Kuuma Vapor Fire Mods

[MooseBucks]

I've got a Kuuma VF100 headed my way - What mods did you install? What do I need to know switching from a Yukon? Located in SE PA.

Thanks!

 

[brenndatomu]

The supply plenum on the Yook is the same size as the VF...I reused mine because it was VERY custom...I just hung it from the ceiling, cut 1" (if I recall correctly) off the bottom, set it right down on the VF once it was slid underneath...then I just had to reconfigure my cold air return duct.
You relining your chimney down to 6"?
Your gonna be totally in love with the VF after living with the Yukon...

 

[MooseBucks]

The supply plenum on the Yook is the same size as the VF...I reused mine because it was VERY custom...I just hung it from the ceiling, cut 1" (if I recall correctly) off the bottom, set it right down on the VF once it was slide underneath...then I just had to reconfigure my cold air return duct.
You relining your chimney down to 6"?
Your gonna be totally in love with the VF after living with the Yukon...

I have what I believe is class A double wall chimney on the exterior and I was going to get a completely new pipe from where the chimney connects to the VF in the basement. Do I need to worry about exterior diameter of the chimney?

I'm certainly nervous about switching because the Yukon could crank out the heat and worked well. Fingers crossed for me that this switch goes well.

 

[brenndatomu]

Do you need it to crank out the heat?
The VF can, but not like the Yooks...it just won't burn wood as fast as the Yukon, so the BTU's are spread out over a longer period.
What are you heating exactly?
How tall is your chimney?
I still have my 8" chimney, but it is an insulated liner in a masonry chimney...and its pretty tall, 27' IIRC...works fine though...6" would be "better" I'm sure, but I have no reason to want to change my setup.

 

[MooseBucks]

Do you need it to crank out the heat?
The VF can, but not like the Yooks...it just won't burn wood as fast as the Yukon, so the BTU's are spread out over a longer period.
What are you heating exactly?
How tall is your chimney?
I still have my 8" chimney, but it is an insulated liner in a masonry chimney...and its pretty tall, 27' IIRC...works fine though...6" would be "better" I'm sure, but I have no reason to want to change my setup.

~2500 SF Home on 1st and 2nd floor and have a finished basement that is serviced mainly by a mini-split but has vents for supplemental heat & A/C. First floor is ~1900 SF. 2nd Floor is ~600 SF.

Tried to find height of chimney on previous permit but it just says 2 stories...I would guess I'm in the ball park of yours though.

Prefer to keep the house ~70-72 and if we continuously fed the Yukon it would be 80.

 

[brenndatomu]

~2500 SF Home on 1st and 2nd floor and have a finished basement that is serviced mainly by a mini-split but has vents for supplemental heat & A/C. First floor is ~1900 SF. 2nd Floor is ~600 SF.

Tried to find height of chimney on previous permit but it just says 2 stories...I would guess I'm in the ball park of yours though.

Prefer to keep the house ~70-72 and if we continuously fed the Yukon it would be 80.

Unless you have some really poor insulation and/or air sealing, you'll be fine.
I have about ~2000 sq ft (~1200 main floor, ~700 upstairs...and 1200 basement, if you want to count that) with very average insulation (not up to current codes though) and the VF just plays with that heat load on all but the very coldest of days...and on our coldest days I finally get to load it over half full...and maybe, maybe, it will come off of low...but has not in the last 2 years though...close, but didn't do it then.
Oh, and we aim for 72* too.

 

[JRHAWK9]

I agree with bren.....looks like you guys may be near the same parallel, so should be similar climate....? I know he pretty much idles his throughout winter. His house is definitely more efficient than ours is though.

This is what our Kuuma is heating, we also aim to keep the house at 72° (although it will drop on those very cold mornings):

EPA 2020 Wood Furnace Intertek Data Comparison

I made up a quick reference comparing the main EPA hot air furnaces in the category by combining the tables from three furnaces. I did this so I could see where I wanted to put the most effort in when building my furnace controller and furnace shed project. I thought it might be useful for...

www.hearth.com

 

[MooseBucks]

I agree with bren.....looks like you guys may be near the same parallel, so should be similar climate....? I know he pretty much idles his throughout winter. His house is definitely more efficient than ours is though.

This is what our Kuuma is heating, we also aim to keep the house at 72° (although it will drop on those very cold mornings):

EPA 2020 Wood Furnace Intertek Data Comparison

I made up a quick reference comparing the main EPA hot air furnaces in the category by combining the tables from three furnaces. I did this so I could see where I wanted to put the most effort in when building my furnace controller and furnace shed project. I thought it might be useful for...

www.hearth.com

What do you use for your temp tracking?

 

[JRHAWK9]

What do you use for your temp tracking?

This to monitor temps:

Smoke® Remote BBQ Alarm Thermometer

Specializing in cool, unique and professional temperature tools. Super-Fast thermocouples, thermistors, infrared thermometers, data logging and more.

www.thermoworks.com

Then this to upload them to the cloud and log data/creat graphs:

Smoke® Gateway (Wi-Fi bridge for Smoke only)

Specializing in cool, unique and professional temperature tools. Super-Fast thermocouples, thermistors, infrared thermometers, data logging and more.

www.thermoworks.com

 

[Micdrew]

Unless you have some really poor insulation and/or air sealing, you'll be fine.
I have about ~2000 sq ft (~1200 main floor, ~700 upstairs...and 1200 basement, if you want to count that) with very average insulation (not up to current codes though) and the VF just plays with that heat load on all but the very coldest of days...and on our coldest days I finally get to load it over half full...and maybe, maybe, it will come off of low...but has not in the last 2 years though...close, but didn't do it then.
Oh, and we aim for 72* too.

How many cords do you go through a year on average?

 

[brenndatomu]

How many cords do you go through a year on average?

Oh, somewhere's in the 4 to 4.5 range, depending on how long and how cold the winter is.
I always have some wood laying around that was dry and ready to burn as soon as I bring it home, so I often supplement what I have racked up for the winter with this stuff since there is no point in stacking it to dry with the "green" wood...this supplemental wood throws my cord count off...so all I end up with at the end of the winter is a record of how many pounds I used...but depending on species and moisture content, that doesn't help figure the exact quantity/volume...still tells me pretty close on the BTU's used though.

 

[Micdrew]

Going off measurements that’s about where I’m at, I told myself once April hit I was done….fire was going this morning… the wife has gotten spoiled with the 72 degree house.

 

[brenndatomu]

I don't mind running a bit of oil once it gets closer to spring, but if the outdoor temp is below 50-55* I can easily get the draft going, so I'll run a small load of wood if looks like the weather is going to be such that the oil would need to run more than just once or twice.

 

[JRHAWK9]

all I end up with at the end of the winter is a record of how many pounds I used...but depending on species and moisture content, that doesn't help figure the exact quantity/volume.

You can just convert to whatever species you burn the most of.

How many cords do you go through a year on average?

I feel using pounds is a much better way to quantify wood usage. All wood as roughly the same BTU's/lb (assuming the same moisture content). At least for me it's better, as the wood I burn every year has reached it's equilibrium moisture, so it's all going to be similar moisture from year to year......unless we have an abnormally dry or humid summer. I then just convert the pounds to the one species volume I burn the most of, red oak, if I want to know cords. Over the years when I checked cords calculated by weight vs actual cords measured by volume, it was remarkably close. This year was the exception, as I had lots of short pieces, some maple and lighter splits of unknown species that threw it off......which is why I am glad I compare weights of what I burn and not volume.

Going off measurements that’s about where I’m at, I told myself once April hit I was done….fire was going this morning… the wife has gotten spoiled with the 72 degree house.

I light fires up until I have to. Last year I lit a couple fires on May 28th and 29th. I actually average burning ~300lbs of wood in May and 1,130lbs in April.

 

[Micdrew]

You can just convert to whatever species you burn the most of.



I feel using pounds is a much better way to quantify wood usage. All wood as roughly the same BTU's/lb (assuming the same moisture content). At least for me it's better, as the wood I burn every year has reached it's equilibrium moisture, so it's all going to be similar moisture from year to year......unless we have an abnormally dry or humid summer. I then just convert the pounds to the one species volume I burn the most of, red oak, if I want to know cords. Over the years when I checked cords calculated by weight vs actual cords measured by volume, it was remarkably close. This year was the exception, as I had lots of short pieces, some maple and lighter splits of unknown species that threw it off......which is why I am glad I compare weights of what I burn and not volume.



I light fires up until I have to. Last year I lit a couple fires on May 28th and 29th. I actually average burning ~300lbs of wood in May and 1,130lbs in April.

Wow that’s crazy, our winters aren’t nearly that bad here in NE Maryland. I talked to my buddy today who delivers heating oil it’s going for over $6 per gallon, not sure what LP is going for but I’m so thankful for the kuuma, who knows what heating fuel will be going for next year.

 

[JRHAWK9]

Wow that’s crazy, our winters aren’t nearly that bad here in NE Maryland. I talked to my buddy today who delivers heating oil it’s going for over $6 per gallon, not sure what LP is going for but I’m so thankful for the kuuma, who knows what heating fuel will be going for next year.

LP here is not too bad. It was much worse the winter of 13/14. It actually went down to $2.25 (from $2.35 at the highest) when I just called to check the price yesterday. I call every month during the heating season just to keep track.

I don't call the months of June through September, so the graph below just connects May to October.

 

[JRHAWK9]

Wow that’s crazy, our winters aren’t nearly that bad here in NE Maryland.

The very first winter we had the Kuuma we had a somewhat of a warm couple of days in early March and figured that was going to be it for burning so I shut it down and took apart the stove pipe to see how it looked. I was a bit antsy to look at the chimney. Well, the LP furnace ended up running for 200 hours the rest of the heating season.

 

[salecker]

Wow that’s crazy, our winters aren’t nearly that bad here in NE Maryland. I talked to my buddy today who delivers heating oil it’s going for over $6 per gallon, not sure what LP is going for but I’m so thankful for the kuuma, who knows what heating fuel will be going for next year.

Heating oil was $1.54 a liter here plus $.1341 a liter carbon tax plus 5% GST comes to $5.34 a US gallon so i don't feel as bad as I did about charging these prices.The highest it's ever been.