Fireplace Insert

[dieselscout80]

We bought a Oak Ridge fireplace insert that is from the 1980s that we are going to install it in our masonary fireplace.

The outlet of the insert is 12" x 8.125" which is about 96 square inches. Our chimney is lined with tile that is 11" x 10.25" which is about 110 square inches, but it looks it's not lined all the way down.

Since we are in South Carolina do we need to line our chimney all the way up or just up to the tile lining?

How can I make an adapter to connect the insert to chimney pipe?

[Raspy]

Get a piece of stainless chimney pipe and slip it down the chimney. The adapters to go to the insert vent fitting are available. Even if you have to go to a smaller size it will work fine as the new pipe is less massive and will draw well. Also, most stoves run damped down and actually have more chimney area than needed. In my area it is actually required by code to insert a new pipe.

You can cut out the old damper if needed to get a bigger vent through.

If your house is reasonably air tight you might need an outside air source. If you can't get a good draft, open a door and see if that fixes it. If so, give it outside air. Be sure the top cap on the chimney the correct type that doesn't cause problems in the wind.

Inserts are not the most efficient, but far better than a simple masonry fireplace.

[Bob1070]

Dieselscout,

I live in New England and have used a BetterNBen's insert like yours for over twenty years with good results. I agree that you should put a stainless steel one-piece insert liner into your chimmney top to stove the same size as the outlet of your stove. ( likely 6") I bought mine based on low price via the Internet.

Just last weekend I installed an Osburn 2400 insert ($2000. cash) in place of the old stove and am VERY pleased with the new technology that gets you a much longer, even burn with the same amount of wood, and you get to view the flames thru the glass front door. Got $400. for the old stove and sold it in a week.

[dieselscout80]

How big of a liner should I use?

The masonary chimney is about 13' tall.

I'm thinking 8", but if I could use 6" it would make it easier to get it through the masonary chimney's damper and it would be less money too.

[KennyG]

How big of a liner should I use?

The masonary chimney is about 13' tall.

I'm thinking 8", but if I could use 6" it would make it easier to get it through the masonary chimney's damper and it would be less money too.

The liner size should match the size of the chimney connection on your insert. Height doesn't matter.

[KennyG]

How big of a liner should I use?

The masonary chimney is about 13' tall.

I'm thinking 8", but if I could use 6" it would make it easier to get it through the masonary chimney's damper and it would be less money too.

The liner size should match the size of the chimney connection on your insert. Height doesn't matter.

[Raspy]

Your square top stove vent will need an adapter to fit the chimney pipe. If you can get an 8" down the existing chimney, that would be nice, but six inch will work fine. Eight will run longer with poor wood without clogging.

The height does matter and matters a lot. That is what makes the draft. With 13' of vertical, 6' would be a good size. It's the most common on wood stoves. There is going to be a lot less air going up the stack than with a conventional fireplace, that's one of the reasons inserts are more efficient.

[KennyG]

Your square top stove vent will need an adapter to fit the chimney pipe. If you can get an 8" down the existing chimney, that would be nice, but six inch will work fine. Eight will run longer with poor wood without clogging.

The height does matter and matters a lot. That is what makes the draft. With 13' of vertical, 6' would be a good size. It's the most common on wood stoves. There is going to be a lot less air going up the stack than with a conventional fireplace, that's one of the reasons inserts are more efficient.

My understanding is that you should, if possible, not have the chimney larger than the stove/insert outlet. The larger the chimney, the slower the flow and greater the heat loss, leading to greater creosote buildup. Height is important for good draft, but doesn't have an impact on the proper chimney diameter.

[dieselscout80]

My understanding is that you should, if possible, not have the chimney larger than the stove/insert outlet. The larger the chimney, the slower the flow and greater the heat loss, leading to greater creosote buildup. Height is important for good draft, but doesn't have an impact on the proper chimney diameter.

The opening on my insert is 12" x 8.125" which equals 96 square inches.

Liner pipe:
6" = 28.27 square inches
8" = 50.26 Square inches

Is 6" liner pipe large enough for my insert?

[KennyG]

Sorry, I missed the size and age in your original post. Most modern inserts have round outlets sized to use chimney pipe. I'm at a loss to know exactly how to size it but most wood stoves up to 100,000 BTU or over today have 6 inch pipe so I know it has a lot of capacity. I can't guarantee anything, but I can't imagine building a fire in an insert that 6 inch won't handle.