New house, Old furnace, New Plan.

Sounds like a good plan.

Reformed smoke dragon Sierra? How'd ya do that? I know someone that has one and it needs the whip cracked on it a bit!
Never mind, I just seen your link...

Smoke Signals said:

Yeah, I should update that thread

Click to expand...

I see that...
More preheat and "insulated" firebox to keep temps up. Firebrick, and then ceramic insulation board up top. The heat is then transferred via the top plate being hotter than ever because of the superheated exhaust passing by on the way out. The added mass adds extended heat time when the fire is burning out too. 'Course, it delays heat at the beginning too, so maybe it's a wash.
A ton of time you have in the ole girl there, nice job on 'er too!

What's your square footage, insulation and how tight is your home? Those old furnaces will heat, but like you say they have an appetite.

It sounds like the Tundra would be a good match from what your saying.

Are the Kuuma and Tundra equal in efficiency? If there is a difference, would a loan be in order to upgrade and still have the return on investment? Interest on a loan for a wood burner is way cheaper than heating with propane.

Smoke Signals said:

I see the Tundra is listed as having a 22 5/8 inch deep fire box. If I cut my wood 20" will it fit ok or should I cut it a little shorter?

Click to expand...

20" should be fine

BoiledOver said:

Are the Kuuma and Tundra equal in efficiency? If there is a difference, would a loan be in order to upgrade and still have the return on investment? Interest on a loan for a wood burner is way cheaper than heating with propane.

Click to expand...

The Kuuma is gonna be a bit more efficient if for no other reason than it has a computer constantly monitoring and adjusting to optimize the fire. Is it worth that much more...only you can decide that. There is a pretty good gap between the price of those two units

Smoke Signals said:

This is a great consideration that I had not thought of and it brings about some questions on relating efficiency to actual cords of wood. One way or the other I'm going to be burning wood but the real question here is how much rite? The less wood I have to processes the better in my book but how do we measure the ROI in this situation? No matter if I go with the Kumma or the Tundra the result will be less wood burned over what I am doing now but how much? So the Kumma has an advertised efficiency of 84.4% and the Tundra weighs in at 76%. If we subtract 84.4 from 76 we come up with 8.4%. Taking and educated guess I going to say I will burn 4 cords with the tundra so if I take 4 cords times .084 or 8.4% I come up with .336 of a cord. So ruffly 1/3 of a cord. Hows this look so far? Am I figuring correctly?

Lets do a study of the economics of cord wood. The price difference between the two is about 30 truck loads of wood if they were say $100 a load (I don't buy wood, is this about rite?). As far as I can tell a truck load thrown on is real close to a face cord. So lets say the price difference is about 15 cords of wood. So burning 1/3 of a cord less per year is equal to 1 cord every three years. 1 cord every three years times 15 cords is an ROI of 45 years on the price difference. I my thinking correctly here?

Every one please mull this over, see if I am figuring correctly and let me know.

Click to expand...

Well, without actually double checking the math, sounds about right if you are looking at the $ angle solely.
Don't forget the convenience factor and/or longevity. Convenience plays big with the women folk. Anybody can run a Kuuma. Also, never hafta worry about cleaning your chimney in the middle of the winter with the Kuuma. Built to last a looong time too.
Tundra...I dunno, 10-15 year lifespan?

One other thing to consider is the Kuuma doesn't need a roaring fire to get heat, therefore it's heating curve is much flatter. It may not put out the max BTU's some other furnaces will during their 2 hour window of max BTU's, but it's putting out more even heat over that burn cycle.

The Kuuma has a computer on it which allows you to control how much heat output you want, from low to high. It has a variable potentiometer; meaning you have more than just three settings to control how much heat you want from it. It's marked low, medium and high, but you are not limited to just those three settings. The computer uses a thermocouple to determine current heat output and automatically adjusts the damper (which is also controller by the computer) for whatever rate of burn you have it set at. The hotter you have it set the more air it allows in through the damper and the more heat you will get. The draft is auto regulated by using a barometric damper which is set at 0.06" W.C. There is a two speed fan, which is controlled by an included wall mounted thermostat. When the thermostat calls for heat, the blower system automatically kicks on high. When the temperature is satisfied and the thermostat "kicks off", the blower system switches back to low where it stays until the thermostat calls for heat again. All this means you can fill it full and not worry about adjusting anything but a little dial to control the heat output you want. The burn times are dependent on what heat output setting you have the computer set as well as how much wood you put in the firebox. More wood + low setting = longest burn times. It will still be possible to overheat the house during the shoulder seasons when it's not as cold, but you can help control that by the type & quantity of wood you use during the shoulder seasons. Anything that burns hot and quick would probably be your best bet to take the chill out on those somewhat warmer days.

I will honestly tell you both furnace's compare with efficiency. Your not going to burn a noticible difference of wood between the two. The Kuuma has the advantage with the computer control, but the same results can happen with a Tundra. Neither require a blazing hot fire, both have similar flue temperatures while operating and both utilize secondary combustion and both can be controlled with a thermostat. While the Kuuma is a higher quality furnace, it should be because your comparing a 2000 dollar furnace to a 4500 dollar furnace. As far as I'm concerned, the Tundra is one of the best furnaces to hit the market dollar wise. A large 4 speed blower, secondary heat exchanger, a fully lined firebox with preheated secondary air and a large glass viewing window make it a very nice furnace. If you want something higher quality that's easier to run, thend buy the Kuuma.

laynes69 said:

If you want something higher quality that's easier to run, thend buy the Kuuma.

Click to expand...

Or you could meet in the middle, get a Caddy...

JRHAWK9 said:

One other thing to consider is the Kuuma doesn't need a roaring fire to get heat, therefore it's heating curve is much flatter. It may not put out the max BTU's some other furnaces will during their 2 hour window of max BTU's, but it's putting out more even heat over that burn cycle.

Click to expand...

Hey JR, whats the upper part of the Kuuma firebox look like? I've seen pics of the lower part. It was being discussed recently on one of these forums about the different types of modern clean burn wood heaters out there. I said there is 3 types.
1 "tube type" where secondary air is brought in above the fire.
2 gasifiers where hot air is injected at a nozzle that the smoke/wood gas has to pass through into a secondary burn chamber
3 one with a "cat". Mainly stoves as far as I know

Not sure where exactly the Kuuma falls in there. I have heard the Kuumas being referred to as the only gassifying forced air wood furnace, but I don't know?

PM sent. I will attach this photo I took this fall about 1.5 hours into a burn cycle with the computer set to the lowest setting. It's definitely not as cool as those of you who have windowed doors. It's very hard to capture the "gassification" burn, because as soon as you open the door it disrupts it. I have singed my hair a few times when opening the door in the middle of the burn (to admire the gassification taking place so I positioned my head near the opening) when the burning gases rushed out for a split second.....lol Anyway, the photo below shows the slow burn and I happened to capture just a little bit of the blue flames from the burning gases. I didn't think I got any of them as they disappear so fast after the door opens, until I checked the photo. The blue flames, from the burning gases usually always take place at the front top of the burning chamber. This is where the hot air must get injected. Judging by what I see at times, it's basically like a big ball of blue flames in that area.

brenndatomu said:

Or you could meet in the middle, get a Caddy...

Hey JR, whats the upper part of the Kuuma firebox look like? I've seen pics of the lower part. It was being discussed recently on one of these forums about the different types of modern clean burn wood heaters out there. I said there is 3 types.
1 "tube type" where secondary air is brought in above the fire.
2 gasifiers where hot air is injected at a nozzle that the smoke/wood gas has to pass through into a secondary burn chamber
3 one with a "cat". Mainly stoves as far as I know

Not sure where exactly the Kuuma falls in there. I have heard the Kuumas being referred to as the only gassifying forced air wood furnace, but I don't know?

Click to expand...

Its a combo of 1 and 2. at the front where the entrance to the secondary is, there is 2 riffled pipes. like cutting 4 inches off the barrel of a gun. so the natural draft with the damper closed pulls preheated air and shoots it in a swirling manner right at the choke point of the secondary heat exchanger. most of the gasification is in the secondary compartment that cant be seen.

Smoke Signals said:

Another very good point. Form what I have seen there is a lot to be said for the quality of the Kumma plus it's made i the US and I'm definitely not one to go for the lowest bidder by default. I will pay more for a quality product (if I am in a position to). So I guess this leads to the question of how do you quantify quality? As I laid out in my original post I'm sold on the Kumma and given our current situation (new house and have not sold the old house yet) I'm not in a position to barrow money for the Kumma. But still I would find great interest in a discussion on how to quantify or asses some measure value in terms of quality. Obviously from the manufactures end a price can be put on quality but what about from a consumers point of view? How do we put a price on quality?

Click to expand...

I bet it costs kuuma more money paying for their steel in each unit than it would cost to buy a complete tundra at the store. What does that tell you. Also not trying to bash a product, but we are comparing them. I would NEVER buy from a company that I knew, knew that they were selling units that could kill your whole family, then not take them off the shelf till they fixed the problem. It really bothers me that people recommend these units after what happened, just because there cheap.

STIHLY DAN said:

I bet it costs kuuma more money paying for their steel in each unit than it would cost to buy a complete tundra at the store.

Click to expand...

That's probably true.
I gotta say, I was surprised to see the weight on the Tundra is listed as 590 lbs. My Yukon Big Jack was 595 and built like a tank! Heavy 10 gauge metal, lots of heavy firebrick, and 2 really heavy grates. I guess the Tundra gets it's weight just because there is a lot going on there, lots of metal passage ways and chambers and whatnot. On the other hand the Yukon is pretty simple, HD firebox, with what is basically a HD barrel welded to it.

STIHLY DAN said:

I would NEVER buy from a company that I knew, knew that they were selling units that could kill your whole family, then not take them off the shelf till they fixed the problem. It really bothers me that people recommend these units after what happened, just because they're cheap.

Click to expand...

What happened?

JRHAWK9 said:

What happened?

Click to expand...

Their ash pan was in the supply air plenum. not sealed into the fire box. So all the carbon monoxide from smoldering ash's was going right into the room air. Also all the ash dust throughout the ductwork. They were notified, and while they were engineering a fix they just kept on selling them. Then there is the question of how many of them are out there that did not get the retrofit fix.

STIHLY DAN said:

Their ash pan was in the supply air plenum. not sealed into the fire box

Click to expand...

It wasn't exactly in the supply plenum. The ash pan drawer just wasn't sealed completely airtight from the blower air stream. Ash pans are not sealed on many free standing stoves, pretty common, I guess the blower was causing enough turbulence to stir things up and cause problems on the Tundra though.
I thought they halted sales until the fix was available? And from what I understand all registered owners were contacted and even a lot of unregistered owners were tracked down.

STIHLY DAN said:

It really bothers me that people recommend these units after what happened, just because there cheap.

Click to expand...

I'm fortunate in the fact my wife and I make a good living, and I've been in the opposite situation. Our economy is not well, and many people can't afford to heat their homes on their wages. It's easy to say buy the best, but for many even a 1000 dollar furnace is too much. Many can't do financing either for one reason or another.

SBI produces thousands of stoves and furnaces every year. With the volume of business they do, they don't pay what others pay for their supplies. If Kuuma produced the numbers others produced, I'm sure their prices would be lower.

As far as a Tundra killing you, the company wouldn't do something like that deliberately. It was unfortuate, but they took care of the problems. No company would stay in business otherwise.