Unvented gas heater

(redirected from Vent-free gas heater)

Unvented gas heater

Gas-burning space heater that is not vented to the outdoors. Although unvented gas heaters burn very efficiently, indoor air quality experts strongly discourage their use because combustion gases, including high levels of water vapor, are released into the room or building.
References in periodicals archive ?
All vent-free gas heaters are equipped with an ODS.
Critics of vent-free gas heaters point out that we know little about the long-term effects of low-level exposure to combustion by-products, and that even vented furnaces have produced several hundred deaths because of malfunctions.