stove raises the mano reading so much, the duct will be even more affective and controllable. He's already proved that whatever stack affect his house has would not make the duct ineffective. Otherwise the open window would have made no difference to the mano reading (like it does in my leaky, three story house with it's greater stack affect). The fact that the window seven feet away helped the stove shows me that the duct less than a foot away will help the stove too.

The tricky part is just going to be finding out how much air the duct needs to bring in to only the help the stove and no more than that. An adjustable register will allow that and it can be determined in just a few minutes.

Paul

Randy,

Some simple tests of the stoves ability to draw from a duct ending under the front of the stove.

Just light a piece of cotton string and blow out the flame letting it just smolder. Hold the smoldering end at floor level in front of the stove. It will show the air currents as they move around and up the stove.

Next open the window again and using the string smoke, see where the air moves near the window, and then again, near the stove. Try closing the window to smaller and smaller openings and see what it's affect on air movement to the stove is (and affect on the mano too ).

If you want to really see the affect. Put a length of hose from the open window to the stove base at floor level. Block off the rest of the window opening with towels stuffed in.

See where the string smoke goes as it exits the end of the hose. Then run the hose behind and under the stove so it's end is near the front of the stove and it can warm up from stove heat. Again, watch the smoke.

Then, about the time you see a pattern to the air movement, . . . go shut off that screaming smoke alarm.

Paul