Lady BK and I took a drive out to Woodstock to see what all the fuss was about. It was a perfectly gorgeous day for a drive in the country. It is drop-dead beautiful from our house right through Vermont and into New Hampshire, so we needed little extra inducement for travel that way. Factor in that we had a good chance of meeting the legendary Backwoods Savage, plus a chance to replenish our depleted liquor stores (no sales tax in NH), and we were on the road by 10 AM.
When we got there they were serving the pig, so we grabbed a couple plates and a beer and got that out of the way. De-licious! They had a pretty decent old-time fiddler playing off to the side, which lent a nice country flavor to the event. When we were satisfied, we headed into the showroom to check out the stoves. Neither one of us had ever seen a Woodstock stove in the flesh because they only sell direct and none of our acquaintances burn in a Woodstock. I was not prepared for how beautiful they look in real life. Stunning, really.
We went into the workshop and were impressed with the size of the facility. Extremely well organized, with separate workstations for each operation of assembly. I was directed to a burning Fireview to check it out in action. It was 2 PM, but there was still three or four partially consumed splits in the stove from the morning firing. I am a nerd, so I brought along my IR thermometer to check out the stove temps. The top was still at over 500ºF six hours after the stove was lit. Temps were remarkably even all around the stove as well. I was unable to find a 100º difference between any two places on the outside, and a scan of all the surfaces produced an average temp of 475º. That was with the air set around 2. A bit later they opened it up to a little over 2 (max is 4) to get some flames, and you could really feel the heat pour off it, even in the cavernous space that the stove sat in.
Next stop was to visit Frankenstove. Butch from R&D took the time to describe what was going on with it, and what they hoped to achieve. The prototype is expected sometime during the next year, with a possible release date prior to next burn season. But these guys aren't rushing this baby. They really want to get this right, so there will be no doubt about it meeting any new EPA standard. In fact, they are realistically trying to achieve efficiency in the 90% range! Toward this goal, they have a very impressive array of gizmos and gadgets (sensors, probes, meters, computers, etc.) attached to it, reinforcing the "Frankenstein" appearance of the stove.
The stove sits on a scale at all times. It is loaded with wood of known moisture content, and as the burn proceeds, CO, CO2, VOCs and particulate matter are all measured in real time. This is compared with the decreasing weight of the stove as the wood is burned. This enables them to get a true measure of the stove's efficiency, since anything that wasn't water in the wood and didn't go up the flue or appear as ash at the bottom must be assumed to have been completely burned into water and carbon dioxide. From this information, they are able to estimate the actual BTUs being produced at any given stage of the burn, based upon the known energy potential of the dry weight of the wood. Expected on this 3 cu.ft. stove when they are done with it... a whopping 75-80,000 BTUs.
I went out there to get the hard facts from the horse's mouth, and I didn't leave disappointed. A few interesting things that I learned:
- Moisture doesn't hurt a cat. In fact, Tom told me that they actually took unseasoned wood and rolled it around in the snow before filling the stove up. No damage at all. This was good news, since most of the water that comes from a burn is actually coming from combustion itself and cannot be avoided. It's not water that kills a cat, it's the potassium contained in the fly ash that passes through the combustor. The solution? Zap the stuff at high temps right before it hits the cat.
They were told of several metals that might do this, but none could withstand the intense heat for long. Finally, they came upon a high-temp alloy made of iron, nickle and chrome that was available in a mesh, and now the fly ash will encounter this super-heated screen and be relieved of its potassium before it can damage the cat. They are also replacing the old-style ceramic cats with stainless because they found the ceramic surfaces lose their 3-D micro-texture over time or when over-fired, and will no longer effectively hold the oxygen molecules in place. The metal surface eliminates this. Plus, there will be greater surface area for the gases to pass over, further increasing the efficiency of the units.
- Even with the air wide open, stoves run out of oxygen at some point in the burn path. They had suspected this for a while, so they started to look at CO emissions (a major lost fuel source). They found out that when they introduced air into the stove in excess of what the the draft was pulling in, the CO emissions dropped like a stone. Increased burn efficiency is the result.
- The EPA stoves with secondary air tubes are only efficient at high outputs. A cat stove is efficient at low output. The cat on the new stove won't do much at all, since the secondary air will do the job most of the time. It will only be needed when the emissions are higher during low-output burns. Best of both worlds.
Finally, there was the burning of the mortgage, and what place more suitable than in the new stove. With little fanfare, Tom opened the side door on Frankenstove and dropped it in. I caught the event on my iPhone:
When we got there they were serving the pig, so we grabbed a couple plates and a beer and got that out of the way. De-licious! They had a pretty decent old-time fiddler playing off to the side, which lent a nice country flavor to the event. When we were satisfied, we headed into the showroom to check out the stoves. Neither one of us had ever seen a Woodstock stove in the flesh because they only sell direct and none of our acquaintances burn in a Woodstock. I was not prepared for how beautiful they look in real life. Stunning, really.
We went into the workshop and were impressed with the size of the facility. Extremely well organized, with separate workstations for each operation of assembly. I was directed to a burning Fireview to check it out in action. It was 2 PM, but there was still three or four partially consumed splits in the stove from the morning firing. I am a nerd, so I brought along my IR thermometer to check out the stove temps. The top was still at over 500ºF six hours after the stove was lit. Temps were remarkably even all around the stove as well. I was unable to find a 100º difference between any two places on the outside, and a scan of all the surfaces produced an average temp of 475º. That was with the air set around 2. A bit later they opened it up to a little over 2 (max is 4) to get some flames, and you could really feel the heat pour off it, even in the cavernous space that the stove sat in.
Next stop was to visit Frankenstove. Butch from R&D took the time to describe what was going on with it, and what they hoped to achieve. The prototype is expected sometime during the next year, with a possible release date prior to next burn season. But these guys aren't rushing this baby. They really want to get this right, so there will be no doubt about it meeting any new EPA standard. In fact, they are realistically trying to achieve efficiency in the 90% range! Toward this goal, they have a very impressive array of gizmos and gadgets (sensors, probes, meters, computers, etc.) attached to it, reinforcing the "Frankenstein" appearance of the stove.
The stove sits on a scale at all times. It is loaded with wood of known moisture content, and as the burn proceeds, CO, CO2, VOCs and particulate matter are all measured in real time. This is compared with the decreasing weight of the stove as the wood is burned. This enables them to get a true measure of the stove's efficiency, since anything that wasn't water in the wood and didn't go up the flue or appear as ash at the bottom must be assumed to have been completely burned into water and carbon dioxide. From this information, they are able to estimate the actual BTUs being produced at any given stage of the burn, based upon the known energy potential of the dry weight of the wood. Expected on this 3 cu.ft. stove when they are done with it... a whopping 75-80,000 BTUs.
I went out there to get the hard facts from the horse's mouth, and I didn't leave disappointed. A few interesting things that I learned:
- Moisture doesn't hurt a cat. In fact, Tom told me that they actually took unseasoned wood and rolled it around in the snow before filling the stove up. No damage at all. This was good news, since most of the water that comes from a burn is actually coming from combustion itself and cannot be avoided. It's not water that kills a cat, it's the potassium contained in the fly ash that passes through the combustor. The solution? Zap the stuff at high temps right before it hits the cat.
They were told of several metals that might do this, but none could withstand the intense heat for long. Finally, they came upon a high-temp alloy made of iron, nickle and chrome that was available in a mesh, and now the fly ash will encounter this super-heated screen and be relieved of its potassium before it can damage the cat. They are also replacing the old-style ceramic cats with stainless because they found the ceramic surfaces lose their 3-D micro-texture over time or when over-fired, and will no longer effectively hold the oxygen molecules in place. The metal surface eliminates this. Plus, there will be greater surface area for the gases to pass over, further increasing the efficiency of the units.
- Even with the air wide open, stoves run out of oxygen at some point in the burn path. They had suspected this for a while, so they started to look at CO emissions (a major lost fuel source). They found out that when they introduced air into the stove in excess of what the the draft was pulling in, the CO emissions dropped like a stone. Increased burn efficiency is the result.
- The EPA stoves with secondary air tubes are only efficient at high outputs. A cat stove is efficient at low output. The cat on the new stove won't do much at all, since the secondary air will do the job most of the time. It will only be needed when the emissions are higher during low-output burns. Best of both worlds.
Finally, there was the burning of the mortgage, and what place more suitable than in the new stove. With little fanfare, Tom opened the side door on Frankenstove and dropped it in. I caught the event on my iPhone:
