I have been thinking of installing a gasification wood boiler in the house I plan on building this fall.The home will be 24x38 single floor on a full walkout basement. The slab will be heated by the wood boiler and the domestic hot water will also be supplied by the wood boiler. Propane is curently at 5/gal cord wood is at around 170 for hardwood green cut split delivered.... I read that propane contains around 91k btus/gall and cord wood contains 26million btus/ cord. I also read online that is takes right around 26500btus to heat 40 gallons of water for a hot shower. The wood boilers I have been looking at all claim about 90% efficiency. Even at 70% efficiency the cord would should provide me with around 18million btus or equal to almost 200 gallons of propane which at $5/per gallon is a considerable savings. I expect my savings would be even greater considering I plan on heating the slab floor with it also.. I haven't even tried to figure what that would cost me in propane but expect that it would be much more expensive than with wood. I also figure I will need some large storage tanks to store the hot water and expect to consistantly feed the boiler from day to day. I look at this set up as a great savings over propane...

$5/gallon?

What area are you in? I've been paying about $2.50 this Winter

It's worth it to check your calculations under all conditions. Hardwood yields are best averaged at about 20 MMBTU/cord and might even go even lower. At 70% efficiency you'll get 14 MMBTU out of that cord which is about 150 gallons of propane. Is it going to be worth it receiving, stacking and handling the wood on a daily basis for a few hundred dollars?

Although, wood is a great backup fuel if you own the woodlot.

Even at $ 2.50/gallon and with 70% efficiency,newer wood boilers are pushing 90%, That is still a few hundred dollars savings. I figure with my family of 3...eventually 4, we will need around 400 gallons of domestic hot water for showers and dishes, not including infloor heat. If it takes 26500 btus to heat 40 gallons of water for a shower than it will take 265000btus to heat 400 gallons... which equals $7.5 per day with propane at $2.5 with wood that equals about 1/52 of a cord or $3.26 a day and thats at 70% efficiency. It just seems like a no brainer to me and as the price of propane increases the savings will just be better and better....Think of all the money in gym memberships I will be saving by stacking and splitting.

to heat 40 gallons of water for a shower

Just helping you adjust expectations a little. 40 gallons is a BIG shower. Average shower runs 10 minutes. At 2.5 gpm, that's 25 gallons and about 75% of that is HOT water, so less than 20 gal of HOT water used. If showers are a big use of hot water in your home, you might look into Drain Water Heat Recovery units.

Most, if not all of the people I know have a limited period of usage on wood-fired energy devices. In fact, just saw the last ones go from all-wood heat to a ductless mini-split last month. After a couple seasons the gym membership starts to look attractive again.

Thank you for your feed back.The drain water recovery units are a great device and will plan on using them in my new home. Why did these people go from wood to the mini split system? just sick of feeding the boiler or un happy with it's output?

Why did these people go from wood to the mini split system?

Tired of wood related chores. First person home in the evening had to do wood, and pretty soon, no one was going home anymore......

I heat with a wood "gasser"- in the house (not a owb) with infloor radiant and DHW. (thanks NRTRob) The fuel truck does not come around here any more! (well maybe once a year). Wood burning is not for all folks, it is almost a life style, but for those that choose it, it is very rewarding. Check out hearth.com and visit "the boiler room" listen and learn there. Lots of opinions and lots of experience and know how also. Modern wood burning boilers may be very different from what you are imagining. There are also pellet boilers that are just about as simple as operating your wall thermostat that you have now on your oil/gas burning unit. We all know that conventional fuels are not going to come down in cost, and if you complaining now, what about  in a few years? For any one that has ever had a veg. garden, notice that some how your's (veggies) are much better than the grocery stoor's? Well every evening, some how that how water coming out of the shower head feels better also. (I cut and split my own wood) no gym membership or therapist required!

This discussion is making me feel better and better about heating my hot water with solar thermal without getting splinters in my fingers, pains in the lower back, or burning much natural gas!    Of course, I live in a sunny location, so it is not a universal solution.  Heating mostly with wood for a while was rewarding, but it does sort of stink up the neighborhood, at least with the older generation wood stoves.

Pioneer pretty much summed up the wood burning thing.  There are some negatives, though.  We own our wood lot and have been heating with wood (wood stove) off and on since the late '70's.  I've saved a whole lot of money in that time over the oil alternative I had, but there is a cost...saws, equipment to haul wood out of the woods, wear and tear on my truck, etc.  Most recently, wear and tear on my body, as I injured 3 discs in my back last June working on my wood supply.  Actually, that didn't happen all at once, just the result of many years of being hard on my back (much of it working on the never ending wood supply).  Cutting wood is also dangerous, even when you know what you're doing.  Just 1 mistake is all it takes to really ruin your (and your family's) day.  Honestly, I loved heating with wood.  There's something to be said for being personally responsible for your heat (or lack of it).  It gives you a different outlook on the whole thing.

If I were building your house, though, I'd seriously be looking at insulation levels first, heating system second.  For the thousand square foot house you're talking about (if single storey), if you get the insulation and air sealing right, pay attention to orientation of the house and window placement (if you have some southern exposure) just to take advantage of the winter sun to help the heat load some, you won't need a large heating system, and the boiler would be overkill.  As already mentioned, you could probably heat it cheaper than you could buy split wood, by using a mini-split heat pump.  If you want to do some wood too, a wood stove would be more efficient than using an outdoor boiler.  Burn the wood when it's really cold or when you want to sit by a fire.  Use the heat pump the rest of the time.  This way, you're not tied to having to be home all the time to keep the house warm (vacations are nice in the winter too).  Hot water could be preheated with a solar water heater that you could build yourself, with a conventional electric water heater as backup.

We burned wood all these years because our older house used a lot of heat and wood made a lot of sense.  We've recently switched to a ground source heat pump (geothermal) since I haven't been cutting any wood this year.  If I were building a house from scratch, though, I'd go small and make it efficient enough that it really wouldn't matter what I used for heat as I wouldn't need much of it. 

2 cents from someone who's cut a lot of trees to stay warm.

Burn wood pellets. They are more cost effective and a good boiler will have an automated feed and ignition system. I have a friend in northern NY who logs during the winter months. He sells all of the firewood he produces and purchases wood pellets, that should give you an idea of the route to consider.

I've yet to see a market where the per-BTU cost of pellets were better than cordwood, but it's sure a lot more convenient. That said, a 5'1" co-worker of mine has a hard time schlepping the bagged pellets up her icy driveway then downstairs to the hopper for her pellet stove, to the point where she has injured herself. Bulk fuels of any type are a PITA- it's only a matter of degree.

In many places the per-BTU cost of heating with a mini-split is lower than cordwood, and a HELUVA lot more convenient, and usually well under half the cost of heating with propane.