# Add-On Furnace



## troxell (Oct 23, 2007)

I am thinking about getting a wood add on furnace for my house. I have heard alot about DAKA and some other brands. I was just curious as to which brands everyone suggests and doesnt suggest.


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## ktm rider (Oct 23, 2007)

I used to own a Englander add on wood/coal furnace. it worked very well but it didn't have shaker grates so it didn't burn coal that well but it worked great with wood. I had to get rid of it because when the power went out so did the heat. The blower blew almost all the heat straight into the duct work. It didn't radiate heat too well like a regular wood stove. But, then again, it wasn't designed to do that. I live WAY back in the sticks and have alot of power outages. So, I had to get a regular wood/coal stove ( a Harman Mark II) So I could have radiant heat when the power was out. I also have a big coal boiler in my garage but there again , it takes power to run the pumps. 

This is the one I had and would recommend it for sure. 

http://www.englanderstoves.com/28-3500.html


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## aandabooks (Oct 24, 2007)

I have a Daka and am very pleased with it. Especially considering the price. Under $700 from Menards. I'm on my third season and just the usual maintenance. Oil the blower motor, rope seal in the door. I run mine into my gas furnace's plenum and use the big blower on the furnace to circulate the air. 

I heat a 2000 square foot home that is well insulated with mine. I figured that it had paid for itself half way through the second season. My heat bill is half what it used to be in the winter.

This is my first woodburner and I looked at a lot of models that were way more expensive. If I had my way about it, I would like to eventually put in an outdoor woodburner. But there is a certain point where you are not saving money on heating when you drop $5000-$7000 on one.

Matt


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## wdchuck (Oct 24, 2007)

I have been using a DAKA for three winters, and it keeps up with our old, drafty farmhouse on the coldest of nights. When the power goes out, I just turn the door damper down to PFS (power failure setting), and take the external sheetmetal off(2minutes), it radiates from the basement up through the stairwells and still keeps the core of the house plenty warm. 

One thing that seems to more prevalent in newer furnaces, is a secondary burn ability, to get more heat, and use less wood, cleaner chimney, of course the price is higher, but it's something to think about. 

My DAKA ran me $500, and with pipe, it was paid for in 1-1/2 _months_ of heating.


I would not hesitate to buy another one, and use it in my garage.


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## CharlieG (Oct 24, 2007)

I would also recommend a regular wood stove. No worries about power outages and such. I experience enough power outages to realize a radiant wood burning stove is the way to go. And no additional cost of electric to power the blowers. My Hearthsone "Mansfield" model, a soapstone stove,was $4500installed, and paid for itself in two heating seasons. .It heats my home very comfortably. Keeps the oil man at bay! It is an attractive, functional stove that sits in my living room working quietly.


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## aandabooks (Oct 24, 2007)

When we were making our decision, the stoves that sit in the living room were immediately ruled out. We just did not want to take up the liveable floor space and bring the mess that comes with woodburning into the living room. I also have 3 small kids and have seen what we go through at my in-laws with the kids and their woodburner.

That being said, I'm not sure about the radiant heat issue. I have a finished basement and I have all of the ducts closed in the basement due to it being the hottest level in the house in the winter. And since heat rises it has to pass through the 1st and 2nd floor to get to the attic. We have never had the power go out with the woodburner running but the Daka's have a power failure setting that is damper half open. If the power did go out, I guess we would just go to the basement and enjoy the heat.

Matt


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## troxell (Oct 25, 2007)

Thanks for the info. I am thinking about getting a Daka this weekend to put in the basement. The question I have is how hard is it to hook in to the preexisting lp furnace plenum ?


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## wmscott (Oct 25, 2007)

*How to add on a wood furnace*

The Daka is very simular to "Hotblast" furnace I have, and it will have the same drawbacks as well. The design is horrible and inefficient and smokey. The furnace works best with a tall chimney with a strong draft, shorter chimneys with a weak draft will cause smoke to come out the air inlet on the loading door. I ended up sealing close the combustion air inlet in the loading door and just using the one in the ash pan door. The furnace like all old furnace designs will tend to over heat your house and when you cut back on the combustion air to reduce the size of the fire, the fire gets very smokey of course and soots up your chimney. I solved that problem by installing a 1 ½ inch pipe through the front of the fire box to add post combustion air at the edge of the smoke shelf. Now I can dial down my fire without smoking up the neighborhood and my chimney stays much cleaner.

On hooking up the furnace, the easiest way of doing it, is to place the wood furnace next to your gas furnace, with foot or more space in-between to prevent over heating the gas furnace from the radiant heat that the wood furnace will give off. Cut a hole into the plenum, the vent piece that connects your gas furnace to the vents above it, and install a sheet metal piece that blocks off the top of the plenum from the duct system, then using the hole you cut, run a duct to the bottom of the wood furnace on the side towards the gas furnace. You should end up with a large rectangular duck running down between the two furnaces connecting the blocked off plenum of the gas furnace to the bottom of the wood furnace. The Wood furnace should be underneath the largest duct in the duct system, cut a large square hole in the top of the wood furnace covering and in the duct above and connect with a sheet metal plenum. The idea here is to put the wood furnace in series with your gas furnace, with the connecting ducts being large enough not to restrict the air flow. This is the simplest and best way to add on a wood furnace. The control system is simply to wire your gas furnace fan to a fan control switch installed in the wood furnace plenum. If you wish to be able to run the furnace without electricity, install a bypass duct that runs from the cold air return duct to wood furnace with a slide in damper which is only removed when you are operating the wood furnace without electric power. When the side in damper is removed, the air from the cold air return is directly connected to the bottom of your wood furnace and with a large plenum you can probably heat your house pretty well without the fan to move the air. 

The above is the best way of hooking up a hot air wood furnace, but, it does require that you are rather good at sheet metal duct work. They do sell prefab duct parts and you can make a large plenum by putting two or more smaller ducts together as one. Otherwise the quick and dirty way to add on one of the cheap wood furnaces is to use 6 inch round duct and just connect the hot air from the wood furnace into the duct work, and tie the fans of both furnaces together electrically so they both run when either one runs. (stupid, stupid, stupid) That is how they will tell you to do it, and it can work, but wastes power and has big problems if one fan has much stronger 'push' than the other. If your gas furnace fan has higher out put air pressure than the fan on your wood furnace, it will push the hot air backwards right out of the fan housing on the wood furnace and you would end up heating the basement instead of the upstairs. Which is why the series hook up is the best, it takes more work to set up, but avoids lots of problem and doesn't waste power running two fans.

I also will recommend that you shop around on the internet for a better wood furnace, DAKA is cheap junk and will waste a lot of wood. A better furnace will give you the same heat for half the wood and will not be smokey. The only two draw backs are higher cost and they need electricity to run. Check out Yukon's "Wood Jack" add on wood furnace. "Woodchuck" is nice too and burns coal also. Always look for furnaces that have "post combustion air" or don't buy one.

Sincerely Yours; Wm Scott Anderson


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## troxell (Oct 25, 2007)

When I was looking at the daka furnaces at Menards they also had a Norseman brand that seemed similar in construction but cost a few hundred more. Was just wondering if these are any better or had any advantages/disadvantages ?


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## wdchuck (Oct 25, 2007)

troxell said:


> Thanks for the info. I am thinking about getting a Daka this weekend to put in the basement. The question I have is how hard is it to hook in to the preexisting lp furnace plenum ?




It can be done with standard ductwork parts from the store, the DAKA installation guide/pictures are on their site in PDF form. Having some of the sheetmetal forming tools that the hardware store sells makes the job easier and neater, but you can get away with snips and real foil tape, better to take the time to do the best job you can, or get help for the duct hookup anyway.

It really isn't that difficult, just measure three times and cut once, have a few extra pieces so you don't have to run to the store if you make a mistake.

Good luck, stay warm.


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## shaunbagone (Oct 25, 2007)

Whats the difference in foil tape and duct tape?


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## wdchuck (Oct 25, 2007)

The difference between the two is, foil tape is real duct tape, excellent adhesive qualities if applied to a clean surface, doesn't dry out, and has better thermal tolerances.

Duck Tape, is a mesh material with an adhesive strip married to it, really quite useless as duct tape. 

I have not seen foil tape at Menards, but Home Depot carries foil tape.


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## aandabooks (Oct 25, 2007)

wmscott,

What kind of wood are you running in yours to end up with a lot of smoke? I run oak, locust and elm through mine. Starting this season with some maple and cottonwood that was in the pile. The only time mine smokes alot is when I am blazing the fire in the morning after work and that also serves to clean out the pipes. When I run the damper down with a full load of wood in, there is little smoke from the chimney. I usually shut it down in January and clean the chimney. Then again either after the season or before the next season of burning. 

I have a 33 ft. clay lined cinder block chimney that drafts unbelievably well. The only problem that I had in the beginning was loading enough wood in for the night without having smoke coming out the door. I figured out that if about 5 minutes before loading I open the ash pan and damper it cuts down on the smoke. 

Matt


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## wmscott (Oct 26, 2007)

Matt;

I burn mostly hardwoods, oak, Hickory, etc. I also burn some paper to get the fire going and also use twigs. With the Hotblast, cutting down the air, results in incomplete combustion, as it does in any furnace without post combustion air. What helps is to burn the fire hot and then dial down the air intake, with the fire down to coals, the smoking isn't that bad even without post combustion air. So the biggest problems with smoking I had was adding wood to a fire and having to dail it down right away, like for the night. The new wood in the low oxygen fire would of course smoke quite a bit. Or just putting in way too much wood, and having to cut back on the air with a fire that is still getting up to speed. The part of wood that burns first in a fire is the part that makes the most smoke if there isn't enough air, the part that burns last, is not as smokey and reducing the air to a fire that is down to hot coals is not going to create anywhere as much smoke as cutting the air to a new fire.


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## Moddoo (Oct 26, 2007)

aandabooks,
I agree with your post.
I am running a similar design furnace built by Johnson Energy Systems.
I have a very similar chimney but mine is about 22ft.
Mine stays very clean, with only a bit of 'corn flakes" to pull from the cleanout about once a month.
Opening the door slowly or the ash pan trick work very well for me too.
Sometimes I like a little bit of oak smoke in the house though! Smells great.
I don't know how efficient these things are, but mine seems to heat the house pretty well without using too much wood.
My firebox is fairly large @ 30"x20"x18".
This makes it best when you have a large fire going.
But, small fires work well too.
It will burn for 12+ hours when it's below zero.

I altered my built in blower damper so that it will gravity heat when the blower is off. this helps cut down on the amount of time the blower runs, and probably makes it a little more efficient

wmscott-
Adding a lot of wood and immediately damping it down is when mine gets smokey too.
I have learned to get good coals going and if I need to fill her up, let it burn for a bit after its full to get the new stuff starting to coal.

I have tried to carefully stack mine full with the idea that fresh pieces will fall onto the coals as they are consumed. with limited success.


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## wdchuck (Oct 26, 2007)

aandabooks said:


> wmscott,
> 
> I have a 33 ft. clay lined cinder block chimney that drafts unbelievably well. The only problem that I had in the beginning was loading enough wood in for the night without having smoke coming out the door. I figured out that if about 5 minutes before loading I open the ash pan and damper it cuts down on the smoke.
> 
> Matt



I'd like to know the internal size of your chimney, round or square, what are the dimensions in inches.

Mine is chimney blocks, with an internal measurement of 11"x11" by about 40' tall through the center of the house, and the draft is only good during perfect conditions, and I would consider it barely acceptable the rest of the time. A low pressure system or high winds really mess it up. 

Is it possible that it's too big and the heat from my furnace is insufficent to push the cold air up/out?


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## aandabooks (Oct 26, 2007)

wdchuck,

Mine is 7x7 square clay liner from the floor to the top of the chimney. The pipe from the stove is in the chimney about 4 feet off the ground. Makes a good angle from the back of the woodburner to the hole for the pipe. You may have too much volume in you're chimney if it is not drafting well. Mine flows right up and I have very little creosote at the top of the chimney. So far I have never taken more that 4 gallons of creosote out of the chimney and pipe for a full season.

Matt


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## Moddoo (Oct 26, 2007)

aandabooks said:


> wdchuck,
> 
> Mine is 7x7 square clay liner from the floor to the top of the chimney. The pipe from the stove is in the chimney about 4 feet off the ground. Makes a good angle from the back of the woodburner to the hole for the pipe. You may have too much volume in you're chimney if it is not drafting well. Mine flows right up and I have very little creosote at the top of the chimney. So far I have never taken more that 4 gallons of creosote out of the chimney and pipe for a full season.
> 
> Matt



I have pretty much the exact same setup.
Never any draft problems, and I have 40 & 60 ft trees close to the house.
I burnt a lot of not so seasoned wood last year, and creosote was about the same as yours. Probably about a 1/2 gal a month.
Plenty of nice dry wood this year.


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## aandabooks (Oct 26, 2007)

I kind of screwed up last year though. I can get wood through work. Most of the time I take home a pallet of 3x3 cottonwood boards that are 63". Cut them in thirds and burn them to start the fire or first thing in the morning. Then add split wood. Last year I brought home 2-3 big, 4x3x4 ft, boxes of cut-offs from our pallet woodshop. All 2x6 or 1x4 cutoffs of pine. Ran those through the woodburner and I'll never do that again. Bad creosote and more handling than it was worth.

Matt


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## wdchuck (Oct 28, 2007)

Picked up some 6" black smoke pipe a couple weeks ago, to run down my chimney and hook up to the stove pipe, it sounds like that will increase my draft to a sufficient level. If this does what it should then I'll look into more permanent measures the following year. 

Thanks guys.


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## shaunbagone (Oct 28, 2007)

about buring palletts. I have been cutting up pallets and using them to start my fire. Is this a bad idea? Or am I ok as long as I dont use them constatly. I just started using this furnace last week (its new.)


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## shaunbagone (Oct 28, 2007)

Another question about my new DAKA. I installed it in my garage and have the 2 8" ducts ran to my furnace in the basement. Once the duct goes in the house I used the insulated flex duct up to the furnace then went back to steel to 90's pointing up inside the plentum. I ran a intake duct stubbed into my basement wall so Im not pulling air out of the garage. The intake duct is only 6". Should I install a larger one? Or maybee 2 6" ducts? Its been going all day today and right now its about 35-40 outside and 71-74 inside. Working good but seems like it could be better. Anything wrong with using the flex ducts? Thanks in advance.


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## Moddoo (Oct 28, 2007)

I would run 2 x 8" for your intake if possible.
The colder it gets, the more flow you will wish you had.
You get a big fire going and you want that heat in the house asap.
I have a large 1/3 hp blower on mine with an 8" x 16" opening from my cold air return ducted to the blower, and 2 x 8" rounds into the main trunk like you.
It works well for me.


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## sefh3 (Oct 28, 2007)

OK guys I need your help. I'm have a wood stove Grizzly (I believe) from TSC hook up to a fuel oil furnance. The wood stove runs for about 30 sec then shuts off. Both stoves have blowers on them. I have the wood stove hooked into the plantum and a 6" duct going the the chimey. The problems that I'm having is that the stove runs for a short period of time then shuts off and I go through alot of wood in the winter. Do I have it hooked up wrong or do I need another thermostat because I have two blowers? Or do I eliminate one of the blowers and just use the one off the furnace? Thanks


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## Moddoo (Oct 28, 2007)

sefh3 said:


> OK guys I need your help. I'm have a wood stove Grizzly (I believe) from TSC hook up to a fuel oil furnance. The wood stove runs for about 30 sec then shuts off. Both stoves have blowers on them. I have the wood stove hooked into the plantum and a 6" duct going the the chimey. The problems that I'm having is that the stove runs for a short period of time then shuts off and I go through alot of wood in the winter. Do I have it hooked up wrong or do I need another thermostat because I have two blowers? Or do I eliminate one of the blowers and just use the one off the furnace? Thanks



Maybe start a new thread with some decent pics of your setup.

Somebody will be able to help with more info.


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## shaunbagone (Oct 28, 2007)

Yea, after I thought about it im taking in about half the air that im expecting it to put out. So I should assume that I should atleast have 2 8" intakes? Do you think that this will significanly help the heat output into the house?


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## wdchuck (Oct 28, 2007)

shaunbagone said:


> Another question about my new DAKA. I installed it in my garage and have the 2 8" ducts ran to my furnace in the basement. Once the duct goes in the house I used the insulated flex duct up to the furnace then went back to steel to 90's pointing up inside the plentum. I ran a intake duct stubbed into my basement wall so Im not pulling air out of the garage. The intake duct is only 6". Should I install a larger one? Or maybee 2 6" ducts? Its been going all day today and right now its about 35-40 outside and 71-74 inside. Working good but seems like it could be better. Anything wrong with using the flex ducts? Thanks in advance.




Flex duct is a last resort, it really reduces flow, by creating turbulence in the pipe, another thiing to keep in mind is, each 90* elbow is like adding 10' of straight pipe, so try to work with other methods for better flow.

THe DAKA installation manual describes a 10">8">6" to the cold air intake on the fan, follow their instructions, it makes quite a difference. 

I removed 100' of flex duct from my system, installed rigid duct from the store, much better velocity at the registers.


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## aandabooks (Oct 28, 2007)

I run 2 8" ducts into the plenum of the furnace from about 3' away. They go straight up from the Daka to the level of the plenum, turn 90 degrees and head into the plenum. 

On the gas furnace, I have a secondary thermostat for the blower installed in the plenum. It is a Honeywell snapdisc control and it is set so that the blower on the furnace doesn't kick on until the plenum reaches 90 degrees. There is also a top level. I use this so that the blower on the gas furnace doesn't kick on when the air in the plenum is too cold and defeats the woodburner by sending cold air through the house. 

The snap disc controller that comes on the Daka is set to turn on when the air jacket reaches 110 degrees and is not adjustable. With the temperatures only being in the 30s at night and 50s during the day here in Central Illinois, I haven't even had the blower on the gas furnace on. Just moved the temperature setting up to 150 and it won't come on.

Matt


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## shaunbagone (Oct 28, 2007)

Thanks for the advice. I thought maybee I was getting turbulance from the flex pipe. The ducts run about 6 ft. to the wall then another 15 ft. inside the basement to the plentum. There are quite a few bends along the way. If I replace the flex with rigid and add bigger intake I should see a good result. As for now im OK but I guess its just something to play with until I get the results I want. I love the garage being warm!!


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## aandabooks (Oct 29, 2007)

shaunbagone,

In the Daka book it says that the units are not to be put in a garage. What did you do to yours to make it safe for garage operation? I had thought of doing it anyway just for convenience but running the pipes to the basement would be a serious problem. Now I'm looking for a small woodburner to put in the garage. Not for all the time heat but just to fire up about an hour before I want to work in the garage.

Matt


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## shaunbagone (Oct 29, 2007)

aandabooks,

I called the company to ask why I couldnt put it in the garage. Daka told me many people use them in a garage and there was no problem with that. Sounded more like a liability thing to me. Also depends on what your insurance company thinks about it. I havent had my ins. guy out yet.


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## troxell (Oct 30, 2007)

When you hook up the daka to your existing furnace and use the big furnace blower on the existing, do you need someone kind of a backdraft damper in the ducts going from the woodburner to the exhisting so the blower doesnt create cold air and cut out your small blowers warm air ?


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## wdchuck (Oct 30, 2007)

troxell said:


> When you hook up the daka to your existing furnace and use the big furnace blower on the existing, do you need someone kind of a backdraft damper in the ducts going from the woodburner to the existing so the blower doesnt create cold air and cut out your small blowers warm air ?




There are a few ways to run the 8" ducts into the warm air plenum to avoid the situation you are talking about, the installation manual covers a couple of recommendations. The backdraft damper they cover in the manual is to prevent very hot air going the wrong way into your furnaces secondary and causing damage. 

In my case, I installed thermostatic switch to control the large fan based on plenum temperature, it's set to come on at 135*, and turn off at 85*. That gives the nice warm air when the blower cycles on. 
Regarding the large fan overpowering the small fan, you could have the ducts from the daka enter your system a little downstream from the plenum, and have them enter at an angle, not connected at 90*, it's worked for some, there's pics in this forum too.

You could always set it up in a series configuration, some of the guys here have had success with that and only run one fan then.

This thread has some pics:http://www.arboristsite.com/showthread.php?t=53916

.


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## troxell (Oct 31, 2007)

wdchuck said:


> There are a few ways to run the 8" ducts into the warm air plenum to avoid the situation you are talking about, the installation manual covers a couple of recommendations. The backdraft damper they cover in the manual is to prevent very hot air going the wrong way into your furnaces secondary and causing damage.
> 
> In my case, I installed thermostatic switch to control the large fan based on plenum temperature, it's set to come on at 135*, and turn off at 85*. That gives the nice warm air when the blower cycles on.
> Regarding the large fan overpowering the small fan, you could have the ducts from the daka enter your system a little downstream from the plenum, and have them enter at an angle, not connected at 90*, it's worked for some, there's pics in this forum too.
> ...



Tell me about the backdraft dampers that are spring loaded and fit in with the 8". The are recomended on the norseman furnace. Would a damper like that be suitable ?


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## DaKAnoob (Nov 26, 2016)

Sorry to hijack this thread but I am in the boat of a newly purchased Daka 521FB and in need of help installing this.

I have been searching the forums, but I think I'm over complicating the install in my head. But I do have concerns:
1. I do not have a chimney
2. Little knowledge of Furnaces - So when I read plenum, and seen the images/drawings I figured it is the immediate box above the existing furnace Right? or wrong?
3. Need some guidance - Im good with tools and Im sure I have what it takes to complete this task, just lack the knowledge

Can I get some help?

Please see attached to see some images of my basement set up near my furnace and Daka wood burner

Background on home:
Wisconsin - winter will be here soon
Just purchased - 2900 sqft
no Chimney
Two story home


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