Brand of Flue And Size

[Frankdozer]

I have 2 stoves. A Papa Bear with a 6” rear flue and a Grandma Bear with an 8” top flue. I need to install the flue vent now for renovation purposes. From the top of the stoves to the wood ceiling is approx. 6’. I then need to go up thru another floor of 10’ thru that ceiling / roof which has a slight pitch is 2/12.

I have not decided on which stove to use which brings me to what size flue to use either 6” or 8”.

Also at what point do I use single wall pipe and change to double wall pipe.

Should I use a tee ... then connect to the stove or.....

And finally which Brand of double wall flue pipe do you recommend and is the best.

Thanks,
Frank

 

[coaly]

Single wall is connector pipe from stove to the start of chimney which would be at the ceiling above stove. If you don't have 18 clearance to the connector pipe, you need double wall connector pipe from stove to chimney. That is the terminology of single and double wall pipe.
Pack type chimney having 2 walls is preferable to triple wall chimney sections. 2 wall chimney uses a 2 inch smaller opening than triple wall. All are safety rated the same so brand is a matter of preference.

I would use a Tee on the rear vent, straight up on the top vent.

First consider heat output between the stoves with Papa being higher for a larger area or less insulation. Your area probably requires the most you can get from either, so Papa is better for the needed heat. You need to compare a Grandpa for the same heat output with more fuel waste compared to Papa.

I would use 6 inch with the Papa Bear for a few reasons. (but rear vent and top vent have different installation clearances, so you can't compare a top vent to a side or rear vent that are built for different installation configurations) You need a top vent if you're going straight up and don't have the clearance for pipe behind stove. If the stove is in the middle of room for the best circulation, top or rear doesn't matter. A corner installation would require top vent...... You need a top vent Papa to compare the two for that type of installation.

First, Papa is a more efficient stove. Only if fire viewing is a necessity would I consider the Grandma. I used a Goldilocks for years that has two doors and screen option and only used the stove with doors open in Fireplace Mode when starting with storm dampened wood. That was the only use I ever had for open door burning. They are not considered a radiant heater in Fireplace Mode.
Second, if you upgrade to a newer EPA stove you will have the correct size chimney in place for most new stoves.

I would bet with no elbows and insulated chimney all the way that the Grandma would draft fine with the 6 inch chimney, but it is technically against code to reduce more than 1 inch when using NFPA 211 Standard and NO reduction is allowed when using the International Code Council Mechanical Code that regulates chimneys and venting, adopted in most states.

Like you, most people today have the stove or a selection to choose from, but buying new at a Fisher dealer you would be asked the size area you're heating to get you to the correct stove first. Then choose the vent configuration for your installation. Each model and vent configuration are purpose built.