What is your opiniong on off-set box?

[Dmitry]

I'm installing free standing woodstove in my masonry fireplace opening. Might not be getting far enough to connect to liner . What is your opinion of those off set boxes. Got around 20 ft straight shot liner from there.
https://www.rockfordchimneysupply.com/off-set-box.php

 

[Woody Stover]

An offset is going to complicate cleaning.
I was able to get enough down-angle to the stove top with a 15* elbow.

 

[ColdNorCal]

SBI makes Century, Drolet, Osburn which require a 12' min chimney length measured from stove top. With an offset installed for an insert, the requirement is 20' . The manual also states not to install one unless necessary. Check with your stove manufacturer.

I installed a free standing with flu going through the fireplace. Had to install a 90 elbow on top of stove because I wanted the stove sitting outside the fireplace. The 90 is angled about 75 degrees. The insulated flex liner makes a nice sweeping bend to create the vertical run up the chimney. Total height is 16' and this thing drafts great. Never, I repeat, never any smoke in the house and at times less draft maybe better. And this is in an area with very moderate winter outdoor temps of 30-40 night and 50-60 day. ymmv

 

[bholler]

I'm installing free standing woodstove in my masonry fireplace opening. Might not be getting far enough to connect to liner . What is your opinion of those off set boxes. Got around 20 ft straight shot liner from there.
https://www.rockfordchimneysupply.com/off-set-box.php

I would avoid it if at all possible if I were you. I as a pro will not install one. They just compromise performance too much and make it really difficult to clean