How would you install a Kuuma in this situation?

[motoguy]

Here is a thread regarding the wood burning stove situation in our new home. This will show the layout of the home, as well as the existing ductwork:

https://www.hearth.com/talk/threads/pipe-q-changing-from-top-exit-to-rear-exit-stove.138673/

The existing propane furnace is located immediately behind the bookshelf in this photo, next to the door:

In this photo, it's just out of frame the immediate right. The door in the photo above, and the photo below, is the same door. The "out of view" area is the area behind the book case, on the other side of the wall:

We just moved in, and as such, we're buying wood and just going to "make do" this year. My goal is to offset as much propane use as possible. However, by next winter, I'd like to have a more permanent solution in effect, in addition to wood cut this spring. Previously, I had been thinking along the lines of an OWB. I liked the idea of heating our hot water in addition to providing heat. But man, they are a pretty penny to install. I've also grown to like the idea of stocking the stove while in my shorts. I step out onto the patio for wood, step back in, and load 'er up! As such, I've shifted back to the indoor wood furnace mindset.

I think I've finally started to figure out how to get the 2nd stage to kick in on this little stove, and I must say, I'm impressed. I had previously been disappointed with the output, and kept thinking "why don't I just get a good old, 'throw wood in and forget about it' stove?" After seeing the heat/wood appetite benefits of the secondary burn...I think I'm sold!

I've thought about the Tundra, the Caddy, the Kuuma...but my concern, is how would it be plumbed into my existing system? The wall thimble on the above stove is cut through a concrete foundation wall. It's double walled tube inside, and double walled stainless stack on the outside. As an add-on, the chimney is completely exterior to the home on the outside.

Ideally (as far as the HVAC is concerned), the furnace would be located in the room with all the woodworking equipment (that stuff is not there now...this is a realtor photo of the previous owner). This is an unlikely possibility, as that room is below grade.

What would be the plumbing options if the furnace is kept in the same location as the existing wood stove? that would be my preferred choice, and we could even wall it off and create a room for the furnace and some wood storage.

 

[grammy]

Personally, I'd go with the Caddy or a Kuuma in the existing stove location. I'd extend your cold/warm supply and returns over to the furnace and partition that area off. Looks like you'll still have a large room left over even with the space lost. The only disadvantage is you'll lose the benefit of being able to enjoy watching the fire.

I just changed from an older wood oil forced air combo to an electric furnace with a RSF fireplace (which dumps into the heating system). I found burning wood in the furnace was a bit of a chore, but you actually can enjoy the fire with a glass door...

Another issue is how are going to get your wood to the stove. You don't want to be tracking it too far through the house.

 

[motoguy]

Personally, I'd go with the Caddy or a Kuuma in the existing stove location.

You just made my day! That's the answer I wanted! lol

I'd extend your cold/warm supply and returns over to the furnace and partition that area off. Looks like you'll still have a large room left over even with the space lost. The only disadvantage is you'll lose the benefit of being able to enjoy watching the fire.

Another issue is how are going to get your wood to the stove. You don't want to be tracking it too far through the house.

Ok. Do I want to have a woodstove guy do the ductwork, or an HVAC guy? If I can leave the heat source in the current location, and get the ductwork to it, and get adequate flow, I'm super happy.

currently, I'm carrying wood through the house. The door is in the middle of the room, on the wall with all the windows. It's basically to the immediate right in the first photo above. The tile area runs between the exterior door and the interior stairwell, so crap isn't tracked onto the carpet as you come inside, and head up the stairs. That being said, I'm currently managing to track plenty of crap across the carpet right now.

As the wall w/ windows is a framed exterior wall (walkout basement...it's the only wall that isn't concrete), it would be pretty easy to add a door over by the furnace. If I enclose the furnace in it's own room, the I'd basically have an exterior door to that room, which would make wood storage clean, and easy. If it's this easy, I'm super excited.

 

[STIHLY DAN]

Is there a 2nd floor in that place? If the pics are all you are heating a furnace will be to big.

 

[motoguy]

Is there a 2nd floor in that place? If the pics are all you are heating a furnace will be to big.

Clicking on the link above the photos will take you to the other thread, with photos of the upstairs. It's 3600sq ft overall.

 

[STIHLY DAN]

I see. Nice house. Ideally I think a 2nd chimney and the furnace in the un finished section would be best. Keep in mind during shoulder season furnaces tend to over heat. That 2nd stove would be perfect to take the chill out.

 

[maple1]

Looks like an ideal situation for a kuuma to me. Walkout basement? Heck ya.

I would look to an HVAC guy for ductwork, but there are increased clearance issues for ducting of wood heat. What is directly above the stove? Another issue to consider is vertical duct flow for overheat protection & heating capability in a power outage. Looking forward to feedback from more kuuma & furnace guys here...

 

[grammy]

As as all the warm air ducts are above the unit, the heat will rise naturally out of the furnace and power failure is not an issue. It looks as though that is the case in this application.

HVAC guy would be your best bet if you have one in your area.

Check the CFM and BTU of your current furnace compared to the CFM of BTU of the unit you're looking at replacing it with and you'll have a good idea if they are up to the task.

Will you keep your current furnace as backup heat?

 

[motoguy]

I see. Nice house. Ideally I think a 2nd chimney and the furnace in the un finished section would be best. Keep in mind during shoulder season furnaces tend to over heat. That 2nd stove would be perfect to take the chill out.

I will get a photo from the outside in the next couple of days. The unfinished room with all the woodworking equipment is below grade. The existing stove pipe exits around waist high above grade.

 

[motoguy]

I would look to an HVAC guy for ductwork, but there are increased clearance issues for ducting of wood heat. What is directly above the stove?

The master bedroom is located on the floor above the stove. The stove is almost exactly under our bed. As far as the immediate area above the stove...there is a duct for the master bedroom, and some phone/tv cables and an electric run or two.

 

[motoguy]

Check the CFM and BTU of your current furnace compared to the CFM of BTU of the unit you're looking at replacing it with and you'll have a good idea if they are up to the task.

Will you keep your current furnace as backup heat?

I'll check. The current furnace is a Thermalzone, but I haven't been able to find the sticker to determine model. I'll be keeping the propane furnace installed and active. It'll be a backup, kicking in when the temps fall below the thermostat setting.

ETA: Additional reading has now created doubt. Several runs of ductwork are flex duct, and the space between joists are used as runs also. It's my current understanding that solid-fuel heat sources must have metal ductwork along the full length. Next, possibly running into clearance issues. 2" clearance for fist 10' shouldn't be an issue, but the additional 1" everywhere else may be. The ductwork is tucked up against the joists in several places...

anyway to turn the Kuuma into a boiler? lol The more I read about the Kuuma, the more I like it. I like the idea of sucking every last ounce of heat out of a piece of wood, and my wife likes the idea of "put wood in, close the door, dial the heat, and forget it". She's not at ALL a fan of the gymnastics required to get the combustor to light up in the Arbor, nor the time it takes. She's actually 100% on board with a Kuuma installation for next winter.

The duct work seems to be the largest stumbling block at this point. I guess, worst case, I have the current flex and "between the joists" runs replaced with metal, and sized to have 1" clearance. That's do-able. I liked the "keep the wood out of the house" aspect of an OWB, but the more I read, the more it seems the Kuuma is a much more efficient option. Hell, if I build a room around it, and add an exterior door, it'll keep all the "nastyness" outside the living area. Since it'll effectively be it's own room (likely lined with concrete board), I could even add an exhaust system to clear the smoke out of the room, and keep it out of the house.

I guess I just need to figure out how to duct the Kuuma, and how to best use the water-coil option to my benefit. I'm still learning about all of this (all started by that little Arbor)..I'm completely open to ideas, suggestions, and input.

I'd LOVE to have the Kuuma installed for next year. We have a mill nearby (about an hour, not too bad) that sells green oak $40/cord, buyer picks it up. At that price, I could buy a bunch of that in month or two, let it start drying, and have "nearly free" heat for the next winter (and as long as he's in business).

 

[STIHLY DAN]

I could even add an exhaust system to clear the smoke out of the room, and keep it out of the house.

What smoke?

 

[motoguy]

What smoke?

The smoke that I let out when I fill it improperly.

 

[motoguy]

After checking things out last night, I'm very excited. The flexible ductwork should be pretty easy to replace with metal tube. The runs using joists as channels are for return air, not heat side. It looks like I can move the return air intake on the furnace a bit, and that will open up access to the hot side plenum. Then run a duct from the furnace location, through the wall, and underneath the existing hot air outlet. The furnace output should then plug right into the existing plenum.

I'll put op some photos (and my proposed plan) in the next couple of days, and see how it looks. I think this is very doable, as long as the distance from Kuuma to plenum on propane furnace isn't an issue.

 

[motoguy]

I've sent a message off to Daryl at Kuuma. We're very excited to have the VF100 in place for the winter, provided we have a viable install.