Kuuma worth it?

[dromlyn]

All wood burning furnaces will have a bell shaped heat output cycle. The Kuuma's will be more flat because of the computer control. The max BTU's won't be quite as high because there is never a "raging fire". This means the BTU's released during the beginning and the ends of the burn cycle will be a bit more though resulting in a more even heat throughout the burn cycle.

Due to the computer control, I'm curious what happens when the electricity goes out. How does the Kuuma handle this?

 

[JRHAWK9]

Due to the computer control, I'm curious what happens when the electricity goes out. How does the Kuuma handle this?

When power is cut to the computer it automatically closes the damper which cuts off the primary air supply. It is recommended your supply ducts be large enough for gravity feed and your dampers be setup to allow for gravity feed.

 

[dromlyn]

When power is cut to the computer it automatically closes the damper which cuts off the primary air supply. It is recommended your supply ducts be large enough for gravity feed and your dampers be setup to allow for gravity feed.

Good to know. Can you still run it at all in a pinch?

Any kumma vaporfire 100 users out there that love/hate the furnace? Looking for something to burn 10-12 hours is this possible? 70s built cathedral ceilings A frame or chalet. Dont have a walk out basement but windows are large and will make a great chute. Is the price worth it over the drolet tundra??

I'm curious how everyone feels the "Max Caddy" compares to the Tundra and the VaporFire 100

 

[JRHAWK9]

Good to know. Can you still run it at all in a pinch?

yes, the plenum is as big as it is so one can use it for gravity airflow.

I'm curious how everyone feels the "Max Caddy" compares to the Tundra and the VaporFire 100

Following is my opinion........Tundra is not in the same league as the other two. I also think the Max Caddy may be capable of putting out more MAX BTU's, as it's for sure capable of burning wood faster than the Kuuma. The Kuuma is still more efficient, easier to operate and cleaner burning though.

 

[dromlyn]

I also think the Max Caddy may be capable of putting out more MAX BTU's, as it's for sure capable of burning wood faster than the Kuuma. The Kuuma is still more efficient, easier to operate and cleaner burning though.

Just called a dealer about a Max Caddy ... I think they're a bit less expensive too (maybe around 3.5k compared to the Kuuma's 5.5k).

 

[JRHAWK9]

Just called a dealer about a Max Caddy ... I think they're a bit less expensive too (maybe around 3.5k compared to the Kuuma's 5.5k).

Be careful about listening to any dealer........they have vested interest and it's amazing how the products they happen to offer and make the most profit on are the best out there. ;-)

 

[laynes69]

yes, the plenum is as big as it is so one can use it for gravity airflow.



Following is my opinion........Tundra is not in the same league as the other two. I also think the Max Caddy may be capable of putting out more MAX BTU's, as it's for sure capable of burning wood faster than the Kuuma. The Kuuma is still more efficient, easier to operate and cleaner burning though.

Just because the combustion of a Caddy furnace isn't computerized, doesn't mean it's not efficient. Side by side a Caddy will produce the same flue temperatures as will the Kuuma, while producing a clean burn. The Max Caddy will also produce more heat not because of quicker combustion, but a much larger firebox. More fuel, more heat. The Caddy line of furnaces are not difficult to operate. You open the damper, load, then close the damper. From there, the house temperature determines the stage of fire.

 

[JRHAWK9]

Just because the combustion of a Caddy furnace isn't computerized, doesn't mean it's not efficient. Side by side a Caddy will produce the same flue temperatures as will the Kuuma, while producing a clean burn. The Max Caddy will also produce more heat not because of quicker combustion, but a much larger firebox. More fuel, more heat. The Caddy line of furnaces are not difficult to operate. You open the damper, load, then close the damper. From there, the house temperature determines the stage of fire.

Never said it wasn't efficient I just wish there was a single standard to test these furnaces so we all not just guessing.

It has a larger firebox too, but it's also able to burn wood faster. Like Stihly said above, our Kuuma's physically can't burn a full firebox worth of wood in any less time than 8 hours or so. Burning 50lbs of wood in 8 hours puts out less average BTU's per hour than burning it in 6 hours....assuming the same efficiency. Just because it has more fuel doesn't necessarily mean it has to burn it quicker. The older Kuuma's (like the one Daryl, the owner has) had an 20" deep firebox. By increasing it to 22" he got longer burn times but didn't change the BTU rating per hour of the unit.

 

[brenndatomu]

assuming the same efficiency

That's the thing, set the Kuuma on high and set the Max on high (damper open) in that scenario I guarantee the Kuuma is WAY more efficient

The older Kuuma's (like the one Daryl, the owner has)

I would be interested in knowing how they controlled the burn on those old Kuumas, before computers, like when they started in the 70s? I hear it burned just as clean

 

[JRHAWK9]

That's the thing, set the Kuuma on high and set the Max on high (damper open) in that scenario I guarantee the Kuuma is WAY more efficient

I would be interested in knowing how they controlled the burn on those old Kuumas, before computers, like when they started in the 70s? I hear it burned just as clean

I agree. The more the primary damper is open the less efficient it will be. When the Kuuma gets going, the primary damper is closed for the majority of the burn, allowing the secondary air to enter and the gassification process to take place. It opens and closes by itself right after a fresh load, then goes on cruise control for hours and then opens and closes towards the end of the burn.

What I would like to see is another switch or something that could allow you to override the computer to open up the damper when the thermostat calls for heat in the event you would ever need more heat. That would probably really decrease the overall efficiency though.

 

[Monaco]

Does the Kuuma come with a thermostat, and if not, or can it be hooked up to one?

 

[JRHAWK9]

Does the Kuuma come with a thermostat, and if not, or can it be hooked up to one?

yes, it comes with a thermostat, which controls the blower motor. When the thermostat calls for heat the blower turns on high. Unlike the Caddy line of furnaces, the thermostat does not control the level of burn or the primary damper. Those are solely controlled by the dial on the computer for whatever level of burn you want (low to high.....it's a variable potentiometer).

 

[3fordasho]

yes, it comes with a thermostat, which controls the blower motor. When the thermostat calls for heat the blower turns on high. Unlike the Caddy line of furnaces, the thermostat does not control the level of burn or the primary damper. Those are solely controlled by the dial on the computer for whatever level of burn you want (low to high.....it's a variable potentiometer).

Question for Kuuma owners- is the air inlet damper control an open/closed type affair or does it have the ability to partially open the inlet?

 

[JRHAWK9]

Question for Kuuma owners- is the air inlet damper control an open/closed type affair or does it have the ability to partially open the inlet?

-THIS- video will answer that.

 

[Monaco]

yes, it comes with a thermostat, which controls the blower motor. When the thermostat calls for heat the blower turns on high. Unlike the Caddy line of furnaces, the thermostat does not control the level of burn or the primary damper. Those are solely controlled by the dial on the computer for whatever level of burn you want (low to high.....it's a variable potentiometer).

This video makes it seem like you'd have to go down to the furnace to adjust the house heat.Is there another normal thermostat that you could put upstairs to control the blower speed?

I noticed the blower has two speeds. Would there be a benefit of a variable-speed blower?

 

[Highbeam]

Just called a dealer about a Max Caddy ... I think they're a bit less expensive too (maybe around 3.5k compared to the Kuuma's 5.5k).

I've compared these stoves and the max caddy, while much cheaper and EPA certified today, is much dirtier. It's a dirty burner at 6.6 gph which makes it illegal in some states such as mine. Compare that to sub 1 gph for the kuuma but nearly double the cost, a four month waiting line, and no EPA approval to date.

Both great furnaces and I would be thrilled to have either one of them. These guys seem to be head and shoulders above the competition today. As more brands develop new furnaces to meet EPA guidelines we will have more to choose from.

 

[Highbeam]

$5,295 plus shipping

And that shipping is going to be expensive. I recall it is two crates and total weight over 700#.

 

[brenndatomu]

Is there another normal thermostat that you could put upstairs to control the blower speed?

No. I don't have one but I have investigated these things pretty well and have talked with Kuuma several times

This video makes it seem like you'd have to go down to the furnace to adjust the house heat

No, I think most of these guys will tell you that they leave it on low most of the time and there would really be no reason to change more than once per day, and then only if some drastic weather front came through.

 

[Monaco]

And that shipping is going to be expensive. I recall it is two crates and total weight over 700#.

$ 277.03 + $100 crating

 

[Highbeam]

I'm curious how everyone feels the "Max Caddy" compares to the Tundra and the VaporFire 100

Looking at that website, the MSRP of the max caddy is 4200$ PLUS you have to buy the blower separately (specs say required) for another 1200$. So bam, we're back up to 5400$ for the max caddy. It has a window!

 

[Wisneaky]

Isn't the max caddy also a required dealer install?

 

[brenndatomu]

Looking at that website, the MSRP of the max caddy is 4200$ PLUS you have to buy the blower separately (specs say required) for another 1200$. So bam, we're back up to 5400$ for the max caddy. It has a window!

There are dealers out there that will sell them for MUCH less than that...I know personally (well, through a friend) that there is one in the NE corner of OH that will (does)

 

[Highbeam]

There are dealers out there that will sell them for MUCH less than that...I know personally (well, through a friend) that there is one in the NE corner of OH that will (does)

That is good information and really critical to this discussion. We saw "about 3500$" earlier upthread but don't know if that includes the silly expensive blower. The efficiency of the max caddy is quite good and almost 5 CF of firebox is also nice. Still a dirty burner but EPA certified for most states.

 

[JRHAWK9]

Here's how I see it. The Kuuma's primary damper is designed and computer controlled to constantly keep the fire in an optimum state of burn which results in the high efficiency and a cleaner burn. It keeps the fire in the gassification stage as long as it can by closing off primary air to allow the heated secondary air to enter the firebox at designed locations in order for gassification process to take place. I'd think you'd lose a lot of efficiency if you decided to somehow change the damper control over so the house thermostat had some control over the primary air supply. For instance, say the fire is in the middle of a burn and the computer has the damper shut allowing secondary air to fuel the gassification process and then your thermostat calls for heat which would open up the damper. As soon as that damper opens to allow primary air in the gassification stops and you lose the clean, efficient burn. Will it release more heat....sure, at the expense of efficiency and burn times.

Another thing to keep in mind. There is no such thing as a raging fire with the Kuuma. It burns front to back while burning the gasses at the very front top of the firebox. If you open up the door quickly after about an hour or so of a fresh load, you'll catch a glimpse of the bright blue flames in front and above the actual wood. What you are seeing is the tail end of the gassification, which quickly stops when the door is opened.

 

[lampmfg]

As far as I know the EPA testing on our competitor was done to the wood stove criteria. There has been many discussions about this on multiple forms in the past so I won't get into here again. If you look here at the new criteria http://www2.epa.gov/residential-woo...y-requirements-wood-fired-forced-air-furnaces you can see what the emissions requirements will be to gain actual EPA furnace certification will be going forward in 2016 and 2020. Needless to say it will require a very clean burn.