Hard to say without seeing it but typically you can use the existing flue provided you add the proper direct vent chimney insert for your particular gas fireplace.
Direct vent gas fireplace through existing chimney.
This type of fireplace has a completely sealed combustion chamber which allows it to vent directly out a side wall of the home.
The fans preinstalled in the insert control the amount of heat entering the room.
Next i will remove the firepla.
However the glass doors enhance the conversion of most of the fuel into usable heat preventing significant heat loss.
Alternatively you can possibly knock a hole in the back of your chimney and just go out the side if you d prefer more labor but less flue inserts you d need to purchase.
The heat generated remains inside the room rather than vanishing through the chimney.
Rather you can run a special vent to the outside through an exterior wall.
Gas fireplaces burn natural gas and propane just like a traditional wood fireplace.
Unlike traditional fireplaces which need a flue through the roof gas fireplaces are vent free.
Be sure to read them carefully because they might differ slightly from what we show here.
For the diy guy here is how to install a gas fireplace insert with a chimney liner.
A direct vent gas fireplace doesn t need a chimney.
A gas stove can be vented through an existing chimney whether it is a manufactured or masonry chimney.
Direct vent is a term used to describe a specifically designed fireplace that performs differently from the traditionally vented fireplace which use a chimney.
To ensure proper venting however a liner must first be installed in the chimney.
The first thing i do is clean the chimney.