Garage heater venting

[Harvesters01]

I want to install a powered vent garage heater in my attached garage. Question is, can I vent it vertically through an existing fireplace chase.

Vent pipe would run on an upward angle aprox. 8', enter the side wall of the chimney chase (exterior to the home, non masonry) and exit vertically through the chimney cap next to the existing fireplace vent.

 

[HoosierBuddy]

Is this a functional fireplace?

Maybe I misunderstood...you're not saying it will penetrate the wall of the chimney, just be immediately adjacent to it?

 

[Harvesters01]

the existing chimney sits on an outside wall and is wood framed. The thought was that I would vent the heater from the garage up into the attic space and than an upward vertical angle until meeting the fireplace, penetrate the chimney wall (wood) then discharge vertically, next to the existing fireplace flue. Can i do that?

 

[Harvesters01]

something like the sketch shown

 

[Kunze]

You could so long as clearance to combustibles can still be met for the fireplace venting system in chase. You will also want to put a wall pass-through/fire stop at the penetration to the chase.

 

[Harvesters01]

clearance to combustibles for the fireplace venting: Does that include the new venting for the garage heater? Accounting for the raincaps there will be some amount of stand-off build in.

Another question: I can't seem to find a specification on how far of a run like this would be allowed. The manuals for both Modine Hot Dawg and Mr. Heater talk only to "vertical" and "horizontal" installations.