Kuuma Vaporfire in Mild Weather

Thank you Matthewchopswood that’s helpful. My wife is concerned that she can’t control the temperature with the thermostat like usual, so working on that next. I so appreciate the help and input from you and brenndatomu !

 

It’s not like using the thermostat on your propane furnace. However, if you want nice level heat throughout your home and enjoy burning wood the VP-100 is a dream machine.

We have a fireplace for ambiance but the Kuuma is the workhorse.

 

Exactly...the heat is more consistent...not the "freeze then melt" you get with fossil fuel forced air furnaces...which when they run, are running full blast 80-100k BTU (more?)(unless you have one of the newer dual stage units) and satisfy the tstat in 20 minutes or so...then its off for an hour or two while things cool off...and starts to feel cold.
On the other hand, the Kuuma is steady making 30-40k BTU (just as an example...could be less) (45k is about peak I think) per hour so the temp doesn't have that quick spike...or quick drop...the temp is controlled by how high you set the Kuumas controller, and how much wood you load in too...you will quickly learn to control your house temp to within a degree or two, it really is pretty easy.
If you have a couple different zones, you could let the Kuuma handle the main heat load, then let the (gas?) furnace kinda "fine tune" things as needed...there's a lot can be done with power dampers and wifi/wireless tstat/controls these days...if you have a good HVAC tech this should come together nicely.
JRHAWK9 might have some good input here too...

 

My other half had the same concern. Every house is different, but you will come to learn how much wood to load for the outside temp. It may take some time, but you will get it figured out. Like mentioned above, with burning wood you will not be able to keep it within a half degree like you can with forced air, but Kuuma's are probably the most even heat output wood burning furnace there is.

 

Even so...it will still feel much "warmer", and after having it, your wife won't want to be without wood heat again...

 

Operating my Vapor Fire 200 has been a learning curve for me. If it is in the teens I will build a fire early morning and late afternoon/evening with usually 3 splits. I let the propane heat make up the difference. Once I get the inside temps in a comfortable range the 6000 btu propane heater will keep it there for 10 or so hours. It is such a simple stove to operate.

 

This will be my first full season on my vf100. I quickly realized it doesn’t take much wood to get cooked out of the house. I’m more used to outdoor wood boilers where you can load them full and it will produce heat in the house only if your t stat is calling for it. So tried that with mine. It wasn’t long and it was 78 in the house. I was also trying to stretch the time between reloads and not having to relight a new fire all the time.

Now it’s much easier to have less wood in the fire box to regulate heat. And just relight if needed.


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Yeah I'm still perfecting my "mild weather" SOP, but generally I can do one to two small (4 average size splits...or 20-25 lbs total) loads a day without too much trouble and keep the house ~72*...might not always be a matchless re-light, but easier than a complete "cold start" though too.

 

Never fear a relight!

 

Exactly what I’ve been using for over 30 years. Great for warming the chimney a little when necessary also on a cold light.

 

I like the gas axe!

 

same here...but not for 30 years, more like the past couple.

 

My HVAC contractor says that this is not possible if the furnaces are hooked to the same ductwork. He is not a fan of the blower fans competing with each other. If I could use the wood furnace for heat and let the propane take over as the fire cools I would be super happy as would my wife. Do you have it set up to run both blowers at the same time?

 

I do, however, it never really happens. Although I also don't have my Kuuma hooked up to the cold air. It just shares the same supply duct. The way I have things wired with multiple relays and such, my two furnaces pretty much can "dance" with each other if need be. If my LP furnace calls for heat while my Kuuma's blower is active, my relays automatically switch from the speed controller powering the high speed tap on the Kuuma blower to the full 120V on the low speed tap on the Kuuma blower. My LP furnace is using the low speed tap on it's blower as well when heating, so the SP in my supply ducts is not crazy high. Here's a very crude wiring diagram of how I have things wired up. Along with my notes and checks of different situations before I actually wired it up this way to make sure I don't here any unexpected "pops" one day. I went through all the scenerios and everything works as it should. It's been wired this way now for 2-3 years. The only thing different is I swapped a Honeywell limit control in place of my low limit snap switch.

 

Can the Kuuma be put on its own separate duct system? Even if its very basic...just dumps heat to the main areas of the house to keep the gas furnace off as much as possible...

 

Thanks for the detailed post! That's impressive! Unfortunately, I can't hook mine up like that and retain my 10 year warranty on my brand new heat pumps/furnaces.

I was thinking about a separate duct system all afternoon, and then brenndatomu suggested the same! I am going to make this happen! Not exactly sure how, but I’m gonna make it a priority.

 

yeah, there is not one install that will work for everybody.

 

Seems like there should be a way to use the existing duct work. Can you just set the propane furnaces at lower temperatures so the units are not running at the same time?

 

I like the idea of seperate wood furnace duct work. It can then run independently of the central furnace, can be designed to match the wood blower, can be built with the special rules for wood like metal only and clearance to combustibles. And it’s also completely removable since let’s face it, not every future buyer will appreciate the wood furnace.