Gas fireplaces, including inserts ... and less energy-efficient since heat escapes up the chimney. Unvented or vent-free systems are usually less expensive, but they aren’t designed to provide ...

All in all, the average pro installation costs between $3,500 and $7,500. Pros Cons A vent-free gas fireplace takes in air through a grid, usually in the bottom, and exhausts air back into the ...