Primary air intake plenum. Need thoughts please.

I have a Alaska Kodiak for the last 10 years. It works perfectly, but I'm always trying to make it better. A bunch of heat and humidity are feeding the primary/secondary air via the cleanout door.

I've been kicking around getting my primary air from below the stove in my unused crawl space. I can drill through the floor and come up in a 1 inch hose to the cleanout/air door. (See picture)

Can anyone suggest a vent cover/method of covering the shutters on the door that connects to a 1 inch hose? I can picture HVAC galvanized pieces being available but unsure how to find them.

Thanks

If there is ever a pressure differential between the location of your stove and your crawlspace (and there inevitably will be) you could potentially backdraft your chimney and cause a carbon monoxide problem.

That said, I seriously doubt that a 1" hose can provide sufficient air to your stove. The pressure drop through a 1" hose is appreciable. Read literature and government requirements on confined space air requirements vs. a solid fuel heating appliances rated input BTUH and you will see that air brought in "exclusively" from the outside needs a pretty huge diameter pipe. For example, from memory, I would need something on the order of a 12" diameter air pipe if all of my boilers air was to be sourced from outside. And to meet code and be legal, I would need two of such pipes. And on top of that they can not legally be tied directly into the appliance (due I believe to paragraph 1 above). One 12" (for my case) pipe must terminate within a few inches of the ceiling in the room where the solid fuel appliance resides, and the other must terminate about 6" off the floor within the same room.

A homes air turnover demand is amazingly huge, stove or none. All of the air in a typical house is fully replaced by outside air something on the order of every 1.5 to 2 hours (from memory). Weigh the potential benefit of a 1" hose against that.

Another good way to kill yourself would be to pipe your barometric damper directly to outside air, or even to a room other than the one the solid fuel appliance resides in. I've seen cases where stove users have contemplated saving heat by doing this, contending that their barometric damper is sending too much home heat directly out the chimney. In truth, you either draft and send 70-80 degree room air out the chimney via the baro-damper, or you draft the same volume of air up through your fire, heat it to a few hundred degrees or more, and then have it go out the chimney.

63roundbadge wrote: ↑

Sun. Oct. 21, 2018 11:32 am

A bunch of heat and humidity are feeding the primary/secondary air via the cleanout door.

I personally feel this is a non issue. As soon as the combustion air hits the fuel bed it's super heated to several hundred degrees effectively dropping the relative humidity of that air to a negligible percentage.

I also agree with Larry about the pressure differences between the living space and other places separated from it, including the crawl space.

I wouldn't pursue this.

I'd like to add that I feel it's a misconception that the baro or combustion air intake "steal" heat from the house. The reasoning is because of air turnover that is already naturally occurring and the impact that it (it being baro and combustion air usage) has on the neural pressure plane inside the house.

The only instance that I would agree that dedicated combustion air is needed is if the chimney will not maintain draft. If that's not the case, a dedicated combustion air source will increase air turnover and just make it harder to heat your house.

Here's where things get controversial, but that's my belief... and I believe it because that's what the science behind it supports.

i'm afraid my experience doesn't support this venture and you will find it disappointing in both effort and outcome.

just as a side note if anything, your stove is taking the coolest possible air in your house as intake even if it seems to be some of the closet to the stove. in reality the upper stove body is convecting just about all the air directly around the stove up and away from it and that is causing cool air to be drawn toward the stove from just inches above the floor.

if anything, this is in fact helping to heat your house not defeating it because it is causing there to be 'room" for more warmed air to stay in there. as far as the humidity thing goes Lightning is correct it too is a non issue because the instant it hits the bottom of the grates it is flash evaporated.

best advise, just keep pouring coal in it, sit back and actually enjoy "coal easy street"

steve