new Vapor Fire 100 with very poor heat

[ExxWhy]

I wanted to throw my 2 cents in. I know zero about wood furnaces and little about forced air systems in general, so maybe it doesn't correlate. But BTU's are BTU's I think.

I am heating a 3000 sf house that was built in 1969, so you know the insulation is weak at best. Not century home bad, but weak by modern standards. My bottom boards aren't insulated at all, the basement is drafty. Our northern Ohio weather has been similar to the OP as well. I would think our heat loss has to be similar. I am using hot water baseboard with a 140K btu rated wood boiler and storage. Burning that for 5-6 hours per day and the house is as warm as you want to set it. Optimistically I am getting 700K BTU supply.

Looking at the Vapor Fire website, looks like your furnace should put out 60K. I assume you are burning all day, so if it's really putting out that much you should be producing over a million BTU per day. And yet you are cold.

Not sure when your's was built, but looks similar vintage. I have a hard time imagining a house that is smaller than mine that has double the heat loss of mine without some obvious flaws. Leads me back to the conclusion that furnace isn't putting out the BTU's it should. On paper, how does the rated BTU output compare between this new furnace and the old one?

 

[maple1]

I wanted to throw my 2 cents in. I know zero about wood furnaces and little about forced air systems in general, so maybe it doesn't correlate. But BTU's are BTU's I think.

I am heating a 3000 sf house that was built in 1969, so you know the insulation is weak at best. Not century home bad, but weak by modern standards. My bottom boards aren't insulated at all, the basement is drafty. Our northern Ohio weather has been similar to the OP as well. I would think our heat loss has to be similar. I am using hot water baseboard with a 140K btu rated wood boiler and storage. Burning that for 5-6 hours per day and the house is as warm as you want to set it. Optimistically I am getting 700K BTU supply.

Looking at the Vapor Fire website, looks like your furnace should put out 60K. I assume you are burning all day, so if it's really putting out that much you should be producing over a million BTU per day. And yet you are cold.

Not sure when your's was built, but looks similar vintage. I have a hard time imagining a house that is smaller than mine that has double the heat loss of mine without some obvious flaws. Leads me back to the conclusion that furnace isn't putting out the BTU's it should. On paper, how does the rated BTU output compare between this new furnace and the old one?

There is a big difference. Ductwork in what we think are cold places.

 

[TCaldwell]

Unfortunately it’s not the same, transferring btu’s by water is exponentially more efficient than by air.

 

[maple1]

Don't think the integrity of the entire ductwork has been touched on yet either?

 

[JRHAWK9]

Works great for me.

This is what I did at the end of January when we had those -37° nights. I loaded 5 partial loads a day instead of filling the firebox for two of them. It helped keep firebox temps up w/o having to wait for a bunch of coals to burn down between loadings. It also helped me burn more wood per day.

 

[JRHAWK9]

Don't think the integrity of the entire ductwork has been touched on yet either?

I don't think it has. Waiting to see some temps taken at the same time at all his registers as well as plenum. Would be nice if it was in a spreadsheet showing distance from the furnace to the register so one could take that into consideration as well.

 

[gary38532]

I don't think it has. Waiting to see some temps taken at the same time at all his registers as well as plenum. Would be nice if it was in a spreadsheet showing distance from the furnace to the register so one could take that into consideration as well.

Ill get that posted tomorrow

 

[gary38532]

I wanted to throw my 2 cents in. I know zero about wood furnaces and little about forced air systems in general, so maybe it doesn't correlate. But BTU's are BTU's I think.

I am heating a 3000 sf house that was built in 1969, so you know the insulation is weak at best. Not century home bad, but weak by modern standards. My bottom boards aren't insulated at all, the basement is drafty. Our northern Ohio weather has been similar to the OP as well. I would think our heat loss has to be similar. I am using hot water baseboard with a 140K btu rated wood boiler and storage. Burning that for 5-6 hours per day and the house is as warm as you want to set it. Optimistically I am getting 700K BTU supply.

Looking at the Vapor Fire website, looks like your furnace should put out 60K. I assume you are burning all day, so if it's really putting out that much you should be producing over a million BTU per day. And yet you are cold.

Not sure when your's was built, but looks similar vintage. I have a hard time imagining a house that is smaller than mine that has double the heat loss of mine without some obvious flaws. Leads me back to the conclusion that furnace isn't putting out the BTU's it should. On paper, how does the rated BTU output compare between this new furnace and the old one?

I'm not sure if I said it or not before but the house was bulit in 1990. As far as the stove putting the BTUs out everybody seems to agree it is. I kown the duct work would get much warmer when it was hooked to the clayton but I never measured the temps back then. I didn't have a reason to do so I could make the place whatever I wanted back then too. According to what Dale from Lamppa told me he said you cant really compare the two stoves (clayton vs VF100) he said they are just too different. Ive been burning two full loads a day with it if thats any help... The house must be leaking a lot if it is... it broke 50 today outside and the house is only 69 I only see a 2 degree increase in the room temps on avg. They always drop through out the night regardless of load size, fan speed, and computer setting. 50 with the clayton going was like hell to keep the house from getting to hot... I would only put 3 or 4 logs in on days like today and still come home to 80 in the house... I just dont know what to say about it at this point... im going to move forward with air sealing it. Its the only card I have to play at this point.

 

[gary38532]

This is what I did at the end of January when we had those -37° nights. I loaded 5 partial loads a day instead of filling the firebox for two of them. It helped keep firebox temps up w/o having to wait for a bunch of coals to burn down between loadings. It also helped me burn more wood per day.

I did half loads yesterday not much of a diff on my end... still coals up and I have to wait... Im waiting right now as a matter of fact.. When its ready we are going out for dinner... when its ready... I never thought I would be waiting for the wood stove but here I am lol

 

[SpaceBus]

My stove will burn down coals pretty fast if I just open the air wide open. Perhaps put a few small soft wood splits or kindling on the coals.

 

[gary38532]

My stove will burn down coals pretty fast if I just open the air wide open. Perhaps put a few small soft wood splits or kindling on the coals.

I knew someone was going to say that lol ... Ive tried that a million times... a million ways... its takes a bout a hour or 2 no matter what. I did the 2x4 thing also... all its does is waste my fire start stuff

 

[gary38532]

to get the stove to burn down I useally wake up at 4am pull it forward and go back to bed... wake up at 5am clean up ash and pull it forward again then a shower and its ready for wood before I leave for work alot more work then the clayton was sorry to say

 

[gary38532]

I've been very temped to just throw the wood on top of the coals all ready but the Lamppa say thats bad so I dont. Kind of like being adrift in the ocean with all that water but don't drink... haha

 

[brenndatomu]

I did half loads yesterday not much of a diff on my end... still coals up and I have to wait... Im waiting right now as a matter of fact.. When its ready we are going out for dinner... when its ready... I never thought I would be waiting for the wood stove but here I am lol

Sounds like you need a whole semi load of dry pine...or some other soft wood that doesn't coal up...

 

[brenndatomu]

it broke 50 today outside and the house is only 69 I only see a 2 degree increase in the room temps on avg.

My first impression after reading this is that there has to be a ton of heat going to the foundation...basement floor, foundation, crawlspace, that's all just a 50 ton heat sink basically...heats up slooooowly, and with many BTU's put into it to gain any temp! That's why radiant floor heat is so nice in a commercial shop...someone opens the door to get a vehicle in/out, door is shut, temp is right back to normal almost instantly...because the slab is warm.
I would think that if it was just insulation issues upstairs, the indoor temp should be easily raised on a 50* day.
I just cant figure why there is such a drastic difference in the way the Clayton heated the place...almost seems like it was more than just huge BTU output (although that is part of it I'm sure)...just can't wrap my head around this one...

 

[woodey]

Looking at the pics on the install I am curious as to the reason the Baro- damper is installed at the thimble to the chimney and not closer to the furnace.

 

[Socratic Monologue]

I just cant figure why there is such a drastic difference in the way the Clayton heated the place...almost seems like it was more than just huge BTU output (although that is part of it I'm sure)...just can't wrap my head around this one...

I made a similar switch this last year: from a Hotblast 1557 to a Tundra 2.

The Hotblast heated much of 3000 sq feet, part of the basement, and a large furnace room down to zero F outside pretty easily. The HB could be run flat out, all day, without issue. It would burn any wood -- wet, dry, big, small, with bark, with dirty ice stuck to it. If it was organic and you could jam it through the loading door, it was heat. Below 20% MC? Whatever, says the Hotblast, just feed me. Ash and coal build up was not an issue -- shake the grate, hard if necessary, dump the ash pan and feed it more. Barometric damper? Nah. More air = more heat. No buildup in the flue, either -- 800F once a day to clean it out.

The T2 heats the same down to about 15F, then it struggles. Struggles slightly more if the hx tubes need a cleaning. Wood must be dry, splits not too large, and not too much bark, please and thank you. It has to stop between loads to make tea and rest. You want the house warmer now? Should've thought of that two hours ago. "Don't reload me yet," it says, "I'm an artist, not an Amazon Fulfillment Center employee. And don't expect me to burn this wood too fast -- I'll do it right, or not at all."

I'm starting to be trained by the T2, but it is a very different burning experience and still a bit odd. Also, the furnace has me sealing drafty spots and installing more cellular blinds and interior storm windows when I'm not busy resplitting all those chunks.

 

[gary38532]

Sounds like you need a whole semi load of dry pine...or some other soft wood that doesn't coal up...

Looking at the pics on the install I am curious as to the reason the Baro- damper is installed at the thimble to the chimney and not closer to the furnace.

It's closer to the furance now

 

[gary38532]

Sounds like you need a whole semi load of dry pine...or some other soft wood that doesn't coal up...

Most of my wood is mixed but it all some kind of hard wood. There is some ash mixed into it but not very much

 

[gary38532]

To be fair the Loft has been off all month... I turned it back on to make the measurement. This was about 2 hours into a full load at med with computer on c. Also distance measurements are approximated.

 

[Woodman1]

Well I think you have found your problem, and from what I can tell you knew it when you titled this thread. It's going to be hard to heat your house with those register temperatures. I00 degree plenum temperature after 2 hours doesn't sound right to me. If that is the way it is designed to operate and as good as it is going to get, I'd be reinstalling the Clayton

 

[brenndatomu]

Hmm...that plenum temp is low...but then again the return air temp is probably low too...was that blower on high or low?

 

[brenndatomu]

If that is the way it is designed to operate and as good as it is going to get, I'd be reinstalling the Clayton

It's not...if it was, this thread wouldn't have so many people reading along just out of shock, because they have never heard of a disappointed Kuuma owner before.
Like I said earlier in the thread, I've personally only ever heard of 2 people that had big ole drafty houses and had to sell their Kuuma...one installed a OWB, the other sold his to me, and went back to gas as far as I know.
But this house sure seems like it should be within the realm of the VF100 to heat...just need to figure out where things are wrong...

 

[gary38532]

Hmm...that plenum temp is low...but then again the return air temp is probably low too...was that blower on high or low?

High

 

[gary38532]

Well I think you have found your problem, and from what I can tell you knew it when you titled this thread. It's going to be hard to heat your house with those register temperatures. I00 degree plenum temperature after 2 hours doesn't sound right to me. If that is the way it is designed to operate and as good as it is going to get, I'd be reinstalling the Clayton

It gets much worse as the fire burns it's fuel up the registers are cool to touch at that point. Unfortunately puting the clayton back is going going to be hard the chimney is now only a 6in pipe... clayton needs a 8in.