Is this the right way to measure for a rear-exit flue?

[williaty]

In our new house, I have an existing masonry open-hearth fireplace that I'd like to convert to a wood stove via sitting a stove in front of it and running a rear-exit flue up the chimney. From a little searching, I've found that the limiting factor is the height of the rear exit flue on the stove vs the height of the opening in the existing hearth. However, I haven't found instructions for exactly how to figure this out. Here's what I've come up with and hopefully you guys can tell me if I did this right or wrong.

1) The distance from the existing floor to the top of the hearth opening is 29.5"

2) Looking at manufacturers specs for 6" double-wall stove pipe, it seems like they mostly come in at 7" or just a hair less in diameter

3) Half of that 7" diameter is a 3.5" radius

4) 29.5-3.5"=26". So as long as the centerline height of the rear exit on the stove is at or below 26", it should be possible to make it work.

5) The thickness of any hearth pad required by the specific stove has to be subtracted from the 26".

Did I get this right?

 

[begreen]

Yes, good job so far. Some stoves require only ember protection of the hearth and can sit on the hearth extension if it is deep enough. If you can post some pictures of the setup, that will help. For that short connection, it may be possible to use single-wall for the connection to the tee that connect to the chimney liner. There are even some tees that have a long snout to accomplish this without additional fittings.

Also take note of the stove's clearance requirements, especially if there is a combustible mantel or trim nearby.

 

[williaty]

Yes, good job so far. Some stoves require only ember protection of the hearth and can sit on the hearth extension if it is deep enough. If you can post some pictures of the setup, that will help. For that short connection, it may be possible to use single-wall for the connection to the tee that connect to the chimney liner. There are even some tees that have a long snout to accomplish this without additional fittings.

Also take note of the stove's clearance requirements, especially if there is a combustible mantel or trim nearby.

OK, going to try to make sure I answer everything.

1) Stoves under consideration are the Hearthstone soapstone stoves (not sure which size yet) which require ember protection only, the Woodstock Progress Hybrid with the short legs which requires R 0.80 for the hearth pad, and the Ideal Steel, which also requires R 0.80.

2) Respecting the rear clearance will mean that the stove sits well forward of the existing bit of masonry hearth, so I'm going to have to use a fairly large hearth pad to cover everything.

3) Only picture I currently have of the space was taken for the flooring work but you can kind of get the lay of the land around the existing fireplace.

 

[williaty]

FWIW, I have an Ideal Steel now at our current house and, while I like many things about it, I'm a little wary of getting another one because it's just way, way too much heat and we can hardly ever use it lest it overheat the whole house. It also has a little bit of a tendency to run away and scare the chit out of us.

OTOH, the Hearthstone models have a bad rap for wear problems and terrible customer service, so I'm honestly not sure what to do.

 

[begreen]

It's unfortunate that the rear exit stove list has decreased substantially due to changing EPA regs and market conditions. There used to be several more. Look at the Jotul F400 and F500 as possible options. They can be ordered with short legs to lower the flue outlet by a couple of inches.