Outdoor Wood Furnace Info

Outdoor Furnaces - Manufacturers WITH EPA-Certified Models => Portage & Main => Topic started by: dutch on January 19, 2017, 12:33:59 PM

Title: fan damper
Post by: dutch on January 19, 2017, 12:33:59 PM
just kinda wondering how other users have the damper set on there bl 28-40 , i have always had it wide open, should it be set closed a little.
Title: Re: fan damper
Post by: Sloppy_Snood on January 20, 2017, 08:09:50 AM
Depends... are you not getting good hot burns or not long enough burn times?
Title: Re: fan damper
Post by: Elguano on January 01, 2018, 06:38:05 PM
Same question here, really a newbie at OWB, and was wondering if i should close the damper in the back of the fan, I get about 12 hrs if i stock the furnace enough, otherwise it would be a 8hr burn.
Title: Re: fan damper
Post by: Range91 on January 02, 2018, 04:54:06 PM
I run mine wide open and honestly believe could use a little more air. Stove burns pretty clean but always has some smoke unless I'm down to just a coal bed. If I open the door a crack when it's smoking under load it will clear right up and you can see all the smoke burning in the chamber. I'm heating around 3700sqft plus a 900 sqft garage and domestic water with crappy under ground pipe and can go 12hrs on 6-7 splits and a 10-12" round oak on cold days. 30 and above 4 or 5 splits is all. I keep my ash pretty low keep brick exposed quite a bit. I also blocked off 2 air passages at rear of stove with a plate and firebrick this helps keep more air under where I have the fire which is more in the front and also helps with more secondary air. I also clean my stove once a week religiously pulling all ash from upper heat exchanger and push it back into the firebox. I also scrape the creosote off the what I would call the ceiling of the upper heat exchanger with the supplied tool. I've seen some stoves on YouTube that guys open up and I think to myself how much wood they are wasting. This is what seems to be working good for me
Title: Re: fan damper
Post by: Range91 on January 06, 2018, 06:39:07 AM
6 degrees this morning.. This is a pic of a 12hr load from last night last pic is this mornings coal bed. One piece of red pine on the bottom rest is oak and beech
Title: Re: fan damper
Post by: Elguano on January 07, 2018, 07:27:43 AM
Yeah no something is definitely wrong with mine, I load it hard, and it will barely make 12 hrs. Ok was -13F or -25C Overnight. It's my first OWB and still trying to figure it out. I couldn't get my hands on oak logs tho, so i had to get tamarack and red pine. Got sold 15 face cord of splitted 16" hardwood, then been told that wouldn't cut it into this boiler, need round big logs (which i must admit is wayyyyyyyyyyy better than the small wood)

It's also the BL 34 44, but am heating a fairly new 3800SQ house (well insulated house), with a dual car garage and a guess house of 1200 Sq ft + a sidearm for HW. But i barely can last 12 hrs. I did setup a data logger to see when the water temp, and it drop every single night, I am thinking of a buffer tank maybe would help.

Trying to pin point what wrong, i run it at 190C and 178C to restart.

And if you look at the datalogging the probe is about 25F offset, been just taped on the valve to get my temperature reading.
Title: Re: fan damper
Post by: hondaracer2oo4 on January 07, 2018, 03:46:39 PM
Data logging is great! Ok so there is only one day on your chart that doesnít have a drastic loss of temp for a while. I counted 25 cycles thst day running 178-190. Is thst right? With the specs for the boiler it has 120 galllons. To bring the water from 178-190 you create 12,672 btus. So if your boiler runs roughly 1 time per hour thst means your house is using 12,672 per hour. Thst is very reasonable!! I am using 22,000 btu per hour heating 2800 sqft with temps between -15 and 10 degrees. Your wood is the problem and the fact that you arenít using a gasser also increases wood usage. 
Title: Re: fan damper
Post by: tinfoilhat2020 on January 08, 2018, 07:11:14 PM
what kind of wood are you burning? sounds the like numbers add up.
Title: Re: fan damper
Post by: Elguano on January 09, 2018, 07:15:41 PM
Tamarack and red pine (softwood) and kinda green too , not exactly sure when it was cut
Title: Re: fan damper
Post by: hondaracer2oo4 on January 09, 2018, 09:03:03 PM
And there's your high wood use.
Title: Re: fan damper
Post by: Elguano on January 11, 2018, 12:28:16 PM
Thanks for the info :) Like i said, really new at running an OWB, I just ordered a truckload of maple for the end of the month, should have the time to season over the summer, should I split it? or Just cut it into 24" Round Logs would do the job?
Title: Re: fan damper
Post by: hondaracer2oo4 on January 11, 2018, 12:29:19 PM
Green maple?
Title: Re: fan damper
Post by: Elguano on January 11, 2018, 02:57:06 PM
Yes cut about 1 month ago
Title: Re: fan damper
Post by: hondaracer2oo4 on January 11, 2018, 03:23:09 PM
You are going to need to split it and figure out what size works best. Probably start out around 6 inch splits with a good coal bed already established and work up or down in size from there. Coal bed is very important with green wood. Order as much wood as you can afford as soon as possible so you can start getting wood seasoned for next year.
Title: Re: fan damper
Post by: Elguano on January 13, 2018, 08:11:06 AM
Any thought about a buffer tank? Seem like a good idea + I have plenty of room inside the house
Title: Re: fan damper
Post by: hondaracer2oo4 on January 13, 2018, 08:33:19 AM
More water capacity isn't going to change the btu needs of your house. They remain the same depending on outside temps. Now if you were going to utiliZe 500-1000+ gallons and batch burn and only use the the stove to heat up that water once per day than you might be able to squeeze some effieincy out of the stove since there would be no idling. Other than that there's no gains in wood use Efficiency.
Title: Re: fan damper
Post by: Elguano on January 19, 2018, 06:08:55 PM
Thanks for all the info ;) appreciate the help

Just as a for my info, live in Ontario Canada, so cold -30C seem to happen often this year. Do you think thoses setting are optimals or i could play with?

On 180F
Off 192F
Damper fully on

Seem to have about a 5F difference from the aquastat and thermometer wrapped analog with thermopaste wrapped around the outlet pipe.

Omce inside the house , am loosing about 5F over 120ft (not bad considering the pipe is only burried 18Ē) and there about a 10F from running thru the house heat exchanger and my sidearm.

Thx

Every thing else is sti
Title: Re: fan damper
Post by: hondaracer2oo4 on January 19, 2018, 07:00:20 PM
Letís clarify. You think you are losing 5 degrees between the boiler and the house? Can you confirm thst? If so your underground lines may have failed. Thatís a lot over 120 feet. Do you have any snow melt?
Title: Re: fan damper
Post by: Elguano on January 21, 2018, 06:08:44 AM
No snow melt, 5F over 120feet , I tough this was actually pretty damn good ;(Don't forget that my pipe is only burried 18" could go deeper we are directly on the rocks
Title: Re: fan damper
Post by: wreckit87 on January 21, 2018, 07:20:23 AM
5 degrees in 120 feet is a lot. What type of underground do you have? 1/2-1 degree per 100ft is pretty standard for good line at 6-7 GPM. If your flow rate is low may have some bearing on the higher drop, but if my math is correct, you're losing 36,000 BTU per hour in the ground if you're flowing 7.2 GPM. That's every hour of every day.

3.6 gallons in 1" pex over 120 ft, 7.2 for supply and return combined.

7.2 GPM means 1 full exchange per minute

7.2 gallons at 8.33 lbs per gallon makes almost 60 LBS of water per minute

60 LBS at 5 degrees each way is 600 BTU per minute lost

600BTU/min for 60 minutes is 36,000

Is that correct Honda?

Title: Re: fan damper
Post by: hondaracer2oo4 on January 21, 2018, 07:24:31 AM
The pipe could be buried 18 feet, should make little to no difference in temp loss. How are you measuring this 5 degree loss. I would expect to see snow melt with a 5 degree loss at that length of run. You have to remember if you lose 5 degrees to the house and 5 degrees back then you are losing 10 degrees just moving the water. If you are moving 8 gpm that means that every minute 8 gallons are dropping 10 degrees and every 10 minutes your are dropping 80 gallons 10 degrees and every 20 mins you are dropping 160 gallons 10 degrees. It adds up fast!
Title: Re: fan damper
Post by: hondaracer2oo4 on January 21, 2018, 07:36:58 AM
Yes Darin. I did it a different way but came out with the same.

1 gallon of water holds 8.3 btu per degree raised. So if you are
Flowing 7.2gpm x 8.3 btu = 597.6 btu * 60 min = 35856 btu per hour.


You would see an enormous wood use at this temp loss.
Title: Re: fan damper
Post by: Mr. Maple on January 21, 2018, 04:54:42 PM
More water capacity isn't going to change the btu needs of your house. They remain the same depending on outside temps. Now if you were going to utiliZe 500-1000+ gallons and batch burn and only use the the stove to heat up that water once per day than you might be able to squeeze some effieincy out of the stove since there would be no idling. Other than that there's no gains in wood use Efficiency.
   I would have to respectfully disagree about water capacity as far as burn times for the furnace,btus going to the house. Not many have benn able to compare furnaces side by side,but being on my third outdoor furnace I think I can put some input into this.
  Our first furnace was an Empyre 450, water capacity 300 gallons,rated for 8000 square feet. My Father's house is a HUGE brick farmhouse,ours is smaller but older,needing improvements to insulation,windows etc as money and time permit. Have never calculated square footage,just went by what our Empyre dealer recommended.The furnace worked very good,just really liked it's wood.
Two wheelbarrow loads of wood about 10:00 at night to carry it through until 6:00 in the morning,so I was looking for a furnace that would last longer and use less wood.
 Next was a BL 4044, water capacity 160 gallons,rated for 12000 square feet( has to be a typo,because there is no way it could handle it)!!! THREE wheelbarrow loads at 10:00 at night,stone cold and out before 6:00 in the morning,had to be out to feed it again by 5:00
Now to the present and best furnace,Heatmaster MF 20000E,500? Gallons I believe ,rated for 20000 square feet. Is it oversized? probably,but TWO wheelbarrow loads in at 8:00 at night easily does until 9:00 or 10:00 the next morning,when it was extremely cold,-36 F,it cut down to 10 hours between loads.
  To recap,SAME heating requirements- furnace 1-300 gallons,TWO wheelbarrow loads for an 8 hour burn in cold but not extreme conditions,furnace 2-160 gallons,THREE wheelbarrow loads for a 6-7 hour burn,and furnace 3-500 gallons,TWO wheelbarrow loads for a 12-14 hour burn.
Title: Re: fan damper
Post by: wreckit87 on January 21, 2018, 05:13:37 PM
More water capacity isn't going to change the btu needs of your house. They remain the same depending on outside temps. Now if you were going to utiliZe 500-1000+ gallons and batch burn and only use the the stove to heat up that water once per day than you might be able to squeeze some effieincy out of the stove since there would be no idling. Other than that there's no gains in wood use Efficiency.
   I would have to respectfully disagree about water capacity as far as burn times for the furnace,btus going to the house. Not many have benn able to compare furnaces side by side,but being on my third outdoor furnace I think I can put some input into this.
  Our first furnace was an Empyre 450, water capacity 300 gallons,rated for 8000 square feet. My Father's house is a HUGE brick farmhouse,ours is smaller but older,needing improvements to insulation,windows etc as money and time permit. Have never calculated square footage,just went by what our Empyre dealer recommended.The furnace worked very good,just really liked it's wood.
Two wheelbarrow loads of wood about 10:00 at night to carry it through until 6:00 in the morning,so I was looking for a furnace that would last longer and use less wood.
 Next was a BL 4044, water capacity 160 gallons,rated for 12000 square feet( has to be a typo,because there is no way it could handle it)!!! THREE wheelbarrow loads at 10:00 at night,stone cold and out before 6:00 in the morning,had to be out to feed it again by 5:00
Now to the present and best furnace,Heatmaster MF 20000E,500? Gallons I believe ,rated for 20000 square feet. Is it oversized? probably,but TWO wheelbarrow loads in at 8:00 at night easily does until 9:00 or 10:00 the next morning,when it was extremely cold,-36 F,it cut down to 10 hours between loads.
  To recap,SAME heating requirements- furnace 1-300 gallons,TWO wheelbarrow loads for an 8 hour burn in cold but not extreme conditions,furnace 2-160 gallons,THREE wheelbarrow loads for a 6-7 hour burn,and furnace 3-500 gallons,TWO wheelbarrow loads for a 12-14 hour burn.

Those are due to the furnace, not the water capacity. If you were to add 500 gallons of storage to any of those 3 stoves, they wouldn't take any less wood. Just doesn't work that way. BTU requirements of the buildings remain the same
Title: Re: fan damper
Post by: hondaracer2oo4 on January 21, 2018, 05:18:48 PM
What you are expierecing is the efficiency of the stove. Stove could have 100 gallons or 1000 gallons. It won't change the effieincy of the boiler at capturing the heat and transferring it into the water.
Title: Re: fan damper
Post by: Elguano on January 21, 2018, 06:16:59 PM
What kind of termostat are you guys using to see what the water temp? I have those wrap around thermometer, they might not be the most accurate one...
Title: Re: fan damper
Post by: wreckit87 on January 21, 2018, 06:34:37 PM
What kind of termostat are you guys using to see what the water temp? I have those wrap around thermometer, they might not be the most accurate one...

I try to put immersion/well type thermometers in everything, but a simple infrared gun works pretty well if you have access to one. A single wrap of black electrical tape around the pipe, and then physically hold the gun against that tape for a second. They don't measure exact water temp, but will get very close in measuring the difference between say, the supply at the boiler and the supply entering the house
Title: Re: fan damper
Post by: hondaracer2oo4 on January 21, 2018, 06:56:44 PM
Those temp gauges that wrap around the pipe I found to be wildly inaccurate.
Title: Re: fan damper
Post by: shepherd boy on January 21, 2018, 07:17:05 PM
What you are expierecing is the efficiency of the stove. Stove could have 100 gallons or 1000 gallons. It won't change the effieincy of the boiler at capturing the heat and transferring it into the water.

  One thing may be happening is better heat transfer due to large amount of steel to transfer heat to the water jacket in the large stove. 
  Those sq. ft. ratings are a joke. And untested BTU ratings.
  My first stove was a T450 Taylor hooked to a greenhouse. Loaded every 3hrs. Put in another stove held about 80 gals. less and would run all night.
Title: Re: fan damper
Post by: Elguano on January 23, 2018, 07:06:05 AM
What kind of diffencial you guys are using?
Title: Re: fan damper
Post by: wreckit87 on January 23, 2018, 08:35:36 AM
What kind of diffencial you guys are using?

10-15
Title: Re: fan damper
Post by: Range91 on January 23, 2018, 05:37:50 PM
185 set point 5-6 diff. My stove recovers fast at this temp and if I let it do a long burn it starts to boil pretty bad
Title: Re: fan damper
Post by: Revx1000 on January 24, 2018, 08:33:31 PM
I run mine at 180 out with a 6 diff  when I first set it up 5 years ago I tried a number of setting found the 180 mark to work the best for me. My heater is 85 ft from the building . With Temps running -15 and up I will add once a day 24 hour burn with loading to the bottom of the door , I run my damper half way open I find that running it wide open burns way more wood. I was measuring stake temputure this is where I found the most efficient . Iam heating 3600 sq ft with two 14 ft over head doors , all in floor heat no over head or furnace . It will hit -40 here I will load 1/2 in am and a 3/4 load at night . I am extremely pleased with this 3444 heater it has never missed a beat . One other thing I did learn the first year was to have proper seasoned and DRY wood makes a big difference in how long a load will last . Wet or green wood will use over 30 % of the wood to dry it self out before it will start burning properly and making heat .

Vernn
Title: Re: fan damper
Post by: Elguano on January 25, 2018, 07:21:39 PM
Thx this is great info, I will give it try and keep u posted, and what kind of wood do you throw in there? What size of logs too? Splitted or round?
Title: Re: fan damper
Post by: Revx1000 on January 26, 2018, 10:11:13 PM
Popular for the most part  I use tamarack when really cold mixed with a few sticks of the popular.  The unsplit I cut to 38" long up to 12" in diameter anything larger is just to heavy !!! Then the large ends cut to 24" split in half or three . I find that the split ones do not last as long as the rounds due . So in fall and spring (warmer ) weather I used the split stuff . Again well seasoned and dry makes a huge difference to burn time as well as the fire box stays cleaner . I built a 50 ft wood shed which is full then in spring I load my pallets ,cover with osb on the top set out ready for fall . I built 13 8ft long x 42 deep x4 ft high crates from 1" sq tubing that I cover with a sheet of osb . Move them with bobcat works great for the 38 inch rounds  the 24 " I have pallets with sides and osb on top . We purchased 14 acres about 7 years ago all bush land  I cleared out about 1200 trees all popular to make the yard site . Still have about 3 years left of them !!!!   My take on the wood is to always be 2,3 years ahead of what I will burn in a season ,keep it covered and dry
Title: Re: fan damper
Post by: Elguano on January 27, 2018, 05:10:24 PM
We got about 80 Acres here that we have bought about 1.5 Yr Ago, but most of the wood is cedar and pine... I don't think it any good to burn, maybe mixed with something else, like I said, really a rookie at this whole Outside wood boiler stuff, still figuring out... But so far, really enjoying the free heat (well not exactly free, but when you compare to the 5K last year it costed in propane... this year it's almost free :)

Title: Re: fan damper
Post by: wreckit87 on January 28, 2018, 10:40:12 AM
We got about 80 Acres here that we have bought about 1.5 Yr Ago, but most of the wood is cedar and pine... I don't think it any good to burn, maybe mixed with something else, like I said, really a rookie at this whole Outside wood boiler stuff, still figuring out... But so far, really enjoying the free heat (well not exactly free, but when you compare to the 5K last year it costed in propane... this year it's almost free :)

Depending on the species of pine, it's not THAT bad. Couple years ago I had a cord of white pine, mostly 6-10" rounds but still 30ish percent moisture and I swear the stuff lasted as well as oak. The sap was terrible but I didn't cut it, I took it on trade for something else lol. Had some green white cedar that did surprisingly well also. Now Poplar on the other hand isn't worth the gas to cut up IMO, I've got acres of it in my backyard and I won't bother blocking it anymore when they break off. They get pushed on a pile with the Bobcat and burned whole.