So, I'm looking for a gas (propane) fireplace insert to be installed in my fireplace opening. I'm looking for something to heat my living room and kitchen only (probably 600 sq. ft.) for a little while when I get home after work until I get my woodstove fired up and cooking. This will not be a primary heat source for my house. Just for looks and a little temporary heat when needed. I was wondering what your thoughts are on vent free units. I know they are efficient but do they give off any harmful or discoloring stuff I need to worry about? Im looking for an easy install and of course keeping costs down. Thanks in advance!