Environmental Protection Agency approved wood stoves. They pass a test on low emission particulates contained in wood smoke. The vast majority are non-catalytic. So, exactly what is a non-catalytic appliance?
The stove I now have is the Hearthstone Homestead. Non-catalytic. As I am renovating this house, I am currently coloring grout lines because the color of the grout is too light. So, I have been on my knees and able to actually spend time watching the cycle of burn in this unit. As some know I am not happy with the stove and have ordered a replacement for it. It's also a non-cat EPA.
This Homestead seems to have two essential features which make it different from non-cat stoves I have owned - a ceramic baffle, and three secondary combustion tubes at the roof of the box, front to back. I see no particular air stream paths that make it different from other non cat stoves I have used. The main air intake is a curse, to me, cutting a path through a load of wood generally leaving unburned chunks left and right. Not always, but enough to leave me frustrated in the morning, or as I watch logs on top fall into the door to burn as those beneath collapse in two pieces after being torched through the middle. That leaves a big ash mess when the door is opened and everything just falls forward. I know that's what lips are for. Still, other stoves I have owned made no such mess. I think the Fireview andirons are a decent idea.
So, is that it? The ceramic baffle and the burn tubes or some sort of perforated metal which jets secondary air into the firebox? And is that the common denominator in non cat EPA stoves?
In watching this Homestead closely, in running the stove at various settings, temps and load sizes I see no apparent effect of the ceramic baffle. The tubes show evidence of burning 'something' as the cycle moves along. There is no visible smoke in the box, save for start up when the tubes remain dormant. So, it becomes logical invisible, volatile gases are being burned in the jets of air from the tubes. But in my observations the only times the tubes are visibly burning those gases is when flames are shooting up into them. No flames, no visible jets of secondary combustion. The holes remain dormant until flames get to them.
While all this may pass a test for the EPA, logically, to my thinking and observation, if combustion activity is not forced through a secondary combustion zone or chamber, such as a catalytic zone, most of the smoke, gases and combustion particulates are traveling out the firebox exit (which in this case is the front top of the stove), moving across the underside of the top of the stove, and then up the flue. Perhaps there is manufacturing evidence/claim that is also a secondary zone, but it is not visible.
I have noticed fast, fully-loaded box, hot fires work best in this stove for cleanliness and full combustion of burn cycle. The manual of the stove I have coming (Pacific Fusion) states the same, save for a fully loaded box. Currently the unit is functioning at 500 with the draft half closed. But I'm also watching around 70% of the flames go right up the firebox exit. The back tube is dormant, the middle tube 60/40% involved in combustion and the front tube 70/30%, logically since most of the flames are exiting right in front of it. The observable percentages of secondary combustion do not seem very good overall. Most of this combustion is going straight out the exit and up the flue.
In watching the cycle of cat stoves I owned, those percentages were dramatically different, logically because all combustion - smoke, etc, were forced through the cat zone where they were observably consumed. The top of my flue showed that as well. No creosote tars, only small flaking at the end of a burning season. Thus far with this stove, after putting in a steel liner as well, the creosote is visible, though nowhere near as much as before the liner was installed. So, some benefit has been received, but only a small observable difference in burn cycle activity. I still get a face full of smoke when I open the door to reload. It's especially bad when I start a fire on coals and do not get my wood in the box fast enough. The first splits catch and before I get third or fourth into the box smoke is exiting the stove out the door. I find this firebox very difficult to load easily, mostly because of the shape of the firebox. My wood is 16-19% so it is sufficiently dry. The flue is now 17 - 18' up with two bends - into and out of the heart wall and up the flue. Seeing so many pics of that set up gives me evidence my flue is not unacceptable. Not a perfect straight shot up and out, but still quite acceptable.
I'd like other non cat owners to explain their firebox and draft systems and state what makes their EPA stove an EPA stove. After watching this one my camp yet settles in the catalytic field.
The stove I now have is the Hearthstone Homestead. Non-catalytic. As I am renovating this house, I am currently coloring grout lines because the color of the grout is too light. So, I have been on my knees and able to actually spend time watching the cycle of burn in this unit. As some know I am not happy with the stove and have ordered a replacement for it. It's also a non-cat EPA.
This Homestead seems to have two essential features which make it different from non-cat stoves I have owned - a ceramic baffle, and three secondary combustion tubes at the roof of the box, front to back. I see no particular air stream paths that make it different from other non cat stoves I have used. The main air intake is a curse, to me, cutting a path through a load of wood generally leaving unburned chunks left and right. Not always, but enough to leave me frustrated in the morning, or as I watch logs on top fall into the door to burn as those beneath collapse in two pieces after being torched through the middle. That leaves a big ash mess when the door is opened and everything just falls forward. I know that's what lips are for. Still, other stoves I have owned made no such mess. I think the Fireview andirons are a decent idea.
So, is that it? The ceramic baffle and the burn tubes or some sort of perforated metal which jets secondary air into the firebox? And is that the common denominator in non cat EPA stoves?
In watching this Homestead closely, in running the stove at various settings, temps and load sizes I see no apparent effect of the ceramic baffle. The tubes show evidence of burning 'something' as the cycle moves along. There is no visible smoke in the box, save for start up when the tubes remain dormant. So, it becomes logical invisible, volatile gases are being burned in the jets of air from the tubes. But in my observations the only times the tubes are visibly burning those gases is when flames are shooting up into them. No flames, no visible jets of secondary combustion. The holes remain dormant until flames get to them.
While all this may pass a test for the EPA, logically, to my thinking and observation, if combustion activity is not forced through a secondary combustion zone or chamber, such as a catalytic zone, most of the smoke, gases and combustion particulates are traveling out the firebox exit (which in this case is the front top of the stove), moving across the underside of the top of the stove, and then up the flue. Perhaps there is manufacturing evidence/claim that is also a secondary zone, but it is not visible.
I have noticed fast, fully-loaded box, hot fires work best in this stove for cleanliness and full combustion of burn cycle. The manual of the stove I have coming (Pacific Fusion) states the same, save for a fully loaded box. Currently the unit is functioning at 500 with the draft half closed. But I'm also watching around 70% of the flames go right up the firebox exit. The back tube is dormant, the middle tube 60/40% involved in combustion and the front tube 70/30%, logically since most of the flames are exiting right in front of it. The observable percentages of secondary combustion do not seem very good overall. Most of this combustion is going straight out the exit and up the flue.
In watching the cycle of cat stoves I owned, those percentages were dramatically different, logically because all combustion - smoke, etc, were forced through the cat zone where they were observably consumed. The top of my flue showed that as well. No creosote tars, only small flaking at the end of a burning season. Thus far with this stove, after putting in a steel liner as well, the creosote is visible, though nowhere near as much as before the liner was installed. So, some benefit has been received, but only a small observable difference in burn cycle activity. I still get a face full of smoke when I open the door to reload. It's especially bad when I start a fire on coals and do not get my wood in the box fast enough. The first splits catch and before I get third or fourth into the box smoke is exiting the stove out the door. I find this firebox very difficult to load easily, mostly because of the shape of the firebox. My wood is 16-19% so it is sufficiently dry. The flue is now 17 - 18' up with two bends - into and out of the heart wall and up the flue. Seeing so many pics of that set up gives me evidence my flue is not unacceptable. Not a perfect straight shot up and out, but still quite acceptable.
I'd like other non cat owners to explain their firebox and draft systems and state what makes their EPA stove an EPA stove. After watching this one my camp yet settles in the catalytic field.