Woodfired Boiler For Home Radiant Heating?

If you find some, let me know--they seem to be hard to find at reasonable prices.

I've had some thoughts of making my own. We might talk about that off-list sometime--write to me via CR4 if you're interested.

But, tell us some more:

• how big (sq.ft.) is your home
• how many floors
• general layout

I installed a wood / coal stove in my family room shortly after I moved into my house (~30 years ago). The layout is a two story colonial with attached two car garage, family room behind the garage, no 2nd story over the garage or family room, and the family room "isolated" from the main part of the house by a wall. (There is a doorway but no door.) I installed a small (6") computer type fan in an opening I created in the top of that wall. The coal/wood stove is installed at the far (furthest from the house) of the family room.

The original heat for the house was a central forced air heat pump with electric (resistance) auxillary (sp?) heat.

I've typically used the wood/coal stove as supplemental heat. I also usually ran the furnace fan continuously to try to circulate the heat from the stove.

Trying to get 75 degrees or so in the rest of the house made the family room almost uninhabitable.

(I also (a few years later) installed a coal fired boiler in the basement with a hot water coil in the furnace--I'll ignore that story for now ;-) (It works, but burns more coal than it should, is a pain to restart, but tends to go out on warmer days when heat is not called for often enough--I often crack a window on warmer days to keep the boiler going. (Also, the gravity feed system tends to "bridge" and not feed coal--I make it a practice to run a rod through the coal at least every 4 hours to prevent that--in fact, that may be the bigger problem than not calling for heat often enough--last year I kept the boiler going without cracking a window by religiously poking the coal feed.)

This year, I've been using the wood / coal stove alone (burning wood so far) and managed to mostly keep the house at 68 degrees. Sometimes in the morning we wake up and the house (in the far locations) is down to 63 degrees or so (cold nights / mornings) and then I stoke up the fire a little hotter to get it back to 68 degrees.

By the way, the temperature in the family room is not unbearable--I guess I'll have to stick a thermometer in there to check it--I doubt that it's hit 80 degrees--it is warmer, but that gives a nice place to come and warm up if I sit sedentary at my computer and start to get a chill.

This year (so far) has been a little warmer than our climate sometimes is--in years past we got periods of -5 (and maybe even -10) degrees--this year the worst I've seen was 5 degrees (one night so far) with several nights around 10 degrees.

I've also had good (sugar maple) dry wood to burn this year--sometimes my wood is not as good.

Anyway, my point is that depending on the layout of your house (and related factors) and where you can put the stove, a wood / coal stove (as opposed to a boiler) might not be that bad at all.

If I totally had my druthers, I'd move the wood / coal stove to the living room, sort of centrally located in the floor plan--the heat would be much easier to distribute and would have a bigger area to disperse so that I could raise the house temperature without driving us out of the living room. (My wife hasn't bought into the idea so far.)

As another option, I've thought about moving the wood / coal stove to the near end of the family room.

(The problem with either of these options is I'd need a new chimney.)

Finally, either in conjunction with moving the wood / coal stove to the near end of the family room or not, I've thought about:

• knocking out the wall between the family room and the rest of the house (the kitchen is on the other side of that wall)
• adding more "thru the wall" fans like between the kitchen and dining room and the kitchen (or dining room) and the living room

(Aside: I have thoughts about trying to convert the coal / wood stove I have to a boiler--I'd have to do some more investigation, but I suspect that there's a reasonable chance I could do that, but based on this year's experience, I'm beginning to think it's not necessary.)

My current objective is to improve the insulation on the house, both the attic and window insulation... Then maybe get some solar heating aimed at heating hot water, but also aimed at supplementing the house heating system.

Anyway, I guess I intended all this as food for thought.

Great input, Thanks. My house is primary 1 level with two "bonus rooms" above garage and MB. It is about 3000 SF. The central portion of the house has 8 meter ceiling! There are fans there, but they need to be changed out after ten years of use. We have not been using them as they make noise and oscillate. The New York Boiler Option has a 90,000 BTU unit that takes 60 pounds of wood. That may be good with a couple of storage units (Water Heaters, ELectric back-up).[p/]

I also like the idea of small radiators with fans. That may be easier than radiant.

You said"I also like the idea of small radiators with fans. That may be easier than radiant."

That is a good move and easy to arrange, even using double normal room radiators and the small fans arranged with a temperature sensor, so once warm water is "noticed" by the sensor, say around 40°C, the fans run. That way a normal rad thermostat, controls the room temperature via the fans, but no electrical connection, fans blow when water is warm!

It would also then be possible for a room to have smaller rads than is normal. But if a power failure stops the fans.....I feel that its something more to go wrong!

I personally went a slightly different way, I installed larger than normal rads, because this allows a lower water temperature, and still allows rapid heating from cold. The lower temperature is good for the boiler, less lime scale..

I also took out my wood burner and replaced it with a pellets stove, controlled by a timer and temperature sensor, almost 12 years ago. I wake up to warm rooms and a really nice heat.....My back does not allow cutting of wood and the rest of it any more!!

What might be possible, is to buy a small machine for making the wood pellets, maybe in a cooperative with others, as chips are by far the most efficient way to burn wood and easy electronically controlled.....With a large hopper, you may only need to load up once a year!!

I buy my chips bagged at 15Kg a bag, or in a so called big bag, one metric ton.....Either are great!!

Best of luck whatever you do!

here is a design you might like for a water heater. Use your existing wood fired space heater /stove . and add a heat exchanger (3/4 K copper) to the upper 1/3 of the fire box. Connect these two pipes to a 40 gal gas water heater. Top of heat exchanger pipe to bottom of storage, and bottom of H X to top of storage. Fill the tank till water is at the top, then shut off. Start a hot fast fire, (aspen is good, no soot) and the tank will heat up from top to bottom, to whatever temperature you want. All by convection ) if plumbed right) . All the steam will come out the top. Let the fire box cool down and close the top of the tank. Open a cold water line to the bottom of the tank and push out the 40 gallons of hot water to where ever you want. If you choose to keep it pressurized, ABSOLUTLY NO FIRES allowed). when you have used that 40 gallons, or transfered it some where else, you can shut off bottom and open top again and turn up the fire again. It does not take too long to heat 40 gallons this way depending on your application.

All of the old cook stoves and pot bellys were plumbed this way and worked well untill some one forgot and left it pressurized, KABOOM.

Bottom line is that they work well , and you are already buring wood.

I've come across nothing this side of the world, but was thinking of a DIY alternative as follows.

Building is "level", so I will have to move the water through the system as I cannot get a convection system operating.

Was considering one "hot" line to the far end of the house with a return line (fitted with a simple non-return valve so that water can flow when all radiators are turned "off".

The radiators that I have been looking at are motor bike radiators, or auto transmission coolers. Well constructed, highly efficient, and easily repalced. These are to be inside a small enclosure to stop direct contact and then (maybe) fitted with a computer fan to enhance the air flow.

The priority has dropped away since the kids moved out. We don't need to heat that end of the house now.

First have you installed fans in the ceiling to move the hot air down. I built an Underground home you can view it at (www.domehome.ca) and I used in floor radiant heating and very efficient. The wood furnaces or boilers to be efficient must take the heat from the flue not heat the water directly, There may be some inside stoves that can heat water that you can use but you need a circulation pump for best warmth. I saw such a stove in a straw house in the area of my underground. My late father installed in floor heating in our old farm house about 1950 and used convection for 10 years then when we installed a new boiler the difference was astounding. Much better with forced circulation. There is no reason you cannot install yourself and there are several books on it as well as the net. Nothing to fear. You can cover pipes with concrete or another layer of floor. Of course the bigger the house the bigger the project. Components should be sized to do the job. Good luck

one of the best posts. Build small, insulate/ventilate well, use solar aspects of wood, and water and mass, burn hot and fast (aspen), solar tax credits, the list goes on.

we need more solar (not PV) posts.

I added a south greenhouse with a 50 degree roof where 3 thermal water collectors keep a 500 gallon s/s tank (heavy insulated) using 1 pump. Along with the wood backup we keep 500 gallons at 145 degrees for some times 310 days a year (s w co) the mass in the foundation,washed river rock, the floors etc keep the house in the comfort zone with very low utilities. during the very coldest days we just ad wood (which is solar). A big advantage of the solar green house, is obvious. Most people like a year long crops.

Good solar greenhouse homes should get the very highest tax credits, and be built way more often.

I have a solar greenhouse too, but never managed to get the infrastructure which you have - you really have built an outstanding system. I use my greenhouse for growing though and it is great to step out and get fresh leeks or greens in the winter. Leeks are kind of amazing as the only food I know of that will continue growing when there's less than ten hours of sunlight a day, and temperatures near freezing.

The trees near my house have gotten a lot bigger in 20 years. They are starting to lose their tops and footing as well. At the moment we're having a howling storm with gusts to only 100 kph thankfully. These trees really need to be cut now because not only shading the greenhouse in fall and winter, they are a huge hazard with the crazy storms we're getting.

Growing a wood supply is another project. I decided to try European Alder here - these are big trees, fast growing and are pollarded for firewood in France. They are said to make the best charcoal, and they certainly are a great firewood with cleaner BTUs. Of a number of trees, this one has done very well here and I think it is a useful addition to our species-poor environment.

Not fast fires and a manually operated system (no t-stats) have been used from the beginning. People (and builders) have become lazy. Best post I've seen in some time. T Y

If I were you I would get Uponor's Design Manual and look at John Siegenthaler's book, Modern Hydronic Heating.

But what are really better are some of Seigenthaler's articles published in Plumbing and Mechanics magazine. I think they are available on CD.

Unless you have large quantities of wood at very low prices (do consider your time as a cost as well, even if you rate yourself quite cheaply).

Also, and you are happy to feed the furnace at regular intervals, every 1 to 3 hours is normal, split and transport wood. Also the smoke is very fine particles that are really bad for your lungs, like smoking cigarettes....

Do give a pellets burner a look at. they are totally automatic nowadays, feed themselves from a big hopper with probably anything from 1 to 5 tons of pellets. The pellets can be delivered in what looks like an oil bowser truck and are "blown" into your silo, dust is extracted and returned to the truck at the same time....

Its no more difficult than burning oil, but has a renewable carbon footprint.......

Give it some thought.

I also feel that with your house that radiators and underfloor may be a good idea. Radiators for those in between days between winter and summer, underfloor for winter.....new fans in the high places are also a good idea, set to switch with a thermostat....

Wood = Exercise + Chainsaw + managing Children. (Quite a blessing, little expense).

I like the idea of thermostatic controlled fans. I look into these. Thanks.

Are you selling?

I think that your "stored carbon" idea is a good one. It takes the energy of the sun to grow the "tree", then when you burn it, and vent it properly, (hot and fast), you allow this energy to "re radiate" it into your mass. (warm friendly floors). If you add passive energy (hot and cool), and proper solar orientation to your home, and it becomes a "receiver" so you can cut your energy costs to the bone, and still maintain a "comfort level" to your home. The amount of electricity to run your pumps for a year is a fraction of your overall energy costs, and Remember, the footprint your home can capture the 55 degree earth temperature with no moving parts. In the south west, the ancients, used their solar architecture as the language to be passed on to every generation. The kiva worked for them. note on pumps and circulators; constantly starting and stopping them costs way more than longer runs.

A good passive foot print is the bit of resistance which allows it to "fly" better ( it's always in trim) than standard architecture.

As far as in floor heating goes, since "good water" is the best heat transfer fluid, and won't freeze when moving, this "mass" , gives you the most bang for your buck that I talked about in my first reply. Also it gives you options as a "captain of your ship" when a storm comes, and you have to prepare for it in advance. Instead of an automatic thermostat, you take the controls. Then when it passes, the auto pilot is re engaged.