I see that a straight pipe out the wall and terminated with a diffuser is not the" best" method of exausting these fireplaces . I understand the out and min 3 ft of vertical pipe then an elbow is the best but i have a window and dont want to ruin the view with a candy cane of 4" pipe . i will be useing a battery back up so that i dont get a smoke filled fire pot migrating into the house . Just asking for your thought before i go this route . and has anyone have a better suggestion than the inverter from harman on the the battery back up . problems or issues please forward .