New guy, lots of questions.

[pjcassidy]

Hi all, Patrick here.
I'm trying to decide what to do...here's the situation:
I'm a nurse, so I work 12 hr. shifts, so make that 14 hours away from home at a time. My wife is unable to lift/load wood, and we can't have a woodstove in the house due to her health issues.
I've been looking at this MEN article: (broken link removed to http://www.motherearthnews.com/Modern-Homesteading/1979-01-01/Wood-Burning-Furnace.aspx)
It is from 1979, so I'm sure there have been improvements since then.

We live on 300 acres of woods, and since I work 3 days/week, I have time to cut wood. Essentially free (I know my time isn't free.......).

I've looked at different avenues of doing "wood boiler".
I finally decided on radiant floor heating. The heating unit will have to be in its own building, no basement. But we live on a hillside with some draws and I was going to put as much of it underground as possible. I'm not sure exactly how far from the house it will be....100' maybe. So I'm planning on putting the heater, storage tanks, the whole "works" in this building with covered wood storage outside.
I had been planning on building this myself, including the heating unit above. So I have searched and saved 3 ~200 gallon fuel oil tanks, I wouldn't think these could be pressurized.

The house is 1050 sqft, but has cathedral ceiling over 1/2 of it, so the cuft is more than normal. (I've read to increase my calc's by 50% for this?) We also have plans for additions up to ~3000 sqft.

So, my question, gentlemen,
What other information do I need to assess before making a decision here?
What other information do I need to give you guys so you can help me?
I read another similar thread, and everyone was suggesting the Garn unit.

Thanks for any information,
Patrick

 

[heaterman]

Hi all, Patrick here.
I'm trying to decide what to do...here's the situation:
I'm a nurse, so I work 12 hr. shifts, so make that 14 hours away from home at a time. My wife is unable to lift/load wood, and we can't have a woodstove in the house due to her health issues.
I've been looking at this MEN article: (broken link removed to http://www.motherearthnews.com/Modern-Homesteading/1979-01-01/Wood-Burning-Furnace.aspx)
It is from 1979, so I'm sure there have been improvements since then.

We live on 300 acres of woods, and since I work 3 days/week, I have time to cut wood. Essentially free (I know my time isn't free.......).

I've looked at different avenues of doing "wood boiler".
I finally decided on radiant floor heating. The heating unit will have to be in its own building, no basement. But we live on a hillside with some draws and I was going to put as much of it underground as possible. I'm not sure exactly how far from the house it will be....100' maybe. So I'm planning on putting the heater, storage tanks, the whole "works" in this building with covered wood storage outside.
I had been planning on building this myself, including the heating unit above. So I have searched and saved 3 ~200 gallon fuel oil tanks, I wouldn't think these could be pressurized.

The house is 1050 sqft, but has cathedral ceiling over 1/2 of it, so the cuft is more than normal. (I've read to increase my calc's by 50% for this?) We also have plans for additions up to ~3000 sqft.

So, my question, gentlemen,
What other information do I need to assess before making a decision here?
What other information do I need to give you guys so you can help me?
I read another similar thread, and everyone was suggesting the Garn unit.

Thanks for any information,
Patrick

Sounds like you have some good things going for you.
A secure job in the health care industry +
You are here asking questions BEFORE you buy a wood fired heating source ++
You have selected a low temperature heating system IE; radiant floor +++
Anticipating an out building for the wood heater ++++
You are thinking about storage+++++........you get the point

I would offer these suggestions based on your info.
1. You definitely want to include as much storage as possible due to the amount of time the unit will be unattended
2. You will need to protect a typical gasification boiler from the low return water temps coming from a radiant floor. However, if you design the system to heat from storage only and not directly from the boiler that may not be an issue you need to address. In the instance you would select a Garn this would not be a concern.
3. If you are going to add the additional sq ft you talked about I would say offhand that you would need 1500 gallons of storage to give you reliable unattended heating cycles of the lenght you need.
4. Get a years worth (or 2) of wood cut and seasoned before you actually need it. Dry wood makes an incredible difference no matter what you burn it in.

Best of luck to you and keep asking questions.

PS Welcome aboard and don't be bashful with the questions. We all started at the bottom of the knowledge ladder

 

[Eric Johnson]

Welcome, Patrick. I think heaterman provided enough information to get you started. As he said, don't be afraid to ask questions as you continue your research.

 

[pjcassidy]

Thank you guys.

I have a 1500 gal "green Ag" tank. I'm not sure what water temps these things can hold, any ideas?

I read in another thread also that since radiant floor is "cooler" than other forms (I think it said 120*).

It'd really be great if that tank would work. We used it for a water cistern for the first 2 years we lived in the house.
I built the house, with help from my dad about 10 years ago.

 

[heaterman]

Thank you guys.

I have a 1500 gal "green Ag" tank. I'm not sure what water temps these things can hold, any ideas?

I read in another thread also that since radiant floor is "cooler" than other forms (I think it said 120*).

It'd really be great if that tank would work. We used it for a water cistern for the first 2 years we lived in the house.
I built the house, with help from my dad about 10 years ago.

They are not temperature rated at all. Strictly meant for storing liquids at ambient temp.

 

[91220da]

Hi Patrick the only thing that jumped out at me is when you said your boiler room/building may be 100 feet away. My garage is 33 feet from my house and a 5 am and 10pm in minus temp weather it feels like a million miles. Think closer if you can.

 

[pjcassidy]

Ok, I'll forget about the plastic water tank.

Right now we're heating with electric baseboards, those bills are killing us.

I'm not sure about our other future additions to the house, that is why I'm thinking of putting it that far away.

When I work, I get home at 3am or 5am...but it's only 3 days a week....

Thanks again,
Patrick

 

[Hunderliggur]

IMHO - Definitely an outbuilding. You will be surprised at the cost of the insulated flue pipe - figure $100/foot (accounts for straight pipe and the necessary fittings). I was looking at poly tanks also - we have a 1500 gallon fresh water cistern. Definitely NOT for hot water. I use two refurbished 500 gallon propane tanks and they work well. You can probably find these locally cheap - perhaps a farm that no longer has brooders or dryers - check with your local propane supplier for possibilities. My boiler is 75 feet from the house - not too bad but our weather is not too cold for the walk. I have a separate boiler and storage and it seems to work well (storage is in the house). With boiler and storage in the same building you just pump the hot water to use it in the house. The Garn is an interesting unit from a combined heat and storage design but it is a beast - best to use a crane to put it on your hill before you enclose the building. Garn or storage - water is heavy and it is a concentrated load. I would not put it on anything but a concrete slab. With your schedule it looks like to could easily get 5 days of wood heat (4 you are at home plus storage the first day you are working. You can probably get one or two burns to storage between shifts (some say you can lite a fire in 6 minutes - plan on 30 initially - it is a learning curve), you should have pretty good wood coverage. Good luck!

 

[flyingcow]

Hi Patrick the only thing that jumped out at me is when you said your boiler room/building may be 100 feet away. My garage is 33 feet from my house and a 5 am and 10pm in minus temp weather it feels like a million miles. Think closer if you can.

When I go out to start fire once a day, not a big deal. I walk about 75ft. This is what is nice about storage!!

 

[heaterman]

Son in law is heating about 5500 sq ft with one 4 hour burn per day supplying a radiant system. It's 250' from the house in a lightly insulated pole barn that's kept at about 35-40* inside. He has 2000 gallons of unpressurized storage and roughly 400,000 btu/hr burn rate.

 

[pjcassidy]

The thing about building my "shed" into the ground, is that it will be around 50* most of the time, technically.
I think the Garn 2000 would more than heat the house even at its largest concieved size.
<heaterman> If I'm reading your first post right, a Garn doesn't need additional storage, because it already has XXXX gal. of water? What if you add it, does that just make it better?

If the heater states it produces "X" btu, and I'm not using that, the rest just goes into the storage tank.


No one has said anything about the "building my own" furnace idea. Any comments?

I work nights on the weekends...so I'll be around!

Patrick

 

[pybyr]

I don't own a Garn-- I own an Econoburn 150, and am very pleased with it. I did not want to do an outbuilding, and I did want my boiler in the basement, and there's no way I could've shoehorned a Garn down the hatch of my old farmhouse cellar.

If I were in your situation, I'd look really closely at the Garn. It's proven, it's simple, and (especially given your schedule) you can do a huge fast fire and then have a lot of BTUs banked for some time. The Garn "looks" more expensive than the other systems because it's one integrated unit-- but the consensus seems to be that unless you are unusually fortunate/ resourceful in your plumbing, storage, and control design and construction, the 'system level' cost of the efficient separate boilers + control + storage ends up being in the same territory as a Garn. The Garn also needs no real "chimney" which can be another substantial savings in overall install costs. A gasifier in an outbuilding with pressurized storage in your house/ cellar would also be a pretty sweet solution. The beauty of storage in or under your conditioned space is that any "losses" help heat the house.

With radiant floor, you'll need to keep the temps modest, especially if you will have wood finish floors over the radiant; to maximize heat storage, you'll want your storage as hot as you can practicably and safely achieve. In order to solve that apparent paradox, the water is mixed so that the floor only receives water at the intended temperature.

 

[pybyr]

[quote author="pjcassidy" date="1263722047"

... What if you add [to storage], does that just make it better?

...No one has said anything about the "building my own" furnace idea. Any comments?

Patrick[/quote]

Some people have done the DIY option, including some on here (one who comes to mind goes by "Garnification"); some have had great results, others have had a lot of frustration. It's probably not a task for anyone who hasn't done A LOT of very involved metal fabrication.

More storage is better up to a point-- but at some point, you get into diminishing returns, or, if the storage is well beyond the heat output of your boiler, then it could become a drawback (too hard/ time consuming to heat the storage up to full temperature). It seems that those with under 500-700 gallons total don't get the full benefit of the convenience of being able to go a long time between fires, and at the same time, over 1000-1500 gallons seems unnecessary unless you have a lot of space to heat, and a boiler big enough to heat that volume in a reasonable amount of time. From all I know about the Garns, it seems that they size the burn chamber and heat tubes inside of it so that the tank is about right for the unit's fire's output & vice-versa.

Most of all, if your house is going to grow substantially, try to use the most efficient materials and techniques that you can; it's easier to keep warmth in than to try to feed lotso' BTUs into a structure that's letting them into the great outdoors.

 

[pjcassidy]

I think I see what you're saying pybyr about the Garn being equivilant in price. So you are getting most of the storage and the heater with the Garn, in one unit, instead of having things spread around.

Let me change gears....
Once :whatever: is in the building and pipes ran to the house; I will run the water through a manifold to supply the underfloor (between joists system?) runs of tubing. I think I figured out I will need three zones.
I'm supposing there will need to be a thermostat in the house, connected to "X" to make the water run through the tubes or not. Will "X" be a pump I'm guessing? I mean, when the temps drop in the house, the pump would kick on to circulate the water, which will heat up the house. Right?
With other makes of heater, and I guess the Garn too, there is a thermostat in the water that causes the heater to fire to raise the water to a preset temp....?
And I guess there are probably some automated zone valves that will open and close by thermostat control to keep different zones at different temps?

So, the big question, what will one of these Garn 2000 cost me?

 

[Tony H]

What about building a little closer possibly a garage / storage building in one side and a garn in the other ? After all your gonna want a tractor to haul wood and it would be a shame to park it outside. :smirk:

 

[pjcassidy]

Already got the tractor, and it does have to live outside. :blank:

 

[Gooserider]

I think I see what you're saying pybyr about the Garn being equivilant in price. So you are getting most of the storage and the heater with the Garn, in one unit, instead of having things spread around.

Let me change gears....
Once :whatever: is in the building and pipes ran to the house; I will run the water through a manifold to supply the underfloor (between joists system?) runs of tubing. I think I figured out I will need three zones.
I'm supposing there will need to be a thermostat in the house, connected to "X" to make the water run through the tubes or not. Will "X" be a pump I'm guessing? I mean, when the temps drop in the house, the pump would kick on to circulate the water, which will heat up the house. Right?
With other makes of heater, and I guess the Garn too, there is a thermostat in the water that causes the heater to fire to raise the water to a preset temp....?
And I guess there are probably some automated zone valves that will open and close by thermostat control to keep different zones at different temps?

So, the big question, what will one of these Garn 2000 cost me?

There are a LOT of different options for plumbing and control, with varying degrees of complexity and cost - however you will need, at a minimum, a pump to circulate water from the Garn to the house distribution system, and some zone valves and / or additional pumps to move the water around the zones. (BTW, if you haven't already planned on it, you should add another zone to do your DHW - one of the little extra bonuses you get with a well done wood setup is effectively unlimited hot water...) Each zone will need its own thermostat, in order to control that zone's operation.

The way that the Garn operates, the water temperature and the firing are more or less independent - you essentially have a firebox that is inside the storage tank, which has a serpentine exhaust path through the water, to get the fire heat into the water storage. You build a fire in the firebox, and set a timer on the blower, which makes the fire burn full blast until it goes out and the timer shuts off the blower (Part of the learning curve is getting the timer to shut off as the fire goes out) This raises the water temperature in the tank. Repeat the fire building process as needed to get the water to max operating temps (180-190°F) but not over boiling, as you DON'T want to see 2,000 gallons of boiling water! The house pulls heat from the tank as it needs it, which cools the tank back down. At your convenience, and / or when the tank drops to your minimum operating temp, you build another fire and repeat. The fire end is purely manual, though some of our users have worked on automating a few of the control functions... The advantage is there is no need to worry about burn times, or regular restoking of the fires.

As a backup, most folks do have an electric or fossil heating system as well, which is set up to come on if the wood setup can't supply the required heat...

I don't have Garn pricing, but as a general rule of thumb, you can figure your installed cost for a system will be about 1.5 x the cost of the unit itself - more if you get a lot of the work done by pros, less if you DIY.... The other thing that can seriously run the price up, which applies to any "outbuilding" install is that it can really be tempting when putting up a building anyway to make it larger in order to have more covered storage, a workshop, etc...

Two arguments that are also worth mentioning in terms of the distance consideration - you will need to run pipes between the outbuilding and the house.... The further the run, the larger diameter pipes you will need, and the greater the attention you will need to pay to insulating them well, and even when well insulated, the more heating efficiency you will lose to the ground the pipes run through... The underground lines will probably be the biggest expense item after the boiler itself, and the building it goes in.... The shorter the run, the less it will cost...

Gooserider

 

[pjcassidy]

Thanks, I just re-read my post. I knew the fire didn't "automatically" restart....I meant more like opening a damper...but I guess with this type of heater, the fire is long gone out before needed to refire it.
I'll have to go out and look around the house and try to decided on a place to put this building....

My parents have been heating with wood off and on as long as I can remember. They have a Grandma Fisher stove. Mom has a Home Comfort wood cookstove too. I'm no stranger to cutting wood!

Thanks everyone,
Patrick

 

[flyingcow]

go to www.garn.com should be a video of one in use and also the specs of it. Gives you an idea about it. Keep in mind, you have to insulate this beast once put in place. Not a big deal. Many, at this site, have insulated it various ways. Quite a few have a blog, or at least many pics of installs, from the ground up. Very useful. Heaterman has an insualtion kit that he has been working on, i thnik it might be something he's selling now.
In my set up, my storage is in the basement of my house, very little heat loss from tank, but what is lost helps keeps the cellar warm, and floor above. I go out to my garage usually once a day (4pmish). Start a fire, fill the unit and thats it later. If it's subzero days, I'll refill it. With 3 kids in to sports and other activities, I'm having to run 'em around, so I already have my boots on. Just throw a few more sticks if needed.

 

[sbleiweiss]

There is an easy calculation that you can do to determine how much storage you need. If you wildly over-size the storage, you will suffer higher standby losses. The advantages of really big storage is to have less temperature drop between fires or go longer between fires. Smaller storage comes up to temp quicker requiring less firing of the boiler and has less standby loss (assuming both are insulated equally well). Anyway, you can calculate the smallest storage that you would want by calculating how many BTU's you will use between fires.

Since you have electric heat, this is easy. Take your highest monthly KWH usage and multiply it by 3412.3 BTU per kWh. Divide this by 30 days in a month. This will give you the BTU's you need per day. Since you want to plan for expansion, multiply these BTU needs by some amount to account for those needs. Also multiply by how long you need to go between firings (1.5 if you need to go 36 hours for example)

Now determine the temperature swing that you can live with in the storage tank. Radiant floor is OK down to 120 degrees I have heard, so running storage from 180 down to 120 gives a 60 degree swing for example. Take the BTU's needed, divide it by the temperature swing then divide by 8.35 lbs per gallon.

So for example if you calculate you need 700,000 BTU's per firing interval, you would neeed:
700000 / (60 * 8.35) = 1397 gallons.

There is of course another way to go... OWB's are now required to meet EPA "White Tag" specifications in some states. This is pushing them to gassification technology. Eventually one of them will get it right and it might be a practical alternative.

 

[sgschwend]

Patrick I would appreciate a payback calculation based on the savings you would achieve? Such as: we spend $1000 per month on electricity to heat our home, times the number of months you would deem a decent payback period.

Might help decide on how to proceed, heck you may want to purchase a manual sawmill and cut all your own lumber. That would sure keep the cost down.

 

[pjcassidy]

I'll see what I can do as far as these calculations.

Steve, a sawmill is definatly in the future, much to my wifes dismay. My great-grandad ran a circle mill all his life. My house is just behind where that mill still sits in pitiful shape.
I've looked at every make of portable mill available. What are your suggestions?
Right now I have a neighbor that runs a circle mill and cuts most of my lumber for free, since we let him and his son cut hay off our fields. But he is 85 and although in great shape for his age, he buried a cow with a shovel last spring, he is cutting less and less these days.

Patrick

 

[sgschwend]

The industry is down and has been that way for several years. I would suggest picking up a use mill from someone who is getting out of the business. You can look at sawmill exchange, or forestry forum or even wood web and find equipment. Cutting for yourself would mean using your own tractor to move the logs to the mill, you can make a log arch very easily to move the logs and keep them clean. A band sawmill is the most flexible. Manual mills work well just slower; you can rig a beam over the mill and then use it to lift and turn the log. That would be a good saving replacing the work that a hydraulic mills can do, hydraulic mills are nearly double the cost. There is something like 70 portable sawmill manufactures out there, a lot to choose from. It is pretty easy reading about how people like each brand by using the forums I listed.

Cutting by yourself on a manual mill you could cut 1000 bf per day. That would be 100 2X6 enough to frame 100' of wall. Or enough siding to cover a 100' long wall. In two days you would have save yourself over $1000. It really makes sense when you need to build and you have tree or can get them.

When you get closer to a purchase just drop me a PM.

 

[leaddog]

No one has said anything about the "building my own" furnace idea. Any comments?

I work nights on the weekends...so I'll be around!

Patrick

Just alittle history of my experiences,
I built my house in 1975 and heard about this great wood boiler in mother earth new called a Hassa. It was a firebox surrounded with sand with water pipes buried all thru it. It was great sounding and so I and another guy bought the plans and each built it. Now it did work but there were some design problems that weren't aparent at first. The other guys melted down and I had several failure modes and as I tried to improve each time I rebuilt it I kept putting in more money and TIME. Finally gave up even though I liked the idea but decided that in the long run propane was easier and cheaper.
Propane prices went thru the roof and since the OWB were becomeing the latest and greatest thing I started to look into them. Being very handy I found some plans on the internet and welded up one for myself and my son. I also liked it so well that I bought up steel for several others and was going to go into production. There was 3 types in this plan and for mine I made the most efficiant one. Well it was but because it was so efficiant I didn't have enough stack temp, got condensation and it rusted out in 2 years. I put making them on hold and started to learn more about boilers. My sons was made different so it lasted 4 years and I was using one just like it after the first one and had 2 years on it.
Knowing I was on borrowed time I started to research for something better. I learned about the gasification boilers and have done a lot of learning about them. There are several good ones that are proven and there are alot of new startups that aren't.
So knowing this___________ my advice is to look for a proven gasification unit. DON"T try and invent the wheel. You will spend more money, time and headach and not have as good a unit. This is old technology but all the pieces have to fit. Just look at Central Boiler. They have been making one of the best OWBs and have been working on there gasification OWB for the last few years. It's been out for a couple years now and they diffently are having some growing pains. Look at the proven ones, Figure on storage, and spray foam your underground lines.
leaddog

 

[pjcassidy]

Thanks leaddog. You kinda sound like my wife. "It's not that I don't think you can do it, you don't have time to do it."
You've been there and done it and it just doesn't always work like it is supposed to.
I'd looked into the HAHSA heater too....and read about people melting them down and such.

Patrick