OWB vs. Indoor wood boiler

[JSNH]

I have had both.

Heating with wood In New Hampshire.

I have been heating with wood for 31 years. The first 10 with an air tight wood stove in the house. I burned good dry hard wood. The house was either too hot or too cold. You had to bring the wood into the house and the house was drafty due to pulling in combustion air. You had to clean the chimney.

I then got a wood gasification furnace it also stored the heat in a 2,000 gal water tank. I burned good dry hard wood. I heated that way for 17 years. It would be similar to the tarm with a storage tank. It worked well every room was exactly the temp you wanted. Base boards for heat. I don't think I burned 300 gal of oil in those 17 years. It burned so hot no chimney cleaning was required except to pull a bit of dust out of the clean out every other year and weekly heat exchanger clean outs. You had to bring the wood into the house and the house was drafty due to pulling in combustion air plus when it was running the fan and circulator were loud. In the dead of winter I would have a fire for 6 to 8 hours a day. Every day was bring wood in start fire 15 or so minutes. Each hour fill with wood 5 minutes each time. So that was 40 minutes a day in the winter. The stove's fire brick burned out and it needed a major rebuild. The fire brick shapes in it were custom and no longer available plus the tank developed a leak. I replaced it with an outdoor boiler.

I went with a standard Central Boiler 5036 outdoor boiler. It is great. I am into my 4th winter. I did not want a gasification one. I am glad I did not get of those. In my opinion they are too complicated and problematic. I may burn a bit more wood but I burn everything, pine, hemlock poplar and hardwood. I swear it runs better with pine. No chimney cleaning. No wood in the house. No drafts. No sound. I spend way less time filling, poking, cleaning and can spend more time with the family. 5 minutes in the morning and 5 minutes at night. I am saving a half an hour a day thats over 3 days saved in 6 months. The house it totally comfortable. We have more room in the house without the wood stove and without the furnace. No mess no bugs no smoke in the house.

[mrwood]

I have never had an indoor wood model. The cb OWB was my first experience to a wood burning stove. The only way I sold it to my wife was that it was outdoor. She really hates smoke and the mess of wood. After haveing this outdoor, I could not amagine without one. I swear by it. I enjoy the work. It does chew up more wood than say and indoor IMO. but for me the other benefits make up for it.

[Grunex]

About five years ago our old indoor furnace was getting tired, had a few cracks in it as it had been installed in the early 70's,  seemed every day I would come into the house and find the wife and baby tired, sleepy and within a few minutes I'd feel the same way.  One day I went to town and bought a carbon monoxide detector and installed the batteries. Before I made it half way down the steps the alarm went off!!!!   I had suspected the source for a little while, but didn't know it was that bad!!!  I went back to town and bought a number of space heaters in order to keep the house warm for a few more weeks (late Feb when this happened) and promptly ordered steel to build my own OWB.  It's not fancy, but at least the carbon monoxide is not in the house any longer.  I just could not justify that kind of health risk!  My insurance went down, and I designed the system, built it, and installed it for a grand total of around 6500.00 dollars.
As I said it was nothing fancy, the system consisted of a yard shed type structure for the boiler, a well insulated boiler, pex, two side arm heat exchangers, a forced air heat exchanger, and a heat exchanger to cycle water into the house.  (for radiator type heating) and lastly circulator pumps to get the hot water where it needs to be.  we've had absolutely zero problems with it since it was built.  I burn a lot more wood right now that I used to but my electricity cost have gone down, fuel oil is zero, and propane is zero.....

[Farmertan]

I had an indoor unit installed in November, and love it. It's a WoodGun with oil backup. In our town, they are pretty ignorant about wood boilers and the permitting process is difficult. Once I showed them the info and emission specs, they were ok with it. I do not think they would permit a non-gasifier. As for indoor vs outdoor, I can totally understand the pros and cons I've read. I don't worry about burning down the house because my boiler won't burn well with the door open, and not at all with the blower shut down, which happens automatically at 185 degrees. I also have a smoke hood vented to the outseide that captures the puffs that some out when I open the door. Having never had an OWB, I can still see pros and cons:

OWB Pro: no noise, dust, smoke in the house if the chimney is properly sited.
Con: having to go outside in the wind/cold/rain/snow (imagine doing that if you've got the flu)

IWB Pro: no heat loss, load the boiler without changing out of my pajamas, nice, warm basement and workshop
Cons: bringing in wood (not an issue for me because I have a walkout basement with garage door), noise

[DGK]

I have a Greenwood Hydronic Wood Boiler installed in my attached garage. The reason I went with the indoor one was because the insurance company would only insure the outdoor boiler if I cleared a very large  area 50'+ radius around it of all trees, buildings, combustibles, etc. Since my property is nicely treed and I wanted it to stay that way, indoors it went. Having it in the attached garage gives the benefit of being able to load and monitor it without going outside, the only drawback is that you do get some smoke in the garage when loading on occasion. I have recently installed a smoke hood with fan to exhaust any escaping smoke. This is an older pic without the smoke hood.


 

[Piston]

Thank you to all who have contributed to this thread, it was very educational for me. 

[TCBNH]

I've been researching the same subject.  I have a friend that move from an indoor to an outdoor simply because he had access to a lot of pine that he could get for free and he was afraid of burning that in his indoor boiler.  I've heard that outdoor boilers are less efficient just because of location.  I work with a guy that used to install TARM indoor boilers....he says they are fantastic and very efficient, but they are also very expensive.

[711ac]

There is another problem with indoor burners of any kind that offsets any heat savings from having the stove indoors.

The chimney sends the products of combustion outside along with a lot of air from inside the house. That air has to come from somewhere and the cold outside air infiltrates thru every crack, door, and window in the house. Yes you can put in a air make up heater to control the air make up but they are costly too. Plus the exhaust in the winter takes moisture out of the house and requires some type of humidification.

So having the heater in the house creates more problems than you gain from having the insulation losses from the stove stay in the house.

My indoor wood boiler uses outside air for combustion! Just as all high efficiency heating appliances do. ;)

[beenthere]

There is another problem with indoor burners of any kind that offsets any heat savings from having the stove indoors.

The chimney sends the products of combustion outside along with a lot of air from inside the house. That air has to come from somewhere and the cold outside air infiltrates thru every crack, door, and window in the house. Yes you can put in a air make up heater to control the air make up but they are costly too. Plus the exhaust in the winter takes moisture out of the house and requires some type of humidification.

So having the heater in the house creates more problems than you gain from having the insulation losses from the stove stay in the house.

I have an indoor wood boiler (35 yrs now), and I don't think this summary is even close to right. Sorry Gary.   

[nctacoma]

as an update to this thread, We were able to get a wood boiler at our house.  We went with an indoor wood gasification boiler made by Froling.  IT is made in Austria.  It will heat all of our hot water baseboards and supply us with all of our domestic hot water.  We have been using it for about three weeks now.  One fire a day or sometimes every other day.  The installer estimated that we will use less than 6 cords a wood a year.  For summer hot water they said one fire a week will be sufficient.  The boiler is connected to two 300 gallon thermal storage tanks which act like a battery for the heat and hot water systems.  So you don't need the boiler to be firing to have heat available. 

I normally fire it in the morning before I leave for work and just check the temperature at night of the tanks to see if I need to top it off with another small fire.  So far I haven't had to, but it isn't winter yet...

[WmFritz]

Have you been heating with wood... if so, how many cords have you been using?

From everything I have read, Froling builds quality boilers. Does your unit have Lamba controls?

[nctacoma]

We have been heating with wood before the boiler. We were using about 4 cords and using the propane boiler as backup. The problem was we could only have two warmish rooms in the house. The room the woodstove was in as well as the room above it. Rest of the house was frigid.
Yes the boiler has the lambda controls.