Question: hello- I-m in the process of buying a gas fireplace insert. I have been somewhat confused by some of the dealers. Some tell me should go with a direct vent insert which 2-4inch pipes go up my chimney and that this unit has a sealed chamber which doesn't allow gases to come back in my house. Some dealers say that this is new and the conventional fireplace is just as safe. what should i do? thank you in advance- Gilles Answer: Gas Fireplace inserts area available in "direct vent" which is the two pipe system you mentioned- and "b-vent" which is a one pipe system. The b vent takes it's combustion air from the home and sends it up the chimney..The direct vent takes combustion air from the outside and exhausts back outside. Both are fine- but a properly installed direct vent may be a bit more efficient. Also- if you live in a very cold climate the direct vent may be better - draft wise.