new Vapor Fire 100 with very poor heat

[gary38532]

I think I understand way people give up on them now.

 

[brenndatomu]

On who?

 

[gary38532]

On who?

The VF100

 

[JRHAWK9]

The other think is that when dealing with cathedral ceilings, you have to consider cubic ft too, not just sq ft.
JRHawk and I have similar sized houses, but he has cathedral ceilings, I don't...between that, and less HDD here, I don't have to run mine as hard as he does.

yep, not only cathedral, but a pretty tall peak (25' I believe) seeing it's a 12/12 pitch roof. Although I only run it harder when it gets below zero for extended periods of time, as that's when this house becomes harder to heat Back when we had that 7 day stretch last January of 70 - 84 HDD's I was burning as much wood as fast as I possibly could with it. I do load on more coals and increase loading size when it gets around 20° or so, but I still leave it on minimum burn. About 20° daily average (~45 HDD's) is about when I can keep it on minimum burn and start to leave a healthy fire going 24/7 and load on, what I consider, a perfect amount of coals so the Kuuma goes back to pilot relatively quickly. In temps over 25°-30° or so I can't do that, the house will get too warm. I weathered a couple single digit night lows in a row a couple weeks ago with leaving it on low. The point where I need it to consume wood faster so I can load more wood is when I take the Kuuma off low. Hasn't happened this year yet though, except those few times when I previously loaded too much and needed to load again (to leave for work or go to bed) and needed to burn the coals down in order to do so.

Like I've mentioned before though, before my cold/warm air supply tweaks, the house did not heat as easy as it does now, at least in temps above 10° or so.

 

[JRHAWK9]

That doesnt help at all...and where is the Kuuma placed in that 70'? Middle?
Heat loss to the ducts can be significant, especially if they run through cooler (or even worse, unheated) spaces...that can make a bunch of heat just "magically disappear" in a hurry!

That's another strike we have here. The Kuuma is on the -very- north end of the house, luckily the house has a 32'x42' footprint, so it's probably not too big of an issue.

 

[SpaceBus]

There is clearly something happening that is not being factored into the equation. My has no insulation in two corner bays, most of the band joist on the first floor, and four sliding glass doors but I can keep it warm with a 31k btu (definitely not into the house) wood cookstove once the house is up to 70df with temps in the 20's outside with wind. At night the 35k btu (Edit: this is peak, nominal is more like 27k BTU) Morso 2b classic can do the job on soft woods with temps above 20df. Any colder and I load it up with birch if I don't want to wake up and feed it. I brought in a wheel barrow of several years aged hard maple for the upcoming cold front, but that should last me weeks.

 

[JRHAWK9]

When you bought the furnace from Lampa, did they say it would be able to heat 2800 sq ft in your heating zone ? @JRHAWK9 or @brenndatomu please correct me if I am wrong, but wouldn't that be at the high end of what a Kuuma could handle ?

I think the Caddy and Kuuma are "similar" in size. I'm heating a smaller house that has pretty good insulation and I have less HDD's than you do and there is no way it would be able to heat 2800 sq ft with temps below 20 - 25F. When temps are below 10F or so my Caddy can keep the house at 70 - 73F but I need to check it more often and usually have to fill it on a pretty healthy coal bed.

I believe Daryl (the owner) has a 30 year old Kuuma heating his personal home way up in N MN where it's always COLD. I believe he's heating ~3,000SF (IIRC) and he told me he hardly has to take it off low. He admits though, his house is sealed and insulated very well.

 

[moresnow]

I brought in a wheel barrow of several years aged hard maple for the upcoming cold front, but that should last me weeks.

Damn Talk about efficient! One wheel barrow. Weeks? Holy smokes

 

[Woodman1]

I am telling you there is no way a 2800 sq foot house could use more than 100k btu per hour unless you have the equivalent of a window open. I think there is something very basic being missed here and I am just trying to save you from a costly mistake. Think about it, what was the efficiency of the Clayton? 50% And it took 9 cords to heat. That sounds more like a mid 20k btu average over 180 heating days

 

[brenndatomu]

I think I understand way people give up on them now.

On who?

The VF100

I've only ever personally heard of 2 people "giving up on them"...and they both openly admitted that they had big ole leaky houses and just didnt do their homework on what it was gonna take BTU wise to heat the place...the one went to a OWB then, the other back to gas (I think)

 

[brenndatomu]

I believe Daryl (the owner) has a 30 year old Kuuma heating his personal home way up in N MN where it's always COLD. I believe he's heating ~3,000SF (IIRC) and he told me he hardly has to take it off low. He admits though, his house is sealed and insulated very well.

Yeah, they are up there where they are lucky to have the ice all melted by Memorial day, and to be able to swim by the 4th of July!

 

[JRHAWK9]

I've only ever personally heard of 2 people "giving up on them"...and they both openly admitted that they had big ole leaky houses and just didnt do their homework on what it was gonna take BTU wise to heat the place...the one went to a OWB then, the other back to gas (I think)

Yep, it's hard for anybody to know a heatload when the house owner doesn't know it.

I think there is something very basic being missed here and I am just trying to save you from a costly mistake.

I've always wondered if it's a return air issue. When I played around years ago and disturbed my return air to the furnace, it made a HUGE difference in the ability of the Kuuma to heat the house.

 

[SpaceBus]

Damn Talk about efficient! One wheel barrow. Weeks? Holy smokes

I was a bit vague there, I should have specified the one wheel barrow of maple should last two weeks only burning it at night. I burn about a half cord a month (85% spruce and fir) cooking and heating. Sometimes on heavy cooking days I have to crack a window if it's not too cold. On a day above 40 df I won't light the Morso at all. I don't usually burn hard woods in the cooker, they take longer to burn and it's usually a waste.

 

[JRHAWK9]

About 20° daily average (~45 HDD's) is about when I can keep it on minimum burn and start to leave a healthy fire going 24/7 and load on, what I consider, a perfect amount of coals so the Kuuma goes back to pilot relatively quickly. In temps over 25°-30° or so I can't do that, the house will get too warm.

Case in point....low last night of 15° and a high today of 25° and cloudy (45 HDD).....Kuuma is about 2.5 hours from being re-loaded.

 

[moresnow]

I've always wondered if it's a return air issue. When I played around years ago and disturbed my return air to the furnace, it made a HUGE difference in the ability of the Kuuma to heat the house.

Elaborate on the "disturbed" return air please!
Are you guys using warmed upstairs return air? Or cold basement floor air?

 

[maple1]

The insulation guys just left and said there is not much they can really do to make it any much better. They said the best they could do was to inject all the walls in the home for about 10k but he said after you spend that and fix the drywall he said it wont have any "wow" differences. He said in his opinion the furnace is just under powered for the home.

Sounds like no blower door test or no thermal imaging? They just looked and did a visual assessment?

I think I would term it more like, too much heat loss that is overpowering the furnace. Looking back at just the quick IR pic you posted a couple pages back, I think I see lots of heat signature. If you had a qualified auditor available who could do a blower test or proper imaging, I think that would tell the tale. But maybe you don't?

 

[gary38532]

Sounds like no blower door test or no thermal imaging? They just looked and did a visual assessment?

I think I would term it more like, too much heat loss that is overpowering the furnace. Looking back at just the quick IR pic you posted a couple pages back, I think I see lots of heat signature. If you had a qualified auditor available who could do a blower test or proper imaging, I think that would tell the tale. But maybe you don't?

no I all ready looked into it no one around here has even heard of a blower test.....

 

[JRHAWK9]

Elaborate on the "disturbed" return air please!
Are you guys using warmed upstairs return air? Or cold basement floor air?

I don't have my return air hooked up to the main house duct, done for a reason. My furnace room is in an enclosed area of the basement, so I can shut the door and have it enclosed (not completely air tight). Back then I was pulling the cold air off the basement floor.
Back years ago when I was experimenting with trying to warm up my return air I closed that door wanting to see what would happen overnight if I got that room heated more than it already was. So I basically totally disrupted the natural cold air down the staircase and into the furnace room flow. It was trying to pull air from wherever it could, which was probably mostly down the open clothes chute, which extends all the way up to the loft. Lets just say it was not a successful experiment!

 

[moresnow]

no I all ready looked into it no one around here has even heard of a blower test.....

Contact your local utility/power provider. If they have not heard of it..... You are really in the sticks

 

[gary38532]

I am telling you there is no way a 2800 sq foot house could use more than 100k btu per hour unless you have the equivalent of a window open. I think there is something very basic being missed here and I am just trying to save you from a costly mistake. Think about it, what was the efficiency of the Clayton? 50% And it took 9 cords to heat. That sounds more like a mid 20k btu average over 180 heating days

Then what is going on then? Its the same setup (minus the chimmny) the old one used...

 

[gary38532]

Contact your local utility/power provider. If they have not heard of it..... You are really in the sticks

ok! I'll call them right now

 

[gary38532]

Contact your local utility/power provider. If they have not heard of it..... You are really in the sticks

They said they dont do that kind of stuff and they dont know of anyone that does. I also asked for electric use records and they said they only keep them for the past 2 years so no help there....

 

[SpaceBus]

I don't have time to read the whole thread again, but what's the firewood situation like? The Clayton probably didn't have an opinion, but the Kuuma does.

 

[moresnow]

They said they dont do that kind of stuff and they dont know of anyone that does. I also asked for electric use records and they said they only keep them for the past 2 years so no help there....

Wow. Hard to believe in todays energy conscious society.

 

[brenndatomu]

They said they dont do that kind of stuff and they dont know of anyone that does. I also asked for electric use records and they said they only keep them for the past 2 years so no help there....

Still not sure where you are exactly...North of Scranton? But here are a couple places that can probably do a blower door test...or know someone that can...at least they will know what you are talking about anyways!

Blower Door Test

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www.nepaconstructionservices.com

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