Most people associate a fireplace with firewood and a big chimney useful for ventilation and for Santa. But technology and advances in fuel delivery have now allowed our homes to be outfitted with ventless gas fireplaces. No chimney necessary, and they can even be purchased online.
Why don't ventless fireplaces need a chimney? Well, Unlike wood burning fireplaces, a ventless fireplace uses natural gas or gel to produce heat. These types of fuels are deemed to have a lower emissions rate than wood.
Despite that, The Boston Globe considered the question of ventless fireplace safety and generally came out with the view they could be hazardous.

