OWB vent size reduced

[R W Ohio]

Has anyone reduced the size of your OWB vent and if so did you get a longer burn time?

 

[Marklambert61]

Burn time

Burn time is based on heat loss up the chimney and BTU need in your heated space. If you could close the flue off during off cycles could lenthen your burn time. Just reducing your flue size will only limit your max BTU capisity. You could do the same thing safer by restricting the combustion air if BTU output redution is your goal.

Mark

Love my Heatmor stove

 

[MS-310]

Yes it will help it keeps alot of the "gases" in the boiler to be reburnt. It works!

 

[ktm250rider]

Cant comment as this is my first year with mine. I did put a cheap extension kit on mine and capped it with a reducer.

 

[ghitch75]

got mine necked down from 8" to 4"...mine heats up a 1/3 again faster and uses a 1/3 less wood than at 8".....now heres the kicker!.....you must have a boiler with forced air...natural draft won't work(from what i have found) not enough draft to keep the fire going....smoke bomb!!!

btw smokes a lot less on heating cycle....

 

[ktm250rider]

did you neck down right off the top of the boiler or did you add an extension?

 

[ghitch75]

i have mine 8" to 6" 2 2 ft sections of 6" then 6" to 4"...

 

[Bill Bednarick]

What kind of pipe did you use ghitch75 ?

 

[ghitch75]

i just use galvanized 24g pipe and fittings...lasts about 4 months.....i'm making a reducer setup out of shld 40 gas pipe that should out last the stove...

 

[zsteinmetz]

why did you go 8 to 6 then 6 to 4 just because you couldnt find the right reducer? has anyone else done this to their stoves and burnt less wood?

 

[hockeypuck]

the only drawback I could see would be burning out the blower motor prematurely (probably still last many years, but just thinking out loud).

 

[Bill Bednarick]

How would vent size effect motor life?
Doesn't seem like it would run more, in fact it may run less if the stove is burning the wood gas instead of just letting it go up the chimney mostly unburnt.

I'm going to try this soon, I like the idea of getting a better burn.
I'm happy with my woodmaster, but even good things can be improved.

 

[hockeypuck]

How would vent size effect motor life?
Doesn't seem like it would run more, in fact it may run less if the stove is burning the wood gas instead of just letting it go up the chimney mostly unburnt.

I'm going to try this soon, I like the idea of getting a better burn.
I'm happy with my woodmaster, but even good things can be improved.

You are creating more of a load on the fan by reducing the size of the chimney.

 

[ghitch75]

already checked amp draw 3.2 amps with or without.....

 

[laynes69]

There is no way it will cause backpressure with a 4" exhaust. Those little fans aren't pushing enough cfms to cause back pressure.

 

[HUSKYMAN]

I have to agree with Layne on this one, 4" is still plenty to evacuate anything the blower can put out.

I have a 4" straight pipe on my 5.9 Cummins turbo diesel, if that thing cannot max out a 4" pipe then a 3 amp motor sure as heck can't

 

[zsteinmetz]

lets see some pics of it running with it reduced

 

[ghitch75]

I have to agree with Layne on this one, 4" is still plenty to evacuate anything the blower can put out.

I have a 4" straight pipe on my 5.9 Cummins turbo diesel, if that thing cannot max out a 4" pipe then a 3 amp motor sure as heck can't

both my 6.5 turbo's have 4" pipes....they turn 375 cfm and the boiler blower turns 150 cfm....i'll post some pic's when it's firin'....3 degrees f here this morning....

here are the pic's...

 

[zsteinmetz]

why wouldn the factory put them all out like this? Seems logical.

 

[Dono]

I have a friend that put a damper on top of his heatmor. He also put the blower motors on a reastat switch to slow them down and reduce his wood consumption. He claims it works better this way. This is my first year with my heatmor and so far i love it although it is very hungry.