Help and suggestions needed for wood burning furnace

[coppermouse]

I have been heating my house with a wood stove for 10 years and I have decided to get a wood furnace. I am tired of the mess in the living room from the bark, sawdust, bugs and ashes. Also I am tired of one really hot rooms and the opposite corner of the house being cold. So here is my plan and questions. Any help suggestions would be greatly appreciated.
First off I am thinking of either a USSC 1557 or a Vogelzang Wood/Coal Model# 2500. Is one significantly better than the other. Any feature(s) on one which are better? Any other brand you might suggest in the $1000 range? The USSC is convenient because I can go pick it up at Tractor supply.

I want to install it in my attached garage. Just on the other side of the wall in the basement is the furnace so I can just run 2 ducts through the wall under the first floor of the house. I know it would be more efficient to put it in the basement, but then I have to haul wood through the house into the basement and still have the mess problem. There is no outside access to the basement and I would have to cart it down the stairs. It would be so easy to fill in the garage. Plus it would keep the garage warm. I would have to use 8" supply and return ducts. Any thoughts on this configuration?

When you connect the furnace to the existing furnace, the units are in parallel. I still have to use the propane furnace bacuse I travel quite a bit and have to keep the house warm when I am out of town.
When they are in parallel how do you prevent one from backfeeding air through the other (ie. When the propane furnace runs the air could flow through the wood furnace to the cold air return? and vice versa. Do you install butterfly valves or something?

Where can I find info on installing the chimney to code? I live near Columbus Ohio. one of the main things is where the chimney exits the roof of the garage, it will be next to the wall of the second story. I need to know clearance for that etc.. There is no room to run the chimney horizontal out the back of the stove and up the side of the house.

How does the thermostat how on those. Does the call for hot air from the thermostat in the house just turn on the forced combustion air blower? Are the internal blowers for warm air circulation controlled by an internal thermostat to cool the plenum to a fixed temp? basically how do I control it?
Thanks in advance.
Tim

 

[laynes69]

Those units are okay, but I would look into the new EPA Certified wood furnaces made by US Stove. I have one like the ones you are looking into and I had to rebuild it to have any quality. First off, whats the square footage and age of the house? Second off, if you put it in your garage, it will pull the cool air from the garage into the home, including fumes and CO2. I modified mine so that it runs in series, which the new ones run that way. You get less pressure in the ductwork, and more heat from them. I would tie a furnace in series, and put it in the basement. Just make youtself a wood chute going into the basement for easy access to the wood. You keep your basement warm, and the floors of the home, and the home itself. If you need warmth in the garagem tie a small duct into your main ductwork to warm it a little. If you install parallel, then you need a series of dampers so they don't backfeed. With series you dont need it, which is another good reason to go with the EPA Furnace. The Epa furnace has viewing glass so you can see the fire and also burns much cleaner. Depending on the age of the woodstove, you will more than likely use more wood. About local codes, contact the local courts, and Im sure you can get information. The way these furnaces work, there is no way to control the heat. They either have a thermocouple, or a control/limit switch. On ours, we have a limit/control thats tied into our main furnaces circuit board. When the wood furnace hits 140 degrees, the main blower kicks on and pushes the heat from the wood furnace through the ductwork into the home. The only way to control how much it heats it produces is by managing how much wood you put in them. I have a forced draft that runs off of a thermostat in the home. But you can't take heat away from the home, just add it. They produce a hell of alot of heat but you really have to tweak them for a good clean long burn. Plus you can't burn anthracite coal in them, I have tried many times. If there is any more questions, I will try to answer them.

 

[wdchuck]

Coppermouse, welcome to AS.

http://www.dakacorp.com/furnaces.cfm
The installation/user manual is in pdf form, it shows just the way you'd get it at the store(Menards). $700. + $$ for ductwork connections/smokepipe.

Here's what I have in my home, heating 3000sq ft, it's installed right next to the LP furnace, and the wood comes in through a ground level window. There is a thermocouple in the ductwork that is set to come on at 135*, and off at 85*. Mine is installed in parrallel, as it is recommended by the manufacturer, however, running it in series as Laynes69 talked about works well also, he set his up quite well.
You talked about the garage, your insurance company will have issues with that, (gas cans, gas engines, etc.), not to mention the long runs to your existing furnace ductwork, heat loss, cold air returns, do you have a basement window well you can feed the wood through?

Laynes69, didn't we do a pictorial for another poster last winter, should pull that thread as a link.

 

[coppermouse]

Ok, I can't put it into the garage so the basement it is.
I do have a basement window located under my deck, so I could make a trap door in the deck and then put the wood through the window.
My house is 2500 sq ft. plus basement.
A few questions:
US stove 1950 is the only model I see EPA certified. Is this what you are talking about? It is a little pricey(3K). Any other manufacturers/models you may suggest?
Can I run the chimney out the basement window (If I were to replace the window with a steel plate with a feedthrough, the run up the side of the house outside? How do I find out my code requirements? I have called about every county office and no one can tell me. Do I need double or triple wall stainless outside?
It may be difficult to run it in series without major modification.

 

[ericjeeper]

Build a mechanical room.

Within the garage, Put up two walls in a corner and a door. Then it is no longer "in the garage"

 

[AngelofDarkness]

My friend has a forced air wood furnace in his garage. He has it installed with two 8" ducts ran through a hole in the foundation feeding warm air into the supply air ductwork system on his furnace. Cold air is drawn directly from his garage. Anyway he burns a tremendous amount of wood for heating an 800 sq. ft home, almost 7 cords last winter. I don't think he is running very efficient. The blowers on those add-on furnaces do not seem to move the air like a normal furnace blower, maybe a bigger blower would work better. Also,m would it work better to connect the supply ducts from the furnace to the cold air system of the gas furnace and then wire the blower of the gas furnace to come on with the other blower?

 

[coppermouse]

Thanks for the info. I am going to go with the basement install.
The main thing now is deciding on a furnace.
I do like the US stove 1950 EPA certified model.
Question: Does any other manufacturer of the feature of secondary combustion? that seems key to efficiency as well as keeping the chimney clean. Thanks for everyones input
Any opinions on the Woodchuck, Kuuma vaporfire?

 

[wdchuck]

Addressing the stovepipe through the window idea, can you do it, yes, should you do it, there's better ways, one big reason not to is called 'stack effect', the chimney is outside, where its cold, so the draft from the furnace has that much more to overcome, and there is the possibility condenstion to form, freeze, and reduce the inside diameter of the chimney pipe, do a google on it.
The best way, for chimney/furnace performance is to run it up through the middle of the house, one, the chimney stays warm from the ambient air temperature, and two, the it will exit the roof at a higher point, and require less pipe external to the house to gain the required height.
A common route is up through closets.

Type of chimney pipe, insulated double/triple wall stainless, with the proper rating is the way to go. A double walled smoke pipe is also a good idea.

If you want to use the unit as a standalone, then a 500-cfm blower will be insufficient, 1,000-cfm however will be fine, but since it sounds like you are using it as an add-on, then the supplied blower will be fine.

Secondary burn process, the one thing I wish mine had, for all of its benefits.

Something to keep in mind, be able to detach the ductwork and cap the connection from the woodfurnace to the regular one, if you have A/C that is, no need to backfeed conditioned air that way.
I've tried the 8" backflow prevention pieces from an HVAC supply, the high temperature woodfurnce air will damage the foam in them.

Hope this is of help to you.

 

[wdchuck]

Connecting the hot air feed from the wood furnace to the cold air return of the main furnace will cook the secondary parts, lots of plastic stuff in there, and ruin the furnace. There are stainless secondaries in some furnaces, but only the very high end, and are spec'd by owner/architect, read--really expensive.

 

[AngelofDarkness]

My friend' furnace has no plastic or electronic anything, theres a huge cast iron firepot with a big, single inshot gas burner. It's at least 40 years old. What I want to do is connect one of the supply sucts from the wood furnace directly to the cold air return and wire the furnace blower to come on with the wood furnace blower, this would draw the warm air in from the wood furnace and mix it with cold house air before distributing it. As long as the air temp. is below 110 F when it enters the return air cabinet it should be fine.

 

[wdchuck]

My friend' furnace has no plastic or electronic anything, theres a huge cast iron firepot with a big, single inshot gas burner. It's at least 40 years old. What I want to do is connect one of the supply sucts from the wood furnace directly to the cold air return and wire the furnace blower to come on with the wood furnace blower, this would draw the warm air in from the wood furnace and mix it with cold house air before distributing it. As long as the air temp. is below 110 F when it enters the return air cabinet it should be fine.

It's age and design make for an exception, typical F/A units will not withstand the 180* air coming in that way. My info comes from licensed HVAC system designers, engineers, regarding what can/should be done, but your friend's system certainly sounds different.
The air temp coming out of my wood furnace has exceeded 190*, that's HOT.

It sounds like you'd be better off connecting things in series then, there are pics of what some guys have done in this forum, and it seems to work well, might be an approach worth looking into, that way you can eliminate the smaller blower all together.
For the situation you desire, to mix the air first, you may want a delay between the two fans starting time, it would result in a better outcome, maybe 1-2 minutes.

 

[AngelofDarkness]

I am not planning on connecting the supply from the wood furnace to the return directly at the furnace, it will be a ways upstream. The two airstreams will have about 6-7 feet to intermingle and mix before it actually reaches the furnace.

Over 180 for a supply air temp, now that is HOT!

 

[JeffHK454]

Pics of how my 1600M is installed.

I also hear varying opinions of how things will or should be installed , I take it there will be no permit,code or insurance involved in this installation?

 

[laynes69]

There should be pics and discussions on woodfurnaces. The only other model that is epa certified is the caddy. Do a search for Caddy Epa Wood Furnace. If you don't want to deal with multiple blowers and small ducting check into one of these. They will put out 140,000 btus, and use 40% less wood than a non-epa wood furnace. Also they are made to be installed in series, and they use your furnaces blower, so there are no dampers of any kind. They are around 2300 for one without a blower. Then just use your furnaces blower to push the heat. The Caddy is the first epa wood furnace ever created, I think usstove got the rights to it and thats why there are 2 now. Trust me if you are serious about a wood furnace I would get the US Stove, or the caddy. I would opt for the caddy first due to the price. And because of the series installation, they have removable panels from either side so you have options. Your chimney will stay clean, and you will get a hell of alot of heat.

http://www.psg-distribution.com/product.aspx?CategoId=15&Id=325

Here within a few years, this will be my new baby!

 

[coppermouse]

Pics of how my 1600M is installed.

I also hear varying opinions of how things will or should be installed , I take it there will be no permit,code or insurance involved in this installation?

I would like to make it to code, but I do not need a permit or insurance inspection. Is there a butterfly valve or something on pipe coming out of the hotair plenum to prevent backfeeding?
I was thinking of a damper or butterfly valves for this purpose

I think I have narrowed my search down to the US stove 1950 (EPA model) or the woodchuck 2900. Any opinions which is better

 

[wdchuck]

Laynes69, thanks for that link, I was never aware of that particular add-on furnace, and three dealers within 50 miles too, I'll have to contact them to get a look.

I know mine won't last forever, but it paid for itself the first winter.

Even though I installed our add-on, the insurance co. came over for some measurements for clearances, took some pics, and adjusted my policy, so we are covered and it was painless for the 10 minutes they were here to check on it.

JeffHk454, that is a very nice looking installation, it looks like you are bypassing the furnace filter though, from the way the CA return runs to the 1600 and the air flow direction, does it work different than the way it looks?

 

[JeffHK454]

By back feed you mean heat going back down the plenum toward the gas furnace rather than up into the ducting? If that's what you meant then , no flapper !

When I started reserching doing this install myself I worried about how to direct my heat into my ducting and control back flow , turned out to be fairly simple. I was instructed buy the HVAC supplier I got my supplies from to angle the outgoing plenum feed at no less than 30* upward and combined with convection my flow would take care of itself.

I do get some air past my wood furnace cold air intake but not much. If I put a block off plate in my cold air return so that 100% of returned air goes through my wood add-on I can achieve 175+* outgoing air temp and without block-off it drops by 15*. Eventually I'm going to put a electric gate valve in my cold return that can direct cold air to gas or wood depending on which is running. I did put manual butterfly valves in so I can isolate my wood burner during AC season.

Jeff

 

[JeffHK454]

Good eye wdchuck, the filtration is lacking in my setup. The way my furnace sits combined with the pancake type electric air filter made incorporating it into my plain impossible. I Have a single slid-in type furnace filter between the blower box and the wood burner, not perfect but good enough. The fact that the squirrel cage sees unfiltered air is less than desirable but I was running out of ideas and winter was coming

Jeff

 

[wdchuck]

Jeff, I did the same thing you have, and it was hurting my flow and temperatures, so I just ran a vortex setup, 6">8">10" round duct up towards the basement ceiling, where the air is warmer anyway, and put a pleated filter on top of the duct open end, the suction keeps in place quite well, and the system performs just fine. The 10">6" is recommended by the woodfurnace mfgr, so it's a tested method.

This way I'm not detracting from the flow of air through the main furnace, nor is the CA return line in a flow flux between the two pulling air flows.


There seems to be a variety of ways to make these setups work, I had backflow issues, so had an outfit make a 3 blade louvre to sit on top of the A-coil , that and the 135*on/85*off switch for the main fan in the plenum really made a difference for mine. But my hot air feed plenum also contains an A-coil, so it only left me with 7" of plenum before the distribution part of the duct started, there isn't much to work with.

I'll be tinkering and refining the connections this season, all my fiddling to this point have uglied it up some, give me something to do when it's cold out.

 

[JeffHK454]

There seems to be a variety of ways to make these setups work, I had backflow issues, so had an outfit make a 3 blade louvre to sit on top of the A-coil , that and the 135*on/85*off switch for the main fan in the plenum really made a difference for mine. But my hot air feed plenum also contains an A-coil, so it only left me with 7" of plenum before the distribution part of the duct started, there isn't much to work with.

I like this little louvre idea, I thought about something like that but had no idea as to where or how to come up with one.

They sell electrically actuated "flapper" valves but only in predetermined L"xW"xH" and would require a completely reconstructed of the plenum area.

Tell me more about this 3 blade "flow blocker" this would definitely help my system !

Custom made $$$$ dollar piece ?