Re gardless if you do or don't have gas you should have a
"CARBON MONITOR"!!! Well worth the 30-40 bucks!!!! You should have one if you burn wood; coal or especially if you have an attached garage with a car in it!!! Remember carbon is "ODORLESS & TASTELESS and a SILENT KILLER"!!!!
When using a gas fire place you may have to increase the diameter of your pipe if you use an x amount of elbows!!!!
My gas fire place located in middle of house, has a verticle of 9' w/elbow, 4' diagnal w/elbow and 4' thru the roof, calls for an 8" double walled pipe, air comes in one section and gases go out thru the middle!!!!
if you are on an exterior wall you need very little length of pipe!!!!