Question: Do you know if anyone makes gas fireplace inserts that vent out the back instead of on the top? I am having trouble finding an insert that will work in my fireplace opening as I have approx 16 inches of stone going back into my opening before you get to the metal fireplace and the height of my opening is only 23 inches. On all of the inserts I have looked at the vent is about 19 or 20 inches high and I don't know if I can bend the vent pipe enough to get it onto the vent collar with only a few inches of clearance. Please let me know if you have any suggestions. The dimensions of my opening is 32 width 23 height and 34 deep but as I said I have 16 inches of stone going back into my opening before I can go up with a vent pipe Answer: You are right that most come out the top. I'll query my friends in the business. You could, however, use a B-Vent or direct vent STOVE - and many of these do come out the rear. Depending on the height of the stove, it could be set in front or partway in the opening.