Apples too Apples For OWB

[DHIBBS75]

Ive read several different opinions on water tank size... I want too see what your burn times and cycle times for 24 hrs on equal size stoves..water tank capacity... with water temp up to temp..... not from cold start....about the same btu requirements.... I am fixing to build an OWB to heat a 2500 sq ft house and 900 sq ft garage....

Here is my thoughts about this subject... If you have a large capacity of water you will have long burn times but less cycle times..

With small capacity you will have shorter burn times but more cycle times..... I think in the end you will still burn the same amount of time...

My stove I THINK will be 1/4 thick fire box 36 dia x36 long and water tank 60x60x36... Still have to figure out tank capacity....

Have to see what dimension the metal comes and have it bent....
I will post a pic soon....

OPINIONS WELCOME:monkey:

 

[DHIBBS75]

View attachment 167960

 

[ctrees4$]

:monkey: could you repeat the question please.....I couldn't stop looking at your avatar!

 

[applefarmer]

My house is 2800 ft, my garage is 600. House is kept at 73 when we are here 69 when we are not (about 50/50 I think). Garage is kept at 50 except if I am working out there, then I will bump it to 62ish (not often). I live in SW lower Michigan, this last week we have had lows ranging from -10 to +teens, highs have been in the 20's. With these temps if I totaly packed my boiler full I might make 24hours but I don't think so. My routine is 2/3 full at 5:00 pm then rake the coals/left over wood at 8:30 the next day, then throw a couple logs in at noon. When temps are in the high 30's low 40's I can go 24 hrs easy on 2/3 full load. I have the hawken he1000, the water capacity is 150 gals. the firebox is round and is 44" long. Hope this helps!

 

[DHIBBS75]

Which is better PSI or open tank?????? Do you want the taco pump on the return or supply?????

Most pumps are designed to push and not pull... I will probably have to push water to the second level of the house.. Do I need a second pump just for this....

Im heating basement, mainfloor, upstairs.. The Stove will be about 50-100 ft away.....

 

[Chuck Diesel]

WM 4400 heats 3600 sq. 117 gals of water. fire box is 36 x 42. 5 logs 6 x 30 holds for 12 hrs. at 6 above.
Good Luck
Chuck D.

 

[H-Ranch]

My house is ~2700 square feet with 30' ceilings in the main living area and 20' ceilings in the upstairs bedrooms. No garage heat yet. I usually load wood when I get up and when I go to bed and have no problem maintaining temperature on that schedule. Usually much less than a full load but for the coldest days - it works best when I estimate the wood usage until the next fill so I don't end up with too many coals. My system has a 1/4" thick, 32" diameter x 48" firebox and has around a 200 gallon capacity. It's close to 100' run from the OWB to the house. Seems to me the burn time is usually relatively short to recover from 150 to 155 - maybe 10 minutes at the most.

Open system is the way to go so there is significantly less danger of pressure explosion in my opinion. I put the circulation pump in the basement on the return line to the OWB.

Rough calculation says about 400 gallons as you describe your design.

 

[1harlowr]

The water jacket would be 561 gal.
I think you'd burn less wood with longer burns as it would be at a higher temp for a longer period of time. Shorter burns you'd have more cycles which would translate into more times with start up temps on the fire.

 

[DHIBBS75]

Thanks fellas...

Been on grainger tonight pricing and looking up parts... Still not for sure on which Taco pump Heres what Ive found so far.....

Blower Dayton 146 cfm Grainger 1TDP7 $80.00
Aquastat Honeywell L6006A1244 grainger #2gzk3 $112.00
Taco Pump 009bf5-J $135 not grainger prices
011bf4-j $151.66 not grainer prices
Thermometer 3" dial 50-550f 4 " probe 3/4 npt grainer 1nfy7 $51.50
well grainer $23.94
Ball valves 1" npt $20.00 X 5

I know I can get Better prices else were....Just havent looked yet....
I will be putting a thermometer in the inlet and outlet pipes just for me to rack my brain.... Whats left.....

The Taco pumps are my only ????? so far.....

I will be using 1" pex..... I will be using a plate xchanger for water heat... thinking of using radiant floor heat for the main floor thus will heat the basement, then either radiant floor heat for 2 level above the garage or base board in both rooms.... then the garage probably a radiator and box fan for garage heat....

 

[jackel440]

ebay and industrial surplus houses are great places to find good deals on parts.Now I don't know what kind of field of work you are in,but I would look to find industrial type components to use.That's what I did on my build.That way you get better quality components that will not fail like cheaper consumer grade stuff.
You will have to do some leg work to figure out what works where.
Just like the Belimo damper/actuator I used on the air box on my gasifier.
I bought Grundfos pumps for my OWB.they are 3 spd units.If you watch the auctions on ebag you can find about the best deal there on them.
If you have a Menards store they have a pump that is either a rebadged Grunfos or a heck of a knock off for a good price.
I would look into getting a Ranco controller to operate the furnace,and then use a standard Honeywell aquastat for a high limit like I did.So if for some reason the controler malfunctions.The stat will break open not letting power to fow to your damper and blower.to keep from an boil over condition.
Have you considered where you air will come into your stove?bottom,back,top?
ash pan,with grates?tons of decisions to be made.Take your time ,and don't get in a hurry just to weld metal together.Really think about how efficient you can make it burn,and then extract the btu's from the burn.
Look at the different exhaust styles.Before I decided to go with a gasifier.I was going to model my exhaust with a double bypass similar to a "Portage and Maine" stove.
Go to the different manufactureres,and look at what they have done.See what works and what doesn't.They have spent the money on R&D to see what works.No need to reinvent the wheel.
Good luck

 

[jackel440]

You definately want to build an open system.Less hassle ,and your square style water tank will balloon with not too much pressure.
I got about 15 psi of air in mine when checking for leaks,and warped the crap out of the side where an inner antiballon brace ripped free from the pressure.
I then used about 8 to 10 psi to check for leaks.When that sucker expands it can hurt ya.
Now a round style tank would be suited to pressure. unless you are a certified pressure vessel welder ,and want to have the tank pressure tested I would stick to an open system.

 

[scag52]

Heres a good place for the parts.

PEX - Radiant Heat - Radiant Heating - Plumbing Supplies - PexSupply.com

Ranco thermostat 50.00 on ebay

get a 3 speed pump so you have some flow adjustment

 

[Steveguy]

One thing to remember is that you are not just pumping water up hill. You are circulating water in a closed loop. The water coming back down one side helps pull the water up the other, just like a siphon. For the most part, you don't have to worry much about elevation on a loop, more just concern with friction losses in the loop. This is true even if your boiler is an open design and not pressurized. My system has a CB5036 which is open design, stationed well below the house level. (10-15 ft lower) I use a bell and gosset pump that is about the same as a 009 taco, located on the stove. The stove is about 175 feet from the house and the system works well. You would think the water would drain downhill to the stove and overflow it, but that doesn't happen unless you let air in at the top of the loop.
As far as water capacity, compare the size of firebox to the tank size of major stove brands. There is a balance there to give good capacity and avoid excessive standby losses, and the possibility of too long between burns, putting out the fire in mild weather.
Just my thoughts....

 

[mtfallsmikey]

Have you done a heat loss calc. on your house? Any other information is meaningless until you do...See disclaimer below....

 

[DHIBBS75]

Thanks fellas... Lots of good info....My trade is a mechanic for caterpillar dealer... Im a halfass welder with mig and stick.... Ive upgraded from dogballs to pretty damn good welds... Ill trust my life and the familys with my welds.........Im still researching all the owbs.... I think my stack will go out the back and Im going to have a plate come down about 3/4 of the way down inside the firebox infront of the outlet to help keep the heat in as much and make the smoke go back down close to the fire....???? I will put a flap at the top so when Im feeding the monster hopefully I wont get smoked to bad....Im still researching all the products and Thanks Jackel 440 for the belimo info...

 

[DHIBBS75]

For the heat loss calculation......LOTS... Only insulation is the in the attic,,, new windows,, 1935 brick house freezer in the winter and oven in the summer.... Working on trying to figure out insulating...