Ventless fireplaces are also known as "unvented" or "vent-free" fireplaces. They're a type of fireplace that pipes natural gas or propane into a gas-burning unit. ... They're actually designed to burn gas more efficiently than vented versions, so they produce less fumes and don't require a flue or a chimney.

Does a ventless fireplace produce carbon monoxide?

Ventless fireplaces produce small amounts of nitrous dioxide and carbon monoxide which can be deadly in large doses. ... In addition to carbon monoxide, ventless fireplaces also produce a high levels of water vapor. The increased level of water vapor in the home will increase humidity, increasing the risk of mold growth.

What kind of fireplace does not need a chimney?

Ventless gas fireplaces are a sub-category of gas fireplaces. They run on natural gas or liquid propane. They are designed to operate without a chimney or vent. The design is achieved by reducing the number of emissions by burning less gas.