Installing Direct Vent Fireplace in existing masonry fireplace

[packman_]

Hi all,

I've searched and searched on this subject, but can't ever find an answer to my questions. We have a traditional wood fireplace that we converted to gas last winter. It's a typical vented gas log setup -- and we hate it. It doesn't provide any heat, we get gusts of exhaust down the chimney, and never use it. After doing research, it seems that Direct Vent is the solution for an alternative heat source (feel free to chime in if I'm wrong!).

I found this site with multiple installation diagrams:
https://www.chimneysweeponline.com/hodvent.htm
I'm planning on doing #6 or 7, but was wondering if it was possible to do a horizontal vent through the back of the masonry chimney. That would save some cost on all the conversion kits and flex piping I would need to buy.

If that's possible, how would I go about doing it?

Or, is it possible to just build a block-off plate to replace the damper like this article:
https://www.hearth.com/econtent/index.php/articles/making_a_block_off_plate/
If I went this route, would I even need to buy flex piping to go all the way to the termination cap (2 story chimney), or is the chimney sufficient for the exhaust/draw air.

Thanks!

 

[DAKSY]

For ease of installation, you'd be better served by a DV gas INSERT, not a fireplace.
You didn't give us any dimensions, so you will have to research to find what will fit in there.
Many gas fireplaces are not tested for co-linear adaptation so there's another reason to go with an insert.
If you WERE to try to adapt a horizontally vented gas FIREPLACE in there you would have to drill, chisel, abrasively grind or saw
thru to the inside for the DV pipe to attach to the cap. Then you will have to get creative with trimming any
uncovered opening to hide it. DV insert have differnt sized surrounds to add a finished look.
A co-linear kit will cast you less than $500 & will include the cap & will extend up to 30'.
There are adapters to add length to that 30', if you need to.
As far as the venting of a DV unit, you HAVE TO run the exhaust ALL the way to the cap.
The incoming (combustion air) can be drawn from within the chimney.
HTH

 

[packman_]

For ease of installation, you'd be better served by a DV gas INSERT, not a fireplace.

I think I meant an insert, that's the self-contained unit, correct? Completely sealed combustion? I'm planning on dropping an insert into the existing masonry firebox.

As far as the venting of a DV unit, you HAVE TO run the exhaust ALL the way to the cap.
The incoming (combustion air) can be drawn from within the chimney.
HTH

This is helpful, and this sounds like the way to go. Is there any benefit of running the exhaust to the top while keeping the combustion air drawn from chimney versus the co-linear adaptation (2 flex pipes all the way to the top)?

I guess my process is looking like this:
1) Buying and placing insert into existing firebox (looks like most 36" units will fit my space)
2) Remove my damper and install block off plate.
3) Coaxial pipe goes from insert to the block off plate
4) single flex pipe goes from the exhaust portion (inner pipe) all the way to cap. No need to install another pipe for combustion air.

Does this sound right?

 

[DAKSY]

I think I meant an insert, that's the self-contained unit, correct? Completely sealed combustion? I'm planning on dropping an insert into the existing masonry firebox.

Yes an insert is a sealed combustion unit.

This is helpful, and this sounds like the way to go. Is there any benefit of running the exhaust to the top while keeping the combustion air drawn from chimney versus the co-linear adaptation (2 flex pipes all the way to the top)?

Having BOTH go from the insert to the cap allows you to double up on the insulation. You can insulate at the damper & you can insulate under the cap. This will create a column of dead air (between the insulated areas), which will ALSO act as insulation...All kits come with the two full liners. You might as well use them...

I guess my process is looking like this:
1) Buying and placing insert into existing firebox (looks like most 36" units will fit my space)

You will need to measure the opening width & height, the depth top & bottom & the rear width at the top & bottom...

2) Remove my damper and install block off plate.

No. Open the damper far enough to allow the passage of the co-linear liners. You may have to disable the opening mechanism, but there is generally no need to remove it. The liners will usually be 3" diameter. Most dampers will open that far.

3) Coaxial pipe goes from insert to the block off plate

Inserts do not use coaxial venting as a rule. They primarily use co-linear liners. With a gas insert a block-off plate is NOT required. You simply cram a LOT of un-faced fiberglass insulation in the damper area, around & between the liners.

4) single flex pipe goes from the exhaust portion (inner pipe) all the way to cap. No need to install another pipe for combustion air.

Does this sound right?

See my answers above...