Direct Connect was "Safe Slammer"

[mass_burner]

If you could make any modification to an older stove, could you make a slammer as safe as an open fireplace?

 

[Nick Mystic]

When you talk about a "slammer" I take it you are referring to an insert being placed inside a fireplace with no flex liner attached that goes all the way up to the top of the chimney. Instead, there is either just a short piece of pipe attached to the insert only past the smoke chamber or nothing at all attached to the insert and it just dumps smoke into the firebox of the fireplace and the smoke goes up the masonry chimney. Assuming this is what you are talking about, I would say it depends a lot on the size of the clay tile flue. One big problem with slammer installs is that there is no easy way to clean the chimney since the insert needs to be pulled out each time you do a sweep or else the creosote and ash ends up falling down the chimney where it ends up accumulating in the smoke chamber, the top of the insert, and inside the fireplace firebox.

If you were going to modify anything to improve the safety of a slammer install I don't think you'd modify the stove, rather you would want to modify the connection between the insert and the clay tile liner. I would think if the flue wasn't too large for the insert you might be able to fabricate something that connects to the insert and then flares out in such a way as to make an airtight connection with the clay liner. If you could do this successfully you would then keep all the creosote contained inside the insert like it is with a modern installation. Of course, this assumes that the insert you were using allowed you to access the top of the baffle or wherever the debris from the sweep ends up falling so you could remove it.

 

[begreen]

Yes, attach a full liner.

 

[mass_burner]

When you talk about a "slammer" I take it you are referring to an insert being placed inside a fireplace with no flex liner attached that goes all the way up to the top of the chimney. Instead, there is either just a short piece of pipe attached to the insert only past the smoke chamber or nothing at all attached to the insert and it just dumps smoke into the firebox of the fireplace and the smoke goes up the masonry chimney. Assuming this is what you are talking about, I would say it depends a lot on the size of the clay tile flue. One big problem with slammer installs is that there is no easy way to clean the chimney since the insert needs to be pulled out each time you do a sweep or else the creosote and ash ends up falling down the chimney where it ends up accumulating in the smoke chamber, the top of the insert, and inside the fireplace firebox.

If you were going to modify anything to improve the safety of a slammer install I don't think you'd modify the stove, rather you would want to modify the connection between the insert and the clay tile liner. I would think if the flue wasn't too large for the insert you might be able to fabricate something that connects to the insert and then flares out in such a way as to make an airtight connection with the clay liner. If you could do this successfully you would then keep all the creosote contained inside the insert like it is with a modern installation. Of course, this assumes that the insert you were using allowed you to access the top of the baffle or wherever the debris from the sweep ends up falling so you could remove it.

I was thinking more of a free standing stove. What are the dangers and what could done to reduce/eliminate them?

 

[begreen]

Slammer refers to an insert installation. Most inserts are not designed or tested to be freestanding. Most Buck stoves are an exception. Are you talking about an insert? If so, assuming 36" clearances, what would be the hearth insulation requirement?

 

[mass_burner]

Slammer refers to an insert installation. Most inserts are not designed or tested to be freestanding. Most Buck stoves are an exception. Are you talking about an insert? If so, assuming 36" clearances, what would be the hearth insulation requirement?

ok, so I'm not referring to an insert or slammer; but a freestanding stove not attached to a full liner. What is this called, a floater?

 

[begreen]

It's called a freestanding stove. It's made safe by installing it with a proper flue system that honors clearances and code requirements; that has an appropriately sized and insulated hearth; and that honors clearance requirements for the stove.

Pre-UL stoves require 36" clearances in all directions. NFPA outlines the stove installation requirements. Is there a particular freestanding stove in mind?

 

[mass_burner]

Okay, let's assume clearances are fine and a wide and raised brick hearth is in place. Is there any danger in venting up the masonry flu w/o a liner? Let's say you put a 2' section of pipe from the stove to the open damper.

 

[trguitar]

My insert was installed this way 4 years ago. The certified sweep (CCS) said this was ok for my install because it is an internal chimney (i.e. it goes up the middle of the house). I get it sweeped every other year, and there is barely any creosote.

 

[begreen]

That's a direct connect. The damper area must be sealed with a block-off plate. This is assuming that the chimney is tile-lined and installed correctly with 2" clearance to combustibles all the way up. (Many are not!)

It "may" work, but may not draft well if the area of the chimney is much more than the area of the stove flue. Safety wise it may be riskier due to increased cooling of the flue gases causing creosote. Higher flue temps from the stove may be another possibility and it will certainly be dirtier because brushing the chimney will cause most of the sote to accumulate on the smoke shelf around the pipe and not in it. So judging the amount of creosote from a sweeping can be deceptive. And having a big pile gathering around the hot flue pipe stud is not the safest.

For the little additional cost and benefits of a full liner, not putting up a liner is penny-wise and pound foolish, IMO.