I would never consider a gas log as a reasonable method of heating.. More
for effect than for effeciency..
Anything do on an open hearth is a waste of fuel, going up the chimney..
A true insert would help since they are suppose to be designed to capture a
higher percent of the btu that might go up the chimney.. Some of the
fireplace inserts will have heat radiating baffles and blowers to circulate
the room air around the fire box.. Some are designed for wood and others for
Visit a reputable gas insert dealer and ask about an insert that is truly
for efficient heating. It should be of an approved type for the sake of
safety. I think it is HUD that has this approval responsibilty, if not it
may be UL or something. I would look at the label on my free standing
fireplace but it is too hot to look on the back. Hehhehe!