Direct vent in existing fireplace

[TheGewp]

I am installing a Zero clearance direct vent Kozy Heat gas fireplace in my existing cement fireplace. The Kozy Heat came with a vertical heat shield to be used with venting vertically. The space in the existing firebox isn't tall enough for it though, i am using 2 90's to jog the pipe back 12 or so inches to get it up the flue. Can i cut the heat shield down to fit the space? The top of the existing firebox is all non-combustible. Thanks!!

 

[DAKSY]

I am installing a Zero clearance direct vent Kozy Heat gas fireplace in my existing cement fireplace. The Kozy Heat came with a vertical heat shield to be used with venting vertically. The space in the existing firebox isn't tall enough for it though, i am using 2 90's to jog the pipe back 12 or so inches to get it up the flue. Can i cut the heat shield down to fit the space? The top of the existing firebox is all non-combustible. Thanks!!View attachment 177895

What model are you installing? Your post doesn't indicate the model.
I would like to look at the install manual before replying to your question.

 

[TheGewp]

Whoops! It's a Kozy Heat Bayport 36 Glass. Manual is here: http://www.kozyheat.com/wp-content/uploads/2015/10/Bayport-36-Glass-R.5-1-16-EN.pdf

 

[DAKSY]

After reading the install manual you provided, I can see that you are not in compliance the venting installation instructions.
The manual clearly states for a combination horizontal/vertical top venting combination, which is what you are attempting,
must have a MINIMUM of a 6" vertical section BEFORE the first elbow. Without it, your unit may not draft properly, at least
at start up. I'd worry more about that than the heat shield, but I think I'd protect the framing members at the front wall...&
divert the heat off the vent towards the existing chimney...
Not exactly what you were looking for, sorry...If you are planning on having the install inspected & verified as safe, you may
fail due to the venting oversight...

 

[TheGewp]

Well shoot. So it would be considered a combination vent because of the shift? Even though 14' out of 15' of vent is vertical? I think my only other option is to pull the unit forward and rear vent. I hate to give up more livingroom but i do want to pass inspection. Would it be worth contacting the manufacturer for clarification on my install since it should be considered atypical? Thanks for you help.

 

[DAKSY]

Well shoot. So it would be considered a combination vent because of the shift? Even though 14' out of 15' of vent is vertical? I think my only other option is to pull the unit forward and rear vent. I hate to give up more livingroom but i do want to pass inspection. Would it be worth contacting the manufacturer for clarification on my install since it should be considered atypical? Thanks for you help.

I would either contact the manufacturer or the hearth shop where you bought it.
One other option would be to return the rigid vent & use the flexible venting method.
You could get the offset you need with out actually having a 90 degree bend...

 

[TheGewp]

I looked at the flexible venting but the adapter to shift from coaxial to co-linear was too tall to fit. The top of the inside of the fireplace is only 11.5 inches from the top of the insert, and the adapters are 10 inches without the flex. I'll give Kozy Heat a call and see what they say. My permit allows for 2 inspections, so i may give it a go as is and if it fails i'll re work it for rear venting. Thanks again for the help.