Hello fellow WoodHeads,
I recently installed the Kuma Sequoia as a wood burning insert into my fireplace and while the install itself had some issues, I have to say that I couldn't be more pleased with the product. I did a tremendous amount of research regarding the type of stove to get and every time I used my criteria the Sequoia always came to the top.
Here is the quick review of the requirements I used for selection:
I live in Western Washington and have only electric heat at my place so alternate source of heat is necessary in case of power outage which occurs in our area either during severe wind storms or in below freezing weather where trees snap from the cold and down power lines.
In all honest, after applying just the top 4 criteria at once, Sequoia was the ONLY stove that satisfied them and it was just the cherry on top that it actually satisfied all 6. Pacific Energy was a close second, although their efficiency was considerably lower than Kuma, Fireplace Xtrodinair, Quadra Fire and Enviro all had great products as well. Once all of the criteria was compared though, Kuma was at the top every single time especially because of the convection heating design that creates a tremendous amount of airflow without a fan.
Here are the specs of Kuma as a quick overview:
OK, enough about the stove. Bottom line, if you own one you're happy as a clam and warm as warm gets, if you don't own one and you're looking for a stove GET IT and never look back.
Now onto the actual install and overall initial experience.
The install was a bit of a hassle in all honesty. The 8" flue size is the biggest obstacle you will find. Even though my chimney is well over 9" in size, it was still a bit of an issue sliding the stainless steel liner down it. Yes, STAINLESS IS A MUST so this thing doesn't flex or move much. Overall, though, once the liner was sorted out, the install went smoothly and easily. The second issue that I had was the fact that while the fireplace was big enough, the hearth in the front caused clearance issues and I had to remove the hearth completely in order to install the unit. This really wasn't an issue for me because it was just a brick hearth so upgrade was in order anyways but I wish I didn't have to do this in the middle of the install. So bottom line, MAKE SURE YOU MEASURE THE OPENING and not just the fireplace.
After the install I was excited to get the first fire burning and I will say that starting a fire in that unit is a breeze, even if you have a cursory knowledge of fire-starting. Once the fire was started I loaded the unit and was rewarded by a quick rise in the room temperature. First impression was WOW, THIS THING PUTS OUT HEAT. The disappointing part was that after loading the unit at night, I woke up to a cold stove and no coals less than 8 hours after loading it full. I called Kuma and I have to say that I am pleasantly surprised by their customer service. EVERYONE THERE TAKES A CALL. If you call them, no matter if they are a sales rep, owner or the loading dock guy, they will answer the phone and answer your questions.
So, after a couple of calls I ended up talking to the guy that designed the Sequoia stove, and through the discussion I was able to hone in on the exact cause of my short burn time and the solution for my particular issue.
First, here is the general basic design parameters for the Sequoia.
The unit is designed for best draft in 16 foot chimney, non-insulated pipe to the outside for ability to perform in subzero temperatures. Meaning that if you have a 23 foot brick and mortar chimney and live in area where it is usually 30-50 degrees during the winter, the draft will be SIGNIFICANTLY stronger to the point that it will overpower both the intake and the catalyst. While I was getting 600 degree temperatures in the catalyst the unit was not burning efficiently and the inflow of the fresh air was keeping the catalyst temperature down.
So, if you have short burn times, I would say your draft is the number one issue you should be looking at. Ultimately, the longer the chimney, the more draft you will have, especially if the pipe is insulated or the liner is installed in a brick and mortar chimney where the heat can be trapped and temperature drop in exhaust gasses between the bottom and the top is minimal. Also if the chimney is relatively straight, the airflow will be stronger. Ultimately, the hotter the air, the longer the passage and straighter the path the more acceleration the air will have ultimately causing a strong draft.
There are two ways to remedy this. First is being some kind of a butterfly valve installed at the top of the exhaust vent of the unit. If you have installed it as a stove, this might work as a good option but if you have installed this unit as an insert, only viable option is to place a starting collar on the 4" intake port and use some flex piping for HVAC to direct the air intake to the front of the stove where you can fine-tune the amount of air the unit is taking.
For me, due to the restrictions in clearance, I had to modify a 4" to 3" reducer as a starting collar, then connect 3" flex piping to the front of the unit so I can restrict airflow and have easy access to it if I need adjustments. According to the catalyst manufacturer, the catalyst performs best at temps between 700 and 1,300 degrees, with the low end being best for longer burn times. So, in order to reach optimal airflow that provides catalyst burn temperatures between 700 and 1,000 degrees at the most restricted handle position, I had to restrict the intake hole size to about a diameter of a US Quarter. The way you would find the optimal airflow is to reduce the size of your intake opening to the point that reducing the size of the hole would reduce the catalytic chamber temperature and opening it would increase it. Then finetune the opening until you can consistently reach 700 degrees in the catalytic chamber. At that point, go outside and look at your exhaust from the chimney and see what the "smoke" coming out looks like. The three byproducts of the chemical process of catalytic burn is #1 HEAT, the important part we want, second two are water and CO2. As CO2 is invisible, the only thing you should be seeing out of your chimney is steam, that's it. It should look as if the fire is barely going. With my stove at about 700-900 degrees in the catalytic chamber, the steam looks as if it is coming off a pot that is just about to start boiling. If you don't see steam but see just the heat rising (like off the asphalt in the middle of the summer), it means the catalytic chamber is too hot and the steam is superheated. If you actually see white/blue or black smoke, it means your catalyst is not doing the job and you need to troubleshoot some more. In some rare instances, you will have the stove dialed in just right without any steam or vapor showing, that's possible due to RH/temperature in the outside air. This is very rare but possible.
Anyways, once I as able to dial in the stove, currently I get about 10 hours of full on burn time plus another 2-3 hours of hot coals in the bottom but the catalyst not fully engaged as it is at around 400-500 degrees. If you have the steel-core catalyst, then you're still engaged but ceramic catalysts are not operating at this temp. The coals are still glowing red and I can use them to start another fire instantly by loading more wood, opening the bypass vent, opening the air intake vent and cracking the stove door a tiny bit. This will re-engage the catalyst within 15 minutes and the stove will start humming once again.
In all honesty, this fix and troubleshooting guide is not limited to the Kuma Sequoia but all catalytic burn stoves. I just had the Sequoia to work with.
I have attached a link to a short video that I shot showing the unit and the fix I have implemented. Please excuse not having the hearthstone in yet, the masonry guy is taking his sweet time installing it.
(broken link removed to https://drive.google.com/file/d/0B60Z-DLSrYJiOWxUcUhJN0pUTE0/view?usp=sharing)
I have also attached the pictures showing the unit with the catalyst fully engaged, my fix using flex pipe and 3M duct joint tape and the catalyst thermometer temperature showing full combustion.
One last tip... if you are using a stove with a catalytic burner, make sure that you have a good mix of wood you use for a fire. Obviously, seasoned wood is a must but other than that you need a good mix that will help you burn most efficiently. My stove HATES pure wood burn, meaning only hardwoods like Alder and Maple. For best results, when refueling, I put down a layer of good Cedar and Red Pine logs and then top them off with Alder and Maple. This gives me the immediate heat and flames needed to get the catalyst engaged again with a really good benefit of prolonged burn times of the hardwoods. Engaging that catalyst quickly is the number one priority and with hardwoods alone, it will take you a LONG time before you get it hot enough.
Anyways, if you've made it this far. Thanks for reading my post. Good luck in your adventures!
*Edited to fix grammar and formating
I recently installed the Kuma Sequoia as a wood burning insert into my fireplace and while the install itself had some issues, I have to say that I couldn't be more pleased with the product. I did a tremendous amount of research regarding the type of stove to get and every time I used my criteria the Sequoia always came to the top.
Here is the quick review of the requirements I used for selection:
I live in Western Washington and have only electric heat at my place so alternate source of heat is necessary in case of power outage which occurs in our area either during severe wind storms or in below freezing weather where trees snap from the cold and down power lines.
- EPA Certified Wood Burning Stove (County Requirement, $1,500 fine if caught burning in non-certified stove)
- Able to heat 3,000 SQ FT in below freezing weather without a blower fan
- Wood burning efficiency above 80%
- Minimum burn times of 10 hours or longer, 12+ hours preferred
- Full installation cost not to exceed $4,500 (This has changed a little bit but I will explain later)
- Made in USA, Preferably in PNW (I like to buy American but more importantly I like to help my local community)
In all honest, after applying just the top 4 criteria at once, Sequoia was the ONLY stove that satisfied them and it was just the cherry on top that it actually satisfied all 6. Pacific Energy was a close second, although their efficiency was considerably lower than Kuma, Fireplace Xtrodinair, Quadra Fire and Enviro all had great products as well. Once all of the criteria was compared though, Kuma was at the top every single time especially because of the convection heating design that creates a tremendous amount of airflow without a fan.
Here are the specs of Kuma as a quick overview:
- 90,000BTU/HR (Second to Pacific Energy's 99,000BTU/HR),
- Efficiency 84%/91% (Top in industry),
- can heat 3,500 SQ FT (Top in industry),
- 14 hour burn time (Top in Industry),
- Particulate Emissions 2.2 gr/hr (Lowest of ANY stove I've found),
- Cost (Fully Loaded with the blower and the Pewter Door, $2,600 through my local dealer plus the install cost, liner, permit and EPA fees... with some strong hand negotiating and haggling of course. The total cost was approximately $3,900 which is well within the budget but I ended up having to replace my hearth top which pushes the total install cost to about $5,000)
OK, enough about the stove. Bottom line, if you own one you're happy as a clam and warm as warm gets, if you don't own one and you're looking for a stove GET IT and never look back.
Now onto the actual install and overall initial experience.
The install was a bit of a hassle in all honesty. The 8" flue size is the biggest obstacle you will find. Even though my chimney is well over 9" in size, it was still a bit of an issue sliding the stainless steel liner down it. Yes, STAINLESS IS A MUST so this thing doesn't flex or move much. Overall, though, once the liner was sorted out, the install went smoothly and easily. The second issue that I had was the fact that while the fireplace was big enough, the hearth in the front caused clearance issues and I had to remove the hearth completely in order to install the unit. This really wasn't an issue for me because it was just a brick hearth so upgrade was in order anyways but I wish I didn't have to do this in the middle of the install. So bottom line, MAKE SURE YOU MEASURE THE OPENING and not just the fireplace.
After the install I was excited to get the first fire burning and I will say that starting a fire in that unit is a breeze, even if you have a cursory knowledge of fire-starting. Once the fire was started I loaded the unit and was rewarded by a quick rise in the room temperature. First impression was WOW, THIS THING PUTS OUT HEAT. The disappointing part was that after loading the unit at night, I woke up to a cold stove and no coals less than 8 hours after loading it full. I called Kuma and I have to say that I am pleasantly surprised by their customer service. EVERYONE THERE TAKES A CALL. If you call them, no matter if they are a sales rep, owner or the loading dock guy, they will answer the phone and answer your questions.
So, after a couple of calls I ended up talking to the guy that designed the Sequoia stove, and through the discussion I was able to hone in on the exact cause of my short burn time and the solution for my particular issue.
First, here is the general basic design parameters for the Sequoia.
The unit is designed for best draft in 16 foot chimney, non-insulated pipe to the outside for ability to perform in subzero temperatures. Meaning that if you have a 23 foot brick and mortar chimney and live in area where it is usually 30-50 degrees during the winter, the draft will be SIGNIFICANTLY stronger to the point that it will overpower both the intake and the catalyst. While I was getting 600 degree temperatures in the catalyst the unit was not burning efficiently and the inflow of the fresh air was keeping the catalyst temperature down.
So, if you have short burn times, I would say your draft is the number one issue you should be looking at. Ultimately, the longer the chimney, the more draft you will have, especially if the pipe is insulated or the liner is installed in a brick and mortar chimney where the heat can be trapped and temperature drop in exhaust gasses between the bottom and the top is minimal. Also if the chimney is relatively straight, the airflow will be stronger. Ultimately, the hotter the air, the longer the passage and straighter the path the more acceleration the air will have ultimately causing a strong draft.
There are two ways to remedy this. First is being some kind of a butterfly valve installed at the top of the exhaust vent of the unit. If you have installed it as a stove, this might work as a good option but if you have installed this unit as an insert, only viable option is to place a starting collar on the 4" intake port and use some flex piping for HVAC to direct the air intake to the front of the stove where you can fine-tune the amount of air the unit is taking.
For me, due to the restrictions in clearance, I had to modify a 4" to 3" reducer as a starting collar, then connect 3" flex piping to the front of the unit so I can restrict airflow and have easy access to it if I need adjustments. According to the catalyst manufacturer, the catalyst performs best at temps between 700 and 1,300 degrees, with the low end being best for longer burn times. So, in order to reach optimal airflow that provides catalyst burn temperatures between 700 and 1,000 degrees at the most restricted handle position, I had to restrict the intake hole size to about a diameter of a US Quarter. The way you would find the optimal airflow is to reduce the size of your intake opening to the point that reducing the size of the hole would reduce the catalytic chamber temperature and opening it would increase it. Then finetune the opening until you can consistently reach 700 degrees in the catalytic chamber. At that point, go outside and look at your exhaust from the chimney and see what the "smoke" coming out looks like. The three byproducts of the chemical process of catalytic burn is #1 HEAT, the important part we want, second two are water and CO2. As CO2 is invisible, the only thing you should be seeing out of your chimney is steam, that's it. It should look as if the fire is barely going. With my stove at about 700-900 degrees in the catalytic chamber, the steam looks as if it is coming off a pot that is just about to start boiling. If you don't see steam but see just the heat rising (like off the asphalt in the middle of the summer), it means the catalytic chamber is too hot and the steam is superheated. If you actually see white/blue or black smoke, it means your catalyst is not doing the job and you need to troubleshoot some more. In some rare instances, you will have the stove dialed in just right without any steam or vapor showing, that's possible due to RH/temperature in the outside air. This is very rare but possible.
Anyways, once I as able to dial in the stove, currently I get about 10 hours of full on burn time plus another 2-3 hours of hot coals in the bottom but the catalyst not fully engaged as it is at around 400-500 degrees. If you have the steel-core catalyst, then you're still engaged but ceramic catalysts are not operating at this temp. The coals are still glowing red and I can use them to start another fire instantly by loading more wood, opening the bypass vent, opening the air intake vent and cracking the stove door a tiny bit. This will re-engage the catalyst within 15 minutes and the stove will start humming once again.
In all honesty, this fix and troubleshooting guide is not limited to the Kuma Sequoia but all catalytic burn stoves. I just had the Sequoia to work with.
I have attached a link to a short video that I shot showing the unit and the fix I have implemented. Please excuse not having the hearthstone in yet, the masonry guy is taking his sweet time installing it.
(broken link removed to https://drive.google.com/file/d/0B60Z-DLSrYJiOWxUcUhJN0pUTE0/view?usp=sharing)
I have also attached the pictures showing the unit with the catalyst fully engaged, my fix using flex pipe and 3M duct joint tape and the catalyst thermometer temperature showing full combustion.
One last tip... if you are using a stove with a catalytic burner, make sure that you have a good mix of wood you use for a fire. Obviously, seasoned wood is a must but other than that you need a good mix that will help you burn most efficiently. My stove HATES pure wood burn, meaning only hardwoods like Alder and Maple. For best results, when refueling, I put down a layer of good Cedar and Red Pine logs and then top them off with Alder and Maple. This gives me the immediate heat and flames needed to get the catalyst engaged again with a really good benefit of prolonged burn times of the hardwoods. Engaging that catalyst quickly is the number one priority and with hardwoods alone, it will take you a LONG time before you get it hot enough.
Anyways, if you've made it this far. Thanks for reading my post. Good luck in your adventures!
*Edited to fix grammar and formating
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