Fisher Grandpa Bear

[bradiowa]

Looking to confirm what how i need to vent my Fisher Grandpa Bear wood stove. I have a rear outlet 8". I am sitting this in the corner of my cabin with vaulted ceiling. My plan was to come out of the back and use to 45 degree stove pipes to go horizontally to the wall (about 3') then using wall thimble to an outside T, from there going up on the outside of the cabin to 7' above the roof eve . roof pitch 6/12. Through wall and outside i planned on using double wall class a piping. Inside standard black stove pipe with a damper.

I read somewhere i need to go vertical atleast one foot before i can run horizontally outside??

Any advise or recommendations would be appreciated. Thanks in advance

 

[coaly]

What model Grandpa is this?
A III with UL tag on integral shield on the back, or unlisted with angle iron legs on the corners?

Installation requirements are in the manuals in the sticky section at top of main forum page.

No need for a vertical rise inside, rear vent stove model is made for horizontal through-the-wall chimney installation. The pipe required is double wall inside for this type installation.

That is also the worst drafting type chimney, (all exterior) and most expensive, so double wall instead of triple wall should be used. (they use denser insulation and stay hotter inside easier).

What size is the cabin? Grandpa heats a very large area. You may be fine with a 6 inch chimney if you don't need the full capacity of that large of a stove. (it is technically against code to reduce the pipe or flue smaller than stove outlet) These were built oversize originally to connect to larger existing chimneys and for open door burning with screen in place. Many work fine reduced. All depends on chimney.

 

[bradiowa]

What model Grandpa is this?
A III with UL tag on integral shield on the back, or unlisted with angle iron legs on the corners?

Installation requirements are in the manuals in the sticky section at top of main forum page.

No need for a vertical rise inside, rear vent stove model is made for horizontal through-the-wall chimney installation. The pipe required is double wall inside for this type installation.

That is also the worst drafting type chimney, (all exterior) and most expensive, so double wall instead of triple wall should be used. (they use denser insulation and stay hotter inside easier).

What size is the cabin? Grandpa heats a very large area. You may be fine with a 6 inch chimney if you don't need the full capacity of that large of a stove. (it is technically against code to reduce the pipe or flue smaller than stove outlet) These were built oversize originally to connect to larger existing chimneys and for open door burning with screen in place. Many work fine reduced. All depends on chimney.

Not sure of the model except it has a star with 76 on the left door.

Cabin has 22' ceiling 1020 sq ft down and 500 sq in the loft. I will attach a couple pics for reference.

My 2 choices are like you said directly out then outside with double wall. I was also considering running it interior in stove Pipe to the roof then transition to double wall.

 

[bradiowa]

Not sure of the model except it has a star with 76 on the left door.

Cabin has 22' ceiling 1020 sq ft down and 500 sq in the loft. I will attach a couple pics for reference.

My 2 choices are like you said directly out then outside with double wall. I was also considering running it interior in stove Pipe to the roof then transition to double wall.

Actually looking at the stove the 76 star is on the right

 

[coaly]

That is the first of the double doors made in 1976 and considered Series I.
The Series III after 1979 is the UL approved version that requires double wall connector pipe (close clearance pipe) inside when used horizontally through the wall.

With a chimney that high outside, you should use double wall connector pipe inside with any stove, if you go horizontal out the wall.
You want the exhaust gasses as hot as you can get them without wasting tons of fuel to keep the chimney hot.

A through the roof kit is much cheaper and requires much less chimney pipe. You mount a support box at the roof and only need a couple chimney sections outside. With the high ceiling, you would need double wall connector pipe inside as well. Single wall cools too much running over 8 feet and the internal flue temperature is not hot enough to keep it clean or cause the stove to work properly.

 

[bradiowa]

That is the first of the double doors made in 1976 and considered Series I.
The Series III after 1979 is the UL approved version that requires double wall connector pipe (close clearance pipe) inside when used horizontally through the wall.

With a chimney that high outside, you should use double wall connector pipe inside with any stove, if you go horizontal out the wall.
You want the exhaust gasses as hot as you can get them without wasting tons of fuel to keep the chimney hot.

A through the roof kit is much cheaper and requires much less chimney pipe. You mount a support box at the roof and only need a couple chimney sections outside. With the high ceiling, you would need double wall connector pipe inside as well. Single wall cools too much running over 8 feet and the internal flue temperature is not hot enough to keep it clean or cause the stove to work properly.

Thanks for all the info.

What would you recommend interior or exterior? Also if I run it interior do you still install a T so you can clean the chimney? Or how would you clean the chimney without a clean out point? Take off the bottom 90?

 

[coaly]

Interior. Double wall pipe to the support box.
I clean from the bottom up through the stove with a chimney whip. (Soot Eater) If you have a metal roof, I'd remove the spark screen. They clog and you have to get up there to clean the screen even when cleaning from the bottom up.

Normally the stove is bought for the pipe and chimney configuration. A top vent stove is made for the straight up installation. The rear vent is made for horizontal or hearth installations. In a corner installation or back wall with a rear vent, pipe clearance to combustible wall becomes an issue. (18 inches single wall pipe / 6 with close clearance double wall) This is avoided with a top vent stove.