Kuuma Vapor Fire 100 Recommendation?

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Tyler Pullen

New Member
Jan 19, 2021
4
Cadillac, MI
I’m pretty convinced the Vapor Fire 100 is the right route for me to go but want some input from other users and users with similar conditions.

I live in a 2 story 1400 sft turn of the century (1900) farmhouse in Cadillac, Michigan. The house is not tight construction and never will be sealed like new construction. The walls are 4” studs with 1” thick boards on both sides. There is old blown in insulation between studs. The attic is not yet reinsulated but that I planned on doing 2 layers of fiberglass batts. (Long story short, we had a bat infestation and had to remove all old insulation and clean attic). There are almost all newer double pane windows. 8’ ceilings on first floor, 6’ 8” ceiling on 2nd floor. The basement is a stone and mortar wall, concrete floor, exposed joists unfinished basement for half of footprint and crawl space type in other half.

I heat with a quadrafire wood stove in the living space. It is definitely not a whole house heat when the temps dip below freezing. It can heat downstairs 800 sft fine. But being a wood stove it really does not distribute heat well.

We have duct work that is currently connected to a propane furnace. This is our backup if we go on vacation. In the short time I run the furnace, the ducts seem adequate. There are return ducts on 1st floor in center of house and supplys on exterior walls. The second floor has only 2 supplys and no returns. Are there any red flags i should look for in suct

I don’t plan on having a backup propane furnace right away for 2 reasons. I would need to create a new chimney for this old one or get a new high efficiency furnace with PVC stack. Also duct work is new for me so it seems challenging enough just to get the VF100 hooked up stand alone.

First question is the chimney. I know I won’t know 100% til it is set up but here it goes. We have an outside brick chimney, about 25-30 ft tall from where stove pipe would enter it. It is currently lined for our old propane furnace so I will be relining for wood furnace. I plan to use an insulated flexible liner. Does it seem likely that draft will be sufficient with the good height and using insulated pipe? The chimney extends 2 ft past peak of the house and no obstruction/trees anywhere near it.

Since we live by the Great Lakes we don’t get the Arctic blasts to the extremes that they seem to get in places like North Dakota and Minnesota. But it occasionally gets brutal and I’d like to be sure it’s going to give me some decent burn times and be able to kick out enough heat when needed. I hear slow steady, even heat output and I wonder if it can run a little harder when needed? I don’t want to be in the situation I am now of really struggling to heat when it goes below 0.

My wife is home most of the time so she keeps fire going when I’m at work. She doesn’t like messing with air controls on our stove so the automatic draft control on VF100 is very exciting. Also with longer burn times she shouldn’t have to load it as much.

Last question. I feel that I will miss the wood stove in the fall and spring since that takes the chill off quickly and with very little wood. Is VF100 straight up not good to run for short burns on shoulder seasons? I planned on putting a wood stove back some day but that’s another story.

I feel like I’m overthinking this but it’s a big commitment and I want to spend money wisely. Also I’m sold on kuuma’s customer service already. You don’t see that much anymore.

Thanks for any input!
 
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sloeffle

Minister of Fire
Mar 1, 2012
859
Central Ohio
I don’t plan on having a backup propane furnace right away for 2 reasons. I would need to create a new chimney for this old one or get a new high efficiency furnace with PVC stack. Also duct work is new for me so it seems challenging enough just to get the VF100 hooked up stand alone.
You might want to talk to your insurance company before you completely remove the propane furnace. Most insurers won't insure your residence with wood as the primary heat source. You would be without central A/C also. I know where you are at doesn't get as warm as Ohio but I'd guess it gets as humid due to the Great Lakes. I'm sure glad I have A/C when August rolls around.

How's the sledding been this year up there ?
 
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brenndatomu

Minister of Fire
Aug 21, 2013
6,428
NE Ohio
Yeah I would re-think pulling out the LP furnace too...even if you need to swap out to an HE LP furnace. Or you could put up another chimney using stainless double wall chimney pipe for the VF100? Your existing chimney should be fine if it has an insulated 6" liner in it by the way.
The best way to do this is to tie the VF into the ductwork of the LP furnace...or tie the LP furnace into the ductwork of the VF, as I did...you will need to get an HVAC guy in there to do it if its not something you are familiar with.
As far as shoulder season...I'd leave your wood stove in place...the VF can do small loads on warmer days, but as with any wood burner, you almost need to fill the firebox to a certain point to really get things working properly...and if you are doing small loads once a day, (even twice) you very well may be doing cold starts each time. It gets old...better to burn a load in the stove upstairs, or just throw the LP guy a bone and burn a bit of that...
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,691
Wisconsin Dells, WI
I second what brenn says, I would also leave the wood stove in place. I think you may regret removing it if you do. We have a traditional fireplace upstairs which we have not used since putting in the Kuuma back in '14, but I wish we had an insert in place of it. It would be nice during the shoulder seasons. In your case, it may also come in handy during those real cold nights when you can run both the Kuuma and the stove at the same time. It sounds like you may have a bit of a higher heat load, so I would not handicap yourself in terms of your ability to produce BTU's. ALL EPA furnaces don't have the raw BTU output of the older ones. They have much more consistent heat output over longer times and burn less wood, but they don't put out as much peak BTU's. If I were you, I would do what other's have mentioned and do it right the first time to try to avoid any "I wish I would have done it differently moments" that would end up costing you even more money later. I'd put in a HE LP furnace at the same time and leave your stove the way it is. I think this setup would be best long term. It will cost more, but it's the ole "cry once" approach. The uninsulated old stone basement would concern me. I'm betting it gets pretty cold down there and never really warms up. Our family's homestead has the same type of basement. I think it would be a necessity to have your cold air hooked up to the Kuuma in this situation. I think your current return ducts are fine.

As far as chimneys. If your current stone one is lined for the LP furnace, what is your current wood stove using for a chimney? Sounds like you could leave your current wood stove in place and have the chimney being used by the LP lined for the Kuuma??? If this is the case, I would not touch the wood stove setup.

As far as running the Kuuma during shoulder seasons. It's fine, you just need to load accordingly. It all depends on the heat load of your home though too. You may enough heat load where you need to put in a decent sized load and run it on low.

Like I said though, I would highly suggest having a HE LP furnace as backup and keeping your current stove for the shoulder seasons and those real cold nights just in case the Kuuma can't do it all. It's easier & cheaper to do it right the first time vs having to go back and re-do things after the fact.....especially if you are having to re-do something that was originally in place.

Wood.......you will need DRY wood. I'd start cutting/splitting/stacking NOW to build up 3-4 years worth to get ahead so you are burning DRY wood.
 

Tyler Pullen

New Member
Jan 19, 2021
4
Cadillac, MI
You might want to talk to your insurance company before you completely remove the propane furnace. Most insurers won't insure your residence with wood as the primary heat source. You would be without central A/C also. I know where you are at doesn't get as warm as Ohio but I'd guess it gets as humid due to the Great Lakes. I'm sure glad I have A/C when August rolls around.

How's the sledding been this year up there ?

Yes I had thought about insurance. We have no insurance right now anyway because they wouldn’t insure a house with siding they say may have asbestos in it. I may just never get insurance. That is a whole different story.

I’m not worried about A/C. We have one window unit that keeps the first floor cold when we need it. It’s not very often.

There’s lots of snow this year. Its been great for winter sports!
 

Tyler Pullen

New Member
Jan 19, 2021
4
Cadillac, MI
I second what brenn says, I would also leave the wood stove in place. I think you may regret removing it if you do. We have a traditional fireplace upstairs which we have not used since putting in the Kuuma back in '14, but I wish we had an insert in place of it. It would be nice during the shoulder seasons. In your case, it may also come in handy during those real cold nights when you can run both the Kuuma and the stove at the same time. It sounds like you may have a bit of a higher heat load, so I would not handicap yourself in terms of your ability to produce BTU's. ALL EPA furnaces don't have the raw BTU output of the older ones. They have much more consistent heat output over longer times and burn less wood, but they don't put out as much peak BTU's. If I were you, I would do what other's have mentioned and do it right the first time to try to avoid any "I wish I would have done it differently moments" that would end up costing you even more money later. I'd put in a HE LP furnace at the same time and leave your stove the way it is. I think this setup would be best long term. It will cost more, but it's the ole "cry once" approach. The uninsulated old stone basement would concern me. I'm betting it gets pretty cold down there and never really warms up. Our family's homestead has the same type of basement. I think it would be a necessity to have your cold air hooked up to the Kuuma in this situation. I think your current return ducts are fine.

As far as chimneys. If your current stone one is lined for the LP furnace, what is your current wood stove using for a chimney? Sounds like you could leave your current wood stove in place and have the chimney being used by the LP lined for the Kuuma??? If this is the case, I would not touch the wood stove setup.

As far as running the Kuuma during shoulder seasons. It's fine, you just need to load accordingly. It all depends on the heat load of your home though too. You may enough heat load where you need to put in a decent sized load and run it on low.

Like I said though, I would highly suggest having a HE LP furnace as backup and keeping your current stove for the shoulder seasons and those real cold nights just in case the Kuuma can't do it all. It's easier & cheaper to do it right the first time vs having to go back and re-do things after the fact.....especially if you are having to re-do something that was originally in place.

Wood.......you will need DRY wood. I'd start cutting/splitting/stacking NOW to build up 3-4 years worth to get ahead so you are burning DRY wood.

Thank you for your response.

Sounds like I should save another year and I’ll put in a HE LP furnace along with Kuuma all at once. Probably just pay a professional to do it at that point.

The wood stove has a good class a chimney but I do not like the location and installation. So that is going to move anyway. It goes through the wall and you the side of the house and through the rafters. It drafts okay but it probably should be a little taller.

Wood won’t be a problem. I live on 80 acres of a lot of hardwood and some softwoods. I’m always a year head ahead and have never burned wet wood. Chimney only has ash dust on it whenever I clean it. I never have trouble starting firesThat being said, I have never checked it with a moisture meter.
 

brenndatomu

Minister of Fire
Aug 21, 2013
6,428
NE Ohio
Sounds like I should save another year and I’ll put in a HE LP furnace along with Kuuma all at once.
You might re-consider this if there is any way you can swing it...as there is 26% tax credit that can be applied to the purchase and install of a VF100 this year, goes down next year...still 22% though...maybe buy the Kuuma this year (December?) then have it put in early next year?
If you have a local HVAC shop do the install, and buy the HE LP from them too, maybe the whole thing would qualify for the tax credit? (HE LP furnace purchase was neccasary part of install due to freeing the chimney up for the VF?)
 
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Tyler Pullen

New Member
Jan 19, 2021
4
Cadillac, MI
Yeah I would re-think pulling out the LP furnace too...even if you need to swap out to an HE LP furnace. Or you could put up another chimney using stainless double wall chimney pipe for the VF100? Your existing chimney should be fine if it has an insulated 6" liner in it by the way.
The best way to do this is to tie the VF into the ductwork of the LP furnace...or tie the LP furnace into the ductwork of the VF, as I did...you will need to get an HVAC guy in there to do it if its not something you are familiar with.
As far as shoulder season...I'd leave your wood stove in place...the VF can do small loads on warmer days, but as with any wood burner, you almost need to fill the firebox to a certain point to really get things working properly...and if you are doing small loads once a day, (even twice) you very well may be doing cold starts each time. It gets old...better to burn a load in the stove upstairs, or just throw the LP guy a bone and burn a bit of that...


You might re-consider this if there is any way you can swing it...as there is 26% tax credit that can be applied to the purchase and install of a VF100 this year, goes down next year...still 22% though...maybe buy the Kuuma this year (December?) then have it put in early next year?
If you have a local HVAC shop do the install, and buy the HE LP from them too, maybe the whole thing would qualify for the tax credit? (HE LP furnace purchase was neccasary part of install due to freeing the chimney up for the VF?)
You might re-consider this if there is any way you can swing it...as there is 26% tax credit that can be applied to the purchase and install of a VF100 this year, goes down next year...still 22% though...maybe buy the Kuuma this year (December?) then have it put in early next year?
If you have a local HVAC shop do the install, and buy the HE LP from them too, maybe the whole thing would qualify for the tax credit? (HE LP furnace purchase was neccasary part of install due to freeing the chimney up for the VF?)

Gotcha that’s a good idea. Thank you.
 

woodey

Burning Hunk
Feb 8, 2018
208
ST. Lawrence Valley N.Y.
I also have no issues heating in the shoulder season with the Kuuma. When stacking the seasons wood in the basement I have a separate stack for the driest pieces just for this purpose. I put on smaller loads, set the computer on low and when it gets close to the coaling stage shut of the computer and let it cruise on pilot. I find that even on pilot the blower will still occasionally kick in.
 
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woodey

Burning Hunk
Feb 8, 2018
208
ST. Lawrence Valley N.Y.
Just throwing this out there to Kuuma owners to see what they think. By employing the above techniques in shoulder season, with the cooler plenum temps would it make sense to lower the setting on the lower limit switch. I'm probably over thinking things here!!
 

brenndatomu

Minister of Fire
Aug 21, 2013
6,428
NE Ohio