How to properly vent a direct vent gas fireplace...
Hey - I imagine this is a strange question this time of year, especially since it will e 90+ degrees in some parts of the country. At any rate, I am in the process of researching how to install a direct vent gas fireplace. I have heard from one fireplace store that the higher the vertical vent goes (within reason), the nicer the flames will be. I have also heard that this makes the fireplace more energy efficient as the intake air has time to heat up. Another store told me that for my planned run through the existing chase (where the wood fireplace once vented) of roughly 18-20 foot, I would need a reducer otherwise the escaping hot air would move too quickly, draw the intake are in too fast, and result in a poor burn pattern as the flames would be blown about.
My question here is, which is correct? I do have the option of just going up about 4 foot and then out horizontally (about a foot of horizontal travel after a 90 degree elbow). Otherwise, I can do my first plan which is 2 45 degree elbows followed by about 18-20 foot of vertical rise. Note both are valid according to the install manual for the Mendota fireplace I am looking at.
If this is the wrong place for this question, please let me know.
Thanks!
Rob